diff --git a/.appveyor.yml b/.appveyor.yml
new file mode 100644
index 0000000..247a550
--- /dev/null
+++ b/.appveyor.yml
@@ -0,0 +1,17 @@
+environment:
+  matrix:
+  - TARGET: x86_64-pc-windows-msvc
+  - TARGET: i686-pc-windows-msvc
+  - TARGET: x86_64-pc-windows-gnu
+  - TARGET: i686-pc-windows-gnu
+  RUST_BACKTRACE: full
+install:
+  - curl -sSf -o rustup-init.exe https://win.rustup.rs/
+  - rustup-init.exe -y --default-host %TARGET%
+  - set PATH=%PATH%;C:\Users\appveyor\.cargo\bin
+  - rustc -vV
+  - cargo -vV
+build: false
+test_script:
+  - cargo build --verbose --features yaml
+  - cargo test --verbose --features yaml
diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
new file mode 100644
index 0000000..69d9675
--- /dev/null
+++ b/.cargo_vcs_info.json
@@ -0,0 +1,5 @@
+{
+  "git": {
+    "sha1": "784524f7eb193e35f81082cc69454c8c21b948f7"
+  }
+}
diff --git a/.clog.toml b/.clog.toml
new file mode 100644
index 0000000..301dd92
--- /dev/null
+++ b/.clog.toml
@@ -0,0 +1,14 @@
+[clog]
+repository = "https://github.com/kbknapp/clap-rs"
+outfile = "CHANGELOG.md"
+from-latest-tag = true
+
+[sections]
+Performance = ["perf"]
+Improvements = ["impr", "im", "imp"]
+Documentation = ["docs"]
+Deprecations = ["depr"]
+Examples = ["examples"]
+"New Settings" = ["setting", "settings"]
+"API Additions" = ["add", "api"]
+"New Sponsor" = ["sponsor"]
diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
new file mode 100644
index 0000000..2c6f752
--- /dev/null
+++ b/.github/CONTRIBUTING.md
@@ -0,0 +1,115 @@
+# How to Contribute
+
+Contributions are always welcome! And there is a multitude of ways in which you can help depending on what you like to do, or are good at. Anything from documentation, code cleanup, issue completion, new features, you name it, even filing issues is contributing and greatly appreciated!
+
+Another really great way to help is if you find an interesting, or helpful way in which to use `clap`. You can either add it to the [examples/](examples) directory, or file an issue and tell me. I'm all about giving credit where credit is due :)
+
+### Testing Code
+
+To test with all features both enabled and disabled, you can run these commands:
+
+```sh
+$ cargo test --no-default-features
+$ cargo test --features "yaml unstable"
+```
+
+Alternatively, if you have [`just`](https://github.com/casey/just) installed you can run the prebuilt recipes. *Not* using `just` is perfectly fine as well, it simply bundles commands automatically.
+
+For example, to test the code, as above simply run:
+
+```sh
+$ just run-tests
+```
+
+From here on, I will list the appropriate `cargo` command as well as the `just` command.
+
+Sometimes it's helpful to only run a subset of the tests, which can be done via:
+
+```sh
+$ cargo test --test <test_name>
+
+# Or
+
+$ just run-test <test_name>
+```
+
+### Linting Code
+
+During the CI process `clap` runs against many different lints using [`clippy`](https://github.com/rust-lang-nursery/rust-clippy). In order to check if these lints pass on your own computer prior to submitting a PR you'll need a nightly compiler.
+
+In order to check the code for lints run either:
+
+```sh
+$ rustup override add nightly
+$ cargo build --features lints
+$ rustup override remove
+
+# Or
+
+$ just lint
+```
+
+### Debugging Code
+
+Another helpful technique is to see the `clap` debug output while developing features. In order to see the debug output while running the full test suite or individual tests, run:
+
+```sh
+$ cargo test --features debug
+
+# Or for individual tests
+$ cargo test --test <test_name> --features debug
+
+# The corresponding just command for individual debugging tests is:
+$ just debug <test_name>
+```
+
+### Commit Messages
+
+I use a [conventional](https://github.com/ajoslin/conventional-changelog/blob/a5505865ff3dd710cf757f50530e73ef0ca641da/conventions/angular.md) changelog format so I can update my changelog automatically using [clog](https://github.com/clog-tool/clog-cli)
+
+ * Please format your commit subject line using the following format: `TYPE(COMPONENT): MESSAGE` where `TYPE` is one of the following:
+    - `api`  - An addition to the API
+    - `setting` - A new `AppSettings` variant
+    - `feat` - A new feature of an existing API
+    - `imp`  - An improvement to an existing feature/API
+    - `perf` - A performance improvement
+    - `docs` - Changes to documentation only
+    - `tests` - Changes to the testing framework or tests only
+    - `fix` - A bug fix
+    - `refactor` - Code functionality doesn't change, but underlying structure may
+    - `style` - Stylistic changes only, no functionality changes
+    - `wip` - A work in progress commit (Should typically be `git rebase`'ed away)
+    - `chore` - Catch all or things that have to do with the build system, etc
+    - `examples` - Changes to existing example, or a new example
+ * The `COMPONENT` is optional, and may be a single file, directory, or logical component. Parenthesis can be omitted if you are opting not to use the `COMPONENT`. 
+
+### Tests and Documentation
+
+1. Create tests for your changes
+2. **Ensure the tests are passing.** Run the tests (`cargo test --features "yaml unstable"`), alternatively `just run-tests` if you have `just` installed.
+3. **Optional** Run the lints (`cargo build --features lints`) (requires a nightly compiler), alternatively `just lint`
+4. Ensure your changes contain documentation if adding new APIs or features.
+
+### Preparing the PR
+
+1. `git rebase` into concise commits and remove `--fixup`s or `wip` commits (`git rebase -i HEAD~NUM` where `NUM` is number of commits back to start the rebase)
+2. Push your changes back to your fork (`git push origin $your-branch`)
+3. Create a pull request against `master`! (You can also create the pull request first, and we'll merge when ready. This a good way to discuss proposed changes.)
+
+### Other ways to contribute
+
+Another really great way to help is if you find an interesting, or helpful way in which to use `clap`. You can either add it to the [examples/](../examples) directory, or file an issue and tell me. I'm all about giving credit where credit is due :)
+
+### Goals
+
+There are a few goals of `clap` that I'd like to maintain throughout contributions. If your proposed changes break, or go against any of these goals we'll discuss the changes further before merging (but will *not* be ignored, all contributes are welcome!). These are by no means hard-and-fast rules, as I'm no expert and break them myself from time to time (even if by mistake or ignorance :P).
+
+* Remain backwards compatible when possible
+  - If backwards compatibility *must* be broken, use deprecation warnings if at all possible before removing legacy code
+  - This does not apply for security concerns
+* Parse arguments quickly
+  - Parsing of arguments shouldn't slow down usage of the main program
+  - This is also true of generating help and usage information (although *slightly* less stringent, as the program is about to exit)
+* Try to be cognizant of memory usage
+  - Once parsing is complete, the memory footprint of `clap` should be low since the  main program is the star of the show
+* `panic!` on *developer* error, exit gracefully on *end-user* error
diff --git a/.github/ISSUE_TEMPLATE.md b/.github/ISSUE_TEMPLATE.md
new file mode 100644
index 0000000..5f94a2c
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE.md
@@ -0,0 +1,46 @@
+<!--
+Please use the following template to assist with creating an issue and to ensure a speedy resolution. If an area is not applicable, feel free to delete the area or mark with `N/A`
+-->
+
+### Rust Version
+
+* Use the output of `rustc -V`
+
+### Affected Version of clap
+
+* Can be found in Cargo.lock of your project (i.e. `grep clap Cargo.lock`)
+
+### Bug or Feature Request Summary
+
+
+### Expected Behavior Summary
+
+
+### Actual Behavior Summary
+
+
+### Steps to Reproduce the issue
+
+
+### Sample Code or Link to Sample Code
+
+
+### Debug output
+
+Compile clap with cargo features `"debug"` such as:
+
+```toml
+[dependencies]
+clap = { version = "2", features = ["debug"] }
+```
+
+<details>
+<summary> Debug Output </summary>
+<pre>
+<code>
+
+Paste Debug Output Here
+
+</code>
+</pre>
+</details>
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..34253e9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,27 @@
+# Compiled files
+*.o
+*.so
+*.rlib
+*.dll
+
+# Executables
+*.exe
+
+# Generated by Cargo
+/target/
+/clap-test/target/
+
+# Cargo files
+Cargo.lock
+
+# Temp files
+.*~
+
+# Backup files
+*.bak
+*.bk
+*.orig
+
+# Project files
+.vscode/*
+.idea/*
diff --git a/.mention-bot b/.mention-bot
new file mode 100644
index 0000000..f339f59
--- /dev/null
+++ b/.mention-bot
@@ -0,0 +1,9 @@
+{
+  "findPotentialReviewers": false, 
+  "alwaysNotifyForPaths": [
+    {
+      "name": "kbknapp", 
+      "files": ["**/*.rs", "**/*.md", "*"] 
+    }
+  ]
+}
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..9eb4044
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,59 @@
+sudo: true
+language: rust
+cache: cargo
+rust:
+  - nightly
+  - beta
+  - stable
+  - 1.31.0
+matrix:
+    allow_failures:
+        - rust: nightly
+before_script:
+  - |
+    pip install git+git://github.com/kbknapp/travis-cargo.git --user &&
+    export PATH=$HOME/.local/bin:$PATH
+  - |
+    if [[ "$TRAVIS_RUST_VERSION" == "1.13.0" ]]; then
+        echo "Old Rust detected, removing version-sync dependency"
+        sed -i "/^version-sync =/d" Cargo.toml
+        rm "tests/version-numbers.rs"
+    fi
+script:
+  - |
+    travis-cargo --only stable test -- --verbose --no-default-features &&
+    travis-cargo --skip nightly test -- --verbose --features "yaml unstable" &&
+    travis-cargo --only nightly test -- --verbose --features "yaml unstable nightly" &&
+    travis-cargo --only nightly bench -- --no-run 
+addons:
+  apt:
+    packages:
+    - binutils-dev 
+    - libcurl4-openssl-dev
+    - libelf-dev
+    - libdw-dev
+    - libiberty-dev
+    - cmake
+    - gcc
+    - zlib1g-dev 
+after_success:
+  - |
+    wget https://github.com/SimonKagstrom/kcov/archive/master.tar.gz &&
+    tar xzf master.tar.gz &&
+    cd kcov-master &&
+    mkdir build &&
+    cd build &&
+    cmake .. &&
+    make &&
+    sudo make install &&
+    cd ../.. &&
+    rm -rf kcov-master &&
+    cargo clean &&
+    cargo test --no-run --features "yaml unstable" &&
+    for file in target/debug/*-*; do mkdir -p "target/cov/$(basename $file)"; kcov --exclude-pattern=/.cargo --verify "target/cov/$(basename $file)" "$file"; done &&
+    kcov --coveralls-id=$TRAVIS_JOB_ID --merge target/cov target/cov/* &&
+    echo "Uploaded code coverage"
+env:
+  global:
+    - TRAVIS_CARGO_NIGHTLY_FEATURE=lints
+    - secure: JLBlgHY6OEmhJ8woewNJHmuBokTNUv7/WvLkJGV8xk0t6bXBwSU0jNloXwlH7FiQTc4TccX0PumPDD4MrMgxIAVFPmmmlQOCmdpYP4tqZJ8xo189E5zk8lKF5OyaVYCs5SMmFC3cxCsKjfwGIexNu3ck5Uhwe9jI0tqgkgM3URA=
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..d1fdd40
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,2855 @@
+<a name="v2.33.0"></a>
+## v2.33.0 (2019-04-06)
+
+#### New Sponsor
+
+*   Stephen Oats is now a sponsor \o/ ([823457c0](https://github.com/kbknapp/clap-rs/commit/823457c0ef5e994ed7080cf62addbfe1aa3b1833))
+* **SPONSORS.md:**  fixes Josh Triplett's info in the sponsor document ([24cb5740](https://github.com/kbknapp/clap-rs/commit/24cb574090a11159b48bba105d5ec2dfb0a20e4e))
+
+#### Features
+
+* **Completions:**  adds completion support for Elvish. ([e9d0562a](https://github.com/kbknapp/clap-rs/commit/e9d0562a1dc5dfe731ed7c767e6cee0af08f0cf9))
+* There is a new setting to disable automatic building of `--help` and `-h` flags (`AppSettings::DisableAutoHelp`)
+
+#### Improvements
+
+* **arg_matches.rs:**  add Debug implementations ([47192b7a](https://github.com/kbknapp/clap-rs/commit/47192b7a2d84ec716b81ae4af621e008a8762dc9))
+* **macros:**  Support shorthand syntax for ArgGroups ([df9095e7](https://github.com/kbknapp/clap-rs/commit/df9095e75bb1e7896415251d0d4ffd8a0ebcd559))
+
+#### Documentation
+
+*   Refer to macOS rather than OSX. ([ab0d767f](https://github.com/kbknapp/clap-rs/commit/ab0d767f3a5a57e2bbb97d0183c2ef63c8c77a6c))
+* **README.md:**  use https for all links ([96a7639a](https://github.com/kbknapp/clap-rs/commit/96a7639a36bcb184c3f45348986883115ef1ab3a))
+
+#### Bug Fixes
+
+*   add debug assertion for missing args in subcommand ArgGroup ([2699d9e5](https://github.com/kbknapp/clap-rs/commit/2699d9e51e7eadc258ba64c4e347c5d1fef61343))
+*   Restore compat with Rust 1.21 ([6b263de1](https://github.com/kbknapp/clap-rs/commit/6b263de1d42ede692ec5ee55019ad2fc6386f92e))
+*   Dont mention unused subcommands ([ef92e2b6](https://github.com/kbknapp/clap-rs/commit/ef92e2b639ed305bdade4741f60fa85cb0101c5a))
+* **OsValues:**  Add `ExactSizeIterator` implementation ([356c69e5](https://github.com/kbknapp/clap-rs/commit/356c69e508fd25a9f0ea2d27bf80ae1d9a8d88f4))
+* **arg_enum!:**
+  *  Fix comma position for valid values. ([1f1f9ff3](https://github.com/kbknapp/clap-rs/commit/1f1f9ff3fa38a43231ef8be9cfea89a32e53f518))
+  *  Invalid expansions of some trailing-comma patterns ([7023184f](https://github.com/kbknapp/clap-rs/commit/7023184fca04e852c270341548d6a16207d13862))
+* **completions:**  improve correctness of completions when whitespace is involved ([5a08ff29](https://github.com/kbknapp/clap-rs/commit/5a08ff295b2aa6ce29420df6252a0e3ff4441bdc))
+* **help message:**  Unconditionally uses long description for subcommands ([6acc8b6a](https://github.com/kbknapp/clap-rs/commit/6acc8b6a621a765cbf513450188000d943676a30), closes [#897](https://github.com/kbknapp/clap-rs/issues/897))
+* **macros:**  fixes broken pattern which prevented calling multi-argument Arg methods ([9e7a352e](https://github.com/kbknapp/clap-rs/commit/9e7a352e13aaf8025d80f2bac5c47fb32528672b))
+* **parser:**  Better interaction between AllowExternalSubcommands and SubcommandRequired ([9601c95a](https://github.com/kbknapp/clap-rs/commit/9601c95a03d2b82bf265c328b4769238f1b79002))
+
+#### Minimum Required Rust
+
+* As of this release, `clap` requires `rustc 1.31.0` or greater.
+
+<a name="v2.32.0"></a>
+## v2.32.0 (2018-06-26)
+
+#### Minimum Required Rust
+
+* As of this release, `clap` requires `rustc 1.21.0` or greater.
+
+
+#### Features
+
+* **Completions:**  adds completion support for Elvish. ([e9d0562a](https://github.com/kbknapp/clap-rs/commit/e9d0562a1dc5dfe731ed7c767e6cee0af08f0cf9))
+
+#### Improvements
+
+* **macros:**  Support shorthand syntax for ArgGroups ([df9095e7](https://github.com/kbknapp/clap-rs/commit/df9095e75bb1e7896415251d0d4ffd8a0ebcd559))
+
+#### Bug Fixes
+
+* **OsValues:**  Add `ExactSizeIterator` implementation ([356c69e5](https://github.com/kbknapp/clap-rs/commit/356c69e508fd25a9f0ea2d27bf80ae1d9a8d88f4))
+* **arg_enum!:**  Invalid expansions of some trailing-comma patterns ([7023184f](https://github.com/kbknapp/clap-rs/commit/7023184fca04e852c270341548d6a16207d13862))
+* **help message:**  Unconditionally uses long description for subcommands ([6acc8b6a](https://github.com/kbknapp/clap-rs/commit/6acc8b6a621a765cbf513450188000d943676a30), closes [#897](https://github.com/kbknapp/clap-rs/issues/897))
+
+#### Documentation
+
+*   Refer to macOS rather than OSX. ([ab0d767f](https://github.com/kbknapp/clap-rs/commit/ab0d767f3a5a57e2bbb97d0183c2ef63c8c77a6c))
+
+
+
+<a name="v2.31.2"></a>
+### v2.31.2 (2018-03-19)
+
+#### Bug Fixes
+
+* **Fish Completions:**  fixes a bug that only allowed a single completion in in Fish Shell ([e8774a8](https://github.com/kbknapp/clap-rs/pull/1214/commits/e8774a84ee4a319c888036e7c595ab46451d8e48), closes [#1212](https://github.com/kbknapp/clap-rs/issues/1212))
+* **AllowExternalSubcommands**: fixes a bug where external subcommands would be blocked by a similarly named subcommand (suggestions were getting in the way). ([a410e85](https://github.com/kbknapp/clap-rs/pull/1215/commits/a410e855bcd82b05f9efa73fa8b9774dc8842c6b))
+
+#### Documentation
+
+* Fixes some typos in the `README.md` ([c8e685d7](https://github.com/kbknapp/clap-rs/commit/c8e685d76adee2a3cc06cac6952ffcf6f9548089))
+
+<a name="v2.31.1"></a>
+### v2.31.1 (2018-03-06)
+
+
+#### Improvements
+
+* **AllowMissingPositional:**  improves the ability of AllowMissingPositional to allow 'skipping' to the last positional arg with '--' ([df20e6e2](https://github.com/kbknapp/clap-rs/commit/df20e6e24b4e782be0b423b484b9798e3e2efe2f))
+
+
+<a name="v2.31.0"></a>
+## v2.31.0 (2018-03-04)
+
+
+#### Features
+
+* **Arg Indices:**  adds the ability to query argument value indices ([f58d0576](https://github.com/kbknapp/clap-rs/commit/f58d05767ec8133c8eb2de117cb642b9ae29ccbc))
+* **Indices:**  implements an Indices<Item=&usize> iterator ([1e67be44](https://github.com/kbknapp/clap-rs/commit/1e67be44f0ccf161cc84c4e6082382072e89c302))
+* **Raw Args** adds a convenience function to `Arg` that allows implying all of `Arg::last` `Arg::allow_hyphen_values` and `Arg::multiple(true)` ([66a78f29](https://github.com/kbknapp/clap-rs/commit/66a78f2972786f5fe7c07937a1ac23da2542afd2))
+
+#### Documentation
+
+*   Fix some typos and markdown issues. ([935ba0dd](https://github.com/kbknapp/clap-rs/commit/935ba0dd547a69c3f636c5486795012019408794))
+* **Arg Indices:**  adds the documentation for the arg index querying methods ([50bc0047](https://github.com/kbknapp/clap-rs/commit/50bc00477afa64dc6cdc5de161d3de3ba1d105a7))
+* **CONTRIBUTING.md:**  fix url to clippy upstream repo to point to https://github.com/rust-lang-nursery/rust-clippy instead of https://github.com/Manishearth/rust-clippy ([42407d7f](https://github.com/kbknapp/clap-rs/commit/42407d7f21d794103cda61f49d2615aae0a4bcd9))
+* **Values:**  improves the docs example of the Values iterator ([74075d65](https://github.com/kbknapp/clap-rs/commit/74075d65e8db1ddb5e2a4558009a5729d749d1b6))
+* Updates readme to hint that the `wrap_help` feature is a thing ([fc7ab227](https://github.com/kbknapp/clap-rs/commit/66a78f2972786f5fe7c07937a1ac23da2542afd2))
+
+### Improvements
+
+*  Cargo.toml: use codegen-units = 1 in release and bench profiles ([19f425ea](https://github.com/kbknapp/clap-rs/commit/66a78f2972786f5fe7c07937a1ac23da2542afd2))
+*  Adds WASM support (clap now compiles on WASM!) ([689949e5](https://github.com/kbknapp/clap-rs/commit/689949e57d390bb61bc69f3ed91f60a2105738d0))
+*  Uses the short help tool-tip for PowerShell completion scripts ([ecda22ce](https://github.com/kbknapp/clap-rs/commit/ecda22ce7210ce56d7b2d1a5445dd1b8a2959656))
+
+
+<a name="v2.30.0"></a>
+## v2.30.0 (2018-02-13)
+
+#### Bug Fixes
+
+* **YAML:** Adds a missing conversion from  `Arg::last` when instantiating from a YAML file ([aab77c81a5](https://github.com/kbknapp/clap-rs/pull/1175/commits/aab77c81a519b045f95946ae0dd3e850f9b93070), closes [#1160](https://github.com/kbknapp/clap-rs/issues/1173))
+
+#### Improvements
+
+* **Bash Completions:**  instead of completing a generic option name, all bash completions fall back to file completions UNLESS `Arg::possible_values` was used ([872f02ae](https://github.com/kbknapp/clap-rs/commit/872f02aea900ffa376850a279eb164645e1234fa))
+* **Deps:**  No longer needlessly compiles `ansi_term` on Windows since its not used ([b57ee946](https://github.com/kbknapp/clap-rs/commit/b57ee94609da3ddc897286cfba968f26ff961491), closes [#1155](https://github.com/kbknapp/clap-rs/issues/1155))
+* **Help Message:** changes the `[values: foo bar baz]` array to `[possible values: foo bar baz]` for consistency with the API ([414707e4e97](https://github.com/kbknapp/clap-rs/pull/1176/commits/414707e4e979d07bfe555247e5d130c546673708), closes [#1160](https://github.com/kbknapp/clap-rs/issues/1160))
+
+
+<a name="v2.29.4"></a>
+### v2.29.4 (2018-02-06)
+
+
+#### Bug Fixes
+
+* **Overrides Self:**  fixes a bug where options with multiple values couldnt ever have multiple values ([d95907cf](https://github.com/kbknapp/clap-rs/commit/d95907cff6d011a901fe35fa00b0f4e18547a1fb))
+
+
+
+<a name="v2.29.3"></a>
+### v2.29.3 (2018-02-05)
+
+
+#### Improvements
+
+* **Overrides:**  clap now supports arguments which override with themselves ([6c7a0010](https://github.com/kbknapp/clap-rs/commit/6c7a001023ca1eac1cc6ffe6c936b4c4a2aa3c45), closes [#976](https://github.com/kbknapp/clap-rs/issues/976))
+
+#### Bug Fixes
+
+* **Requirements:**  fixes an issue where conflicting args would still show up as required ([e06cefac](https://github.com/kbknapp/clap-rs/commit/e06cefac97083838c0a4e1444dcad02a5c3f911e), closes [#1158](https://github.com/kbknapp/clap-rs/issues/1158))
+* Fixes a bug which disallows proper nesting of `--` ([73993fe](https://github.com/kbknapp/clap-rs/commit/73993fe30d135f682e763ec93dcb0814ed518011), closes [#1161](https://github.com/kbknapp/clap-rs/issues/1161))
+
+#### New Settings
+
+* **AllArgsOverrideSelf:**  adds a new convenience setting to allow all args to override themselves ([4670325d](https://github.com/kbknapp/clap-rs/commit/4670325d1bf0369addec2ae2bcb56f1be054c924))
+
+
+
+<a name="v2.29.2"></a>
+### v2.29.2 (2018-01-16)
+
+
+#### Features
+
+* **completions/zsh.rs:**
+  *  Escape possible values for options ([25561dec](https://github.com/kbknapp/clap-rs/commit/25561decf147d329b64634a14d9695673c2fc78f))
+  *  Implement postional argument possible values completion ([f3b0afd2](https://github.com/kbknapp/clap-rs/commit/f3b0afd2bef8b7be97162f8a7802ddf7603dff36))
+  *  Complete positional arguments properly ([e39aeab8](https://github.com/kbknapp/clap-rs/commit/e39aeab8487596046fbdbc6a226e5c8820585245))
+
+#### Bug Fixes
+
+* **completions/zsh.rs:**
+  *  Add missing autoload for is-at-least ([a6522607](https://github.com/kbknapp/clap-rs/commit/a652260795d1519f6ec2a7a09ccc1258499cad7b))
+  *  Don't pass -S to _arguments if Zsh is too old ([16b4f143](https://github.com/kbknapp/clap-rs/commit/16b4f143ff466b7ef18a267bc44ade0f9639109b))
+  *  Maybe fix completions with mixed positionals and subcommands ([1146f0da](https://github.com/kbknapp/clap-rs/commit/1146f0da154d6796fbfcb09db8efa3593cb0d898))
+* **completions/zsh.zsh:**  Remove redundant code from output ([0e185b92](https://github.com/kbknapp/clap-rs/commit/0e185b922ed1e0fd653de00b4cd8d567d72ff68e), closes [#1142](https://github.com/kbknapp/clap-rs/issues/1142))
+
+
+
+<a name="2.29.1"></a>
+### 2.29.1 (2018-01-09)
+
+
+#### Documentation
+
+*   fixes broken links. ([56e734b8](https://github.com/kbknapp/clap-rs/commit/56e734b839303d733d2e5baf7dac39bd7b97b8e4))
+*   updates contributors list ([e1313a5a](https://github.com/kbknapp/clap-rs/commit/e1313a5a0f69d8f4016f73b860a63af8318a6676))
+
+#### Performance
+
+*   further debloating by removing generics from error cases ([eb8d919e](https://github.com/kbknapp/clap-rs/commit/eb8d919e6f3443db279ba0c902f15d76676c02dc))
+*   debloats clap by deduplicating logic and refactors ([03e413d7](https://github.com/kbknapp/clap-rs/commit/03e413d7175d35827cd7d8908d47dbae15a849a3))
+
+#### Bug Fixes
+
+*   fixes the ripgrep benchmark by adding a value to a flag that expects it ([d26ab2b9](https://github.com/kbknapp/clap-rs/commit/d26ab2b97cf9c0ea675b440b7b0eaf6ac3ad01f4))
+* **bash completion:**  Change the bash completion script code generation to support hyphens. ([ba7f1d18](https://github.com/kbknapp/clap-rs/commit/ba7f1d18eba7a07ce7f57e0981986f66c994b639))
+* **completions/zsh.rs:**  Fix completion of long option values ([46365cf8](https://github.com/kbknapp/clap-rs/commit/46365cf8be5331ba04c895eb183e2f230b5aad51))
+
+
+<a name="2.29.0"></a>
+## 2.29.0 (2017-12-02)
+
+
+#### API Additions
+
+* **Arg:**  adds Arg::hide_env_values(bool) which allows one to hide any current env values and display only the key in help messages ([fb41d062](https://github.com/kbknapp/clap-rs/commit/fb41d062eedf37cb4f805c90adca29909bd197d7))
+
+
+
+<a name="2.28.0"></a>
+## 2.28.0 (2017-11-28)
+
+The minimum required Rust is now 1.20. This was done to start using bitflags 1.0 and having >1.0 deps is a *very good* thing!
+
+#### Documentation
+
+*   changes the demo version to 2.28 to stay in sync ([ce6ca492](https://github.com/kbknapp/clap-rs/commit/ce6ca492c7510ab6474075806360b96081b021a9))
+*   Fix URL path to github hosted files ([ce72aada](https://github.com/kbknapp/clap-rs/commit/ce72aada56a9581d4a6cb4bf9bdb861c3906f8df), closes [#1106](https://github.com/kbknapp/clap-rs/issues/1106))
+*   fix typo ([002b07fc](https://github.com/kbknapp/clap-rs/commit/002b07fc98a1c85acb66296b1eec0b2aba906125))
+* **README.md:**  updates the readme and pulls out some redundant sections ([db6caf86](https://github.com/kbknapp/clap-rs/commit/db6caf8663747e679d2f4ed3bd127f33476754aa))
+
+#### Improvements
+
+*   adds '[SUBCOMMAND]' to usage strings with only AppSettings::AllowExternalSubcommands is used with no other subcommands ([e78bb757](https://github.com/kbknapp/clap-rs/commit/e78bb757a3df16e82d539e450c06767a6bfcf859), closes [#1093](https://github.com/kbknapp/clap-rs/issues/1093))
+
+#### API Additions
+
+*   Adds Arg::case_insensitive(bool) which allows matching Arg::possible_values without worrying about ASCII case ([1fec268e](https://github.com/kbknapp/clap-rs/commit/1fec268e51736602e38e67c76266f439e2e0ef12), closes [#1118](https://github.com/kbknapp/clap-rs/issues/1118))
+*   Adds the traits to be used with the clap-derive crate to be able to use Custom Derive ([6f4c3412](https://github.com/kbknapp/clap-rs/commit/6f4c3412415e882f5ca2cc3fbd6d4dce79440828))
+
+#### Bug Fixes
+
+*   Fixes a regression where --help couldn't be overridden ([a283d69f](https://github.com/kbknapp/clap-rs/commit/a283d69fc08aa016ae1bf9ba010012abecc7ba69), closes [#1112](https://github.com/kbknapp/clap-rs/issues/1112))
+*   fixes a bug that allowed options to pass parsing when no value was provided ([2fb75821](https://github.com/kbknapp/clap-rs/commit/2fb758219c7a60d639da67692e100b855a8165ac), closes [#1105](https://github.com/kbknapp/clap-rs/issues/1105))
+*   ignore PropagateGlobalValuesDown deprecation warning ([f61ce3f5](https://github.com/kbknapp/clap-rs/commit/f61ce3f55fe65e16b3db0bd4facdc4575de22767), closes [#1086](https://github.com/kbknapp/clap-rs/issues/1086))
+
+#### Deps
+
+*  Updates `bitflags` to 1.0
+
+
+
+<a name="v2.27.1"></a>
+## v2.27.1 (2017-10-24)
+
+
+#### Bug Fixes
+
+* Adds `term_size` as an optional dependency (with feature `wrap_help`) to fix compile bug
+
+<a name="v2.27.0"></a>
+## v2.27.0 (2017-10-24)
+
+** This release raises the minimum required version of Rust to 1.18 **
+
+** This release also contains a very minor breaking change to fix a bug **
+
+The only CLIs affected will be those using unrestrained multiple values and subcommands where the
+subcommand name can coincide with one of the multiple values.
+
+See the commit [0c223f54](https://github.com/kbknapp/clap-rs/commit/0c223f54ed46da406bc8b43a5806e0b227863b31) for full details.
+
+
+#### Bug Fixes
+
+*   Values from global args are now propagated UP and DOWN!
+*   fixes a bug where using AppSettings::AllowHyphenValues would allow invalid arguments even when there is no way for them to be valid ([77ed4684](https://github.com/kbknapp/clap-rs/commit/77ed46841fc0263d7aa32fcc5cc49ef703b37c04), closes [#1066](https://github.com/kbknapp/clap-rs/issues/1066))
+*   when an argument requires a value and that value happens to match a subcommand name, its parsed as a value ([0c223f54](https://github.com/kbknapp/clap-rs/commit/0c223f54ed46da406bc8b43a5806e0b227863b31), closes [#1031](https://github.com/kbknapp/clap-rs/issues/1031), breaks [#](https://github.com/kbknapp/clap-rs/issues/), [#](https://github.com/kbknapp/clap-rs/issues/))
+*   fixes a bug that prevented number_of_values and default_values to be used together ([5eb342a9](https://github.com/kbknapp/clap-rs/commit/5eb342a99dde07b0f011048efde3e283bc1110fc), closes [#1050](https://github.com/kbknapp/clap-rs/issues/1050), [#1056](https://github.com/kbknapp/clap-rs/issues/1056))
+*   fixes a bug that didn't allow args with default values to have conflicts ([58b5b4be](https://github.com/kbknapp/clap-rs/commit/58b5b4be315280888d50d9b15119b91a9028f050), closes [#1071](https://github.com/kbknapp/clap-rs/issues/1071))
+*   fixes a panic when using global args and calling App::get_matches_from_safe_borrow multiple times ([d86ec797](https://github.com/kbknapp/clap-rs/commit/d86ec79742c77eb3f663fb30e225954515cf25bb), closes [#1076](https://github.com/kbknapp/clap-rs/issues/1076))
+*   fixes issues and potential regressions with global args values not being propagated properly or at all ([a43f9dd4](https://github.com/kbknapp/clap-rs/commit/a43f9dd4aaf1864dd14a3c28dec89ccdd70c61e5), closes [#1010](https://github.com/kbknapp/clap-rs/issues/1010), [#1061](https://github.com/kbknapp/clap-rs/issues/1061), [#978](https://github.com/kbknapp/clap-rs/issues/978))
+*   fixes a bug where default values are not applied if the option supports zero values ([9c248cbf](https://github.com/kbknapp/clap-rs/commit/9c248cbf7d8a825119bc387c23e9a1d1989682b0), closes [#1047](https://github.com/kbknapp/clap-rs/issues/1047))
+
+#### Documentation
+
+*   adds addtional blurbs about using multiples with subcommands ([03455b77](https://github.com/kbknapp/clap-rs/commit/03455b7751a757e7b2f6ffaf2d16168539c99661))
+*   updates the docs to reflect changes to global args and that global args values can now be propagated back up the stack ([ead076f0](https://github.com/kbknapp/clap-rs/commit/ead076f03ada4c322bf3e34203925561ec496d87))
+*   add html_root_url attribute ([e67a061b](https://github.com/kbknapp/clap-rs/commit/e67a061bcf567c6518d6c2f58852e01f02764b22))
+*   sync README version numbers with crate version ([5536361b](https://github.com/kbknapp/clap-rs/commit/5536361bcda29887ed86bb68e43d0b603cbc423f))
+
+#### Improvements
+
+*   args that have require_delimiter(true) is now reflected in help and usage strings ([dce61699](https://github.com/kbknapp/clap-rs/commit/dce616998ed9bd95e8ed3bec1f09a4883da47b85), closes [#1052](https://github.com/kbknapp/clap-rs/issues/1052))
+*   if all subcommands are hidden, the subcommands section of the help message is no longer displayed ([4ae7b046](https://github.com/kbknapp/clap-rs/commit/4ae7b0464750bc07ec80ece38e43f003fdd1b8ae), closes [#1046](https://github.com/kbknapp/clap-rs/issues/1046))
+
+#### Breaking Changes
+
+*   when an argument requires a value and that value happens to match a subcommand name, its parsed as a value ([0c223f54](https://github.com/kbknapp/clap-rs/commit/0c223f54ed46da406bc8b43a5806e0b227863b31), closes [#1031](https://github.com/kbknapp/clap-rs/issues/1031), breaks [#](https://github.com/kbknapp/clap-rs/issues/), [#](https://github.com/kbknapp/clap-rs/issues/))
+
+#### Deprecations
+
+* **AppSettings::PropagateGlobalValuesDown:**  this setting is no longer required to propagate values down or up ([2bb5ddce](https://github.com/kbknapp/clap-rs/commit/2bb5ddcee61c791ca1aaca494fbeb4bd5e277488))
+
+
+
+<a name="v2.26.2"></a>
+### v2.26.2 (2017-09-14)
+
+
+#### Improvements
+
+*   if all subcommands are hidden, the subcommands section of the help message is no longer displayed ([4ae7b046](https://github.com/kbknapp/clap-rs/commit/4ae7b0464750bc07ec80ece38e43f003fdd1b8ae), closes [#1046](https://github.com/kbknapp/clap-rs/issues/1046))
+
+#### Bug Fixes
+
+*   fixes a bug where default values are not applied if the option supports zero values ([9c248cbf](https://github.com/kbknapp/clap-rs/commit/9c248cbf7d8a825119bc387c23e9a1d1989682b0), closes [#1047](https://github.com/kbknapp/clap-rs/issues/1047))
+
+
+
+<a name="v2.26.1"></a>
+### v2.26.1 (2017-09-14)
+
+
+#### Bug Fixes
+
+*   fixes using require_equals(true) and min_values(0) together ([10ae208f](https://github.com/kbknapp/clap-rs/commit/10ae208f68518eff6e98166724065745f4083174), closes [#1044](https://github.com/kbknapp/clap-rs/issues/1044))
+*   escape special characters in zsh and fish completions ([87e019fc](https://github.com/kbknapp/clap-rs/commit/87e019fc84ba6193a8c4ddc26c61eb99efffcd25))
+*   avoid panic generating default help msg if term width set to 0 due to bug in textwrap 0.7.0 ([b3eadb0d](https://github.com/kbknapp/clap-rs/commit/b3eadb0de516106db4e08f078ad32e8f6d6e7a57))
+*   Change `who's` -> `whose` ([53c1ffe8](https://github.com/kbknapp/clap-rs/commit/53c1ffe87f38b05d8804a0f7832412a952845349))
+*   adds a debug assertion to ensure all args added to groups actually exist ([7ad123e2](https://github.com/kbknapp/clap-rs/commit/7ad123e2c02577e3ca30f7e205181e896b157d11), closes [#917](https://github.com/kbknapp/clap-rs/issues/917))
+*   fixes a bug where args that allow values to start with a hyphen couldnt contain a double hyphen -- as a value ([ab2f4c9e](https://github.com/kbknapp/clap-rs/commit/ab2f4c9e563e36ec739a4b55d5a5b76fdb9e9fa4), closes [#960](https://github.com/kbknapp/clap-rs/issues/960))
+*   fixes a bug where positional argument help text is misaligned ([54c16836](https://github.com/kbknapp/clap-rs/commit/54c16836dea4651806a2cfad53146a83fa3abf21))
+* **Help Message:**  fixes long_about not being usable ([a8257ea0](https://github.com/kbknapp/clap-rs/commit/a8257ea0ffb812e552aca256c4a3d2aebfd8065b), closes [#1043](https://github.com/kbknapp/clap-rs/issues/1043))
+* **Suggestions:**  output for flag after subcommand ([434ea5ba](https://github.com/kbknapp/clap-rs/commit/434ea5ba71395d8c1afcf88e69f0b0d8339b01a1))
+
+
+
+<a name="v2.26.0"></a>
+## v2.26.0 (2017-07-29)
+
+Minimum version of Rust is now v1.13.0 (Stable)
+
+
+#### Improvements
+
+*   bumps unicode-segmentation to v1.2 ([cd7b40a2](https://github.com/kbknapp/clap-rs/commit/cd7b40a21c77bae17ba453c5512cb82b7d1ce474))
+
+
+#### Performance
+
+*   update textwrap to version 0.7.0 ([c2d4e637](https://github.com/kbknapp/clap-rs/commit/c2d4e63756a6f070e38c16dff846e9b0a53d6f93))
+
+
+
+
+<a name="v2.25.1"></a>
+### v2.25.1 (2017-07-21)
+
+#### Improvements
+
+* impl Default for Values + OsValues for any lifetime. ([fb7d6231f1](https://github.com/kbknapp/clap-rs/commit/fb7d6231f13a2f79f411e62dca210b7dc9994c18))
+
+#### Documentation
+
+* Various documentation typos and grammar fixes
+
+<a name="v2.25.0"></a>
+### v2.25.0 (2017-06-20)
+
+
+#### Features
+
+*   use textwrap crate for wrapping help texts ([b93870c1](https://github.com/kbknapp/clap-rs/commit/b93870c10ae3bd90d233c586a33e086803117285))
+
+#### Improvements
+
+* **Suggestions:**  suggests to use flag after subcommand when applicable ([2671ca72](https://github.com/kbknapp/clap-rs/commit/2671ca7260119d4311d21c4075466aafdd9da734))
+* Bumps bitflags crate to v0.9
+
+#### Documentation
+
+*   Change `who's` -> `whose` ([53c1ffe8](https://github.com/kbknapp/clap-rs/commit/53c1ffe87f38b05d8804a0f7832412a952845349))
+
+#### Documentation
+
+* **App::template:**  adds details about the necessity to use AppSettings::UnifiedHelpMessage when using {unified} tags in the help template ([cbea3d5a](https://github.com/kbknapp/clap-rs/commit/cbea3d5acf3271a7a734498c4d99c709941c331e), closes [#949](https://github.com/kbknapp/clap-rs/issues/949))
+* **Arg::allow_hyphen_values:**  updates the docs to include warnings for allow_hyphen_values and multiple(true) used together ([f9b0d657](https://github.com/kbknapp/clap-rs/commit/f9b0d657835d3f517f313d70962177dc30acf4a7))
+* **README.md:**
+  *  added a warning about using ~ deps ([821929b5](https://github.com/kbknapp/clap-rs/commit/821929b51bd60213955705900a436c9a64fcb79f), closes [#964](https://github.com/kbknapp/clap-rs/issues/964))
+* **clap_app!:**  adds using the @group specifier to the macro docs ([826048cb](https://github.com/kbknapp/clap-rs/commit/826048cb3cbc0280169303f1498ff0a2b7395883), closes [#932](https://github.com/kbknapp/clap-rs/issues/932))
+
+
+
+<a name="v2.24.2"></a>
+### v2.24.2 (2017-05-15)
+
+
+#### Bug Fixes
+
+*   adds a debug assertion to ensure all args added to groups actually exist ([14f6b8f3](https://github.com/kbknapp/clap-rs/commit/14f6b8f3a2f6df73aeeec9c54a54909b1acfc158), closes [#917](https://github.com/kbknapp/clap-rs/issues/917))
+*   fixes a bug where args that allow values to start with a hyphen couldnt contain a double hyphen -- as a value ([ebf73a09](https://github.com/kbknapp/clap-rs/commit/ebf73a09db6f3c03c19cdd76b1ba6113930e1643), closes [#960](https://github.com/kbknapp/clap-rs/issues/960))
+*   fixes a bug where positional argument help text is misaligned ([54c16836](https://github.com/kbknapp/clap-rs/commit/54c16836dea4651806a2cfad53146a83fa3abf21))
+
+#### Documentation
+
+* **App::template:**  adds details about the necessity to use AppSettings::UnifiedHelpMessage when using {unified} tags in the help template ([cf569438](https://github.com/kbknapp/clap-rs/commit/cf569438f309c199800bb8e46c9f140187de69d7), closes [#949](https://github.com/kbknapp/clap-rs/issues/949))
+* **Arg::allow_hyphen_values:**  updates the docs to include warnings for allow_hyphen_values and multiple(true) used together ([ded5a2f1](https://github.com/kbknapp/clap-rs/commit/ded5a2f15474d4a5bd46a67b130ccb8b6781bd01))
+* **clap_app!:**  adds using the @group specifier to the macro docs ([fe85fcb1](https://github.com/kbknapp/clap-rs/commit/fe85fcb1772b61f13b20b7ea5290e2437a76190c), closes [#932](https://github.com/kbknapp/clap-rs/issues/932))
+
+
+
+<a name="v2.24.0"></a>
+### v2.24.0 (2017-05-07)
+
+
+#### Bug Fixes
+
+*   fixes a bug where args with last(true) and required(true) set were not being printed in the usage string ([3ac533fe](https://github.com/kbknapp/clap-rs/commit/3ac533fedabf713943eedf006f830a5a486bbe80), closes [#944](https://github.com/kbknapp/clap-rs/issues/944))
+*   fixes a bug that was printing the arg name, instead of value name when Arg::last(true) was used ([e1fe8ac3](https://github.com/kbknapp/clap-rs/commit/e1fe8ac3bc1f9cf4e36df0d881f8419755f1787b), closes [#940](https://github.com/kbknapp/clap-rs/issues/940))
+*   fixes a bug where flags were parsed as flags AND positional values when specific combinations of settings were used ([20f83292](https://github.com/kbknapp/clap-rs/commit/20f83292d070038b8cee2a6b47e91f6b0a2f7871), closes [#946](https://github.com/kbknapp/clap-rs/issues/946))
+
+
+
+<a name="v2.24.0"></a>
+## v2.24.0 (2017-05-05)
+
+
+#### Documentation
+
+* **README.md:**  fix some typos ([fa34deac](https://github.com/kbknapp/clap-rs/commit/fa34deac079f334c3af97bb7fb151880ba8887f8))
+
+#### API Additions
+
+* **Arg:**  add `default_value_os` ([d5ef8955](https://github.com/kbknapp/clap-rs/commit/d5ef8955414b1587060f7218385256105b639c88))
+* **arg_matches.rs:**  Added a Default implementation for Values and OsValues iterators. ([0a4384e3](https://github.com/kbknapp/clap-rs/commit/0a4384e350eed74c2a4dc8964c203f21ac64897f))
+
+
+<a name="v2.23.2"></a>
+### v2.23.2 (2017-04-19)
+
+
+#### Bug Fixes
+
+* **PowerShell Completions:**  fixes a bug where powershells completions cant be used if no subcommands are defined ([a8bce558](https://github.com/kbknapp/clap-rs/commit/a8bce55837dc4e0fb187dc93180884a40ae09c6f), closes [#931](https://github.com/kbknapp/clap-rs/issues/931))
+
+#### Improvements
+
+*   bumps term_size to take advantage of better terminal dimension handling ([e05100b7](https://github.com/kbknapp/clap-rs/commit/e05100b73d74066a90876bf38f952adf5e8ee422))
+* **PowerShell Completions:**  massively dedups subcommand names in the generate script to make smaller scripts that are still functionally equiv ([85b0e1cc](https://github.com/kbknapp/clap-rs/commit/85b0e1cc4b9755dda75a93d898d79bc38631552b))
+
+#### Documentation
+
+*   Fix a typo the minimum rust version required ([71dabba3](https://github.com/kbknapp/clap-rs/commit/71dabba3ea0a17c88b0e2199c9d99f0acbf3bc17))
+
+<a name="v2.23.1"></a>
+### v2.23.1 (2017-04-05)
+
+
+#### Bug Fixes
+
+*   fixes a missing newline character in the autogenerated help and version messages in some instances ([5ae9007d](https://github.com/kbknapp/clap-rs/commit/5ae9007d984ae94ae2752df51bcbaeb0ec89bc15))
+
+
+<a name="v2.23.0"></a>
+## v2.23.0 (2017-04-05)
+
+
+#### API Additions
+
+* `App::long_about`
+* `App::long_version`
+* `App::print_long_help`
+* `App::write_long_help`
+* `App::print_long_version`
+* `App::write_long_version`
+* `Arg::long_help`
+
+#### Features
+
+*   allows distinguishing between short and long version messages (-V/short or --version/long) ([59272b06](https://github.com/kbknapp/clap-rs/commit/59272b06cc213289dc604dbc694cb95d383a5d68))
+*   allows distinguishing between short and long help with subcommands in the same manner as args ([6b371891](https://github.com/kbknapp/clap-rs/commit/6b371891a1702173a849d1e95f9fecb168bf6fc4))
+*   allows specifying a short help vs a long help (i.e. varying levels of detail depending on if -h or --help was used) ([ef1b24c3](https://github.com/kbknapp/clap-rs/commit/ef1b24c3a0dff2f58c5e2e90880fbc2b69df20ee))
+* **clap_app!:**  adds support for arg names with hyphens similar to longs with hyphens ([f7a88779](https://github.com/kbknapp/clap-rs/commit/f7a8877978c8f90e6543d4f0d9600c086cf92cd7), closes [#869](https://github.com/kbknapp/clap-rs/issues/869))
+
+#### Bug Fixes
+
+*   fixes a bug that wasn't allowing help and version to be properly overridden ([8b2ceb83](https://github.com/kbknapp/clap-rs/commit/8b2ceb8368bcb70689fadf1c7f4b9549184926c1), closes [#922](https://github.com/kbknapp/clap-rs/issues/922))
+
+#### Documentation
+
+* **clap_app!:**  documents the `--("some-arg")` method for using args with hyphens inside them ([bc08ef3e](https://github.com/kbknapp/clap-rs/commit/bc08ef3e185393073d969d301989b6319c616c1f), closes [#919](https://github.com/kbknapp/clap-rs/issues/919))
+
+
+
+<a name="v2.22.2"></a>
+### v2.22.2 (2017-03-30)
+
+
+#### Bug Fixes
+
+* **Custom Usage Strings:**  fixes the usage string regression when using help templates ([0e4fd96d](https://github.com/kbknapp/clap-rs/commit/0e4fd96d74280d306d09e60ac44f938a82321769))
+
+
+
+<a name="v2.22.1"></a>
+### v2.22.1 (2017-03-24)
+
+
+#### Bug Fixes
+
+* **usage:**  fixes a big regression with custom usage strings ([2c41caba](https://github.com/kbknapp/clap-rs/commit/2c41caba3c7d723a2894e315d04da796b0e97759))
+
+<a name="v2.22.0"></a>
+## v2.22.0 (2017-03-23)
+
+#### API Additions
+
+* **App::name:**  adds the ability to change the name of the App instance after creation ([d49e8292](https://github.com/kbknapp/clap-rs/commit/d49e8292b026b06e2b70447cd9f08299f4fcba76), closes [#908](https://github.com/kbknapp/clap-rs/issues/908))
+* **Arg::hide_default_value:**  adds ability to hide the default value of an argument from the help string ([89e6ea86](https://github.com/kbknapp/clap-rs/commit/89e6ea861e16a1ad56757ca12f6b32d02253e44a), closes [#902](https://github.com/kbknapp/clap-rs/issues/902))
+
+
+<a name="v2.21.3"></a>
+### v2.21.3 (2017-03-23)
+
+#### Bug Fixes
+
+* **yaml:**  adds support for loading author info from yaml ([e04c390c](https://github.com/kbknapp/clap-rs/commit/e04c390c597a55fa27e724050342f16c42f1c5c9))
+
+
+<a name="v2.21.2"></a>
+### v2.21.2 (2017-03-17)
+
+
+#### Improvements
+
+*   add fish subcommand help support ([f8f68cf8](https://github.com/kbknapp/clap-rs/commit/f8f68cf8251669aef4539a25a7c1166f0ac81ea6))
+*   options that use `require_equals(true)` now display the equals sign in help messages, usage strings, and errors" ([c8eb0384](https://github.com/kbknapp/clap-rs/commit/c8eb0384d394d2900ccdc1593099c97808a3fa05), closes [#903](https://github.com/kbknapp/clap-rs/issues/903))
+
+
+#### Bug Fixes
+
+*  setting the max term width now correctly propagates down through child subcommands
+
+
+
+<a name="v2.21.1"></a>
+### v2.21.1 (2017-03-12)
+
+
+#### Bug Fixes
+
+* **ArgRequiredElseHelp:**  fixes the precedence of this error to prioritize over other error messages ([74b751ff](https://github.com/kbknapp/clap-rs/commit/74b751ff2e3631e337b7946347c1119829a41c53), closes [#895](https://github.com/kbknapp/clap-rs/issues/895))
+* **Positionals:**  fixes some regression bugs resulting from old asserts in debug mode. ([9a3bc98e](https://github.com/kbknapp/clap-rs/commit/9a3bc98e9b55e7514b74b73374c5ac8b6e5e0508), closes [#896](https://github.com/kbknapp/clap-rs/issues/896))
+
+
+
+<a name="v2.21.0"></a>
+## v2.21.0 (2017-03-09)
+
+#### Performance
+
+*   doesn't run `arg_post_processing` on multiple values anymore ([ec516182](https://github.com/kbknapp/clap-rs/commit/ec5161828729f6a53f0fccec8648f71697f01f78))
+*   changes internal use of `VecMap` to `Vec` for matched values of `Arg`s ([22bf137a](https://github.com/kbknapp/clap-rs/commit/22bf137ac581684c6ed460d2c3c640c503d62621))
+*   vastly reduces the amount of cloning when adding non-global args minus when they're added from `App::args` which is forced to clone ([8da0303b](https://github.com/kbknapp/clap-rs/commit/8da0303bc02db5fe047cfc0631a9da41d9dc60f7))
+*   refactor to remove unneeded vectors and allocations and checks for significant performance increases ([0efa4119](https://github.com/kbknapp/clap-rs/commit/0efa4119632f134fc5b8b9695b007dd94b76735d))
+
+#### Documentation
+
+*   Fix examples link in CONTRIBUTING.md ([60cf875d](https://github.com/kbknapp/clap-rs/commit/60cf875d67a252e19bb85054be57696fac2c57a1))
+
+#### Improvements
+
+*   when `AppSettings::SubcommandsNegateReqs` and `ArgsNegateSubcommands` are used, a new more accurate double line usage string is shown ([50f02300](https://github.com/kbknapp/clap-rs/commit/50f02300d81788817acefef0697e157e01b6ca32), closes [#871](https://github.com/kbknapp/clap-rs/issues/871))
+
+#### API Additions
+
+* **Arg::last:**  adds the ability to mark a positional argument as 'last' which means it should be used with `--` syntax and can be accessed early ([6a7aea90](https://github.com/kbknapp/clap-rs/commit/6a7aea9043b83badd9ab038b4ecc4c787716147e), closes [#888](https://github.com/kbknapp/clap-rs/issues/888))
+*   provides `default_value_os` and `default_value_if[s]_os` ([0f2a3782](https://github.com/kbknapp/clap-rs/commit/0f2a378219a6930748d178ba350fe5925be5dad5), closes [#849](https://github.com/kbknapp/clap-rs/issues/849))
+*   provides `App::help_message` and `App::version_message` which allows one to override the auto-generated help/version flag associated help ([389c413](https://github.com/kbknapp/clap-rs/commit/389c413b7023dccab8c76aa00577ea1d048e7a99), closes [#889](https://github.com/kbknapp/clap-rs/issues/889))
+
+#### New Settings
+
+* **InferSubcommands:**  adds a setting to allow one to infer shortened subcommands or aliases (i.e. for subcommmand "test", "t", "te", or "tes" would be allowed assuming no other ambiguities) ([11602032](https://github.com/kbknapp/clap-rs/commit/11602032f6ff05881e3adf130356e37d5e66e8f9), closes [#863](https://github.com/kbknapp/clap-rs/issues/863))
+
+#### Bug Fixes
+
+*   doesn't print the argument sections in the help message if all args in that section are hidden ([ce5ee5f5](https://github.com/kbknapp/clap-rs/commit/ce5ee5f5a76f838104aeddd01c8ec956dd347f50))
+*   doesn't include the various [ARGS] [FLAGS] or [OPTIONS] if the only ones available are hidden ([7b4000af](https://github.com/kbknapp/clap-rs/commit/7b4000af97637703645c5fb2ac8bb65bd546b95b), closes [#882](https://github.com/kbknapp/clap-rs/issues/882))
+*   now correctly shows subcommand as required in the usage string when AppSettings::SubcommandRequiredElseHelp is used ([8f0884c1](https://github.com/kbknapp/clap-rs/commit/8f0884c1764983a49b45de52a1eddf8d721564d8))
+*   fixes some memory leaks when an error is detected and clap exits ([8c2dd287](https://github.com/kbknapp/clap-rs/commit/8c2dd28718262ace4ae0db98563809548e02a86b))
+*   fixes a trait that's marked private accidentlly, but should be crate internal public ([1ae21108](https://github.com/kbknapp/clap-rs/commit/1ae21108015cea87e5360402e1747025116c7878))
+* **Completions:**   fixes a bug that tried to propogate global args multiple times when generating multiple completion scripts ([5e9b9cf4](https://github.com/kbknapp/clap-rs/commit/5e9b9cf4dd80fa66a624374fd04e6545635c1f94), closes [#846](https://github.com/kbknapp/clap-rs/issues/846))
+
+#### Features
+
+* **Options:**  adds the ability to require the equals syntax with options --opt=val ([f002693d](https://github.com/kbknapp/clap-rs/commit/f002693dec6a6959c4e9590cb7b7bfffd6d6e5bc), closes [#833](https://github.com/kbknapp/clap-rs/issues/833))
+
+
+
+<a name="v2.20.5"></a>
+### v2.20.5 (2017-02-18)
+
+
+#### Bug Fixes
+
+* **clap_app!:**   fixes a critical bug of a missing fragment specifier when using `!property` style tags. ([5635c1f94](https://github.com/kbknapp/clap-rs/commit/5e9b9cf4dd80fa66a624374fd04e6545635c1f94))
+
+
+<a name="v2.20.4"></a>
+### v2.20.4 (2017-02-15)
+
+
+#### Bug Fixes
+
+* **Completions:**   fixes a bug that tried to propogate global args multiple times when generating multiple completion scripts ([5e9b9cf4](https://github.com/kbknapp/clap-rs/commit/5e9b9cf4dd80fa66a624374fd04e6545635c1f94), closes [#846](https://github.com/kbknapp/clap-rs/issues/846))
+
+#### Documentation
+
+*   Fix examples link in CONTRIBUTING.md ([60cf875d](https://github.com/kbknapp/clap-rs/commit/60cf875d67a252e19bb85054be57696fac2c57a1))
+
+
+<a name="v2.20.3"></a>
+### v2.20.3 (2017-02-03)
+
+
+#### Documentation
+
+* **Macros:**  adds a warning about changing values in Cargo.toml not triggering a rebuild automatically ([112aea3e](https://github.com/kbknapp/clap-rs/commit/112aea3e42ae9e0c0a2d33ebad89496dbdd95e5d), closes [#838](https://github.com/kbknapp/clap-rs/issues/838))
+
+#### Bug Fixes
+
+*   fixes a println->debugln typo ([279aa62e](https://github.com/kbknapp/clap-rs/commit/279aa62eaf08f56ce090ba16b937bc763cbb45be))
+*   fixes bash completions for commands that have an underscore in the name ([7f5cfa72](https://github.com/kbknapp/clap-rs/commit/7f5cfa724f0ac4e098f5fe466c903febddb2d994), closes [#581](https://github.com/kbknapp/clap-rs/issues/581))
+*   fixes a bug where ZSH completions would panic if the binary name had an underscore in it ([891a2a00](https://github.com/kbknapp/clap-rs/commit/891a2a006f775e92c556dda48bb32fac9807c4fb), closes [#581](https://github.com/kbknapp/clap-rs/issues/581))
+*   allow final word to be wrapped in wrap_help ([564c5f0f](https://github.com/kbknapp/clap-rs/commit/564c5f0f1730f4a2c1cdd128664f1a981c31dcd4), closes [#828](https://github.com/kbknapp/clap-rs/issues/828))
+* fixes a bug where global args weren't included in the generated completion scripts ([9a1e006e](https://github.com/kbknapp/clap-rs/commit/9a1e006eb75ad5a6057ebd119aa90f7e06c0ace8), closes [#841](https://github.com/kbknapp/clap-rs/issues/841))
+
+
+
+<a name="v2.20.2"></a>
+### v2.20.2 (2017-02-03)
+
+#### Bug Fixes
+
+*   fixes a critical bug where subcommand settings were being propogated too far ([74648c94](https://github.com/kbknapp/clap-rs/commit/74648c94b893df542bfa5bb595e68c7bb8167e36), closes [#832](https://github.com/kbknapp/clap-rs/issues/832))
+
+
+#### Improvements
+
+*   adds ArgGroup::multiple to the supported YAML fields for building ArgGroups from YAML ([d8590037](https://github.com/kbknapp/clap-rs/commit/d8590037ce07dafd8cd5b26928aa4a9fd3018288), closes [#840](https://github.com/kbknapp/clap-rs/issues/840))
+
+<a name="v2.20.1"></a>
+### v2.20.1 (2017-01-31)
+
+#### Bug Fixes
+
+*   allow final word to be wrapped in wrap_help ([564c5f0f](https://github.com/kbknapp/clap-rs/commit/564c5f0f1730f4a2c1cdd128664f1a981c31dcd4), closes [#828](https://github.com/kbknapp/clap-rs/issues/828))
+*   actually show character in debug output ([84d8c547](https://github.com/kbknapp/clap-rs/commit/84d8c5476de95b7f37d61888bc4f13688b712434))
+*   include final character in line lenght ([aff4ba18](https://github.com/kbknapp/clap-rs/commit/aff4ba18da8147e1259b04b0bfbc1fcb5c78a3c0))
+
+#### Improvements
+
+*   updates libc and term_size deps for the libc version conflict ([6802ac4a](https://github.com/kbknapp/clap-rs/commit/6802ac4a59c142cda9ec55ca0c45ae5cb9a6ab55))
+
+#### Documentation
+
+*   fix link from app_from_crate! to crate_authors! (#822) ([5b29be9b](https://github.com/kbknapp/clap-rs/commit/5b29be9b073330ab1f7227cdd19fe4aab39d5dcb))
+*   fix spelling of "guaranteed" ([4f30a65b](https://github.com/kbknapp/clap-rs/commit/4f30a65b9c03eb09607eb91a929a6396637dc105))
+
+<a name="v2.20.0"></a>
+
+#### New Settings
+
+* **ArgsNegateSubcommands:**  disables args being allowed between subcommands ([5e2af8c9](https://github.com/kbknapp/clap-rs/commit/5e2af8c96adb5ab75fa2d1536237ebcb41869494), closes [#793](https://github.com/kbknapp/clap-rs/issues/793))
+* **DontCollapseArgsInUsage:** disables the collapsing of positional args into `[ARGS]` in the usage string  ([c2978afc](https://github.com/kbknapp/clap-rs/commit/c2978afc61fb46d5263ab3b2d87ecde1c9ce1553), closes [#769](https://github.com/kbknapp/clap-rs/issues/769))
+* **DisableHelpSubcommand:**  disables building the `help` subcommand  ([a10fc859](https://github.com/kbknapp/clap-rs/commit/a10fc859ee20159fbd9ff4337be59b76467a64f2))
+* **AllowMissingPositional:**  allows one to implement `$ prog [optional] <required>` style CLIs where the second postional argument is required, but the first is optional ([1110fdc7](https://github.com/kbknapp/clap-rs/commit/1110fdc7a345c108820dc45783a9bf893fa4c214), closes [#636](https://github.com/kbknapp/clap-rs/issues/636))
+* **PropagateGlobalValuesDown:**  automatically propagats global arg's values down through *used* subcommands ([985536c8](https://github.com/kbknapp/clap-rs/commit/985536c8ebcc09af98aac835f42a8072ad58c262), closes [#694](https://github.com/kbknapp/clap-rs/issues/694))
+
+#### API Additions
+
+##### Arg
+
+* **Arg::value_terminator:**  adds the ability to terminate multiple values with a given string or char ([be64ce0c](https://github.com/kbknapp/clap-rs/commit/be64ce0c373efc106384baca3f487ea99fe7b8cf), closes [#782](https://github.com/kbknapp/clap-rs/issues/782))
+* **Arg::default_value_if[s]:**  adds new methods for *conditional* default values (such as a particular value from another argument was used) ([eb4010e7](https://github.com/kbknapp/clap-rs/commit/eb4010e7b21724447ef837db11ac441915728f22))
+* **Arg::requires_if[s]:**  adds the ability to *conditionally* require additional args (such as if a particular value was used) ([198449d6](https://github.com/kbknapp/clap-rs/commit/198449d64393c265f0bc327aaeac23ec4bb97226))
+* **Arg::required_if[s]:**  adds the ability for an arg to be *conditionally* required (i.e. "arg X is only required if arg Y was used with value Z") ([ee9cfddf](https://github.com/kbknapp/clap-rs/commit/ee9cfddf345a6b5ae2af42ba72aa5c89e2ca7f59))
+* **Arg::validator_os:**  adds ability to validate values which may contain invalid UTF-8 ([47232498](https://github.com/kbknapp/clap-rs/commit/47232498a813db4f3366ccd3e9faf0bff56433a4))
+
+##### Macros
+
+* **crate_description!:** Uses the `Cargo.toml` description field to fill in the `App::about` method at compile time ([4d9a82db](https://github.com/kbknapp/clap-rs/commit/4d9a82db8e875e9b64a9c2a5c6e22c25afc1279d), closes [#778](https://github.com/kbknapp/clap-rs/issues/778))
+* **crate_name!:** Uses the `Cargo.toml` name field to fill in the `App::new` method at compile time ([4d9a82db](https://github.com/kbknapp/clap-rs/commit/4d9a82db8e875e9b64a9c2a5c6e22c25afc1279d), closes [#778](https://github.com/kbknapp/clap-rs/issues/778))
+* **app_from_crate!:** Combines `crate_version!`, `crate_name!`, `crate_description!`, and `crate_authors!` into a single macro call to build a default `App` instance from the `Cargo.toml` fields ([4d9a82db](https://github.com/kbknapp/clap-rs/commit/4d9a82db8e875e9b64a9c2a5c6e22c25afc1279d), closes [#778](https://github.com/kbknapp/clap-rs/issues/778))
+
+
+#### Features
+
+* **no_cargo:**  adds a `no_cargo` feature to disable Cargo-env-var-dependent macros for those *not* using `cargo` to build their crates (#786) ([6fdd2f9d](https://github.com/kbknapp/clap-rs/commit/6fdd2f9d693aaf1118fc61bd362273950703f43d))
+
+#### Bug Fixes
+
+* **Options:**  fixes a critical bug where options weren't forced to have a value ([5a5f2b1e](https://github.com/kbknapp/clap-rs/commit/5a5f2b1e9f598a0d0280ef3e98abbbba2bc41132), closes [#665](https://github.com/kbknapp/clap-rs/issues/665))
+*   fixes a bug where calling the help of a subcommand wasn't ignoring required args of parent commands ([d3d34a2b](https://github.com/kbknapp/clap-rs/commit/d3d34a2b51ef31004055b0ab574f766d801c3adf), closes [#789](https://github.com/kbknapp/clap-rs/issues/789))
+* **Help Subcommand:**  fixes a bug where the help subcommand couldn't be overriden ([d34ec3e0](https://github.com/kbknapp/clap-rs/commit/d34ec3e032d03e402d8e87af9b2942fe2819b2da), closes [#787](https://github.com/kbknapp/clap-rs/issues/787))
+* **Low Index Multiples:**  fixes a bug which caused combinations of LowIndexMultiples and `Arg::allow_hyphen_values` to fail parsing ([26c670ca](https://github.com/kbknapp/clap-rs/commit/26c670ca16d2c80dc26d5c1ce83380ace6357318))
+
+#### Improvements
+
+* **Default Values:**  improves the error message when default values are involved ([1f33de54](https://github.com/kbknapp/clap-rs/commit/1f33de545036e7fd2f80faba251fca009bd519b8), closes [#774](https://github.com/kbknapp/clap-rs/issues/774))
+* **YAML:**  adds conditional requirements and conditional default values to YAML ([9a4df327](https://github.com/kbknapp/clap-rs/commit/9a4df327893486adb5558ffefba790c634ccdc6e), closes [#764](https://github.com/kbknapp/clap-rs/issues/764))
+*  Support `--("some-arg-name")` syntax for defining long arg names when using `clap_app!` macro ([f41ec962](https://github.com/kbknapp/clap-rs/commit/f41ec962c243a5ffff8b1be1ae2ad63970d3d1d4))
+*  Support `("some app name")` syntax for defining app names when using `clap_app!` macro ([9895b671](https://github.com/kbknapp/clap-rs/commit/9895b671cff784f35cf56abcd8270f7c2ba09699), closes [#759](https://github.com/kbknapp/clap-rs/issues/759))
+* **Help Wrapping:**  long app names (with spaces), authors, and descriptions are now wrapped appropriately ([ad4691b7](https://github.com/kbknapp/clap-rs/commit/ad4691b71a63e951ace346318238d8834e04ad8a), closes [#777](https://github.com/kbknapp/clap-rs/issues/777))
+
+
+#### Documentation
+
+* **Conditional Default Values:**  fixes the failing doc tests of Arg::default_value_ifs ([4ef09101](https://github.com/kbknapp/clap-rs/commit/4ef091019c083b4db1a0c13f1c1e95ac363259f2))
+* **Conditional Requirements:**  adds docs for Arg::requires_ifs ([7f296e29](https://github.com/kbknapp/clap-rs/commit/7f296e29db7d9036e76e5dbcc9c8b20dfe7b25bd))
+* **README.md:**  fix some typos ([f22c21b4](https://github.com/kbknapp/clap-rs/commit/f22c21b422d5b287d1a1ac183a379ee02eebf54f))
+* **src/app/mod.rs:**  fix some typos ([5c9b0d47](https://github.com/kbknapp/clap-rs/commit/5c9b0d47ca78dea285c5b9dec79063d24c3e451a))
+
+<a name="v2.19.3"></a>
+### v2.19.3 (2016-12-28)
+
+
+#### Bug Fixes
+
+*   fixes a bug where calling the help of a subcommand wasn't ignoring required args of parent commands ([a0ee4993](https://github.com/kbknapp/clap-rs/commit/a0ee4993015ea97b06b5bc9f378d8bcb18f1c51c), closes [#789](https://github.com/kbknapp/clap-rs/issues/789))
+
+
+
+<a name="v2.19.2"></a>
+### v2.19.2 (2016-12-08)
+
+#### Bug Fixes
+
+* **ZSH Completions:**  escapes square brackets in ZSH completions ([7e17d5a3](https://github.com/kbknapp/clap-rs/commit/7e17d5a36b2cc2cc77e7b15796b14d639ed3cbf7), closes [#771](https://github.com/kbknapp/clap-rs/issues/771))
+
+#### Documentation
+
+* **Examples:**  adds subcommand examples ([0e0f3354](https://github.com/kbknapp/clap-rs/commit/0e0f33547a6901425afc1d9fbe19f7ae3832d9a4), closes [#766](https://github.com/kbknapp/clap-rs/issues/766))
+* **README.md:**  adds guidance on when to use ~ in version pinning, and clarifies breaking change policy ([591eaefc](https://github.com/kbknapp/clap-rs/commit/591eaefc7319142ba921130e502bb0729feed907), closes [#765](https://github.com/kbknapp/clap-rs/issues/765))
+
+
+
+<a name="v2.19.1"></a>
+### v2.19.1 (2016-12-01)
+
+
+#### Bug Fixes
+
+* **Help Messages:**  fixes help message alignment when specific settings are used on options ([cd94b318](https://github.com/kbknapp/clap-rs/commit/cd94b3188d63b63295a319e90e826bca46befcd2), closes [#760](https://github.com/kbknapp/clap-rs/issues/760))
+
+#### Improvements
+
+* **Bash Completion:**  allows bash completion to fall back to traidtional bash completion upon no matching completing function ([b1b16d56](https://github.com/kbknapp/clap-rs/commit/b1b16d56d8fddf819bdbe24b3724bb6a9f3fa613)))
+
+
+<a name="v2.19.0"></a>
+## v2.19.0 (2016-11-21)
+
+#### Features
+
+*   allows specifying AllowLeadingHyphen style values, but only for specific args vice command wide ([c0d70feb](https://github.com/kbknapp/clap-rs/commit/c0d70febad9996a77a54107054daf1914c50d4ef), closes [#742](https://github.com/kbknapp/clap-rs/issues/742))
+
+#### Bug Fixes
+
+* **Required Unless:**  fixes a bug where having required_unless set doesn't work when conflicts are also set ([d20331b6](https://github.com/kbknapp/clap-rs/commit/d20331b6f7940ac3a4e919999f8bb4780875125d), closes [#753](https://github.com/kbknapp/clap-rs/issues/753))
+* **ZSH Completions:**  fixes an issue where zsh completions caused panics if there were no subcommands ([49e7cdab](https://github.com/kbknapp/clap-rs/commit/49e7cdab76dd1ccc07221e360f07808ec62648aa), closes [#754](https://github.com/kbknapp/clap-rs/issues/754))
+
+#### Improvements
+
+* **Validators:**  improves the error messages for validators ([65eb3385](https://github.com/kbknapp/clap-rs/commit/65eb33859d3ff53e7d3277f02a9d3fd9038a9dfb), closes [#744](https://github.com/kbknapp/clap-rs/issues/744))
+
+#### Documentation
+
+*   updates the docs landing page ([01e1e33f](https://github.com/kbknapp/clap-rs/commit/01e1e33f377934099a4a725fab5cd6c5ff50eaa2))
+*   adds the macro version back to the readme ([45eb9bf1](https://github.com/kbknapp/clap-rs/commit/45eb9bf130329c3f3853aba0342c2fe3c64ff80f))
+*   fix broken docs links ([808e7cee](https://github.com/kbknapp/clap-rs/commit/808e7ceeb86d4a319bdc270f51c23a64621dbfb3))
+* **Compatibility Policy:**  adds an official compatibility policy to ([760d66dc](https://github.com/kbknapp/clap-rs/commit/760d66dc17310b357f257776624151da933cd25d), closes [#740](https://github.com/kbknapp/clap-rs/issues/740))
+* **Contributing:**  updates the readme to improve the readability and contributing sections ([eb51316c](https://github.com/kbknapp/clap-rs/commit/eb51316cdfdc7258d287ba13b67ef2f42bd2b8f6))
+
+<a name="v2.18.0"></a>
+## v2.18.0 (2016-11-05)
+
+
+#### Features
+
+* **Completions:**  adds completion support for PowerShell. ([cff82c88](https://github.com/kbknapp/clap-rs/commit/cff82c880e21064fca63351507b80350df6caadf), closes [#729](https://github.com/kbknapp/clap-rs/issues/729))
+
+
+
+<a name="v2.17.1"></a>
+### v2.17.1 (2016-11-02)
+
+
+#### Bug Fixes
+
+* **Low Index Multiples:**  fixes a bug where using low index multiples was propagated to subcommands ([33924e88](https://github.com/kbknapp/clap-rs/commit/33924e884461983c4e6b5ea1330fecc769a4ade7), closes [#725](https://github.com/kbknapp/clap-rs/issues/725))
+
+
+
+<a name="v2.17.0"></a>
+## v2.17.0 (2016-11-01)
+
+
+#### Features
+
+* **Positional Args:**  allows specifying the second to last positional argument as multiple(true) ([1ced2a74](https://github.com/kbknapp/clap-rs/commit/1ced2a7433ea8937a1b260ea65d708f32ca7c95e), closes [#725](https://github.com/kbknapp/clap-rs/issues/725))
+
+
+
+<a name="v2.16.4"></a>
+### v2.16.4 (2016-10-31)
+
+
+#### Improvements
+
+* **Error Output:**  conflicting errors are now symetrical, meaning more consistent and less confusing ([3d37001d](https://github.com/kbknapp/clap-rs/commit/3d37001d1dc647d73cc597ff172f1072d4beb80d), closes [#718](https://github.com/kbknapp/clap-rs/issues/718))
+
+#### Documentation
+
+*   Fix typo in example `13a_enum_values_automatic` ([c22fbc07](https://github.com/kbknapp/clap-rs/commit/c22fbc07356e556ffb5d1a79ec04597d149b915e))
+* **README.md:**  fixes failing yaml example (#715) ([21fba9e6](https://github.com/kbknapp/clap-rs/commit/21fba9e6cd8c163012999cd0ce271ec8780c5695))
+
+#### Bug Fixes
+
+* **ZSH Completions:**  fixes bug that caused panic on subcommands with aliases ([5c70e1a0](https://github.com/kbknapp/clap-rs/commit/5c70e1a01bc977e44c10015d18bb8e215c32dfc8), closes [#714](https://github.com/kbknapp/clap-rs/issues/714))
+* **debug:**  fixes the debug feature (#716) ([6c11ccf4](https://github.com/kbknapp/clap-rs/commit/6c11ccf443d46258d51f7cda33fbcc81e7fe8e90))
+
+
+
+<a name="v2.16.3"></a>
+### v2.16.3 (2016-10-28)
+
+
+#### Bug Fixes
+
+*   Derive display order after propagation ([9cb6facf](https://github.com/kbknapp/clap-rs/commit/9cb6facf507aff7cddd124b8c29714d2b0e7bd13), closes [#706](https://github.com/kbknapp/clap-rs/issues/706))
+* **yaml-example:**  inconsistent args ([847f7199](https://github.com/kbknapp/clap-rs/commit/847f7199219ead5065561d91d64780d99ae4b587))
+
+
+
+<a name="v2.15.1"></a>
+### v2.16.2 (2016-10-25)
+
+
+#### Bug Fixes
+
+* **Fish Completions:**  fixes a bug where single quotes are not escaped ([780b4a18](https://github.com/kbknapp/clap-rs/commit/780b4a18281b6f7f7071e1b9db2290fae653c406), closes [#704](https://github.com/kbknapp/clap-rs/issues/704))
+
+
+<a name="v2.16.1"></a>
+### v2.16.1 (2016-10-24)
+
+
+#### Bug Fixes
+
+* **Help Message:**  fixes a regression bug where args with multiple(true) threw off alignment ([ebddac79](https://github.com/kbknapp/clap-rs/commit/ebddac791f3ceac193d5ad833b4b734b9643a7af), closes [#702](https://github.com/kbknapp/clap-rs/issues/702))
+
+
+
+<a name="v2.16.0"></a>
+## v2.16.0 (2016-10-23)
+
+
+#### Features
+
+* **Completions:**  adds ZSH completion support ([3e36b0ba](https://github.com/kbknapp/clap-rs/commit/3e36b0bac491d3f6194aee14604caf7be26b3d56), closes [#699](https://github.com/kbknapp/clap-rs/issues/699))
+
+
+
+<a name="v2.15.0"></a>
+## v2.15.0 (2016-10-21)
+
+
+#### Features
+
+* **AppSettings:**  adds new setting `AppSettings::AllowNegativeNumbers` ([ab064546](https://github.com/kbknapp/clap-rs/commit/ab06454677fb6aa9b9f804644fcca2168b1eaee3), closes [#696](https://github.com/kbknapp/clap-rs/issues/696))
+
+#### Documentation
+
+* **app/settings.rs:**  moves variants to roughly alphabetical order ([9ed4d4d7](https://github.com/kbknapp/clap-rs/commit/9ed4d4d7957a23357aef60081e45639ab9e3905f))
+
+
+<a name="v2.14.1"></a>
+### v2.14.1 (2016-10-20)
+
+
+#### Documentation
+
+*   Improve documentation around features ([4ee85b95](https://github.com/kbknapp/clap-rs/commit/4ee85b95d2d16708a016a3ba4e6e2c93b89b7fad))
+*   reword docs for ErrorKind and app::Settings ([3ccde7a4](https://github.com/kbknapp/clap-rs/commit/3ccde7a4b8f7a2ea8b916a5415c04a8ff4b5cb7a))
+*   fix tests that fail when the "suggestions" feature is disabled ([996fc381](https://github.com/kbknapp/clap-rs/commit/996fc381763a48d125c7ea8a58fed057fd0b4ac6))
+*   fix the OsString-using doc-tests ([af9e1a39](https://github.com/kbknapp/clap-rs/commit/af9e1a393ce6cdda46a03c8a4f48df222b015a24))
+*   tag non-rust code blocks as such instead of ignoring them ([0ba9f4b1](https://github.com/kbknapp/clap-rs/commit/0ba9f4b123f281952581b6dec948f7e51dd22890))
+* **ErrorKind:**  improve some errors about subcommands ([9f6217a4](https://github.com/kbknapp/clap-rs/commit/9f6217a424da823343d7b801b9c350dee3cd1906))
+* **yaml:**  make sure the doc-tests don't fail before "missing file" ([8c0f5551](https://github.com/kbknapp/clap-rs/commit/8c0f55516f4910c78c9f8a2bdbd822729574f95b))
+
+#### Improvements
+
+*   Stabilize clap_app! ([cd516006](https://github.com/kbknapp/clap-rs/commit/cd516006e35c37b005f329338560a0a53d1f3e00))
+* **with_defaults:**  Deprecate App::with_defaults() ([26085409](https://github.com/kbknapp/clap-rs/commit/2608540940c8bb66e517b65706bc7dea55510682), closes [#638](https://github.com/kbknapp/clap-rs/issues/638))
+
+#### Bug Fixes
+
+*   fixes a bug that made determining when to auto-wrap long help messages inconsistent ([468baadb](https://github.com/kbknapp/clap-rs/commit/468baadb8398fc1d37897b0c49374aef4cf97dca), closes [#688](https://github.com/kbknapp/clap-rs/issues/688))
+* **Completions:**  fish completions for nested subcommands ([a61eaf8a](https://github.com/kbknapp/clap-rs/commit/a61eaf8aade76cfe90ccc0f7125751ebf60e3254))
+* **features:**  Make lints not enable other nightly-requiring features ([835f75e3](https://github.com/kbknapp/clap-rs/commit/835f75e3ba20999117363ed9f916464d777f36ef))
+
+
+
+<a name="v2.14.0"></a>
+## v2.14.0 (2016-10-05)
+
+
+#### Features
+
+* **arg_aliases:**  Ability to alias arguments ([33b5f6ef](https://github.com/kbknapp/clap-rs/commit/33b5f6ef2c9612ecabb31f96b824793e46bfd3dd), closes [#669](https://github.com/kbknapp/clap-rs/issues/669))
+* **flag_aliases:**  Ability to alias flags ([40d6dac9](https://github.com/kbknapp/clap-rs/commit/40d6dac973927dded6ab423481634ef47ee7bfd7))
+
+#### Bug Fixes
+
+* **UsageParser:**  Handle non-ascii names / options. ([1d6a7c6e](https://github.com/kbknapp/clap-rs/commit/1d6a7c6e7e6aadc527346aa822f19d8587f714f3), closes [#664](https://github.com/kbknapp/clap-rs/issues/664))
+
+#### Documentation
+
+*   typo ([bac417fa](https://github.com/kbknapp/clap-rs/commit/bac417fa1cea3d32308334c7cccfcf54546cd9d8))
+
+
+<a name="v2.13.0"></a>
+## v2.13.0 (2016-09-18)
+
+
+#### Documentation
+
+*   updates README.md with new website information and updated video tutorials info ([0c19c580](https://github.com/kbknapp/clap-rs/commit/0c19c580cf50f1b82ff32f70b36708ae2bcac132))
+*   updates the docs about removing implicit value_delimiter(true) ([c81bc722](https://github.com/kbknapp/clap-rs/commit/c81bc722ebb8a86d22be89b5aec98df9fe222a08))
+* **Default Values:**  adds better examples on using default values ([57a8d9ab](https://github.com/kbknapp/clap-rs/commit/57a8d9abb2f973c235a8a14f8fc031673d7a7460), closes [#418](https://github.com/kbknapp/clap-rs/issues/418))
+
+#### Bug Fixes
+
+* **Value Delimiters:**  fixes the confusion around implicitly setting value delimiters. (default is now `false`) ([09d4d0a9](https://github.com/kbknapp/clap-rs/commit/09d4d0a9038d7ce2df55c2aec95e16f36189fcee), closes [#666](https://github.com/kbknapp/clap-rs/issues/666))
+
+
+
+<a name="v2.12.1"></a>
+### v2.12.1 (2016-09-13)
+
+
+#### Bug Fixes
+
+* **Help Wrapping:**  fixes a regression-bug where the old {n} newline char stopped working ([92ac353b](https://github.com/kbknapp/clap-rs/commit/92ac353b48b7caa2511ad2a046d94da93c236cf6), closes [#661](https://github.com/kbknapp/clap-rs/issues/661))
+
+
+
+<a name="v2.12.0"></a>
+## v2.12.0 (2016-09-13)
+
+
+#### Features
+
+* **Help:**  adds ability to hide the possible values on a per argument basis ([9151ef73](https://github.com/kbknapp/clap-rs/commit/9151ef739871f2e74910c342299c0de196b95dec), closes [#640](https://github.com/kbknapp/clap-rs/issues/640))
+* **help:**  allow for limiting detected terminal width ([a43e28af](https://github.com/kbknapp/clap-rs/commit/a43e28af85c9a9deaedd5ef735f4f13008daab29), closes [#653](https://github.com/kbknapp/clap-rs/issues/653))
+
+#### Documentation
+
+* **Help Wrapping:**  removes the verbiage about using `'{n}'` to insert newlines in help text ([c5a2b352](https://github.com/kbknapp/clap-rs/commit/c5a2b352ca600f5b802290ad945731066cd53611))
+* **Value Delimiters:**  updates the docs for the Arg::multiple method WRT value delimiters and default settings ([f9d17a06](https://github.com/kbknapp/clap-rs/commit/f9d17a060aa53f10d0a6e1a7eed5d989d1a59533))
+* **appsettings:**  Document AppSetting::DisableVersion ([94501965](https://github.com/kbknapp/clap-rs/commit/945019654d2ca67eb2b1d6014fdf80b84d528d30), closes [#589](https://github.com/kbknapp/clap-rs/issues/589))
+
+#### Bug Fixes
+
+* **AllowLeadingHyphen:**  fixes a bug where valid args aren't recognized with this setting ([a9699e4d](https://github.com/kbknapp/clap-rs/commit/a9699e4d7cdc9a06e73b845933ff1fe6d76f016a), closes [#588](https://github.com/kbknapp/clap-rs/issues/588))
+
+#### Improvements
+
+* **Help Wrapping:**
+  *  clap now ignores hard newlines in help messages and properly re-aligns text, but still wraps if the term width is too small ([c7678523](https://github.com/kbknapp/clap-rs/commit/c76785239fd42adc8ca04f9202b6fec615aa9f14), closes [#617](https://github.com/kbknapp/clap-rs/issues/617))
+  *  makes some minor changes to when next line help is automatically used ([01cae799](https://github.com/kbknapp/clap-rs/commit/01cae7990a33167ac35103fb36c811b4fe6eb98f))
+* **Value Delimiters:**  changes the default value delimiter rules ([f9e69254](https://github.com/kbknapp/clap-rs/commit/f9e692548e8c94de15f909432de301407d6bb834), closes [#655](https://github.com/kbknapp/clap-rs/issues/655))
+* **YAML:**  supports setting Arg::require_delimiter from YAML ([b9b55a39](https://github.com/kbknapp/clap-rs/commit/b9b55a39dfebcdbdc05dca2692927e503db50816))
+
+#### Performance
+
+* **help:**  fix redundant contains() checks ([a8afed74](https://github.com/kbknapp/clap-rs/commit/a8afed7428bf0733f8e93bb11ad6c00d9e970fcc))
+
+
+
+<a name="v2.11.3"></a>
+### v2.11.3 (2016-09-07)
+
+
+#### Documentation
+
+* **Help Wrapping:**  removes the verbiage about using `'{n}'` to insert newlines in help text ([c5a2b352](https://github.com/kbknapp/clap-rs/commit/c5a2b352ca600f5b802290ad945731066cd53611))
+
+#### Improvements
+
+* **Help Wrapping:**
+  *  clap now ignores hard newlines in help messages and properly re-aligns text, but still wraps if the term width is too small ([c7678523](https://github.com/kbknapp/clap-rs/commit/c76785239fd42adc8ca04f9202b6fec615aa9f14), closes [#617](https://github.com/kbknapp/clap-rs/issues/617))
+  *  makes some minor changes to when next line help is automatically used ([01cae799](https://github.com/kbknapp/clap-rs/commit/01cae7990a33167ac35103fb36c811b4fe6eb98f))
+* **YAML:**  supports setting Arg::require_delimiter from YAML ([b9b55a39](https://github.com/kbknapp/clap-rs/commit/b9b55a39dfebcdbdc05dca2692927e503db50816))
+
+
+
+
+<a name="v2.11.2"></a>
+### v2.11.2 (2016-09-06)
+
+#### Improvements
+
+* **Help Wrapping:**  makes some minor changes to when next line help is automatically used ([5658b117](https://github.com/kbknapp/clap-rs/commit/5658b117aec3e03adff9c8c52a4c4bc1fcb4e1ff))
+
+
+<a name="v2.11.1"></a>
+### v2.11.1 (2016-09-05)
+
+
+#### Bug Fixes
+
+* **Settings:**  fixes an issue where settings weren't propogated down through grand-child subcommands ([b3efc107](https://github.com/kbknapp/clap-rs/commit/b3efc107515d78517b20798ff3890b8a2b04498e), closes [#638](https://github.com/kbknapp/clap-rs/issues/638))
+
+#### Features
+
+* **Errors:**  Errors with custom description ([58512f2f](https://github.com/kbknapp/clap-rs/commit/58512f2fcb430745f1ee6ee8f1c67f62dc216c73))
+
+#### Improvements
+
+* **help:**  use term_size instead of home-grown solution ([fc7327e9](https://github.com/kbknapp/clap-rs/commit/fc7327e9dcf4258ef2baebf0a8714d9c0622855b))
+
+
+
+<a name="v2.11.0"></a>
+### v2.11.0 (2016-08-28)
+
+
+#### Bug Fixes
+
+* **Groups:**  fixes some usage strings that contain both args in groups and ones that conflict with each other ([3d782def](https://github.com/kbknapp/clap-rs/commit/3d782def57725e2de26ca5a5bc5cc2e40ddebefb), closes [#616](https://github.com/kbknapp/clap-rs/issues/616))
+
+#### Documentation
+
+*   moves docs to docs.rs ([03209d5e](https://github.com/kbknapp/clap-rs/commit/03209d5e1300906f00bafec1869c2047a92e5071), closes [#634](https://github.com/kbknapp/clap-rs/issues/634))
+
+#### Improvements
+
+* **Completions:**  uses standard conventions for bash completion files, namely '{bin}.bash-completion' ([27f5bbfb](https://github.com/kbknapp/clap-rs/commit/27f5bbfbcc9474c2f57c2b92b1feb898ae46ee70), closes [#567](https://github.com/kbknapp/clap-rs/issues/567))
+* **Help:**  automatically moves help text to the next line and wraps when term width is determined to be too small, or help text is too long ([150964c4](https://github.com/kbknapp/clap-rs/commit/150964c4e7124d54476c9d9b4b3f2406f0fd00e5), closes [#597](https://github.com/kbknapp/clap-rs/issues/597))
+* **YAML Errors:**  vastly improves error messages when using YAML ([f43b7c65](https://github.com/kbknapp/clap-rs/commit/f43b7c65941c53adc0616b8646a21dc255862eb2), closes [#574](https://github.com/kbknapp/clap-rs/issues/574))
+
+#### Features
+
+*   adds App::with_defaults to automatically use crate_authors! and crate_version! macros ([5520bb01](https://github.com/kbknapp/clap-rs/commit/5520bb012c127dfd299fd55699443c744d8dcd5b), closes [#600](https://github.com/kbknapp/clap-rs/issues/600))
+
+
+
+<a name="v2.10.4"></a>
+### v2.10.4 (2016-08-25)
+
+
+#### Bug Fixes
+
+* **Help Wrapping:**  fixes a bug where help is wrapped incorrectly and causing a panic with some non-English characters ([d0b442c7](https://github.com/kbknapp/clap-rs/commit/d0b442c7beeecac9764406bc3bd171ced0b8825e), closes [#626](https://github.com/kbknapp/clap-rs/issues/626))
+
+
+
+<a name="v2.10.3"></a>
+### v2.10.3 (2016-08-25)
+
+#### Features
+
+* **Help:**  adds new short hand way to use source formatting and ignore term width in help messages ([7dfdaf20](https://github.com/kbknapp/clap-rs/commit/7dfdaf200ebb5c431351a045b48f5e0f0d3f31db), closes [#625](https://github.com/kbknapp/clap-rs/issues/625))
+
+#### Documentation
+
+* **Term Width:**  adds details about set_term_width(0) ([00b8205d](https://github.com/kbknapp/clap-rs/commit/00b8205d22639d1b54b9c453c55c785aace52cb2))
+
+#### Bug Fixes
+
+* **Unicode:**  fixes two bugs where non-English characters were stripped or caused a panic with help wrapping ([763a5c92](https://github.com/kbknapp/clap-rs/commit/763a5c920e23efc74d190af0cb8b5dd714b2d67a), closes [#626](https://github.com/kbknapp/clap-rs/issues/626))
+
+
+
+<a name="v2.10.2"></a>
+### v2.10.2 (2016-08-22)
+
+
+#### Bug Fixes
+
+*   fixes a bug where the help is printed twice ([a643fb28](https://github.com/kbknapp/clap-rs/commit/a643fb283acd9905dc727c4579c5c9fa2ceaa7e7), closes [#623](https://github.com/kbknapp/clap-rs/issues/623))
+
+
+
+<a name="v2.10.1"></a>
+### v2.10.1 (2016-08-21)
+
+
+#### Bug Fixes
+
+* **Help Subcommand:**  fixes misleading usage string when using multi-level subcommmands ([e203515e](https://github.com/kbknapp/clap-rs/commit/e203515e3ac495b405dbba4f78fb6af148fd282e), closes [#618](https://github.com/kbknapp/clap-rs/issues/618))
+
+#### Features
+
+* **YAML:**  allows using lists or single values with arg declarations ([9ade2cd4](https://github.com/kbknapp/clap-rs/commit/9ade2cd4b268d6d7fe828319ce6a523c641b9c38), closes [#614](https://github.com/kbknapp/clap-rs/issues/614), [#613](https://github.com/kbknapp/clap-rs/issues/613))
+
+
+
+<a name="v2.10.0"></a>
+## v2.10.0 (2016-07-29)
+
+
+#### Features
+
+* **Completions:**  one can generate a basic fish completions script at compile time ([1979d2f2](https://github.com/kbknapp/clap-rs/commit/1979d2f2f3216e57d02a97e624a8a8f6cf867ed9))
+
+#### Bug Fixes
+
+* **parser:**  preserve external subcommand name ([875df243](https://github.com/kbknapp/clap-rs/commit/875df24316c266920a073c13bbefbf546bc1f635))
+
+#### Breaking Changes
+
+* **parser:**  preserve external subcommand name ([875df243](https://github.com/kbknapp/clap-rs/commit/875df24316c266920a073c13bbefbf546bc1f635))
+
+#### Documentation
+
+* **YAML:**  fixes example 17's incorrect reference to arg_groups instead of groups ([b6c99e13](https://github.com/kbknapp/clap-rs/commit/b6c99e1377f918e78c16c8faced70a71607da931), closes [#601](https://github.com/kbknapp/clap-rs/issues/601))
+
+
+
+<a name="2.9.3"></a>
+### 2.9.3 (2016-07-24)
+
+
+#### Bug Fixes
+
+*   fixes bug where only first arg in list of required_unless_one is recognized ([1fc3b55b](https://github.com/kbknapp/clap-rs/commit/1fc3b55bd6c8653b02e7c4253749c6b77737d2ac), closes [#575](https://github.com/kbknapp/clap-rs/issues/575))
+* **Settings:**  fixes typo subcommandsrequired->subcommandrequired ([fc72cdf5](https://github.com/kbknapp/clap-rs/commit/fc72cdf591d30f5d9375d0b5cc2a2ff3e812f9f6), closes [#593](https://github.com/kbknapp/clap-rs/issues/593))
+
+#### Features
+
+* **Completions:**  adds the ability to generate completions to io::Write object ([9f62cf73](https://github.com/kbknapp/clap-rs/commit/9f62cf7378ba5acb5ce8c5bac89b4aa60c30755f))
+* **Settings:**  Add unset_setting and unset_settings fns to App (#598) ([0ceba231](https://github.com/kbknapp/clap-rs/commit/0ceba231c6767cd6d88fdb1feeeea41deadf77ff), closes [#590](https://github.com/kbknapp/clap-rs/issues/590))
+
+
+<a name="2.9.2"></a>
+### 2.9.2 (2016-07-03)
+
+
+#### Documentation
+
+* **Completions:**  fixes the formatting of the Cargo.toml excerpt in the completions example ([722f2607](https://github.com/kbknapp/clap-rs/commit/722f2607beaef56b6a0e433db5fd09492d9f028c))
+
+#### Bug Fixes
+
+* **Completions:**  fixes bug where --help and --version short weren't added to the completion list ([e9f2438e](https://github.com/kbknapp/clap-rs/commit/e9f2438e2ce99af0ae570a2eaf541fc7f55b771b), closes [#536](https://github.com/kbknapp/clap-rs/issues/536))
+
+
+
+<a name="2.9.1"></a>
+### 2.9.1 (2016-07-02)
+
+
+#### Improvements
+
+* **Completions:**  allows multiple completions to be built by namespacing with bin name ([57484b2d](https://github.com/kbknapp/clap-rs/commit/57484b2daeaac01c1026e8c84efc8bf099e0eb31))
+
+
+<a name="v2.9.0"></a>
+## v2.9.0 (2016-07-01)
+
+
+#### Documentation
+
+* **Completions:**
+  *  fixes some errors in the completion docs ([9b359bf0](https://github.com/kbknapp/clap-rs/commit/9b359bf06255d3dad8f489308044b60a9d1e6a87))
+  *  adds documentation for completion scripts ([c6c519e4](https://github.com/kbknapp/clap-rs/commit/c6c519e40efd6c4533a9ef5efe8e74fd150391b7))
+
+#### Features
+
+* **Completions:**
+  *  one can now generate a bash completions script at compile time! ([e75b6c7b](https://github.com/kbknapp/clap-rs/commit/e75b6c7b75f729afb9eb1d2a2faf61dca7674634), closes [#376](https://github.com/kbknapp/clap-rs/issues/376))
+  *  completions now include aliases to subcommands, including all subcommand options ([0ab9f840](https://github.com/kbknapp/clap-rs/commit/0ab9f84052a8cf65b5551657f46c0c270841e634), closes [#556](https://github.com/kbknapp/clap-rs/issues/556))
+  *  completions now continue completing even after first completion ([18fc2e5b](https://github.com/kbknapp/clap-rs/commit/18fc2e5b5af63bf54a94b72cec5e1223d49f4806))
+  *  allows matching on possible values in options ([89cc2026](https://github.com/kbknapp/clap-rs/commit/89cc2026ba9ac69cf44c5254360bbf99236d4f89), closes [#557](https://github.com/kbknapp/clap-rs/issues/557))
+
+#### Bug Fixes
+
+* **AllowLeadingHyphen:**  fixes an issue where  isn't ignored like it should be with this setting ([96c24c9a](https://github.com/kbknapp/clap-rs/commit/96c24c9a8fa1f85e06138d3cdd133e51659e19d2), closes [#558](https://github.com/kbknapp/clap-rs/issues/558))
+
+<a name="v2.8.0"></a>
+## v2.8.0 (2016-06-30)
+
+
+#### Features
+
+* **Arg:**  adds new setting `Arg::require_delimiter` which requires val delimiter to parse multiple values ([920b5595](https://github.com/kbknapp/clap-rs/commit/920b5595ed72abfb501ce054ab536067d8df2a66))
+
+#### Bug Fixes
+
+*   Declare term::Winsize as repr(C) ([5d663d90](https://github.com/kbknapp/clap-rs/commit/5d663d905c9829ce6e7a164f1f0896cdd70236dd))
+
+#### Documentation
+
+* **Arg:**  adds docs for ([49af4e38](https://github.com/kbknapp/clap-rs/commit/49af4e38a5dae2ab0a7fc3b4147e2c053d532484))
+
+
+
+<a name="v2.7.1"></a>
+### v2.7.1 (2016-06-29)
+
+
+#### Bug Fixes
+
+* **Options:**
+  *  options with multiple values and using delimiters no longer parse additional values after a trailing space ([cdc500bd](https://github.com/kbknapp/clap-rs/commit/cdc500bdde6abe238c36ade406ddafc2bafff583))
+  *  using options with multiple values and with an = no longer parse args after the trailing space as values ([290f61d0](https://github.com/kbknapp/clap-rs/commit/290f61d07177413cf082ada55526d83405f6d011))
+
+
+
+<a name="v2.7.0"></a>
+## v2.7.0 (2016-06-28)
+
+
+#### Documentation
+
+*   fix typos ([43b3d40b](https://github.com/kbknapp/clap-rs/commit/43b3d40b8c38b1571da75af86b5088be96cccec2))
+* **ArgGroup:**  vastly improves ArgGroup docs by adding better examples ([9e5f4f5d](https://github.com/kbknapp/clap-rs/commit/9e5f4f5d734d630bca5535c3a0aa4fd4f9db3e39), closes [#534](https://github.com/kbknapp/clap-rs/issues/534))
+
+#### Features
+
+* **ArgGroup:**  one can now specify groups which require AT LEAST one of the args ([33689acc](https://github.com/kbknapp/clap-rs/commit/33689acc689b217a8c0ee439f1b1225590c38355), closes [#533](https://github.com/kbknapp/clap-rs/issues/533))
+
+#### Bug Fixes
+
+* **App:**  using `App::print_help` now prints the same as would have been printed by `--help` or the like ([e84cc018](https://github.com/kbknapp/clap-rs/commit/e84cc01836bbe0527e97de6db9889bd9e0fd6ba1), closes [#536](https://github.com/kbknapp/clap-rs/issues/536))
+* **Help:**
+  *  prevents invoking <cmd> help help and displaying incorrect help message ([e3d2893f](https://github.com/kbknapp/clap-rs/commit/e3d2893f377942a2d4cf3c6ff04524d0346e6fdb), closes [#538](https://github.com/kbknapp/clap-rs/issues/538))
+  *  subcommand help messages requested via <cmd> help <sub> now correctly match <cmd> <sub> --help ([08ad1cff](https://github.com/kbknapp/clap-rs/commit/08ad1cff4fec57224ea957a2891a057b323c01bc), closes [#539](https://github.com/kbknapp/clap-rs/issues/539))
+
+#### Improvements
+
+* **ArgGroup:**  Add multiple ArgGroups per Arg ([902e182f](https://github.com/kbknapp/clap-rs/commit/902e182f7a58aff11ff01e0a452abcdbdb2262aa), closes [#426](https://github.com/kbknapp/clap-rs/issues/426))
+* **Usage Strings:**  `[FLAGS]` and `[ARGS]` are no longer blindly added to usage strings ([9b2e45b1](https://github.com/kbknapp/clap-rs/commit/9b2e45b170aff567b038d8b3368880b6046c10c6), closes [#537](https://github.com/kbknapp/clap-rs/issues/537))
+* **arg_enum!:**  allows using meta items like repr(C) with arg_enum!s ([edf9b233](https://github.com/kbknapp/clap-rs/commit/edf9b2331c17a2cbcc13f961add4c55c2778e773), closes [#543](https://github.com/kbknapp/clap-rs/issues/543))
+
+
+
+<a name="v2.6.0"></a>
+## v2.6.0 (2016-06-14)
+
+
+#### Improvements
+
+*   removes extra newline from help output ([86e61d19](https://github.com/kbknapp/clap-rs/commit/86e61d19a748fb9870fcf1175308984e51ca1115))
+*   allows printing version to any io::Write object ([921f5f79](https://github.com/kbknapp/clap-rs/commit/921f5f7916597f1d028cd4a65bfe76a01c801724))
+*   removes extra newline when printing version ([7e2e2cbb](https://github.com/kbknapp/clap-rs/commit/7e2e2cbb4a8a0f050bb8072a376f742fc54b8589))
+* **Aliases:**  improves readability of asliases in help messages ([ca511de7](https://github.com/kbknapp/clap-rs/commit/ca511de71f5b8c2ac419f1b188658e8c63b67846), closes [#526](https://github.com/kbknapp/clap-rs/issues/526), [#529](https://github.com/kbknapp/clap-rs/issues/529))
+* **Usage Strings:**  improves the default usage string when only a single positional arg is present ([ec86f2da](https://github.com/kbknapp/clap-rs/commit/ec86f2dada1545a63fc72355e22fcdc4c466c215), closes [#518](https://github.com/kbknapp/clap-rs/issues/518))
+
+#### Features
+
+* **Help:**  allows wrapping at specified term width (Even on Windows!) ([1761dc0d](https://github.com/kbknapp/clap-rs/commit/1761dc0d27d0d621229d792be40c36fbf65c3014), closes [#451](https://github.com/kbknapp/clap-rs/issues/451))
+* **Settings:**
+  *  adds new setting to stop delimiting values with -- or TrailingVarArg ([fc3e0f5a](https://github.com/kbknapp/clap-rs/commit/fc3e0f5afda6d24cdb3c4676614beebe13e1e870), closes [#511](https://github.com/kbknapp/clap-rs/issues/511))
+  *  one can now set an AppSetting which is propogated down through child subcommands ([e2341835](https://github.com/kbknapp/clap-rs/commit/e23418351a3b98bf08dfd7744bc14377c70d59ee), closes [#519](https://github.com/kbknapp/clap-rs/issues/519))
+* **Subcommands:**  adds support for visible aliases ([7b10e7f8](https://github.com/kbknapp/clap-rs/commit/7b10e7f8937a07fdb8d16a6d8df79ce78d080cd3), closes [#522](https://github.com/kbknapp/clap-rs/issues/522))
+
+#### Bug Fixes
+
+*   fixes bug where args are printed out of order with templates ([05abb534](https://github.com/kbknapp/clap-rs/commit/05abb534864764102031a0d402e64ac65867aa87))
+*   fixes bug where one can't override version or help flags ([90d7d6a2](https://github.com/kbknapp/clap-rs/commit/90d7d6a2ea8240122dd9bf8d82d3c4f5ebb5c703), closes [#514](https://github.com/kbknapp/clap-rs/issues/514))
+*   fixes issue where before_help wasn't printed ([b3faff60](https://github.com/kbknapp/clap-rs/commit/b3faff6030f76a23f26afcfa6a90169002ed7106))
+* **Help:**  `App::before_help` and `App::after_help` now correctly wrap ([1f4da767](https://github.com/kbknapp/clap-rs/commit/1f4da7676e6e71aa8dda799f3eeefad105a47819), closes [#516](https://github.com/kbknapp/clap-rs/issues/516))
+* **Settings:**  fixes bug where new color settings couldn't be converted from strs ([706a7c11](https://github.com/kbknapp/clap-rs/commit/706a7c11b0900be594de6d5a3121938eff197602))
+* **Subcommands:**  subcommands with aliases now display help of the aliased subcommand ([5354d14b](https://github.com/kbknapp/clap-rs/commit/5354d14b51f189885ba110e01e6b76cca3752992), closes [#521](https://github.com/kbknapp/clap-rs/issues/521))
+* **Windows:**  fixes a failing windows build ([01e7dfd6](https://github.com/kbknapp/clap-rs/commit/01e7dfd6c07228c0be6695b3c7bf9370d82860d4))
+* **YAML:**  adds missing YAML methods for App and Arg ([e468faf3](https://github.com/kbknapp/clap-rs/commit/e468faf3f05950fd9f72d84b69aa2061e91c6c64), closes [#528](https://github.com/kbknapp/clap-rs/issues/528))
+
+
+
+<a name="v2.5.2"></a>
+### v2.5.2 (2016-05-31)
+
+
+#### Improvements
+
+*   removes extra newline from help output ([86e61d19](https://github.com/kbknapp/clap-rs/commit/86e61d19a748fb9870fcf1175308984e51ca1115))
+*   allows printing version to any io::Write object ([921f5f79](https://github.com/kbknapp/clap-rs/commit/921f5f7916597f1d028cd4a65bfe76a01c801724))
+*   removes extra newline when printing version ([7e2e2cbb](https://github.com/kbknapp/clap-rs/commit/7e2e2cbb4a8a0f050bb8072a376f742fc54b8589))
+
+#### Bug Fixes
+
+*   fixes bug where args are printed out of order with templates ([3935431d](https://github.com/kbknapp/clap-rs/commit/3935431d5633f577c0826ae2142794b301f4b8ca))
+*   fixes bug where one can't override version or help flags ([90d7d6a2](https://github.com/kbknapp/clap-rs/commit/90d7d6a2ea8240122dd9bf8d82d3c4f5ebb5c703), closes [#514](https://github.com/kbknapp/clap-rs/issues/514))
+*   fixes issue where before_help wasn't printed ([b3faff60](https://github.com/kbknapp/clap-rs/commit/b3faff6030f76a23f26afcfa6a90169002ed7106))
+
+#### Documentation
+
+*   inter-links all types and pages ([3312893d](https://github.com/kbknapp/clap-rs/commit/3312893ddaef3f44d68d8d26ed3d08010be50d97), closes [#505](https://github.com/kbknapp/clap-rs/issues/505))
+*   makes all publicly available types viewable in docs ([52ca6505](https://github.com/kbknapp/clap-rs/commit/52ca6505b4fec7b5c2d53d160c072d395eb21da6))
+
+<a name="v2.5.1"></a>
+### v2.5.1 (2016-05-11)
+
+
+#### Bug Fixes
+
+* **Subcommand Aliases**: fixes lifetime issue when setting multiple aliases at once ([ac42f6cf0](https://github.com/kbknapp/clap-rs/commit/ac42f6cf0de6c4920f703807d63061803930b18d))
+
+<a name="v2.5.0"></a>
+## v2.5.0 (2016-05-10)
+
+
+#### Improvements
+
+* **SubCommand Aliases:**  adds feature to yaml configs too ([69592195](https://github.com/kbknapp/clap-rs/commit/695921954dde46dfd483399dcdef482c9dd7f34a))
+
+#### Features
+
+* **SubCommands:**  adds support for subcommand aliases ([66b4dea6](https://github.com/kbknapp/clap-rs/commit/66b4dea65c44d8f77ff522238a9237aed1bcab6d), closes [#469](https://github.com/kbknapp/clap-rs/issues/469))
+
+
+<a name="v2.4.3"></a>
+### v2.4.3 (2016-05-10)
+
+
+#### Bug Fixes
+
+* **Usage Strings:**
+  *  now properly dedups args that are also in groups ([3ca0947c](https://github.com/kbknapp/clap-rs/commit/3ca0947c166b4f8525752255e3a4fa6565eb9689), closes [#498](https://github.com/kbknapp/clap-rs/issues/498))
+  *  removes duplicate groups from usage strings ([f574fb8a](https://github.com/kbknapp/clap-rs/commit/f574fb8a7cde4d4a2fa4c4481d59be2d0f135427))
+
+#### Improvements
+
+* **Groups:**  formats positional args in groups in a better way ([fef11154](https://github.com/kbknapp/clap-rs/commit/fef11154fb7430d1cbf04a672aabb366e456a368))
+* **Help:**
+  *  moves positionals to standard <> formatting ([03dfe5ce](https://github.com/kbknapp/clap-rs/commit/03dfe5ceff1d63f172788ff688567ddad9fe119b))
+  *  default help subcommand string has been shortened ([5b7fe8e4](https://github.com/kbknapp/clap-rs/commit/5b7fe8e4161e43ab19e2e5fcf55fbe46791134e9), closes [#494](https://github.com/kbknapp/clap-rs/issues/494))
+
+<a name="v2.4.2"></a>
+### v2.4.3 (2016-05-10)
+
+* Ghost Release
+
+<a name="v2.4.1"></a>
+### v2.4.3 (2016-05-10)
+
+* Ghost Release
+
+<a name="v2.4.0"></a>
+## v2.4.0 (2016-05-02)
+
+
+#### Features
+
+* **Help:**  adds support for displaying info before help message ([29fbfa3b](https://github.com/kbknapp/clap-rs/commit/29fbfa3b963f2f3ca7704bf5d3e1201531baa373))
+* **Required:**  adds allowing args that are required unless certain args are present ([af1f7916](https://github.com/kbknapp/clap-rs/commit/af1f79168390ea7da4074d0d9777de458ea64971))
+
+#### Documentation
+
+*   hides formatting from docs ([cb708093](https://github.com/kbknapp/clap-rs/commit/cb708093a7cd057f08c98b7bd1ed54c2db86ae7e))
+* **required_unless:**  adds docs and examples for required_unless ([ca727b52](https://github.com/kbknapp/clap-rs/commit/ca727b52423b9883acd88b2f227b2711bc144573))
+
+#### Bug Fixes
+
+* **Required Args:**  fixes issue where missing required args are sometimes duplicatd in error messages ([3beebd81](https://github.com/kbknapp/clap-rs/commit/3beebd81e7bc2faa4115ac109cf570e512c5477f), closes [#492](https://github.com/kbknapp/clap-rs/issues/492))
+
+
+<a name="v2.3.0"></a>
+## v2.3.0 (2016-04-18)
+
+
+#### Improvements
+
+* **macros.rs:**  Added write_nspaces macro (a new version of write_spaces) ([9d757e86](https://github.com/kbknapp/clap-rs/commit/9d757e8678e334e5a740ac750c76a9ed4e785cba))
+* **parser.rs:**
+  *  Provide a way to create a usage string without the USAGE: title ([a91d378b](https://github.com/kbknapp/clap-rs/commit/a91d378ba0c91b5796457f8c6e881b13226ab735))
+  *  Make Parser's create_usage public allowing to have function outside the parser to generate the help ([d51945f8](https://github.com/kbknapp/clap-rs/commit/d51945f8b82ebb0963f4f40b384a9e8335783091))
+  *  Expose Parser's flags, opts and positionals argument as iterators ([9b23e7ee](https://github.com/kbknapp/clap-rs/commit/9b23e7ee40e51f7a823644c4496be955dc6c9d3a))
+* **src/args:**  Exposes argument display order by introducing a new Trait ([1321630e](https://github.com/kbknapp/clap-rs/commit/1321630ef56955f152c73376d4d85cceb0bb4a12))
+* **srs/args:**  Added longest_filter to AnyArg trait ([65b3f667](https://github.com/kbknapp/clap-rs/commit/65b3f667532685f854c699ddd264d326599cf7e5))
+
+#### Features
+
+* **Authors Macro:**  adds a crate_authors macro ([38fb59ab](https://github.com/kbknapp/clap-rs/commit/38fb59abf480eb2b6feca269097412f8b00b5b54), closes [#447](https://github.com/kbknapp/clap-rs/issues/447))
+* **HELP:**
+  *  implements optional colored help messages ([abc8f669](https://github.com/kbknapp/clap-rs/commit/abc8f669c3c8193ffc3a3b0ac6c3ac2198794d4f), closes [#483](https://github.com/kbknapp/clap-rs/issues/483))
+  *  Add a Templated Help system. ([81e121ed](https://github.com/kbknapp/clap-rs/commit/81e121edd616f7285593f11120c63bcccae0d23e))
+
+#### Bug Fixes
+
+* **HELP:**  Adjust Help to semantic changes introduced in 6933b84 ([8d23806b](https://github.com/kbknapp/clap-rs/commit/8d23806bd67530ad412c34a1dcdcb1435555573d))
+
+<a name="v2.2.6"></a>
+### v2.2.6 (2016-04-11)
+
+#### Bug Fixes
+
+* **Arg Groups**: fixes bug where arg name isn't printed properly ([3019a685](https://github.com/kbknapp/clap-rs/commit/3019a685eee747ccbe6be09ad5dddce0b1d1d4db), closes [#476](https://github.com/kbknapp/clap-rs/issues/476))
+
+
+<a name="v2.2.5"></a>
+### v2.2.5 (2016-04-03)
+
+
+#### Bug Fixes
+
+* **Empty Values:**  fixes bug where empty values weren't stored ([885d166f](https://github.com/kbknapp/clap-rs/commit/885d166f04eb3fb581898ae5818c6c8032e5a686), closes [#470](https://github.com/kbknapp/clap-rs/issues/470))
+* **Help Message:**  fixes bug where arg name is printed twice ([71acf1d5](https://github.com/kbknapp/clap-rs/commit/71acf1d576946658b8bbdb5ae79e6716c43a030f), closes [#472](https://github.com/kbknapp/clap-rs/issues/472))
+
+
+<a name="v2.2.4"></a>
+### v2.2.4 (2016-03-30)
+
+
+#### Bug Fixes
+
+*   fixes compiling with debug cargo feature ([d4b55450](https://github.com/kbknapp/clap-rs/commit/d4b554509928031ac0808076178075bb21f8c1da))
+* **Empty Values:**  fixes bug where empty values weren't stored ([885d166f](https://github.com/kbknapp/clap-rs/commit/885d166f04eb3fb581898ae5818c6c8032e5a686), closes [#470](https://github.com/kbknapp/clap-rs/issues/470))
+
+
+
+<a name="v2.2.3"></a>
+### v2.2.3 (2016-03-28)
+
+
+#### Bug Fixes
+
+* **Help Subcommand:**  fixes issue where help and version flags weren't properly displayed ([205b07bf](https://github.com/kbknapp/clap-rs/commit/205b07bf2e6547851f1290f8cd6b169145e144f1), closes [#466](https://github.com/kbknapp/clap-rs/issues/466))
+
+<a name="v2.2.2"></a>
+### v2.2.2 (2016-03-27)
+
+
+#### Bug Fixes
+
+* **Help Message:**  fixes bug with wrapping in the middle of a unicode sequence ([05365ddc](https://github.com/kbknapp/clap-rs/commit/05365ddcc252e4b49e7a75e199d6001a430bd84d), closes [#456](https://github.com/kbknapp/clap-rs/issues/456))
+* **Usage Strings:**  fixes small bug where -- would appear needlessly in usage strings ([6933b849](https://github.com/kbknapp/clap-rs/commit/6933b8491c2a7e28cdb61b47dcf10caf33c2f78a), closes [#461](https://github.com/kbknapp/clap-rs/issues/461))
+
+
+<a name="2.2.1"></a>
+### 2.2.1 (2016-03-16)
+
+
+#### Features
+
+* **Help Message:**  wraps and aligns the help message of subcommands ([813d75d0](https://github.com/kbknapp/clap-rs/commit/813d75d06fbf077c65762608c0fa5e941cfc393c), closes [#452](https://github.com/kbknapp/clap-rs/issues/452))
+
+#### Bug Fixes
+
+* **Help Message:**  fixes a bug where small terminal sizes causing a loop ([1d73b035](https://github.com/kbknapp/clap-rs/commit/1d73b0355236923aeaf6799abc759762ded7e1d0), closes [#453](https://github.com/kbknapp/clap-rs/issues/453))
+
+
+<a name="v2.2.0"></a>
+## v2.2.0 (2016-03-15)
+
+
+#### Features
+
+* **Help Message:**  can auto wrap and aligning help text to term width ([e36af026](https://github.com/kbknapp/clap-rs/commit/e36af0266635f23e85e951b9088d561e9a5d1bf6), closes [#428](https://github.com/kbknapp/clap-rs/issues/428))
+* **Help Subcommand:**  adds support passing additional subcommands to help subcommand ([2c12757b](https://github.com/kbknapp/clap-rs/commit/2c12757bbdf34ce481f3446c074e24c09c2e60fd), closes [#416](https://github.com/kbknapp/clap-rs/issues/416))
+* **Opts and Flags:**  adds support for custom ordering in help messages ([9803b51e](https://github.com/kbknapp/clap-rs/commit/9803b51e799904c0befaac457418ee766ccc1ab9))
+* **Settings:**  adds support for automatically deriving custom display order of args ([ad86e433](https://github.com/kbknapp/clap-rs/commit/ad86e43334c4f70e86909689a088fb87e26ff95a), closes [#444](https://github.com/kbknapp/clap-rs/issues/444))
+* **Subcommands:**  adds support for custom ordering in help messages ([7d2a2ed4](https://github.com/kbknapp/clap-rs/commit/7d2a2ed413f5517d45988eef0765cdcd663b6372), closes [#442](https://github.com/kbknapp/clap-rs/issues/442))
+
+#### Bug Fixes
+
+* **From Usage:**  fixes a bug where adding empty lines werent ignored ([c5c58c86](https://github.com/kbknapp/clap-rs/commit/c5c58c86b9c503d8de19da356a5a5cffb59fbe84))
+
+#### Documentation
+
+* **Groups:**  explains required ArgGroups better ([4ff0205b](https://github.com/kbknapp/clap-rs/commit/4ff0205b85a45151b59bbaf090a89df13438380f), closes [#439](https://github.com/kbknapp/clap-rs/issues/439))
+
+<a name="v2.1.2"></a>
+### v2.1.2 (2016-02-24)
+
+#### Bug Fixes
+
+* **Nightly:**  fixes failing nightly build ([d752c170](https://github.com/kbknapp/clap-rs/commit/d752c17029598b19037710f204b7943f0830ae75), closes [#434](https://github.com/kbknapp/clap-rs/issues/434))
+
+
+<a name="v2.1.1"></a>
+### v2.1.1 (2016-02-19)
+
+
+#### Documentation
+
+* **AppSettings:**  clarifies that AppSettings do not propagate ([3c8db0e9](https://github.com/kbknapp/clap-rs/commit/3c8db0e9be1d24edaad364359513cbb02abb4186), closes [#429](https://github.com/kbknapp/clap-rs/issues/429))
+* **Arg Examples:**  adds better examples ([1e79cccc](https://github.com/kbknapp/clap-rs/commit/1e79cccc12937bc0e7cd2aad8e404410798e9fff))
+
+#### Improvements
+
+* **Help:**  adds setting for next line help by arg ([066df748](https://github.com/kbknapp/clap-rs/commit/066df7486e684cf50a8479a356a12ba972c34ce1), closes [#427](https://github.com/kbknapp/clap-rs/issues/427))
+
+
+<a name="v2.1.0"></a>
+## v2.1.0 (2016-02-10)
+
+
+#### Features
+
+* **Defult Values:**  adds support for default values in args ([73211952](https://github.com/kbknapp/clap-rs/commit/73211952964a79d97b434dd567e6d7d34be7feb5), closes [#418](https://github.com/kbknapp/clap-rs/issues/418))
+
+#### Documentation
+
+* **Default Values:**  adds better examples and notes for default values ([9facd74f](https://github.com/kbknapp/clap-rs/commit/9facd74f843ef3807c5d35259558a344e6c25905))
+
+
+<a name="v2.0.6"></a>
+### v2.0.6 (2016-02-09)
+
+
+#### Improvements
+
+* **Positional Arguments:**  now displays value name if appropriate ([f0a99916](https://github.com/kbknapp/clap-rs/commit/f0a99916c59ce675515c6dcdfe9a40b130510908), closes [#420](https://github.com/kbknapp/clap-rs/issues/420))
+
+
+<a name="v2.0.5"></a>
+### v2.0.5 (2016-02-05)
+
+
+#### Bug Fixes
+
+* **Multiple Values:**  fixes bug where number_of_values wasnt respected ([72c387da](https://github.com/kbknapp/clap-rs/commit/72c387da0bb8a6f526f863770f08bb8ca0d3de03))
+
+
+<a name="v2.0.4"></a>
+### v2.0.4 (2016-02-04)
+
+
+#### Bug Fixes
+
+*   adds support for building ArgGroups from standalone YAML ([fcbc7e12](https://github.com/kbknapp/clap-rs/commit/fcbc7e12f5d7b023b8f30cba8cad28a01cf6cd26))
+*   Stop lonely hyphens from causing panic ([85b11468](https://github.com/kbknapp/clap-rs/commit/85b11468b0189d5cc15f1cfac5db40d17a0077dc), closes [#410](https://github.com/kbknapp/clap-rs/issues/410))
+* **AppSettings:**  fixes bug where subcmds didn't receive parent ver ([a62e4527](https://github.com/kbknapp/clap-rs/commit/a62e452754b3b0e3ac9a15aa8b5330636229ead1))
+
+<a name="v2.0.3"></a>
+### v2.0.3 (2016-02-02)
+
+
+#### Improvements
+
+* **values:**  adds support for up to u64::max values per arg ([c7abf7d7](https://github.com/kbknapp/clap-rs/commit/c7abf7d7611e317b0d31d97632e3d2e13570947c))
+* **occurrences:**  Allow for more than 256 occurrences of an argument. ([3731ddb3](https://github.com/kbknapp/clap-rs/commit/3731ddb361163f3d6b86844362871e48c80fa530))
+
+#### Features
+
+* **AppSettings:**  adds HidePossibleValuesInHelp to skip writing those values ([cdee7a0e](https://github.com/kbknapp/clap-rs/commit/cdee7a0eb2beeec723cb98acfacf03bf629c1da3))
+
+#### Bug Fixes
+
+* **value_t_or_exit:**  fixes typo which causes value_t_or_exit to return a Result ([ee96baff](https://github.com/kbknapp/clap-rs/commit/ee96baffd306cb8d20ddc5575cf739bb1a6354e8))
+
+
+<a name="v2.0.2"></a>
+### v2.0.2 (2016-01-31)
+
+
+#### Improvements
+
+* **arg_enum:**  enum declared with arg_enum returns [&'static str; #] instead of Vec ([9c4b8a1a](https://github.com/kbknapp/clap-rs/commit/9c4b8a1a6b12949222f17d1074578ad7676b9c0d))
+
+#### Bug Fixes
+
+*   clap_app! should be gated by unstable, not nightly feature ([0c8b84af](https://github.com/kbknapp/clap-rs/commit/0c8b84af6161d5baf683688eafc00874846f83fa))
+* **SubCommands:**  fixed where subcmds weren't recognized after mult args ([c19c17a8](https://github.com/kbknapp/clap-rs/commit/c19c17a8850602990e24347aeb4427cf43316223), closes [#405](https://github.com/kbknapp/clap-rs/issues/405))
+* **Usage Parser:**  fixes a bug where literal single quotes weren't allowed in help strings ([0bcc7120](https://github.com/kbknapp/clap-rs/commit/0bcc71206478074769e311479b34a9f74fe80f5c), closes [#406](https://github.com/kbknapp/clap-rs/issues/406))
+
+
+<a name="v2.0.1"></a>
+### v2.0.1 (2016-01-30)
+
+
+#### Bug Fixes
+
+*   fixes cargo features to NOT require nightly with unstable features ([dcbcc60c](https://github.com/kbknapp/clap-rs/commit/dcbcc60c9ba17894be636472ea4b07a82d86a9db), closes [#402](https://github.com/kbknapp/clap-rs/issues/402))
+
+
+<a name="v2.0.0"></a>
+## v2.0.0 (2016-01-28)
+
+
+#### Improvements
+
+* **From Usage:**  vastly improves the usage parser ([fa3a2f86](https://github.com/kbknapp/clap-rs/commit/fa3a2f86bd674c5eb07128c95098fab7d1437247), closes [#350](https://github.com/kbknapp/clap-rs/issues/350))
+
+#### Features
+
+*   adds support for external subcommands ([177fe5cc](https://github.com/kbknapp/clap-rs/commit/177fe5cce745c2164a8e38c23be4c4460d2d7211), closes [#372](https://github.com/kbknapp/clap-rs/issues/372))
+*   adds support values with a leading hyphen ([e4d429b9](https://github.com/kbknapp/clap-rs/commit/e4d429b9d52e95197bd0b572d59efacecf305a59), closes [#385](https://github.com/kbknapp/clap-rs/issues/385))
+*   adds support for turning off the value delimiter ([508db850](https://github.com/kbknapp/clap-rs/commit/508db850a87c2e251cf6b6ddead9ad56b29f9e57), closes [#352](https://github.com/kbknapp/clap-rs/issues/352))
+*   adds support changing the value delimiter ([dafeae8a](https://github.com/kbknapp/clap-rs/commit/dafeae8a526162640f6a68da434370c64d190889), closes [#353](https://github.com/kbknapp/clap-rs/issues/353))
+*   adds support for comma separated values ([e69da6af](https://github.com/kbknapp/clap-rs/commit/e69da6afcd2fe48a3c458ca031db40997f860eda), closes [#348](https://github.com/kbknapp/clap-rs/issues/348))
+*   adds support with options with optional values ([4555736c](https://github.com/kbknapp/clap-rs/commit/4555736cad01441dcde4ea84a285227e0844c16e), closes [#367](https://github.com/kbknapp/clap-rs/issues/367))
+* **UTF-8:**  adds support for invalid utf8 in values ([c5c59dec](https://github.com/kbknapp/clap-rs/commit/c5c59dec0bc33b86b2e99d30741336f17ec84282), closes [#269](https://github.com/kbknapp/clap-rs/issues/269))
+* **v2:**  implementing the base of 2.x ([a3536054](https://github.com/kbknapp/clap-rs/commit/a3536054512ba833533dc56615ce3663d884381c))
+
+#### Bug Fixes
+
+*   fixes nightly build with new lints ([17599195](https://github.com/kbknapp/clap-rs/commit/175991956c37dc83ba9c49396e927a1cb65c5b11))
+*   fixes Windows build for 2x release ([674c9b48](https://github.com/kbknapp/clap-rs/commit/674c9b48c7c92079cb180cc650a9e39f34781c32), closes [#392](https://github.com/kbknapp/clap-rs/issues/392))
+*   fixes yaml build for 2x base ([adceae64](https://github.com/kbknapp/clap-rs/commit/adceae64c8556d00ab715677377b216f9f468ad7))
+
+#### Documentation
+
+*   updates examples for 2x release ([1303b360](https://github.com/kbknapp/clap-rs/commit/1303b3607468f362ab1b452d5614c1a064dc69b4), closes [#394](https://github.com/kbknapp/clap-rs/issues/394))
+*   updates examples for 2x release ([0a011f31](https://github.com/kbknapp/clap-rs/commit/0a011f3142aec338d388a6c8bfe22fa7036021bb), closes [#394](https://github.com/kbknapp/clap-rs/issues/394))
+*   updates documentation for v2 release ([8d51724e](https://github.com/kbknapp/clap-rs/commit/8d51724ef73dfde5bb94fb9466bc5463a1cc1502))
+*   updating docs for 2x release ([576d0e0e](https://github.com/kbknapp/clap-rs/commit/576d0e0e2c7b8f386589179bbf7419b93abacf1c))
+* **README.md:**
+  *  updates readme for v2 release ([acaba01a](https://github.com/kbknapp/clap-rs/commit/acaba01a353c12144b9cd9a3ce447400691849b0), closes [#393](https://github.com/kbknapp/clap-rs/issues/393))
+  *  fix typo and make documentation conspicuous ([07b9f614](https://github.com/kbknapp/clap-rs/commit/07b9f61495d927f69f7abe6c0d85253f0f4e6107))
+
+#### BREAKING CHANGES
+
+* **Fewer liftimes! Yay!**
+ * `App<'a, 'b, 'c, 'd, 'e, 'f>` => `App<'a, 'b>`
+ * `Arg<'a, 'b, 'c, 'd, 'e, 'f>` => `Arg<'a, 'b>`
+ * `ArgMatches<'a, 'b>` => `ArgMatches<'a>`
+* **Simply Renamed**
+ * `App::arg_group` => `App::group`
+ * `App::arg_groups` => `App::groups`
+ * `ArgGroup::add` => `ArgGroup::arg`
+ * `ArgGroup::add_all` => `ArgGroup::args`
+ * `ClapError` => `Error`
+  * struct field `ClapError::error_type` => `Error::kind`
+ * `ClapResult` => `Result`
+ * `ClapErrorType` => `ErrorKind`
+* **Removed Deprecated Functions and Methods**
+ * `App::subcommands_negate_reqs`
+ * `App::subcommand_required`
+ * `App::arg_required_else_help`
+ * `App::global_version(bool)`
+ * `App::versionless_subcommands`
+ * `App::unified_help_messages`
+ * `App::wait_on_error`
+ * `App::subcommand_required_else_help`
+ * `SubCommand::new`
+ * `App::error_on_no_subcommand`
+ * `Arg::new`
+ * `Arg::mutually_excludes`
+ * `Arg::mutually_excludes_all`
+ * `Arg::mutually_overrides_with`
+ * `simple_enum!`
+* **Renamed Error Variants**
+ * `InvalidUnicode` => `InvalidUtf8`
+ * `InvalidArgument` => `UnknownArgument`
+* **Usage Parser**
+ * Value names can now be specified inline, i.e. `-o, --option <FILE> <FILE2> 'some option which takes two files'`
+ * **There is now a priority of order to determine the name** - This is perhaps the biggest breaking change. See the documentation for full details. Prior to this change, the value name took precedence. **Ensure your args are using the proper names (i.e. typically the long or short and NOT the value name) throughout the code**
+* `ArgMatches::values_of` returns an `Values` now which implements `Iterator` (should not break any code)
+* `crate_version!` returns `&'static str` instead of `String`
+* Using the `clap_app!` macro requires compiling with the `unstable` feature because the syntax could change slightly in the future
+
+
+<a name="v1.5.5"></a>
+### v1.5.5 (2016-01-04)
+
+
+#### Bug Fixes
+
+*   fixes an issue where invalid short args didn't cause an error ([c9bf7e44](https://github.com/kbknapp/clap-rs/commit/c9bf7e4440bd2f9b524ea955311d433c40a7d1e0))
+*   prints the name in version and help instead of binary name ([8f3817f6](https://github.com/kbknapp/clap-rs/commit/8f3817f665c0cab6726bc16c56a53b6a61e44448), closes [#368](https://github.com/kbknapp/clap-rs/issues/368))
+*   fixes an intentional panic issue discovered via clippy ([ea83a3d4](https://github.com/kbknapp/clap-rs/commit/ea83a3d421ea8856d4cac763942834d108b71406))
+
+
+<a name="v1.5.4"></a>
+### v1.5.4 (2015-12-18)
+
+
+#### Examples
+
+* **17_yaml:**  conditinonally compile 17_yaml example ([575de089](https://github.com/kbknapp/clap-rs/commit/575de089a3e240c398cb10e6cf5a5c6b68662c01))
+
+#### Improvements
+
+*   clippy improvements ([99cdebc2](https://github.com/kbknapp/clap-rs/commit/99cdebc23da3a45a165f14b27bebeb2ed828a2ce))
+
+#### Bug Fixes
+
+
+* **errors:**  return correct error type in WrongNumValues error builder ([5ba8ba9d](https://github.com/kbknapp/clap-rs/commit/5ba8ba9dcccdfa74dd1c44260e64b359bbb36be6))
+*   ArgRequiredElseHelp setting now takes precedence over missing required args ([faad83fb](https://github.com/kbknapp/clap-rs/commit/faad83fbef6752f3093b6e98fca09a9449b830f4), closes [#362](https://github.com/kbknapp/clap-rs/issues/362))
+
+
+<a name="v1.5.3"></a>
+### v1.5.3 (2015-11-20)
+
+
+#### Bug Fixes
+
+* **Errors:**  fixes some instances when errors are missing a final newline ([c4d2b171](https://github.com/kbknapp/clap-rs/commit/c4d2b1711994479ad64ee52b6b49d2ceccbf2118))
+
+
+
+
+<a name="v1.5.2"></a>
+### v1.5.2 (2015-11-14)
+
+
+#### Bug Fixes
+
+* **Errors:**  fixes a compiling bug when built on Windows or without the color feature ([a35f7634](https://github.com/kbknapp/clap-rs/commit/a35f76346fe6ecc88dda6a1eb13627186e7ce185))
+
+
+
+<a name="v1.5.1"></a>
+### v1.5.1 (2015-11-13)
+
+
+#### Bug Fixes
+
+* **Required Args:**  fixes a bug where required args are not correctly accounted for ([f03b88a9](https://github.com/kbknapp/clap-rs/commit/f03b88a9766b331a63879bcd747687f2e5a2661b), closes [#343](https://github.com/kbknapp/clap-rs/issues/343))
+
+
+
+<a name="v1.5.0"></a>
+## v1.5.0 (2015-11-13)
+
+
+#### Bug Fixes
+
+*   fixes a bug with required positional args in usage strings ([c6858f78](https://github.com/kbknapp/clap-rs/commit/c6858f78755f8e860204323c828c8355a066dc83))
+
+#### Documentation
+
+* **FAQ:**  updates readme with slight changes to FAQ ([a4ef0fab](https://github.com/kbknapp/clap-rs/commit/a4ef0fab73c8dc68f1b138965d1340459c113398))
+
+#### Improvements
+
+*   massive errors overhaul ([cdc29175](https://github.com/kbknapp/clap-rs/commit/cdc29175bc9c53e5b4aec86cbc04c1743154dae6))
+* **ArgMatcher:**  huge refactor and deduplication of code ([8988853f](https://github.com/kbknapp/clap-rs/commit/8988853fb8825e8f841fde349834cc12cdbad081))
+* **Errors:**  errors have been vastly improved ([e59bc0c1](https://github.com/kbknapp/clap-rs/commit/e59bc0c16046db156a88ba71a037db05028e995c))
+* **Traits:**  refactoring some configuration into traits ([5800cdec](https://github.com/kbknapp/clap-rs/commit/5800cdec6dce3def4242b9f7bd136308afb19685))
+
+#### Performance
+
+* **App:**
+  *  more BTreeMap->Vec, Opts and SubCmds ([bc4495b3](https://github.com/kbknapp/clap-rs/commit/bc4495b32ec752b6c4b29719e831c043ef2a26ce))
+  *  changes flags BTreeMap->Vec ([d357640f](https://github.com/kbknapp/clap-rs/commit/d357640fab55e5964fe83efc3c771e53aa3222fd))
+  *  removed unneeded BTreeMap ([78971fd6](https://github.com/kbknapp/clap-rs/commit/78971fd68d7dc5c8e6811b4520cdc54e4188f733))
+  *  changes BTreeMap to VecMap in some instances ([64b921d0](https://github.com/kbknapp/clap-rs/commit/64b921d087fdd03775c95ba0bcf65d3f5d36f812))
+  *  removed excess clones ([ec0089d4](https://github.com/kbknapp/clap-rs/commit/ec0089d42ed715d293fb668d3a90b0db0aa3ec39))
+
+
+
+<a name="v1.4.7"></a>
+### v1.4.7 (2015-11-03)
+
+
+#### Documentation
+
+*   Clarify behavior of Arg::multiple with options. ([434f497a](https://github.com/kbknapp/clap-rs/commit/434f497ab6d831f8145cf09278c97ca6ee6c6fe7))
+*   Fix typos and improve grammar. ([c1f66b5d](https://github.com/kbknapp/clap-rs/commit/c1f66b5de7b5269fbf8760a005ef8c645edd3229))
+
+#### Bug Fixes
+
+* **Error Status:**  fixes bug where --help and --version return non-zero exit code ([89b51fdf](https://github.com/kbknapp/clap-rs/commit/89b51fdf8b1ab67607567344e2317ff1a757cb12))
+
+
+
+<a name="v1.4.6"></a>
+### v1.4.6 (2015-10-29)
+
+
+#### Features
+
+*   allows parsing without a binary name for daemons and interactive CLIs ([aff89d57](https://github.com/kbknapp/clap-rs/commit/aff89d579b5b85c3dc81b64f16d5865299ec39a2), closes [#318](https://github.com/kbknapp/clap-rs/issues/318))
+
+#### Bug Fixes
+
+* **Errors:**  tones down quoting in some error messages ([34ce59ed](https://github.com/kbknapp/clap-rs/commit/34ce59ede53bfa2eef722c74881cdba7419fd9c7), closes [#309](https://github.com/kbknapp/clap-rs/issues/309))
+* **Help and Version:**  only builds help and version once ([e3be87cf](https://github.com/kbknapp/clap-rs/commit/e3be87cfc095fc41c9811adcdc6d2b079f237d5e))
+* **Option Args:**  fixes bug with args and multiple values ([c9a9548a](https://github.com/kbknapp/clap-rs/commit/c9a9548a8f96cef8a3dd9a980948325fbbc1b91b), closes [#323](https://github.com/kbknapp/clap-rs/issues/323))
+* **POSIX Overrides:**  fixes bug where required args are overridden ([40ed2b50](https://github.com/kbknapp/clap-rs/commit/40ed2b50c3a9fe88bfdbaa43cef9fd6493ecaa8e))
+* **Safe Matches:**  using 'safe' forms of the get_matches family no longer exit the process ([c47025dc](https://github.com/kbknapp/clap-rs/commit/c47025dca2b3305dea0a0acfdd741b09af0c0d05), closes [#256](https://github.com/kbknapp/clap-rs/issues/256))
+* **Versionless SubCommands:**  fixes a bug where the -V flag was needlessly built ([27df8b9d](https://github.com/kbknapp/clap-rs/commit/27df8b9d98d13709dad3929a009f40ebff089a1a), closes [#329](https://github.com/kbknapp/clap-rs/issues/329))
+
+#### Documentation
+
+*   adds comparison in readme ([1a8bf31e](https://github.com/kbknapp/clap-rs/commit/1a8bf31e7a6b87ce48a66af2cde1645b2dd5bc95), closes [#325](https://github.com/kbknapp/clap-rs/issues/325))
+
+
+
+<a name="v1.4.5"></a>
+### v1.4.5 (2015-10-06)
+
+
+#### Bug Fixes
+
+*   fixes crash on invalid arg error ([c78ce128](https://github.com/kbknapp/clap-rs/commit/c78ce128ebbe7b8f730815f8176c29d76f4ade8c))
+
+
+
+<a name="v1.4.4"></a>
+### v1.4.4 (2015-10-06)
+
+
+#### Documentation
+
+*   clean up some formatting ([b7df92d7](https://github.com/kbknapp/clap-rs/commit/b7df92d7ea25835701dd22ddff984b9749f48a00))
+*   move the crate-level docs to top of the lib.rs file ([d7233bf1](https://github.com/kbknapp/clap-rs/commit/d7233bf122dbf80ba8fc79e5641be2df8af10e7a))
+*   changes doc comments to rustdoc comments ([34b601be](https://github.com/kbknapp/clap-rs/commit/34b601be5fdde76c1a0859385b359b96d66b8732))
+*   fixes panic in 14_groups example ([945b00a0](https://github.com/kbknapp/clap-rs/commit/945b00a0c27714b63bdca48d003fe205fcfdc578), closes [#295](https://github.com/kbknapp/clap-rs/issues/295))
+*   avoid suggesting star dependencies. ([d33228f4](https://github.com/kbknapp/clap-rs/commit/d33228f40b5fefb84cf3dd51546bfb340dcd9f5a))
+* **Rustdoc:**  adds portions of the readme to main rustdoc page ([6f9ee181](https://github.com/kbknapp/clap-rs/commit/6f9ee181e69d90bd4206290e59d6f3f1e8f0cbb2), closes [#293](https://github.com/kbknapp/clap-rs/issues/293))
+
+#### Bug Fixes
+
+*   grammar error in some conflicting option errors ([e73b07e1](https://github.com/kbknapp/clap-rs/commit/e73b07e19474323ad2260da66abbf6a6d4ecbd4f))
+* **Unified Help:**  sorts both flags and options as a unified category ([2a223dad](https://github.com/kbknapp/clap-rs/commit/2a223dad82901fa2e74baad3bfc4c7b94509300f))
+* **Usage:**  fixes a bug where required args aren't filtered properly ([72b453dc](https://github.com/kbknapp/clap-rs/commit/72b453dc170af3050bb123d35364f6da77fc06d7), closes [#277](https://github.com/kbknapp/clap-rs/issues/277))
+* **Usage Strings:**  fixes a bug ordering of elements in usage strings ([aaf0d6fe](https://github.com/kbknapp/clap-rs/commit/aaf0d6fe7aa2403e76096c16204d254a9ee61ee2), closes [#298](https://github.com/kbknapp/clap-rs/issues/298))
+
+#### Features
+
+*   supports -aValue style options ([0e3733e4](https://github.com/kbknapp/clap-rs/commit/0e3733e4fec2015c2d566a51432dcd92cb69cad3))
+* **Trailing VarArg:**  adds opt-in setting for final arg being vararg ([27018b18](https://github.com/kbknapp/clap-rs/commit/27018b1821a4bcd5235cfe92abe71b3c99efc24d), closes [#278](https://github.com/kbknapp/clap-rs/issues/278))
+
+
+
+<a name="v1.4.3"></a>
+### v1.4.3 (2015-09-30)
+
+
+#### Features
+
+*   allows accessing arg values by group name ([c92a4b9e](https://github.com/kbknapp/clap-rs/commit/c92a4b9eff2d679957f61c0c41ff404b40d38a91))
+
+#### Documentation
+
+*   use links to examples instead of plain text ([bb4fe237](https://github.com/kbknapp/clap-rs/commit/bb4fe237858535627271465147add537e4556b43))
+
+#### Bug Fixes
+
+* **Help Message:**  required args no longer double list in usage ([1412e639](https://github.com/kbknapp/clap-rs/commit/1412e639e0a79df84936d1101a837f90077d1c83), closes [#277](https://github.com/kbknapp/clap-rs/issues/277))
+* **Possible Values:**  possible value validation is restored ([f121ae74](https://github.com/kbknapp/clap-rs/commit/f121ae749f8f4bfe754ef2e8a6dfc286504b5b75), closes [#287](https://github.com/kbknapp/clap-rs/issues/287))
+
+
+
+<a name="v1.4.2"></a>
+### v1.4.2 (2015-09-23)
+
+
+#### Bug Fixes
+
+* **Conflicts:**  fixes bug with conflicts not removing required args ([e17fcec5](https://github.com/kbknapp/clap-rs/commit/e17fcec53b3216ad047a13dddc6f740473fad1a1), closes [#271](https://github.com/kbknapp/clap-rs/issues/271))
+
+
+
+<a name="v1.4.1"></a>
+### v1.4.1 (2015-09-22)
+
+
+#### Examples
+
+*   add clap_app quick example ([4ba6249c](https://github.com/kbknapp/clap-rs/commit/4ba6249c3cf4d2e083370d1fe4dcc7025282c28a))
+
+#### Features
+
+* **Unicode:**  allows non-panicing on invalid unicode characters ([c5bf7ddc](https://github.com/kbknapp/clap-rs/commit/c5bf7ddc8cfb876ec928a5aaf5591232bbb32e5d))
+
+#### Documentation
+
+*   properly names Examples section for rustdoc ([87ba5445](https://github.com/kbknapp/clap-rs/commit/87ba54451d7ec7b1c9b9ef134f90bbe39e6fac69))
+*   fixes various typos and spelling ([f85640f9](https://github.com/kbknapp/clap-rs/commit/f85640f9f6d8fd3821a40e9b8b7a34fabb789d02))
+* **Arg:**  unhides fields of the Arg struct ([931aea88](https://github.com/kbknapp/clap-rs/commit/931aea88427edf43a3da90d5a500c1ff2b2c3614))
+
+#### Bug Fixes
+
+*   flush the buffer in App::print_version() ([cbc42a37](https://github.com/kbknapp/clap-rs/commit/cbc42a37d212d84d22b1777d08e584ff191934e7))
+*   Macro benchmarks ([13712da1](https://github.com/kbknapp/clap-rs/commit/13712da1d36dc7614eec3a10ad488257ba615751))
+
+
+
+<a name="v1.4.0"></a>
+## v1.4.0 (2015-09-09)
+
+
+#### Features
+
+*   allows printing help message by library consumers ([56b95f32](https://github.com/kbknapp/clap-rs/commit/56b95f320875c62dda82cb91b29059671e120ed1))
+*   allows defining hidden args and subcmds ([2cab4d03](https://github.com/kbknapp/clap-rs/commit/2cab4d0334ea3c2439a1d4bfca5bf9905c7ea9ac), closes [#231](https://github.com/kbknapp/clap-rs/issues/231))
+*   Builder macro to assist with App/Arg/Group/SubCommand building ([443841b0](https://github.com/kbknapp/clap-rs/commit/443841b012a8d795cd5c2bd69ae6e23ef9b16477))
+* **Errors:**  allows consumers to write to stderr and exit on error ([1e6403b6](https://github.com/kbknapp/clap-rs/commit/1e6403b6a863574fa3cb6946b1fb58f034e8664c))
+
+
+
+<a name="v1.3.2"></a>
+### v1.3.2 (2015-09-08)
+
+
+#### Documentation
+
+*   fixed ErrorKind docs ([dd057843](https://github.com/kbknapp/clap-rs/commit/dd05784327fa070eb6ce5ce89a8507e011d8db94))
+* **ErrorKind:**  changed examples content ([b9ca2616](https://github.com/kbknapp/clap-rs/commit/b9ca261634b89613bbf3d98fd74d55cefbb31a8c))
+
+#### Bug Fixes
+
+*   fixes a bug where the help subcommand wasn't overridable ([94003db4](https://github.com/kbknapp/clap-rs/commit/94003db4b5eebe552ca337521c1c001295822745))
+
+#### Features
+
+*   adds abiltiy not consume self when parsing matches and/or exit on help ([94003db4](https://github.com/kbknapp/clap-rs/commit/94003db4b5eebe552ca337521c1c001295822745))
+* **App:**  Added ability for users to handle errors themselves ([934e6fbb](https://github.com/kbknapp/clap-rs/commit/934e6fbb643b2385efc23444fe6fce31494dc288))
+
+
+
+<a name="v1.3.1"></a>
+### v1.3.1 (2015-09-04)
+
+
+#### Examples
+
+* **17_yaml:**  fixed example ([9b848622](https://github.com/kbknapp/clap-rs/commit/9b848622296c8c5c7b9a39b93ddd41f51df790b5))
+
+#### Performance
+
+*   changes ArgGroup HashSets to Vec ([3cb4a48e](https://github.com/kbknapp/clap-rs/commit/3cb4a48ebd15c20692f4f3a2a924284dc7fd5e10))
+*   changes BTreeSet for Vec in some instances ([baab2e3f](https://github.com/kbknapp/clap-rs/commit/baab2e3f4060e811abee14b1654cbcd5cf3b5fea))
+
+
+
+<a name="v1.3.0"></a>
+## v1.3.0 (2015-09-01)
+
+
+#### Features
+
+* **YAML:**  allows building a CLI from YAML files ([86cf4c45](https://github.com/kbknapp/clap-rs/commit/86cf4c45626a36b8115446952f9069f73c1debc3))
+* **ArgGroups:**  adds support for building ArgGroups from yaml ([ecf88665](https://github.com/kbknapp/clap-rs/commit/ecf88665cbff367018b29161a1b75d44a212707d))
+* **Subcommands:**  adds support for subcommands from yaml ([e415cf78](https://github.com/kbknapp/clap-rs/commit/e415cf78ba916052d118a8648deba2b9c16b1530))
+
+#### Documentation
+
+* **YAML:**  adds examples for using YAML to build a CLI ([ab41d7f3](https://github.com/kbknapp/clap-rs/commit/ab41d7f38219544750e6e1426076dc498073191b))
+* **Args from YAML:**  fixes doc examples ([19b348a1](https://github.com/kbknapp/clap-rs/commit/19b348a10050404cd93888dbbbe4f396681b67d0))
+* **Examples:**  adds better usage examples instead of having unused variables ([8cbacd88](https://github.com/kbknapp/clap-rs/commit/8cbacd8883004fe71a8ea036ec4391c7dd8efe94))
+
+#### Examples
+
+*   Add AppSettings example ([12705079](https://github.com/kbknapp/clap-rs/commit/12705079ca96a709b4dd94f7ddd20a833b26838c))
+
+#### Bug Fixes
+
+* **Unified Help Messages:**  fixes a crash from this setting and no opts ([169ffec1](https://github.com/kbknapp/clap-rs/commit/169ffec1003d58d105d7ef2585b3425e57980000), closes [#210](https://github.com/kbknapp/clap-rs/issues/210))
+
+
+
+<a name="v1.2.5"></a>
+### v1.2.5 (2015-08-27)
+
+
+#### Examples
+
+*   add custom validator example ([b9997d1f](https://github.com/kbknapp/clap-rs/commit/b9997d1fca74d4d8f93971f2a01bdf9798f913d5))
+*   fix indentation ([d4f1b740](https://github.com/kbknapp/clap-rs/commit/d4f1b740ede410fd2528b9ecd89592c2fd8b1e20))
+
+#### Features
+
+* **Args:**  allows opts and args to define a name for help and usage msgs ([ad962ec4](https://github.com/kbknapp/clap-rs/commit/ad962ec478da999c7dba0afdb84c266f4d09b1bd))
+
+
+
+<a name="v1.2.4"></a>
+### v1.2.4 (2015-08-26)
+
+
+#### Bug Fixes
+
+* **Possible Values:**  fixes a bug where suggestions arent made when using --long=value format ([3d5e9a6c](https://github.com/kbknapp/clap-rs/commit/3d5e9a6cedb26668839b481c9978e2fbbab8be6f), closes [#192](https://github.com/kbknapp/clap-rs/issues/192))
+
+
+
+<a name="v1.2.3"></a>
+### v1.2.3 (2015-08-24)
+
+
+#### Bug Fixes
+
+* **App, Args:**  fixed subcommand reqs negation ([b41afa8c](https://github.com/kbknapp/clap-rs/commit/b41afa8c3ded3d1be12f7a2f8ea06cc44afc9458), closes [#188](https://github.com/kbknapp/clap-rs/issues/188))
+
+
+
+<a name="v1.2.2"></a>
+### v1.2.2 (2015-08-23)
+
+
+#### Bug Fixes
+
+*   fixed confusing error message, also added test for it ([fc7a31a7](https://github.com/kbknapp/clap-rs/commit/fc7a31a745efbf1768ee2c62cd3bb72bfe30c708))
+* **App:**  fixed requirmets overriding ([9c135eb7](https://github.com/kbknapp/clap-rs/commit/9c135eb790fa16183e5bdb2009ddc3cf9e25f99f))
+
+
+
+<a name="v1.2.1"></a>
+### v1.2.1 (2015-08-20)
+
+
+#### Documentation
+
+* **README.md:**  updates for new features ([16cf9245](https://github.com/kbknapp/clap-rs/commit/16cf9245fb5fc4cf6face898e358368bf9961cbb))
+
+#### Features
+
+*   implements posix compatible conflicts for long args ([8c2d48ac](https://github.com/kbknapp/clap-rs/commit/8c2d48acf5473feebd721a9049a9c9b7051e70f9))
+*   added overrides to support conflicts in POSIX compatible manner ([0b916a00](https://github.com/kbknapp/clap-rs/commit/0b916a00de26f6941538f6bc5f3365fa302083c1))
+* **Args:**  allows defining POSIX compatible argument conflicts ([d715646e](https://github.com/kbknapp/clap-rs/commit/d715646e69759ccd95e01f49b04f489827ecf502))
+
+#### Bug Fixes
+
+*   fixed links in cargo and license buttons ([6d9837ad](https://github.com/kbknapp/clap-rs/commit/6d9837ad9a9e006117cd7372fdc60f9a3889c7e2))
+
+#### Performance
+
+* **Args and Apps:**  changes HashSet->Vec in some instances for increased performance ([d0c3b379](https://github.com/kbknapp/clap-rs/commit/d0c3b379700757e0a9b0c40af709f8af1f5b4949))
+
+
+
+<a name="v1.2.0"></a>
+### v1.2.0 (2015-08-15)
+
+
+#### Bug Fixes
+
+*   fixed misspell and enum name ([7df170d7](https://github.com/kbknapp/clap-rs/commit/7df170d7f4ecff06608317655d1e0c4298f62076))
+*   fixed use for clap crate ([dc3ada73](https://github.com/kbknapp/clap-rs/commit/dc3ada738667d4b689678f79d14251ee82004ece))
+
+#### Documentation
+
+*   updates docs for new features ([03496547](https://github.com/kbknapp/clap-rs/commit/034965471782d872ca495045b58d34b31807c5b1))
+*   fixed docs for previous changes ([ade36778](https://github.com/kbknapp/clap-rs/commit/ade367780c366425de462506d256e0f554ed3b9c))
+
+#### Improvements
+
+* **AppSettings:**  adds ability to add multiple settings at once ([4a00e251](https://github.com/kbknapp/clap-rs/commit/4a00e2510d0ca8d095d5257d51691ba3b61c1374))
+
+#### Features
+
+*   Replace application level settings with enum variants ([618dc4e2](https://github.com/kbknapp/clap-rs/commit/618dc4e2c205bf26bc43146164e65eb1f6b920ed))
+* **Args:**  allows for custom argument value validations to be defined ([84ae2ddb](https://github.com/kbknapp/clap-rs/commit/84ae2ddbceda34b5cbda98a6959edaa52fde2e1a), closes [#170](https://github.com/kbknapp/clap-rs/issues/170))
+
+
+
+<a name="v1.1.6"></a>
+### v1.1.6 (2015-08-01)
+
+
+#### Bug Fixes
+
+*   fixes two bugs in App when printing newlines in help and subcommands required error ([d63c0136](https://github.com/kbknapp/clap-rs/commit/d63c0136310db9dd2b1c7b4745938311601d8938))
+
+
+
+<a name="v1.1.5"></a>
+### v1.1.5 (2015-07-29)
+
+#### Performance
+
+*   removes some unneeded allocations ([93e915df](https://github.com/kbknapp/clap-rs/commit/93e915dfe300f7b7d6209ca93323c6a46f89a8c1))
+
+<a name="v1.1.4"></a>
+### v1.1.4 (2015-07-20)
+
+
+#### Improvements
+
+* **Usage Strings**  displays a [--] when it may be helpful ([86c3be85](https://github.com/kbknapp/clap-rs/commit/86c3be85fb6f77f83b5a6d2df40ae60937486984))
+
+#### Bug Fixes
+
+* **Macros**  fixes a typo in a macro generated error message ([c9195c5f](https://github.com/kbknapp/clap-rs/commit/c9195c5f92abb8cd6a37b4f4fbb2f1fee2a8e368))
+* **Type Errors**  fixes formatting of error output when failed type parsing ([fe5d95c6](https://github.com/kbknapp/clap-rs/commit/fe5d95c64f3296e6eddcbec0cb8b86659800145f))
+
+
+
+<a name="v1.1.3"></a>
+### v1.1.3 (2015-07-18)
+
+
+#### Documentation
+
+*   updates README.md to include lack of color support on Windows ([52f81e17](https://github.com/kbknapp/clap-rs/commit/52f81e17377b18d2bd0f34693b642b7f358998ee))
+
+#### Bug Fixes
+
+*   fixes formatting bug which prevented compiling on windows ([9cb5dceb](https://github.com/kbknapp/clap-rs/commit/9cb5dceb3e5fe5e0e7b24619ff77e5040672b723), closes [#163](https://github.com/kbknapp/clap-rs/issues/163))
+
+
+
+<a name="v1.1.2"></a>
+### v1.1.2 (2015-07-17)
+
+
+#### Bug Fixes
+
+*   fixes a bug when parsing multiple {n} newlines inside help strings ([6d214b54](https://github.com/kbknapp/clap-rs/commit/6d214b549a9b7e189a94e5fa2b7c92cc333ca637))
+
+
+
+<a name="v1.1.1"></a>
+## v1.1.1 (2015-07-17)
+
+
+#### Bug Fixes
+
+*   fixes a logic bug and allows setting Arg::number_of_values() < 2 ([42b6d1fc](https://github.com/kbknapp/clap-rs/commit/42b6d1fc3c519c92dfb3af15276e7d3b635e6cfe), closes [#161](https://github.com/kbknapp/clap-rs/issues/161))
+
+
+
+<a name="v1.1.0"></a>
+## v1.1.0 (2015-07-16)
+
+
+#### Features
+
+*   allows creating unified help messages, a la docopt or getopts ([52bcd892](https://github.com/kbknapp/clap-rs/commit/52bcd892ea51564ce463bc5865acd64f8fe91cb1), closes [#158](https://github.com/kbknapp/clap-rs/issues/158))
+*   allows stating all subcommands should *not* have --version flags ([336c476f](https://github.com/kbknapp/clap-rs/commit/336c476f631d512b54ac56fdca6f29ebdc2c00c5), closes [#156](https://github.com/kbknapp/clap-rs/issues/156))
+*   allows setting version number to auto-propagate through subcommands ([bc66d3c6](https://github.com/kbknapp/clap-rs/commit/bc66d3c6deedeca62463fff95369ab1cfcdd366b), closes [#157](https://github.com/kbknapp/clap-rs/issues/157))
+
+#### Improvements
+
+* **Help Strings**  properly aligns and handles newlines in long help strings ([f9800a29](https://github.com/kbknapp/clap-rs/commit/f9800a29696dd2cc0b0284bf693b3011831e556f), closes [#145](https://github.com/kbknapp/clap-rs/issues/145))
+
+
+#### Performance
+
+* **Help Messages**  big performance improvements when printing help messages ([52bcd892](https://github.com/kbknapp/clap-rs/commit/52bcd892ea51564ce463bc5865acd64f8fe91cb1))
+
+#### Documentation
+
+*   updates readme with new features ([8232f7bb](https://github.com/kbknapp/clap-rs/commit/8232f7bb52e88862bc13c3d4f99ee4f56cfe4bc0))
+*   fix incorrect code example for `App::subcommand_required` ([8889689d](https://github.com/kbknapp/clap-rs/commit/8889689dc6336ccc45b2c9f2cf8e2e483a639e93))
+
+
+<a name="v1.0.3"></a>
+### v1.0.3 (2015-07-11)
+
+
+#### Improvements
+
+* **Errors**  writes errors to stderr ([cc76ab8c](https://github.com/kbknapp/clap-rs/commit/cc76ab8c2b77c67b42f4717ded530df7806142cf), closes [#154](https://github.com/kbknapp/clap-rs/issues/154))
+
+#### Documentation
+
+* **README.md**  updates example help message to new format ([0aca29bd](https://github.com/kbknapp/clap-rs/commit/0aca29bd5d6d1a4e9971bdc88d946ffa58606efa))
+
+
+
+<a name="v1.0.2"></a>
+### v1.0.2 (2015-07-09)
+
+
+#### Improvements
+
+* **Usage**  re-orders optional arguments and required to natural standard ([dc7e1fce](https://github.com/kbknapp/clap-rs/commit/dc7e1fcea5c85d317018fb201d2a9262249131b4), closes [#147](https://github.com/kbknapp/clap-rs/issues/147))
+
+
+
+<a name="v1.0.1"></a>
+### v1.0.1 (2015-07-08)
+
+
+#### Bug Fixes
+
+*   allows empty values when using --long='' syntax ([083f82d3](https://github.com/kbknapp/clap-rs/commit/083f82d333b69720a6ef30074875310921d964d1), closes [#151](https://github.com/kbknapp/clap-rs/issues/151))
+
+
+
+<a name="v1.0.0"></a>
+## v1.0.0 (2015-07-08)
+
+
+#### Documentation
+
+* **README.md**  adds new features to what's new list ([938f7f01](https://github.com/kbknapp/clap-rs/commit/938f7f01340f521969376cf4e2e3d9436bca21f7))
+* **README.md**  use with_name for subcommands ([28b7e316](https://github.com/kbknapp/clap-rs/commit/28b7e3161fb772e5309042648fe8c3a420645bac))
+
+#### Features
+
+*   args can now be parsed from arbitrary locations, not just std::env::args() ([75312528](https://github.com/kbknapp/clap-rs/commit/753125282b1b9bfff875f1557ce27610edcc59e1))
+
+
+
+<a name="v1.0.0"></a>
+## v1.0.0-beta (2015-06-30)
+
+
+#### Features
+
+*   allows waiting for user input on error ([d0da3bdd](https://github.com/kbknapp/clap-rs/commit/d0da3bdd9d1871541907ea9c645322a74d260e07), closes [#140](https://github.com/kbknapp/clap-rs/issues/140))
+* **Help**  allows one to fully override the auto-generated help message ([26d5ae3e](https://github.com/kbknapp/clap-rs/commit/26d5ae3e330d1e150811d5b60b2b01a8f8df854e), closes [#141](https://github.com/kbknapp/clap-rs/issues/141))
+
+#### Documentation
+
+*   adds "whats new" section to readme ([ff149a29](https://github.com/kbknapp/clap-rs/commit/ff149a29dd9e179865e6d577cd7dc87c54f8f95c))
+
+#### Improvements
+
+*   removes deprecated functions in prep for 1.0 ([274484df](https://github.com/kbknapp/clap-rs/commit/274484dfd08fff4859cefd7e9bef3b73d3a9cb5f))
+
+
+
+<a name="v0.11.0"></a>
+## v0.11.0 (2015-06-17) - BREAKING CHANGE
+
+
+#### Documentation
+
+*   updates docs to new version flag defaults ([ebf442eb](https://github.com/kbknapp/clap-rs/commit/ebf442ebebbcd2ec6bfe2c06566c9d362bccb112))
+
+#### Features
+
+* **Help and Version**  default short for version is now `-V` but can be overridden (only breaks manual documentation) (**BREAKING CHANGE** [eb1d9320](https://github.com/kbknapp/clap-rs/commit/eb1d9320c509c1e4e57d7c7959da82bcfe06ada0))
+
+
+
+<a name="v0.10.5"></a>
+### v0.10.5 (2015-06-06)
+
+
+#### Bug Fixes
+
+* **Global Args**  global arguments propogate fully now ([1f377960](https://github.com/kbknapp/clap-rs/commit/1f377960a48c82f54ca5f39eb56bcb393140b046), closes [#137](https://github.com/kbknapp/clap-rs/issues/137))
+
+
+
+<a name="v0.10.4"></a>
+### v0.10.4 (2015-06-06)
+
+
+#### Bug Fixes
+
+* **Global Args**  global arguments propogate fully now ([8f2c0160](https://github.com/kbknapp/clap-rs/commit/8f2c0160c8d844daef375a33dbaec7d89de00a00), closes [#137](https://github.com/kbknapp/clap-rs/issues/137))
+
+
+
+<a name="v0.10.3"></a>
+### v0.10.3 (2015-05-31)
+
+
+#### Bug Fixes
+
+* **Global Args**  fixes a bug where globals only transfer to one subcommand ([a37842ee](https://github.com/kbknapp/clap-rs/commit/a37842eec1ee3162b86fdbda23420b221cdb1e3b), closes [#135](https://github.com/kbknapp/clap-rs/issues/135))
+
+
+
+<a name="v0.10.2"></a>
+### v0.10.2 (2015-05-30)
+
+
+#### Improvements
+
+* **Binary Names**  allows users to override the system determined bin name ([2191fe94](https://github.com/kbknapp/clap-rs/commit/2191fe94bda35771383b52872fb7f5421b178be1), closes [#134](https://github.com/kbknapp/clap-rs/issues/134))
+
+#### Documentation
+
+*   adds contributing guidelines ([6f76bd0a](https://github.com/kbknapp/clap-rs/commit/6f76bd0a07e8b7419b391243ab2d6687cd8a9c5f))
+
+
+
+<a name="v0.10.1"></a>
+### v0.10.1 (2015-05-26)
+
+
+#### Features
+
+*   can now specify that an app or subcommand should display help on no args or subcommands ([29ca7b2f](https://github.com/kbknapp/clap-rs/commit/29ca7b2f74376ca0cdb9d8ee3bfa99f7640cc404), closes [#133](https://github.com/kbknapp/clap-rs/issues/133))
+
+
+
+<a name="v0.10.0"></a>
+## v0.10.0 (2015-05-23)
+
+
+#### Features
+
+* **Global Args**  allows args that propagate down to child commands ([2bcc6137](https://github.com/kbknapp/clap-rs/commit/2bcc6137a83cb07757771a0afea953e68e692f0b), closes [#131](https://github.com/kbknapp/clap-rs/issues/131))
+
+#### Improvements
+
+* **Colors**  implements more structured colored output ([d6c3ed54](https://github.com/kbknapp/clap-rs/commit/d6c3ed54d21cf7b40d9f130d4280ff5448522fc5), closes [#129](https://github.com/kbknapp/clap-rs/issues/129))
+
+#### Deprecations
+
+* **SubCommand/App**  several methods and functions for stable release ([28b73855](https://github.com/kbknapp/clap-rs/commit/28b73855523ad170544afdb20665db98702fbe70))
+
+#### Documentation
+
+*   updates for deprecations and new features ([743eefe8](https://github.com/kbknapp/clap-rs/commit/743eefe8dd40c1260065ce086d572e9e9358bc4c))
+
+
+
+<a name="v0.9.2"></a>
+## v0.9.2 (2015-05-20)
+
+
+#### Bug Fixes
+
+* **help**  allows parent requirements to be ignored with help and version ([52218cc1](https://github.com/kbknapp/clap-rs/commit/52218cc1fdb06a42456c964d98cc2c7ac3432412), closes [#124](https://github.com/kbknapp/clap-rs/issues/124))
+
+
+
+<a name="v0.9.1"></a>
+## v0.9.1 (2015-05-18)
+
+
+#### Bug Fixes
+
+* **help**  fixes a bug where requirements are included as program name in help and version ([08ba3f25](https://github.com/kbknapp/clap-rs/commit/08ba3f25cf38b149229ba8b9cb37a5804fe6b789))
+
+
+
+<a name="v0.9.0"></a>
+## v0.9.0 (2015-05-17)
+
+
+#### Improvements
+
+* **usage**  usage strings now include parent command requirements ([dd8f21c7](https://github.com/kbknapp/clap-rs/commit/dd8f21c7c15cde348fdcf44fa7c205f0e98d2e4a), closes [#125](https://github.com/kbknapp/clap-rs/issues/125))
+* **args**  allows consumer of clap to decide if empty values are allowed or not ([ab4ec609](https://github.com/kbknapp/clap-rs/commit/ab4ec609ccf692b9b72cccef5c9f74f5577e360d), closes [#122](https://github.com/kbknapp/clap-rs/issues/122))
+
+#### Features
+
+* **subcommands**
+  *  allows optionally specifying that no subcommand is an error ([7554f238](https://github.com/kbknapp/clap-rs/commit/7554f238fd3afdd60b7e4dcf00ff4a9eccf842c1), closes [#126](https://github.com/kbknapp/clap-rs/issues/126))
+  *  subcommands can optionally negate parent requirements ([4a4229f5](https://github.com/kbknapp/clap-rs/commit/4a4229f500e21c350e1ef78dd09ef27559653288), closes [#123](https://github.com/kbknapp/clap-rs/issues/123))
+
+
+
+<a name="v0.8.6"></a>
+## v0.8.6 (2015-05-17)
+
+
+#### Bug Fixes
+
+* **args**  `-` can now be parsed as a value for an argument ([bc12e78e](https://github.com/kbknapp/clap-rs/commit/bc12e78eadd7eaf9d008a8469fdd2dfd7990cb5d), closes [#121](https://github.com/kbknapp/clap-rs/issues/121))
+
+
+
+<a name="v0.8.5"></a>
+## v0.8.5 (2015-05-15)
+
+
+#### Bug Fixes
+
+* **macros**  makes macro errors consistent with others ([0c264a8c](https://github.com/kbknapp/clap-rs/commit/0c264a8ca57ec1cfdcb74dae79145d766cdc9b97), closes [#118](https://github.com/kbknapp/clap-rs/issues/118))
+
+#### Features
+
+* **macros**
+  *  arg_enum! and simple_enum! provide a Vec<&str> of variant names ([30fa87ba](https://github.com/kbknapp/clap-rs/commit/30fa87ba4e0f3189351d8f4f78b72e616a30d0bd), closes [#119](https://github.com/kbknapp/clap-rs/issues/119))
+  *  arg_enum! and simple_enum! auto-implement Display ([d1219f0d](https://github.com/kbknapp/clap-rs/commit/d1219f0d1371d872061bd0718057eca4ef47b739), closes [#120](https://github.com/kbknapp/clap-rs/issues/120))
+
+
+
+<a name="v0.8.4"></a>
+## v0.8.4 (2015-05-12)
+
+
+#### Bug Fixes
+
+* **suggestions**  --help and --version now get suggestions ([d2b3b1fa](https://github.com/kbknapp/clap-rs/commit/d2b3b1faa0bdc1c5d2350cc4635aba81e02e9d96), closes [#116](https://github.com/kbknapp/clap-rs/issues/116))
+
+
+
+<a name="v0.8.3"></a>
+## v0.8.3 (2015-05-10)
+
+
+#### Bug Fixes
+
+* **usage**  groups unfold their members in usage strings ([55d15582](https://github.com/kbknapp/clap-rs/commit/55d155827ea4a6b077a83669701e797ce1ad68f4), closes [#114](https://github.com/kbknapp/clap-rs/issues/114))
+
+#### Performance
+
+* **usage**  removes unneeded allocations ([fd53cd18](https://github.com/kbknapp/clap-rs/commit/fd53cd188555f5c3dc8bc341c5d7eb04b761a70f))
+
+
+
+<a name="v0.8.2"></a>
+## v0.8.2 (2015-05-08)
+
+
+#### Bug Fixes
+
+* **usage strings**  positional arguments are presented in index order ([eb0e374e](https://github.com/kbknapp/clap-rs/commit/eb0e374ecf952f1eefbc73113f21e0705936e40b), closes [#112](https://github.com/kbknapp/clap-rs/issues/112))
+
+
+
+<a name="v0.8.1"></a>
+## v0.8.1 (2015-05-06)
+
+
+#### Bug Fixes
+
+* **subcommands**  stops parsing multiple values when subcommands are found ([fc79017e](https://github.com/kbknapp/clap-rs/commit/fc79017eced04fd41cc1801331e5054df41fac17), closes [#109](https://github.com/kbknapp/clap-rs/issues/109))
+
+#### Improvements
+
+* **color**  reduces color in error messages ([aab44cca](https://github.com/kbknapp/clap-rs/commit/aab44cca6352f47e280c296e50c535f5d752dd46), closes [#110](https://github.com/kbknapp/clap-rs/issues/110))
+* **suggestions**  adds suggested arguments to usage strings ([99447414](https://github.com/kbknapp/clap-rs/commit/994474146e9fb8b701af773a52da71553d74d4b7))
+
+
+
+<a name="v0.8.0"></a>
+## v0.8.0 (2015-05-06)
+
+
+#### Bug Fixes
+
+* **did-you-mean**  for review ([0535cfb0](https://github.com/kbknapp/clap-rs/commit/0535cfb0c711331568b4de8080eeef80bd254b68))
+* **Positional**  positionals were ignored if they matched a subcmd, even after '--' ([90e7b081](https://github.com/kbknapp/clap-rs/commit/90e7b0818741668b47cbe3becd029bab588e3553))
+* **help**  fixes bug where space between arg and help is too long ([632fb115](https://github.com/kbknapp/clap-rs/commit/632fb11514c504999ea86bdce47cdd34f8ebf646))
+
+#### Features
+
+* **from_usage**  adds ability to add value names or num of vals in usage string ([3d581976](https://github.com/kbknapp/clap-rs/commit/3d58197674ed7886ca315efb76e411608a327501), closes [#98](https://github.com/kbknapp/clap-rs/issues/98))
+* **did-you-mean**
+  *  gate it behind 'suggestions' ([c0e38351](https://github.com/kbknapp/clap-rs/commit/c0e383515d01bdd5ca459af9c2f7e2cf49e2488b))
+  *  for possible values ([1cc2deb2](https://github.com/kbknapp/clap-rs/commit/1cc2deb29158e0e4e8b434e4ce26b3d819301a7d))
+  *  for long flags (i.e. --long) ([52a0b850](https://github.com/kbknapp/clap-rs/commit/52a0b8505c99354bdf5fd1cd256cf41197ac2d81))
+  *  for subcommands ([06e869b5](https://github.com/kbknapp/clap-rs/commit/06e869b5180258047ed3c60ba099de818dd25fff))
+* **Flags**  adds sugestions functionality ([8745071c](https://github.com/kbknapp/clap-rs/commit/8745071c3257dd327c497013516f12a823df9530))
+* **errors**  colorizes output red on error ([f8b26b13](https://github.com/kbknapp/clap-rs/commit/f8b26b13da82ba3ba9a932d3d1ab4ea45d1ab036))
+
+#### Improvements
+
+* **arg_enum**  allows ascii case insensitivity for enum variants ([b249f965](https://github.com/kbknapp/clap-rs/commit/b249f9657c6921c004764bd80d13ebca81585eec), closes [#104](https://github.com/kbknapp/clap-rs/issues/104))
+* **clap-test**  simplified `make test` invocation ([d17dcb29](https://github.com/kbknapp/clap-rs/commit/d17dcb2920637a1f58c61c596b7bd362fd53047c))
+
+#### Documentation
+
+* **README**  adds details about optional and new features ([960389de](https://github.com/kbknapp/clap-rs/commit/960389de02c9872aaee9adabe86987f71f986e39))
+* **clap**  fix typos caught by codespell ([8891d929](https://github.com/kbknapp/clap-rs/commit/8891d92917aa1a069cca67272be41b99e548356e))
+* **from_usage**  explains new usage strings with multiple values ([05476fc6](https://github.com/kbknapp/clap-rs/commit/05476fc61cd1e5f4a4e750d258c878732a3a9c64))
+
+
+
+<a name="v0.7.6"></a>
+## v0.7.6 (2015-05-05)
+
+
+#### Improvements
+
+* **Options**  adds number of values to options in help/usage ([c1c993c4](https://github.com/kbknapp/clap-rs/commit/c1c993c419d18e35c443785053d8de9a2ef88073))
+
+#### Features
+
+* **from_usage**  adds ability to add value names or num of vals in usage string ([ad55748c](https://github.com/kbknapp/clap-rs/commit/ad55748c265cf27935c7b210307d2040b6a09125), closes [#98](https://github.com/kbknapp/clap-rs/issues/98))
+
+#### Bug Fixes
+
+* **MultipleValues**  properly distinguishes between multiple values and multiple occurrences ([dd2a7564](https://github.com/kbknapp/clap-rs/commit/dd2a75640ca68a91b973faad15f04df891356cef), closes [#99](https://github.com/kbknapp/clap-rs/issues/99))
+* **help**  fixes tab alignment with multiple values ([847001ff](https://github.com/kbknapp/clap-rs/commit/847001ff6d8f4d9518e810fefb8edf746dd0f31e))
+
+#### Documentation
+
+* **from_usage**  explains new usage strings with multiple values ([5a3a42df](https://github.com/kbknapp/clap-rs/commit/5a3a42dfa3a783537f88dedc0fd5f0edcb8ea372))
+
+
+
+<a name="v0.7.5"></a>
+## v0.7.5 (2015-05-04)
+
+
+#### Bug Fixes
+
+* **Options**  fixes bug where options with no value don't error out ([a1fb94be](https://github.com/kbknapp/clap-rs/commit/a1fb94be53141572ffd97aad037295d4ffec82d0))
+
+
+
+<a name="v0.7.4"></a>
+## v0.7.4 (2015-05-03)
+
+
+#### Bug Fixes
+
+* **Options**  fixes a bug where option arguments in succession get their values skipped ([f66334d0](https://github.com/kbknapp/clap-rs/commit/f66334d0ce984e2b56e5c19abb1dd536fae9342a))
+
+
+
+<a name="v0.7.3"></a>
+## v0.7.3 (2015-05-03)
+
+
+#### Bug Fixes
+
+* **RequiredValues**  fixes a bug where missing values are parsed as missing arguments ([93c4a723](https://github.com/kbknapp/clap-rs/commit/93c4a7231ba1a08152648598f7aa4503ea82e4de))
+
+#### Improvements
+
+* **ErrorMessages**  improves error messages and corrections ([a29c3983](https://github.com/kbknapp/clap-rs/commit/a29c3983c4229906655a29146ec15a0e46dd942d))
+* **ArgGroups**  improves requirement and confliction support for groups ([c236dc5f](https://github.com/kbknapp/clap-rs/commit/c236dc5ff475110d2a1b80e62903f80296163ad3))
+
+
+
+<a name="v0.7.2"></a>
+## v0.7.2 (2015-05-03)
+
+
+#### Bug Fixes
+
+* **RequiredArgs**  fixes bug where required-by-default arguments are not listed in usage ([12aea961](https://github.com/kbknapp/clap-rs/commit/12aea9612d290845ba86515c240aeeb0a21198db), closes [#96](https://github.com/kbknapp/clap-rs/issues/96))
+
+
+
+<a name="v0.7.1"></a>
+## v0.7.1 (2015-05-01)
+
+
+#### Bug Fixes
+
+* **MultipleValues**  stops evaluating values if the max or exact number of values was reached ([86d92c9f](https://github.com/kbknapp/clap-rs/commit/86d92c9fdbf9f422442e9562977bbaf268dbbae1))
+
+
+
+<a name="v0.7.0"></a>
+## v0.7.0 (2015-04-30) - BREAKING CHANGE
+
+
+#### Bug Fixes
+
+* **from_usage**  removes bug where usage strings have no help text ([ad4e5451](https://github.com/kbknapp/clap-rs/commit/ad4e54510739aeabf75f0da3278fb0952db531b3), closes [#83](https://github.com/kbknapp/clap-rs/issues/83))
+
+#### Features
+
+* **MultipleValues**
+  *  add support for minimum and maximum number of values ([53f6b8c9](https://github.com/kbknapp/clap-rs/commit/53f6b8c9d8dc408b4fa9f833fc3a63683873c42f))
+  *  adds support limited number and named values ([ae09f05e](https://github.com/kbknapp/clap-rs/commit/ae09f05e92251c1b39a83d372736fcc7b504e432))
+  *  implement shorthand for options with multiple values ([6669f0a9](https://github.com/kbknapp/clap-rs/commit/6669f0a9687d4f668523145d7bd5c007d1eb59a8))
+* **arg**  allow other types besides Vec for multiple value settings (**BREAKING CHANGE** [0cc2f698](https://github.com/kbknapp/clap-rs/commit/0cc2f69839b9b1db5d06330771b494783049a88e), closes [#87](https://github.com/kbknapp/clap-rs/issues/87))
+* **usage**  implement smart usage strings on errors ([d77048ef](https://github.com/kbknapp/clap-rs/commit/d77048efb1e595ffe831f1a2bea2f2700db53b9f), closes [#88](https://github.com/kbknapp/clap-rs/issues/88))
+
+
+
+<a name="v0.6.9"></a>
+## v0.6.9 (2015-04-29)
+
+
+#### Bug Fixes
+
+* **from_usage**  removes bug where usage strings have no help text ([ad4e5451](https://github.com/kbknapp/clap-rs/commit/ad4e54510739aeabf75f0da3278fb0952db531b3), closes [#83](https://github.com/kbknapp/clap-rs/issues/83))
+
+
+
+<a name="0.6.8"></a>
+## 0.6.8 (2015-04-27)
+
+
+#### Bug Fixes
+
+* **help**  change long help --long=long -> --long <long> ([1e25abfc](https://github.com/kbknapp/clap-rs/commit/1e25abfc36679ab89eae71bf98ced4de81992d00))
+* **RequiredArgs**  required by default args should no longer be required when their exclusions are present ([4bb4c3cc](https://github.com/kbknapp/clap-rs/commit/4bb4c3cc076b49e86720e882bf8c489877199f2d))
+
+#### Features
+
+* **ArgGroups**  add ability to create arg groups ([09eb4d98](https://github.com/kbknapp/clap-rs/commit/09eb4d9893af40c347e50e2b717e1adef552357d))
+
+
+
+<a name="v0.6.7"></a>
+## v0.6.7 (2015-04-22)
+
+
+#### Bug Fixes
+
+* **from_usage**  fix bug causing args to not be required ([b76129e9](https://github.com/kbknapp/clap-rs/commit/b76129e9b71a63365d5c77a7f57b58dbd1e94d49))
+
+#### Features
+
+* **apps**  add ability to display additional help info after auto-gen'ed help msg ([65cc259e](https://github.com/kbknapp/clap-rs/commit/65cc259e4559cbe3653c865ec0c4b1e42a389b07))
+
+
+
+<a name="v0.6.6"></a>
+## v0.6.6 (2015-04-19)
+
+
+#### Bug Fixes
+
+* **from_usage**  tabs and spaces should be treated equally ([4fd44181](https://github.com/kbknapp/clap-rs/commit/4fd44181d55d8eb88caab1e625231cfa3129e347))
+
+#### Features
+
+* **macros.rs**  add macro to get version from Cargo.toml ([c630969a](https://github.com/kbknapp/clap-rs/commit/c630969aa3bbd386379219cae27ba1305b117f3e))
+
+
+
+<a name="v0.6.5"></a>
+## v0.6.5 (2015-04-19)
+
+
+#### Bug Fixes
+
+* **macros.rs**  fix use statements for trait impls ([86e4075e](https://github.com/kbknapp/clap-rs/commit/86e4075eb111937c8a7bdb344e866e350429f042))
+
+
+
+<a name="v0.6.4"></a>
+## v0.6.4 (2015-04-17)
+
+
+#### Features
+
+* **macros**  add ability to create enums pub or priv with derives ([2c499f80](https://github.com/kbknapp/clap-rs/commit/2c499f8015a199827cdf1fa3ec4f6f171722f8c7))
+
+
+
+<a name="v0.6.3"></a>
+## v0.6.3 (2015-04-16)
+
+
+#### Features
+
+* **macros**  add macro to create custom enums to use as types ([fb672aff](https://github.com/kbknapp/clap-rs/commit/fb672aff561c29db2e343d6c607138f141aca8b6))
+
+
+
+<a name="v0.6.2"></a>
+## v0.6.2 (2015-04-14)
+
+
+#### Features
+
+* **macros**
+  *  add ability to get multiple typed values or exit ([0b87251f](https://github.com/kbknapp/clap-rs/commit/0b87251fc088234bee51c323c2b652d7254f7a59))
+  *  add ability to get a typed multiple values ([e243fe38](https://github.com/kbknapp/clap-rs/commit/e243fe38ddbbf845a46c0b9baebaac3778c80927))
+  *  add convenience macro to get a typed value or exit ([4b7cd3ea](https://github.com/kbknapp/clap-rs/commit/4b7cd3ea4947780d9daa39f3e1ddab53ad4c7fef))
+  *  add convenience macro to get a typed value ([8752700f](https://github.com/kbknapp/clap-rs/commit/8752700fbb30e89ee68adbce24489ae9a24d33a9))
+
+
+
+<a name="v0.6.1"></a>
+## v0.6.1 (2015-04-13)
+
+
+#### Bug Fixes
+
+* **from_usage**  trim all whitespace before parsing ([91d29045](https://github.com/kbknapp/clap-rs/commit/91d2904599bd602deef2e515dfc65dc2863bdea0))
+
+
+
+<a name="v0.6.0"></a>
+## v0.6.0 (2015-04-13)
+
+
+#### Bug Fixes
+
+* **tests**  fix failing doc tests ([3710cd69](https://github.com/kbknapp/clap-rs/commit/3710cd69162f87221a62464f63437c1ce843ad3c))
+
+#### Features
+
+* **app**  add support for building args from usage strings ([d5d48bcf](https://github.com/kbknapp/clap-rs/commit/d5d48bcf463a4e494ef758836bd69a4c220bbbb5))
+* **args**  add ability to create basic arguments from a usage string ([ab409a8f](https://github.com/kbknapp/clap-rs/commit/ab409a8f1db9e37cc70200f6f4a84a162692e618))
+
+
+
+<a name="v0.5.14"></a>
+## v0.5.14 (2015-04-10)
+
+
+#### Bug Fixes
+
+* **usage**
+  *  remove unneeded space ([51372789](https://github.com/kbknapp/clap-rs/commit/5137278942121bc2593ce6e5dc224ec2682549e6))
+  *  remove warning about unused variables ([ba817b9d](https://github.com/kbknapp/clap-rs/commit/ba817b9d815e37320650973f1bea0e7af3030fd7))
+
+#### Features
+
+* **usage**  add ability to get usage string for subcommands too ([3636afc4](https://github.com/kbknapp/clap-rs/commit/3636afc401c2caa966efb5b1869ef4f1ed3384aa))
+
+
+
+<a name="v0.5.13"></a>
+## v0.5.13 (2015-04-09)
+
+
+#### Features
+
+* **SubCommands**  add method to get name and subcommand matches together ([64e53928](https://github.com/kbknapp/clap-rs/commit/64e539280e23e567cf5de393b346eb0ca20e7eb5))
+* **ArgMatches**  add method to get default usage string ([02462150](https://github.com/kbknapp/clap-rs/commit/02462150ca750bdc7012627d7e8d96379d494d7f))
+
+
+
+<a name="v0.5.12"></a>
+## v0.5.12 (2015-04-08)
+
+
+#### Features
+
+* **help**  sort arguments by name so as to not display a random order ([f4b2bf57](https://github.com/kbknapp/clap-rs/commit/f4b2bf5767386013069fb74862e6e938dacf44d2))
+
+
+
+<a name="v0.5.11"></a>
+## v0.5.11 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **flags**  fix bug not allowing users to specify -v or -h ([90e72cff](https://github.com/kbknapp/clap-rs/commit/90e72cffdee321b79eea7a2207119533540062b4))
+
+
+
+<a name="v0.5.10"></a>
+## v0.5.10 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **help**  fix spacing when option argument has not long version ([ca17fa49](https://github.com/kbknapp/clap-rs/commit/ca17fa494b68e92da83ee364bf64b0687006824b))
+
+
+
+<a name="v0.5.9"></a>
+## v0.5.9 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **positional args**  all previous positional args become required when a latter one is required ([c14c3f31](https://github.com/kbknapp/clap-rs/commit/c14c3f31fd557c165570b60911d8ee483d89d6eb), closes [#50](https://github.com/kbknapp/clap-rs/issues/50))
+* **clap**  remove unstable features for Rust 1.0 ([9abdb438](https://github.com/kbknapp/clap-rs/commit/9abdb438e36e364d41550e7f5d44ebcaa8ee6b10))
+* **args**  improve error messages for arguments with mutual exclusions ([18dbcf37](https://github.com/kbknapp/clap-rs/commit/18dbcf37024daf2b76ca099a6f118b53827aa339), closes [#51](https://github.com/kbknapp/clap-rs/issues/51))
+
+
+
+<a name="v0.5.8"></a>
+## v0.5.8 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **option args**  fix bug in getting the wrong number of occurrences for options ([82ad6ad7](https://github.com/kbknapp/clap-rs/commit/82ad6ad77539cf9f9a03b78db466f575ebd972cc))
+* **help**  fix formatting for option arguments with no long ([e8691004](https://github.com/kbknapp/clap-rs/commit/e869100423d93fa3acff03c4620cbcc0d0e790a1))
+* **flags**  add assertion to catch flags with specific value sets ([a0a2a40f](https://github.com/kbknapp/clap-rs/commit/a0a2a40fed57f7c5ad9d68970d090e9856306c7d), closes [#52](https://github.com/kbknapp/clap-rs/issues/52))
+* **args**  improve error messages for arguments with mutual exclusions ([bff945fc](https://github.com/kbknapp/clap-rs/commit/bff945fc5d03bba4266533340adcffb002508d1b), closes [#51](https://github.com/kbknapp/clap-rs/issues/51))
+* **tests**  add missing .takes_value(true) to option2 ([bdb0e88f](https://github.com/kbknapp/clap-rs/commit/bdb0e88f696c8595c3def3bfb0e52d538c7be085))
+* **positional args**  all previous positional args become required when a latter one is required ([343d47dc](https://github.com/kbknapp/clap-rs/commit/343d47dcbf83786a45c0d0f01b27fd9dd76725de), closes [#50](https://github.com/kbknapp/clap-rs/issues/50))
+
+
+
+<a name="v0.5.7"></a>
+## v0.5.7 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **args**  fix bug in arguments who are required and mutually exclusive ([6ceb88a5](https://github.com/kbknapp/clap-rs/commit/6ceb88a594caae825605abc1cdad95204996bf29))
+
+
+
+<a name="v0.5.6"></a>
+## v0.5.6 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **help**  fix formatting of help and usage ([28691b52](https://github.com/kbknapp/clap-rs/commit/28691b52f67e65c599e10e4ea2a0f6f9765a06b8))
+
+
+
+<a name="v0.5.5"></a>
+## v0.5.5 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **help**  fix formatting of help for flags and options ([6ec10115](https://github.com/kbknapp/clap-rs/commit/6ec1011563a746f0578a93b76d45e63878e0f9a8))
+
+
+
+<a name="v0.5.4"></a>
+## v0.5.4 (2015-04-08)
+
+
+#### Features
+
+* **help**  add '...' to indicate multiple values supported ([297ddba7](https://github.com/kbknapp/clap-rs/commit/297ddba77000e2228762ab0eca50b480f7467386))
+
+
+
+<a name="v0.5.3"></a>
+## v0.5.3 (2015-04-08)
+
+
+#### Features
+
+* **positionals**
+  *  add assertions for positional args with multiple vals ([b7fa72d4](https://github.com/kbknapp/clap-rs/commit/b7fa72d40f18806ec2042dd67a518401c2cf5681))
+  *  add support for multiple values ([80784009](https://github.com/kbknapp/clap-rs/commit/807840094109fbf90b348039ae22669ef27889ba))
+
+
+
+<a name="v0.5.2"></a>
+## v0.5.2 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **apps**  allow use of hyphens in application and subcommand names ([da549dcb](https://github.com/kbknapp/clap-rs/commit/da549dcb6c7e0d773044ab17829744483a8b0f7f))
+
+
+
+<a name="v0.5.1"></a>
+## v0.5.1 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **args**  determine if the only arguments allowed are also required ([0a09eb36](https://github.com/kbknapp/clap-rs/commit/0a09eb365ced9a03faf8ed24f083ef730acc90e8))
+
+
+
+<a name="v0.5.0"></a>
+## v0.5.0 (2015-04-08)
+
+
+#### Features
+
+* **args**  add support for a specific set of allowed values on options or positional arguments ([270eb889](https://github.com/kbknapp/clap-rs/commit/270eb88925b6dc2881bff1f31ee344f085d31809))
+
+
+
+<a name="v0.4.18"></a>
+## v0.4.18 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **usage**  display required args in usage, even if only required by others ([1b7316d4](https://github.com/kbknapp/clap-rs/commit/1b7316d4a8df70b0aa584ccbfd33f68966ad2a54))
+
+#### Features
+
+* **subcommands**  properly list subcommands in help and usage ([4ee02344](https://github.com/kbknapp/clap-rs/commit/4ee023442abc3dba54b68138006a52b714adf331))
+
+
+
+<a name="v0.4.17"></a>
+## v0.4.17 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **tests**  remove cargo test from claptests makefile ([1cf73817](https://github.com/kbknapp/clap-rs/commit/1cf73817d6fb1dccb5b6a23b46c2efa8b567ad62))
+
+
+
+<a name="v0.4.16"></a>
+## v0.4.16 (2015-04-08)
+
+
+#### Bug Fixes
+
+* **option**  fix bug with option occurrence values ([9af52e93](https://github.com/kbknapp/clap-rs/commit/9af52e93cef9e17ac9974963f132013d0b97b946))
+* **tests**  fix testing script bug and formatting ([d8f03a55](https://github.com/kbknapp/clap-rs/commit/d8f03a55c4f74d126710ee06aad5a667246a8001))
+
+#### Features
+
+* **arg**  allow lifetimes other than 'static in arguments ([9e8c1fb9](https://github.com/kbknapp/clap-rs/commit/9e8c1fb9406f8448873ca58bab07fe905f1551e5))
diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
new file mode 100644
index 0000000..f0fd777
--- /dev/null
+++ b/CONTRIBUTORS.md
@@ -0,0 +1,91 @@
+the following is a list of contributors:
+
+
+[<img alt="kbknapp" src="https://avatars1.githubusercontent.com/u/6942134?v=4&s=117" width="117">](https://github.com/kbknapp) |[<img alt="homu" src="https://avatars1.githubusercontent.com/u/10212162?v=4&s=117" width="117">](https://github.com/homu) |[<img alt="Vinatorul" src="https://avatars1.githubusercontent.com/u/6770624?v=4&s=117" width="117">](https://github.com/Vinatorul) |[<img alt="tormol" src="https://avatars3.githubusercontent.com/u/10460821?v=4&s=117" width="117">](https://github.com/tormol) |[<img alt="willmurphyscode" src="https://avatars3.githubusercontent.com/u/12529630?v=4&s=117" width="117">](https://github.com/willmurphyscode) |[<img alt="little-dude" src="https://avatars2.githubusercontent.com/u/6646324?v=4&s=117" width="117">](https://github.com/little-dude) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[kbknapp](https://github.com/kbknapp) |[homu](https://github.com/homu) |[Vinatorul](https://github.com/Vinatorul) |[tormol](https://github.com/tormol) |[willmurphyscode](https://github.com/willmurphyscode) |[little-dude](https://github.com/little-dude) |
+
+[<img alt="sru" src="https://avatars3.githubusercontent.com/u/2485892?v=4&s=117" width="117">](https://github.com/sru) |[<img alt="mgeisler" src="https://avatars0.githubusercontent.com/u/89623?v=4&s=117" width="117">](https://github.com/mgeisler) |[<img alt="nabijaczleweli" src="https://avatars3.githubusercontent.com/u/6709544?v=4&s=117" width="117">](https://github.com/nabijaczleweli) |[<img alt="Byron" src="https://avatars2.githubusercontent.com/u/63622?v=4&s=117" width="117">](https://github.com/Byron) |[<img alt="hgrecco" src="https://avatars0.githubusercontent.com/u/278566?v=4&s=117" width="117">](https://github.com/hgrecco) |[<img alt="bluejekyll" src="https://avatars3.githubusercontent.com/u/986845?v=4&s=117" width="117">](https://github.com/bluejekyll) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[sru](https://github.com/sru) |[mgeisler](https://github.com/mgeisler) |[nabijaczleweli](https://github.com/nabijaczleweli) |[Byron](https://github.com/Byron) |[hgrecco](https://github.com/hgrecco) |[bluejekyll](https://github.com/bluejekyll) |
+
+[<img alt="segevfiner" src="https://avatars0.githubusercontent.com/u/24731903?v=4&s=117" width="117">](https://github.com/segevfiner) |[<img alt="ignatenkobrain" src="https://avatars1.githubusercontent.com/u/2866862?v=4&s=117" width="117">](https://github.com/ignatenkobrain) |[<img alt="james-darkfox" src="https://avatars3.githubusercontent.com/u/637155?v=4&s=117" width="117">](https://github.com/james-darkfox) |[<img alt="H2CO3" src="https://avatars2.githubusercontent.com/u/742370?v=4&s=117" width="117">](https://github.com/H2CO3) |[<img alt="nateozem" src="https://avatars2.githubusercontent.com/u/22719441?v=4&s=117" width="117">](https://github.com/nateozem) |[<img alt="glowing-chemist" src="https://avatars0.githubusercontent.com/u/17074682?v=4&s=117" width="117">](https://github.com/glowing-chemist) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[segevfiner](https://github.com/segevfiner) |[ignatenkobrain](https://github.com/ignatenkobrain) |[james-darkfox](https://github.com/james-darkfox) |[H2CO3](https://github.com/H2CO3) |[nateozem](https://github.com/nateozem) |[glowing-chemist](https://github.com/glowing-chemist) |
+
+[<img alt="discosultan" src="https://avatars1.githubusercontent.com/u/2970736?v=4&s=117" width="117">](https://github.com/discosultan) |[<img alt="rtaycher" src="https://avatars0.githubusercontent.com/u/324733?v=4&s=117" width="117">](https://github.com/rtaycher) |[<img alt="Arnavion" src="https://avatars2.githubusercontent.com/u/1096010?v=4&s=117" width="117">](https://github.com/Arnavion) |[<img alt="japaric" src="https://avatars3.githubusercontent.com/u/5018213?v=4&s=117" width="117">](https://github.com/japaric) |[<img alt="untitaker" src="https://avatars0.githubusercontent.com/u/837573?v=4&s=117" width="117">](https://github.com/untitaker) |[<img alt="afiune" src="https://avatars0.githubusercontent.com/u/5712253?v=4&s=117" width="117">](https://github.com/afiune) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[discosultan](https://github.com/discosultan) |[rtaycher](https://github.com/rtaycher) |[Arnavion](https://github.com/Arnavion) |[japaric](https://github.com/japaric) |[untitaker](https://github.com/untitaker) |[afiune](https://github.com/afiune) |
+
+[<img alt="crazymerlyn" src="https://avatars1.githubusercontent.com/u/6919679?v=4&s=117" width="117">](https://github.com/crazymerlyn) |[<img alt="SuperFluffy" src="https://avatars0.githubusercontent.com/u/701177?v=4&s=117" width="117">](https://github.com/SuperFluffy) |[<img alt="matthiasbeyer" src="https://avatars0.githubusercontent.com/u/427866?v=4&s=117" width="117">](https://github.com/matthiasbeyer) |[<img alt="malbarbo" src="https://avatars3.githubusercontent.com/u/1678126?v=4&s=117" width="117">](https://github.com/malbarbo) |[<img alt="tshepang" src="https://avatars0.githubusercontent.com/u/588486?v=4&s=117" width="117">](https://github.com/tshepang) |[<img alt="golem131" src="https://avatars3.githubusercontent.com/u/2429587?v=4&s=117" width="117">](https://github.com/golem131) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[crazymerlyn](https://github.com/crazymerlyn) |[SuperFluffy](https://github.com/SuperFluffy) |[matthiasbeyer](https://github.com/matthiasbeyer) |[malbarbo](https://github.com/malbarbo) |[tshepang](https://github.com/tshepang) |[golem131](https://github.com/golem131) |
+
+[<img alt="jimmycuadra" src="https://avatars2.githubusercontent.com/u/122457?v=4&s=117" width="117">](https://github.com/jimmycuadra) |[<img alt="Nemo157" src="https://avatars1.githubusercontent.com/u/81079?v=4&s=117" width="117">](https://github.com/Nemo157) |[<img alt="severen" src="https://avatars1.githubusercontent.com/u/4061736?v=4&s=117" width="117">](https://github.com/severen) |[<img alt="Eijebong" src="https://avatars2.githubusercontent.com/u/3650385?v=4&s=117" width="117">](https://github.com/Eijebong) |[<img alt="cstorey" src="https://avatars3.githubusercontent.com/u/743059?v=4&s=117" width="117">](https://github.com/cstorey) |[<img alt="wdv4758h" src="https://avatars1.githubusercontent.com/u/2716047?v=4&s=117" width="117">](https://github.com/wdv4758h) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[jimmycuadra](https://github.com/jimmycuadra) |[Nemo157](https://github.com/Nemo157) |[severen](https://github.com/severen) |[Eijebong](https://github.com/Eijebong) |[cstorey](https://github.com/cstorey) |[wdv4758h](https://github.com/wdv4758h) |
+
+[<img alt="frewsxcv" src="https://avatars2.githubusercontent.com/u/416575?v=4&s=117" width="117">](https://github.com/frewsxcv) |[<img alt="hoodie" src="https://avatars1.githubusercontent.com/u/260370?v=4&s=117" width="117">](https://github.com/hoodie) |[<img alt="huonw" src="https://avatars1.githubusercontent.com/u/1203825?v=4&s=117" width="117">](https://github.com/huonw) |[<img alt="GrappigPanda" src="https://avatars0.githubusercontent.com/u/2055372?v=4&s=117" width="117">](https://github.com/GrappigPanda) |[<img alt="shepmaster" src="https://avatars0.githubusercontent.com/u/174509?v=4&s=117" width="117">](https://github.com/shepmaster) |[<img alt="starkat99" src="https://avatars1.githubusercontent.com/u/8295111?v=4&s=117" width="117">](https://github.com/starkat99) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[frewsxcv](https://github.com/frewsxcv) |[hoodie](https://github.com/hoodie) |[huonw](https://github.com/huonw) |[GrappigPanda](https://github.com/GrappigPanda) |[shepmaster](https://github.com/shepmaster) |[starkat99](https://github.com/starkat99) |
+
+[<img alt="porglezomp" src="https://avatars1.githubusercontent.com/u/1690225?v=4&s=117" width="117">](https://github.com/porglezomp) |[<img alt="kraai" src="https://avatars1.githubusercontent.com/u/552646?v=4&s=117" width="117">](https://github.com/kraai) |[<img alt="musoke" src="https://avatars0.githubusercontent.com/u/16665084?v=4&s=117" width="117">](https://github.com/musoke) |[<img alt="nelsonjchen" src="https://avatars1.githubusercontent.com/u/5363?v=4&s=117" width="117">](https://github.com/nelsonjchen) |[<img alt="pkgw" src="https://avatars0.githubusercontent.com/u/59598?v=4&s=117" width="117">](https://github.com/pkgw) |[<img alt="Deedasmi" src="https://avatars0.githubusercontent.com/u/5093293?v=4&s=117" width="117">](https://github.com/Deedasmi) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[porglezomp](https://github.com/porglezomp) |[kraai](https://github.com/kraai) |[musoke](https://github.com/musoke) |[nelsonjchen](https://github.com/nelsonjchen) |[pkgw](https://github.com/pkgw) |[Deedasmi](https://github.com/Deedasmi) |
+
+[<img alt="vmchale" src="https://avatars1.githubusercontent.com/u/13259982?v=4&s=117" width="117">](https://github.com/vmchale) |[<img alt="etopiei" src="https://avatars3.githubusercontent.com/u/17671663?v=4&s=117" width="117">](https://github.com/etopiei) |[<img alt="messense" src="https://avatars0.githubusercontent.com/u/1556054?v=4&s=117" width="117">](https://github.com/messense) |[<img alt="Keats" src="https://avatars2.githubusercontent.com/u/680355?v=4&s=117" width="117">](https://github.com/Keats) |[<img alt="kieraneglin" src="https://avatars0.githubusercontent.com/u/569917?v=4&s=117" width="117">](https://github.com/kieraneglin) |[<img alt="durka" src="https://avatars3.githubusercontent.com/u/47007?v=4&s=117" width="117">](https://github.com/durka) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[vmchale](https://github.com/vmchale) |[etopiei](https://github.com/etopiei) |[messense](https://github.com/messense) |[Keats](https://github.com/Keats) |[kieraneglin](https://github.com/kieraneglin) |[durka](https://github.com/durka) |
+
+[<img alt="alex-gulyas" src="https://avatars0.githubusercontent.com/u/8698329?v=4&s=117" width="117">](https://github.com/alex-gulyas) |[<img alt="cite-reader" src="https://avatars1.githubusercontent.com/u/4196987?v=4&s=117" width="117">](https://github.com/cite-reader) |[<img alt="alexbool" src="https://avatars3.githubusercontent.com/u/1283792?v=4&s=117" width="117">](https://github.com/alexbool) |[<img alt="AluisioASG" src="https://avatars2.githubusercontent.com/u/1904165?v=4&s=117" width="117">](https://github.com/AluisioASG) |[<img alt="BurntSushi" src="https://avatars3.githubusercontent.com/u/456674?v=4&s=117" width="117">](https://github.com/BurntSushi) |[<img alt="AndrewGaspar" src="https://avatars1.githubusercontent.com/u/2292643?v=4&s=117" width="117">](https://github.com/AndrewGaspar) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[alex-gulyas](https://github.com/alex-gulyas) |[cite-reader](https://github.com/cite-reader) |[alexbool](https://github.com/alexbool) |[AluisioASG](https://github.com/AluisioASG) |[BurntSushi](https://github.com/BurntSushi) |[AndrewGaspar](https://github.com/AndrewGaspar) |
+
+[<img alt="nox" src="https://avatars0.githubusercontent.com/u/123095?v=4&s=117" width="117">](https://github.com/nox) |[<img alt="mitsuhiko" src="https://avatars1.githubusercontent.com/u/7396?v=4&s=117" width="117">](https://github.com/mitsuhiko) |[<img alt="pixelistik" src="https://avatars1.githubusercontent.com/u/170929?v=4&s=117" width="117">](https://github.com/pixelistik) |[<img alt="ogham" src="https://avatars3.githubusercontent.com/u/503760?v=4&s=117" width="117">](https://github.com/ogham) |[<img alt="Bilalh" src="https://avatars0.githubusercontent.com/u/171602?v=4&s=117" width="117">](https://github.com/Bilalh) |[<img alt="dotdash" src="https://avatars1.githubusercontent.com/u/230962?v=4&s=117" width="117">](https://github.com/dotdash) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[nox](https://github.com/nox) |[mitsuhiko](https://github.com/mitsuhiko) |[pixelistik](https://github.com/pixelistik) |[ogham](https://github.com/ogham) |[Bilalh](https://github.com/Bilalh) |[dotdash](https://github.com/dotdash) |
+
+[<img alt="bradurani" src="https://avatars0.githubusercontent.com/u/4195952?v=4&s=117" width="117">](https://github.com/bradurani) |[<img alt="Seeker14491" src="https://avatars2.githubusercontent.com/u/6490497?v=4&s=117" width="117">](https://github.com/Seeker14491) |[<img alt="brianp" src="https://avatars1.githubusercontent.com/u/179134?v=4&s=117" width="117">](https://github.com/brianp) |[<img alt="cldershem" src="https://avatars3.githubusercontent.com/u/201608?v=4&s=117" width="117">](https://github.com/cldershem) |[<img alt="casey" src="https://avatars2.githubusercontent.com/u/1945?v=4&s=117" width="117">](https://github.com/casey) |[<img alt="volks73" src="https://avatars1.githubusercontent.com/u/1915469?v=4&s=117" width="117">](https://github.com/volks73) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[bradurani](https://github.com/bradurani) |[Seeker14491](https://github.com/Seeker14491) |[brianp](https://github.com/brianp) |[cldershem](https://github.com/cldershem) |[casey](https://github.com/casey) |[volks73](https://github.com/volks73) |
+
+[<img alt="daboross" src="https://avatars1.githubusercontent.com/u/1152146?v=4&s=117" width="117">](https://github.com/daboross) |[<img alt="da-x" src="https://avatars1.githubusercontent.com/u/321273?v=4&s=117" width="117">](https://github.com/da-x) |[<img alt="mernen" src="https://avatars0.githubusercontent.com/u/6412?v=4&s=117" width="117">](https://github.com/mernen) |[<img alt="dguo" src="https://avatars0.githubusercontent.com/u/2763135?v=4&s=117" width="117">](https://github.com/dguo) |[<img alt="davidszotten" src="https://avatars3.githubusercontent.com/u/412005?v=4&s=117" width="117">](https://github.com/davidszotten) |[<img alt="drusellers" src="https://avatars1.githubusercontent.com/u/63355?v=4&s=117" width="117">](https://github.com/drusellers) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[daboross](https://github.com/daboross) |[da-x](https://github.com/da-x) |[mernen](https://github.com/mernen) |[dguo](https://github.com/dguo) |[davidszotten](https://github.com/davidszotten) |[drusellers](https://github.com/drusellers) |
+
+[<img alt="eddyb" src="https://avatars2.githubusercontent.com/u/77424?v=4&s=117" width="117">](https://github.com/eddyb) |[<img alt="Enet4" src="https://avatars0.githubusercontent.com/u/4738426?v=4&s=117" width="117">](https://github.com/Enet4) |[<img alt="Fraser999" src="https://avatars3.githubusercontent.com/u/190532?v=4&s=117" width="117">](https://github.com/Fraser999) |[<img alt="birkenfeld" src="https://avatars0.githubusercontent.com/u/144359?v=4&s=117" width="117">](https://github.com/birkenfeld) |[<img alt="guanqun" src="https://avatars0.githubusercontent.com/u/53862?v=4&s=117" width="117">](https://github.com/guanqun) |[<img alt="tanakh" src="https://avatars2.githubusercontent.com/u/109069?v=4&s=117" width="117">](https://github.com/tanakh) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[eddyb](https://github.com/eddyb) |[Enet4](https://github.com/Enet4) |[Fraser999](https://github.com/Fraser999) |[birkenfeld](https://github.com/birkenfeld) |[guanqun](https://github.com/guanqun) |[tanakh](https://github.com/tanakh) |
+
+[<img alt="SirVer" src="https://avatars0.githubusercontent.com/u/140115?v=4&s=117" width="117">](https://github.com/SirVer) |[<img alt="idmit" src="https://avatars1.githubusercontent.com/u/2546728?v=4&s=117" width="117">](https://github.com/idmit) |[<img alt="archer884" src="https://avatars1.githubusercontent.com/u/679494?v=4&s=117" width="117">](https://github.com/archer884) |[<img alt="jacobmischka" src="https://avatars1.githubusercontent.com/u/3939997?v=4&s=117" width="117">](https://github.com/jacobmischka) |[<img alt="jespino" src="https://avatars0.githubusercontent.com/u/290303?v=4&s=117" width="117">](https://github.com/jespino) |[<img alt="jfrankenau" src="https://avatars3.githubusercontent.com/u/2736480?v=4&s=117" width="117">](https://github.com/jfrankenau) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[SirVer](https://github.com/SirVer) |[idmit](https://github.com/idmit) |[archer884](https://github.com/archer884) |[jacobmischka](https://github.com/jacobmischka) |[jespino](https://github.com/jespino) |[jfrankenau](https://github.com/jfrankenau) |
+
+[<img alt="jtdowney" src="https://avatars1.githubusercontent.com/u/44654?v=4&s=117" width="117">](https://github.com/jtdowney) |[<img alt="andete" src="https://avatars2.githubusercontent.com/u/689017?v=4&s=117" width="117">](https://github.com/andete) |[<img alt="joshtriplett" src="https://avatars2.githubusercontent.com/u/162737?v=4&s=117" width="117">](https://github.com/joshtriplett) |[<img alt="Kalwyn" src="https://avatars3.githubusercontent.com/u/22778640?v=4&s=117" width="117">](https://github.com/Kalwyn) |[<img alt="manuel-rhdt" src="https://avatars1.githubusercontent.com/u/3199013?v=4&s=117" width="117">](https://github.com/manuel-rhdt) |[<img alt="Marwes" src="https://avatars3.githubusercontent.com/u/957312?v=4&s=117" width="117">](https://github.com/Marwes) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[jtdowney](https://github.com/jtdowney) |[andete](https://github.com/andete) |[joshtriplett](https://github.com/joshtriplett) |[Kalwyn](https://github.com/Kalwyn) |[manuel-rhdt](https://github.com/manuel-rhdt) |[Marwes](https://github.com/Marwes) |
+
+[<img alt="mdaffin" src="https://avatars1.githubusercontent.com/u/171232?v=4&s=117" width="117">](https://github.com/mdaffin) |[<img alt="iliekturtles" src="https://avatars3.githubusercontent.com/u/5081378?v=4&s=117" width="117">](https://github.com/iliekturtles) |[<img alt="nicompte" src="https://avatars2.githubusercontent.com/u/439369?v=4&s=117" width="117">](https://github.com/nicompte) |[<img alt="NickeZ" src="https://avatars2.githubusercontent.com/u/492753?v=4&s=117" width="117">](https://github.com/NickeZ) |[<img alt="nvzqz" src="https://avatars0.githubusercontent.com/u/10367662?v=4&s=117" width="117">](https://github.com/nvzqz) |[<img alt="nuew" src="https://avatars2.githubusercontent.com/u/26099511?v=4&s=117" width="117">](https://github.com/nuew) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[mdaffin](https://github.com/mdaffin) |[iliekturtles](https://github.com/iliekturtles) |[nicompte](https://github.com/nicompte) |[NickeZ](https://github.com/NickeZ) |[nvzqz](https://github.com/nvzqz) |[nuew](https://github.com/nuew) |
+
+[<img alt="Geogi" src="https://avatars1.githubusercontent.com/u/1818316?v=4&s=117" width="117">](https://github.com/Geogi) |[<img alt="focusaurus" src="https://avatars1.githubusercontent.com/u/482377?v=4&s=117" width="117">](https://github.com/focusaurus) |[<img alt="flying-sheep" src="https://avatars0.githubusercontent.com/u/291575?v=4&s=117" width="117">](https://github.com/flying-sheep) |[<img alt="Phlosioneer" src="https://avatars2.githubusercontent.com/u/4657718?v=4&s=117" width="117">](https://github.com/Phlosioneer) |[<img alt="peppsac" src="https://avatars3.githubusercontent.com/u/2198295?v=4&s=117" width="117">](https://github.com/peppsac) |[<img alt="golddranks" src="https://avatars1.githubusercontent.com/u/2675542?v=4&s=117" width="117">](https://github.com/golddranks) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[Geogi](https://github.com/Geogi) |[focusaurus](https://github.com/focusaurus) |[flying-sheep](https://github.com/flying-sheep) |[Phlosioneer](https://github.com/Phlosioneer) |[peppsac](https://github.com/peppsac) |[golddranks](https://github.com/golddranks) |
+
+[<img alt="hexjelly" src="https://avatars0.githubusercontent.com/u/435283?v=4&s=117" width="117">](https://github.com/hexjelly) |[<img alt="rom1v" src="https://avatars1.githubusercontent.com/u/543275?v=4&s=117" width="117">](https://github.com/rom1v) |[<img alt="rnelson" src="https://avatars3.githubusercontent.com/u/118361?v=4&s=117" width="117">](https://github.com/rnelson) |[<img alt="swatteau" src="https://avatars3.githubusercontent.com/u/5521255?v=4&s=117" width="117">](https://github.com/swatteau) |[<img alt="tchajed" src="https://avatars3.githubusercontent.com/u/1255037?v=4&s=117" width="117">](https://github.com/tchajed) |[<img alt="tspiteri" src="https://avatars0.githubusercontent.com/u/18604588?v=4&s=117" width="117">](https://github.com/tspiteri) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[hexjelly](https://github.com/hexjelly) |[rom1v](https://github.com/rom1v) |[rnelson](https://github.com/rnelson) |[swatteau](https://github.com/swatteau) |[tchajed](https://github.com/tchajed) |[tspiteri](https://github.com/tspiteri) |
+
+[<img alt="siiptuo" src="https://avatars0.githubusercontent.com/u/10729330?v=4&s=117" width="117">](https://github.com/siiptuo) |[<img alt="vks" src="https://avatars2.githubusercontent.com/u/33460?v=4&s=117" width="117">](https://github.com/vks) |[<img alt="vsupalov" src="https://avatars2.githubusercontent.com/u/2801030?v=4&s=117" width="117">](https://github.com/vsupalov) |[<img alt="mineo" src="https://avatars1.githubusercontent.com/u/78236?v=4&s=117" width="117">](https://github.com/mineo) |[<img alt="wabain" src="https://avatars3.githubusercontent.com/u/7651435?v=4&s=117" width="117">](https://github.com/wabain) |[<img alt="grossws" src="https://avatars2.githubusercontent.com/u/171284?v=4&s=117" width="117">](https://github.com/grossws) |
+:---: |:---: |:---: |:---: |:---: |:---: |
+[siiptuo](https://github.com/siiptuo) |[vks](https://github.com/vks) |[vsupalov](https://github.com/vsupalov) |[mineo](https://github.com/mineo) |[wabain](https://github.com/wabain) |[grossws](https://github.com/grossws) |
+
+[<img alt="kennytm" src="https://avatars1.githubusercontent.com/u/103023?v=4&s=117" width="117">](https://github.com/kennytm) |[<img alt="king6cong" src="https://avatars3.githubusercontent.com/u/302560?v=4&s=117" width="117">](https://github.com/king6cong) |[<img alt="mvaude" src="https://avatars1.githubusercontent.com/u/9532611?v=4&s=117" width="117">](https://github.com/mvaude) |[<img alt="panicbit" src="https://avatars2.githubusercontent.com/u/628445?v=4&s=117" width="117">](https://github.com/panicbit) |[<img alt="brennie" src="https://avatars3.githubusercontent.com/u/156585?v=4&s=117" width="117">](https://github.com/brennie) |
+:---: |:---: |:---: |:---: |:---: |
+[kennytm](https://github.com/kennytm) |[king6cong](https://github.com/king6cong) |[mvaude](https://github.com/mvaude) |[panicbit](https://github.com/panicbit) |[brennie](https://github.com/brennie) |
+
+
+
+
+This list was generated by [mgechev/github-contributors-list](https://github.com/mgechev/github-contributors-list)
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..c76ceb4
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,132 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g. crates.io) dependencies
+#
+# If you believe there's an error in this file please file an
+# issue against the rust-lang/cargo repository. If you're
+# editing this file be aware that the upstream Cargo.toml
+# will likely look very different (and much more reasonable)
+
+[package]
+name = "clap"
+version = "2.33.0"
+authors = ["Kevin K. <kbknapp@gmail.com>"]
+exclude = ["examples/*", "clap-test/*", "tests/*", "benches/*", "*.png", "clap-perf/*", "*.dot"]
+description = "A simple to use, efficient, and full-featured Command Line Argument Parser\n"
+homepage = "https://clap.rs/"
+documentation = "https://docs.rs/clap/"
+readme = "README.md"
+keywords = ["argument", "cli", "arg", "parser", "parse"]
+categories = ["command-line-interface"]
+license = "MIT"
+repository = "https://github.com/clap-rs/clap"
+[package.metadata.docs.rs]
+features = ["doc"]
+[profile.test]
+opt-level = 1
+lto = false
+codegen-units = 4
+debug = true
+debug-assertions = true
+rpath = false
+
+[profile.bench]
+opt-level = 3
+lto = true
+codegen-units = 1
+debug = false
+debug-assertions = false
+rpath = false
+
+[profile.dev]
+opt-level = 0
+lto = false
+codegen-units = 4
+debug = true
+debug-assertions = true
+rpath = false
+
+[profile.release]
+opt-level = 3
+lto = true
+codegen-units = 1
+debug = false
+debug-assertions = false
+rpath = false
+[dependencies.atty]
+version = "0.2.2"
+optional = true
+
+[dependencies.bitflags]
+version = "1.0"
+
+[dependencies.clippy]
+version = "~0.0.166"
+optional = true
+
+[dependencies.strsim]
+version = "0.8"
+optional = true
+
+[dependencies.term_size]
+version = "0.3.0"
+optional = true
+
+[dependencies.textwrap]
+version = "0.11.0"
+
+[dependencies.unicode-width]
+version = "0.1.4"
+
+[dependencies.vec_map]
+version = "0.8"
+optional = true
+
+[dependencies.yaml-rust]
+version = "0.3.5"
+optional = true
+[dev-dependencies.lazy_static]
+version = "1.3"
+
+[dev-dependencies.regex]
+version = "1"
+
+[dev-dependencies.version-sync]
+version = "0.8"
+
+[features]
+color = ["ansi_term", "atty"]
+debug = []
+default = ["suggestions", "color", "vec_map"]
+doc = ["yaml"]
+lints = ["clippy"]
+nightly = []
+no_cargo = []
+suggestions = ["strsim"]
+unstable = []
+wrap_help = ["term_size", "textwrap/term_size"]
+yaml = ["yaml-rust"]
+[target."cfg(not(windows))".dependencies.ansi_term]
+version = "0.11"
+optional = true
+[badges.appveyor]
+repository = "clap-rs/clap"
+
+[badges.coveralls]
+branch = "master"
+repository = "clap-rs/clap"
+
+[badges.is-it-maintained-issue-resolution]
+repository = "clap-rs/clap"
+
+[badges.is-it-maintained-open-issues]
+repository = "clap-rs/clap"
+
+[badges.maintenance]
+status = "actively-developed"
+
+[badges.travis-ci]
+repository = "clap-rs/clap"
diff --git a/LICENSE-MIT b/LICENSE-MIT
new file mode 100644
index 0000000..5acedf0
--- /dev/null
+++ b/LICENSE-MIT
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2015-2016 Kevin B. Knapp
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..c95f494
--- /dev/null
+++ b/README.md
@@ -0,0 +1,542 @@
+clap
+====
+
+[![Crates.io](https://img.shields.io/crates/v/clap.svg)](https://crates.io/crates/clap) [![Crates.io](https://img.shields.io/crates/d/clap.svg)](https://crates.io/crates/clap) [![license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/clap-rs/clap/blob/master/LICENSE-MIT) [![Coverage Status](https://coveralls.io/repos/kbknapp/clap-rs/badge.svg?branch=master&service=github)](https://coveralls.io/github/kbknapp/clap-rs?branch=master) [![Join the chat at https://gitter.im/kbknapp/clap-rs](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/kbknapp/clap-rs?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
+Linux: [![Build Status](https://travis-ci.org/clap-rs/clap.svg?branch=master)](https://travis-ci.org/clap-rs/clap)
+Windows: [![Build status](https://ci.appveyor.com/api/projects/status/ejg8c33dn31nhv36/branch/master?svg=true)](https://ci.appveyor.com/project/kbknapp/clap-rs/branch/master)
+
+Command Line Argument Parser for Rust
+
+It is a simple-to-use, efficient, and full-featured library for parsing command line arguments and subcommands when writing console/terminal applications.
+
+* [documentation](https://docs.rs/clap/)
+* [website](https://clap.rs/)
+* [video tutorials](https://www.youtube.com/playlist?list=PLza5oFLQGTl2Z5T8g1pRkIynR3E0_pc7U)
+
+Table of Contents
+=================
+
+* [About](#about)
+* [FAQ](#faq)
+* [Features](#features)
+* [Quick Example](#quick-example)
+* [Try it!](#try-it)
+  * [Pre-Built Test](#pre-built-test)
+  * [BYOB (Build Your Own Binary)](#byob-build-your-own-binary)
+* [Usage](#usage)
+  * [Optional Dependencies / Features](#optional-dependencies--features)
+  * [Dependencies Tree](#dependencies-tree)
+  * [More Information](#more-information)
+    * [Video Tutorials](#video-tutorials)
+* [How to Contribute](#how-to-contribute)
+  * [Compatibility Policy](#compatibility-policy)
+    * [Minimum Version of Rust](#minimum-version-of-rust)
+* [Related Crates](#related-crates)
+* [License](#license)
+* [Recent Breaking Changes](#recent-breaking-changes)
+  * [Deprecations](#deprecations)
+
+Created by [gh-md-toc](https://github.com/ekalinin/github-markdown-toc)
+
+## About
+
+`clap` is used to parse *and validate* the string of command line arguments provided by a user at runtime. You provide the list of valid possibilities, and `clap` handles the rest. This means you focus on your *applications* functionality, and less on the parsing and validating of arguments.
+
+`clap` provides many things 'for free' (with no configuration) including the traditional version and help switches (or flags) along with associated messages. If you are using subcommands, `clap` will also auto-generate a `help` subcommand and separate associated help messages.
+
+Once `clap` parses the user provided string of arguments, it returns the matches along with any applicable values. If the user made an error or typo, `clap` informs them with a friendly message and exits gracefully (or returns a `Result` type and allows you to perform any clean up prior to exit). Because of this, you can make reasonable assumptions in your code about the validity of the arguments prior to your applications main execution.
+
+## FAQ
+
+For a full FAQ and more in depth details, see [the wiki page](https://github.com/clap-rs/clap/wiki/FAQ)
+
+### Comparisons
+
+First, let me say that these comparisons are highly subjective, and not meant in a critical or harsh manner. All the argument parsing libraries out there (to include `clap`) have their own strengths and weaknesses. Sometimes it just comes down to personal taste when all other factors are equal. When in doubt, try them all and pick one that you enjoy :) There's plenty of room in the Rust community for multiple implementations!
+
+#### How does `clap` compare to [getopts](https://github.com/rust-lang-nursery/getopts)?
+
+`getopts` is a very basic, fairly minimalist argument parsing library. This isn't a bad thing, sometimes you don't need tons of features, you just want to parse some simple arguments, and have some help text generated for you based on valid arguments you specify. The downside to this approach is that you must manually implement most of the common features (such as checking to display help messages, usage strings, etc.). If you want a highly custom argument parser, and don't mind writing the majority of the functionality yourself, `getopts` is an excellent base.
+
+`getopts` also doesn't allocate much, or at all. This gives it a very small performance boost. Although, as you start implementing additional features, that boost quickly disappears.
+
+Personally, I find many, many uses of `getopts` are manually implementing features that `clap` provides by default. Using `clap` simplifies your codebase allowing you to focus on your application, and not argument parsing.
+
+#### How does `clap` compare to [docopt.rs](https://github.com/docopt/docopt.rs)?
+
+I first want to say I'm a big a fan of BurntSushi's work, the creator of `Docopt.rs`. I aspire to produce the quality of libraries that this man does! When it comes to comparing these two libraries they are very different. `docopt` tasks you with writing a help message, and then it parsers that message for you to determine all valid arguments and their use. Some people LOVE this approach, others do not. If you're willing to write a detailed help message, it's nice that you can stick that in your program and have `docopt` do the rest. On the downside, it's far less flexible.
+
+`docopt` is also excellent at translating arguments into Rust types automatically. There is even a syntax extension which will do all this for you, if you're willing to use a nightly compiler (use of a stable compiler requires you to somewhat manually translate from arguments to Rust types). To use BurntSushi's words, `docopt` is also a sort of black box. You get what you get, and it's hard to tweak implementation or customize the experience for your use case.
+
+Because `docopt` is doing a ton of work to parse your help messages and determine what you were trying to communicate as valid arguments, it's also one of the more heavy weight parsers performance-wise. For most applications this isn't a concern and this isn't to say `docopt` is slow, in fact far from it. This is just something to keep in mind while comparing.
+
+#### All else being equal, what are some reasons to use `clap`? (The Pitch)
+
+`clap` is as fast, and as lightweight as possible while still giving all the features you'd expect from a modern argument parser. In fact, for the amount and type of features `clap` offers it remains about as fast as `getopts`. If you use `clap` when just need some simple arguments parsed, you'll find it's a walk in the park. `clap` also makes it possible to represent extremely complex, and advanced requirements, without too much thought. `clap` aims to be intuitive, easy to use, and fully capable for wide variety use cases and needs.
+
+#### All else being equal, what are some reasons *not* to use `clap`? (The Anti Pitch)
+
+Depending on the style in which you choose to define the valid arguments, `clap` can be very verbose. `clap` also offers so many fine-tuning knobs and dials, that learning everything can seem overwhelming. I strive to keep the simple cases simple, but when turning all those custom dials it can get complex. `clap` is also opinionated about parsing. Even though so much can be tweaked and tuned with `clap` (and I'm adding more all the time), there are still certain features which `clap` implements in specific ways which may be contrary to some users use-cases. Finally, `clap` is "stringly typed" when referring to arguments which can cause typos in code. This particular paper-cut is being actively worked on, and should be gone in v3.x.
+
+## Features
+
+Below are a few of the features which `clap` supports, full descriptions and usage can be found in the [documentation](https://docs.rs/clap/) and [examples/](examples) directory
+
+* **Auto-generated Help, Version, and Usage information**
+  - Can optionally be fully, or partially overridden if you want a custom help, version, or usage statements
+* **Auto-generated completion scripts at compile time (Bash, Zsh, Fish, and PowerShell)**
+  - Even works through many multiple levels of subcommands
+  - Works with options which only accept certain values
+  - Works with subcommand aliases
+* **Flags / Switches** (i.e. bool fields)
+  - Both short and long versions supported (i.e. `-f` and `--flag` respectively)
+  - Supports combining short versions (i.e. `-fBgoZ` is the same as `-f -B -g -o -Z`)
+  - Supports multiple occurrences (i.e. `-vvv` or `-v -v -v`)
+* **Positional Arguments** (i.e. those which are based off an index from the program name)
+  - Supports multiple values (i.e. `myprog <file>...` such as `myprog file1.txt file2.txt` being two values for the same "file" argument)
+  - Supports Specific Value Sets (See below)
+  - Can set value parameters (such as the minimum number of values, the maximum number of values, or the exact number of values)
+  - Can set custom validations on values to extend the argument parsing capability to truly custom domains
+* **Option Arguments** (i.e. those that take values)
+  - Both short and long versions supported (i.e. `-o value`, `-ovalue`, `-o=value` and `--option value` or `--option=value` respectively)
+  - Supports multiple values (i.e. `-o <val1> -o <val2>` or `-o <val1> <val2>`)
+  - Supports delimited values (i.e. `-o=val1,val2,val3`, can also change the delimiter)
+  - Supports Specific Value Sets (See below)
+  - Supports named values so that the usage/help info appears as `-o <FILE> <INTERFACE>` etc. for when you require specific multiple values
+  - Can set value parameters (such as the minimum number of values, the maximum number of values, or the exact number of values)
+  - Can set custom validations on values to extend the argument parsing capability to truly custom domains
+* **Sub-Commands** (i.e. `git add <file>` where `add` is a sub-command of `git`)
+  - Support their own sub-arguments, and sub-sub-commands independent of the parent
+  - Get their own auto-generated Help, Version, and Usage independent of parent
+* **Support for building CLIs from YAML** - This keeps your Rust source nice and tidy and makes supporting localized translation very simple!
+* **Requirement Rules**: Arguments can define the following types of requirement rules
+  - Can be required by default
+  - Can be required only if certain arguments are present
+  - Can require other arguments to be present
+  - Can be required only if certain values of other arguments are used
+* **Confliction Rules**: Arguments can optionally define the following types of exclusion rules
+  - Can be disallowed when certain arguments are present
+  - Can disallow use of other arguments when present
+* **Groups**: Arguments can be made part of a group
+  - Fully compatible with other relational rules (requirements, conflicts, and overrides) which allows things like requiring the use of any arg in a group, or denying the use of an entire group conditionally
+* **Specific Value Sets**: Positional or Option Arguments can define a specific set of allowed values (i.e. imagine a `--mode` option which may *only* have one of two values `fast` or `slow` such as `--mode fast` or `--mode slow`)
+* **Default Values**
+  - Also supports conditional default values (i.e. a default which only applies if specific arguments are used, or specific values of those arguments)
+* **Automatic Version from Cargo.toml**: `clap` is fully compatible with Rust's `env!()` macro for automatically setting the version of your application to the version in your Cargo.toml. See [09_auto_version example](examples/09_auto_version.rs) for how to do this (Thanks to [jhelwig](https://github.com/jhelwig) for pointing this out)
+* **Typed Values**: You can use several convenience macros provided by `clap` to get typed values (i.e. `i32`, `u8`, etc.) from positional or option arguments so long as the type you request implements `std::str::FromStr` See the [12_typed_values example](examples/12_typed_values.rs). You can also use `clap`s `arg_enum!` macro to create an enum with variants that automatically implement `std::str::FromStr`. See [13a_enum_values_automatic example](examples/13a_enum_values_automatic.rs) for details
+* **Suggestions**: Suggests corrections when the user enters a typo. For example, if you defined a `--myoption` argument, and the user mistakenly typed `--moyption` (notice `y` and `o` transposed), they would receive a `Did you mean '--myoption'?` error and exit gracefully. This also works for subcommands and flags. (Thanks to [Byron](https://github.com/Byron) for the implementation) (This feature can optionally be disabled, see 'Optional Dependencies / Features')
+* **Colorized Errors (Non Windows OS only)**: Error message are printed in in colored text (this feature can optionally be disabled, see 'Optional Dependencies / Features').
+* **Global Arguments**: Arguments can optionally be defined once, and be available to all child subcommands. There values will also be propagated up/down throughout all subcommands.
+* **Custom Validations**: You can define a function to use as a validator of argument values. Imagine defining a function to validate IP addresses, or fail parsing upon error. This means your application logic can be solely focused on *using* values.
+* **POSIX Compatible Conflicts/Overrides** - In POSIX args can be conflicting, but not fail parsing because whichever arg comes *last* "wins" so to speak. This allows things such as aliases (i.e. `alias ls='ls -l'` but then using `ls -C` in your terminal which ends up passing `ls -l -C` as the final arguments. Since `-l` and `-C` aren't compatible, this effectively runs `ls -C` in `clap` if you choose...`clap` also supports hard conflicts that fail parsing). (Thanks to [Vinatorul](https://github.com/Vinatorul)!)
+* Supports the Unix `--` meaning, only positional arguments follow
+
+## Quick Example
+
+The following examples show a quick example of some of the very basic functionality of `clap`. For more advanced usage, such as requirements, conflicts, groups, multiple values and occurrences see the [documentation](https://docs.rs/clap/), [examples/](examples) directory of this repository or the [video tutorials](https://www.youtube.com/playlist?list=PLza5oFLQGTl2Z5T8g1pRkIynR3E0_pc7U).
+
+ **NOTE:** All of these examples are functionally the same, but show different styles in which to use `clap`. These different styles are purely a matter of personal preference.
+
+The first example shows a method using the 'Builder Pattern' which allows more advanced configuration options (not shown in this small example), or even dynamically generating arguments when desired.
+
+```rust
+// (Full example with detailed comments in examples/01b_quick_example.rs)
+//
+// This example demonstrates clap's full 'builder pattern' style of creating arguments which is
+// more verbose, but allows easier editing, and at times more advanced options, or the possibility
+// to generate arguments dynamically.
+extern crate clap;
+use clap::{Arg, App, SubCommand};
+
+fn main() {
+    let matches = App::new("My Super Program")
+                          .version("1.0")
+                          .author("Kevin K. <kbknapp@gmail.com>")
+                          .about("Does awesome things")
+                          .arg(Arg::with_name("config")
+                               .short("c")
+                               .long("config")
+                               .value_name("FILE")
+                               .help("Sets a custom config file")
+                               .takes_value(true))
+                          .arg(Arg::with_name("INPUT")
+                               .help("Sets the input file to use")
+                               .required(true)
+                               .index(1))
+                          .arg(Arg::with_name("v")
+                               .short("v")
+                               .multiple(true)
+                               .help("Sets the level of verbosity"))
+                          .subcommand(SubCommand::with_name("test")
+                                      .about("controls testing features")
+                                      .version("1.3")
+                                      .author("Someone E. <someone_else@other.com>")
+                                      .arg(Arg::with_name("debug")
+                                          .short("d")
+                                          .help("print debug information verbosely")))
+                          .get_matches();
+
+    // Gets a value for config if supplied by user, or defaults to "default.conf"
+    let config = matches.value_of("config").unwrap_or("default.conf");
+    println!("Value for config: {}", config);
+
+    // Calling .unwrap() is safe here because "INPUT" is required (if "INPUT" wasn't
+    // required we could have used an 'if let' to conditionally get the value)
+    println!("Using input file: {}", matches.value_of("INPUT").unwrap());
+
+    // Vary the output based on how many times the user used the "verbose" flag
+    // (i.e. 'myprog -v -v -v' or 'myprog -vvv' vs 'myprog -v'
+    match matches.occurrences_of("v") {
+        0 => println!("No verbose info"),
+        1 => println!("Some verbose info"),
+        2 => println!("Tons of verbose info"),
+        3 | _ => println!("Don't be crazy"),
+    }
+
+    // You can handle information about subcommands by requesting their matches by name
+    // (as below), requesting just the name used, or both at the same time
+    if let Some(matches) = matches.subcommand_matches("test") {
+        if matches.is_present("debug") {
+            println!("Printing debug info...");
+        } else {
+            println!("Printing normally...");
+        }
+    }
+
+    // more program logic goes here...
+}
+```
+
+One could also optionally declare their CLI in YAML format and keep your Rust source tidy
+or support multiple localized translations by having different YAML files for each localization.
+
+First, create the `cli.yml` file to hold your CLI options, but it could be called anything we like:
+
+```yaml
+name: myapp
+version: "1.0"
+author: Kevin K. <kbknapp@gmail.com>
+about: Does awesome things
+args:
+    - config:
+        short: c
+        long: config
+        value_name: FILE
+        help: Sets a custom config file
+        takes_value: true
+    - INPUT:
+        help: Sets the input file to use
+        required: true
+        index: 1
+    - verbose:
+        short: v
+        multiple: true
+        help: Sets the level of verbosity
+subcommands:
+    - test:
+        about: controls testing features
+        version: "1.3"
+        author: Someone E. <someone_else@other.com>
+        args:
+            - debug:
+                short: d
+                help: print debug information
+```
+
+Since this feature requires additional dependencies that not everyone may want, it is *not* compiled in by default and we need to enable a feature flag in Cargo.toml:
+
+Simply change your `clap = "2.33"` to `clap = {version = "2.33", features = ["yaml"]}`.
+
+Finally we create our `main.rs` file just like we would have with the previous two examples:
+
+```rust
+// (Full example with detailed comments in examples/17_yaml.rs)
+//
+// This example demonstrates clap's building from YAML style of creating arguments which is far
+// more clean, but takes a very small performance hit compared to the other two methods.
+#[macro_use]
+extern crate clap;
+use clap::App;
+
+fn main() {
+    // The YAML file is found relative to the current file, similar to how modules are found
+    let yaml = load_yaml!("cli.yml");
+    let matches = App::from_yaml(yaml).get_matches();
+
+    // Same as previous examples...
+}
+```
+
+If you were to compile any of the above programs and run them with the flag `--help` or `-h` (or `help` subcommand, since we defined `test` as a subcommand) the following would be output
+
+```sh
+$ myprog --help
+My Super Program 1.0
+Kevin K. <kbknapp@gmail.com>
+Does awesome things
+
+USAGE:
+    MyApp [FLAGS] [OPTIONS] <INPUT> [SUBCOMMAND]
+
+FLAGS:
+    -h, --help       Prints help information
+    -v               Sets the level of verbosity
+    -V, --version    Prints version information
+
+OPTIONS:
+    -c, --config <FILE>    Sets a custom config file
+
+ARGS:
+    INPUT    The input file to use
+
+SUBCOMMANDS:
+    help    Prints this message or the help of the given subcommand(s)
+    test    Controls testing features
+```
+
+**NOTE:** You could also run `myapp test --help` or `myapp help test` to see the help message for the `test` subcommand.
+
+There are also two other methods to create CLIs. Which style you choose is largely a matter of personal preference. The two other methods are:
+
+* Using [usage strings (examples/01a_quick_example.rs)](examples/01a_quick_example.rs) similar to (but not exact) docopt style usage statements. This is far less verbose than the above methods, but incurs a slight runtime penalty.
+* Using [a macro (examples/01c_quick_example.rs)](examples/01c_quick_example.rs) which is like a hybrid of the builder and usage string style. It's less verbose, but doesn't incur the runtime penalty of the usage string style. The downside is that it's harder to debug, and more opaque.
+
+Examples of each method can be found in the [examples/](examples) directory of this repository.
+
+## Try it!
+
+### Pre-Built Test
+
+To try out the pre-built examples, use the following steps:
+
+* Clone the repository `$ git clone https://github.com/clap-rs/clap && cd clap-rs/`
+* Compile the example `$ cargo build --example <EXAMPLE>`
+* Run the help info `$ ./target/debug/examples/<EXAMPLE> --help`
+* Play with the arguments!
+* You can also do a onetime run via `$ cargo run --example <EXAMPLE> -- [args to example]`
+
+### BYOB (Build Your Own Binary)
+
+To test out `clap`'s default auto-generated help/version follow these steps:
+* Create a new cargo project `$ cargo new fake --bin && cd fake`
+* Add `clap` to your `Cargo.toml`
+
+```toml
+[dependencies]
+clap = "2"
+```
+
+* Add the following to your `src/main.rs`
+
+```rust
+extern crate clap;
+use clap::App;
+
+fn main() {
+  App::new("fake").version("v1.0-beta").get_matches();
+}
+```
+
+* Build your program `$ cargo build --release`
+* Run with help or version `$ ./target/release/fake --help` or `$ ./target/release/fake --version`
+
+## Usage
+
+For full usage, add `clap` as a dependency in your `Cargo.toml` () to use from crates.io:
+
+```toml
+[dependencies]
+clap = "~2.33"
+```
+
+(**note**: If you are concerned with supporting a minimum version of Rust that is *older* than the current stable Rust minus 2 stable releases, it's recommended to use the `~major.minor.patch` style versions in your `Cargo.toml` which will only update the patch version automatically. For more information see the [Compatibility Policy](#compatibility-policy))
+
+Then add `extern crate clap;` to your crate root.
+
+Define a list of valid arguments for your program (see the [documentation](https://docs.rs/clap/) or [examples/](examples) directory of this repo)
+
+Then run `cargo build` or `cargo update && cargo build` for your project.
+
+### Optional Dependencies / Features
+
+#### Features enabled by default
+
+* **"suggestions"**: Turns on the `Did you mean '--myoption'?` feature for when users make typos. (builds dependency `strsim`)
+* **"color"**: Turns on colored error messages. This feature only works on non-Windows OSs. (builds dependency `ansi-term` only on non-Windows targets)
+* **"vec_map"**: Use [`VecMap`](https://crates.io/crates/vec_map) internally instead of a [`BTreeMap`](https://doc.rust-lang.org/stable/std/collections/struct.BTreeMap.html). This feature provides a _slight_ performance improvement. (builds dependency `vec_map`)
+
+To disable these, add this to your `Cargo.toml`:
+
+```toml
+[dependencies.clap]
+version = "2.33"
+default-features = false
+```
+
+You can also selectively enable only the features you'd like to include, by adding:
+
+```toml
+[dependencies.clap]
+version = "2.33"
+default-features = false
+
+# Cherry-pick the features you'd like to use
+features = [ "suggestions", "color" ]
+```
+
+#### Opt-in features
+
+* **"yaml"**: Enables building CLIs from YAML documents. (builds dependency `yaml-rust`)
+* **"unstable"**: Enables unstable `clap` features that may change from release to release
+* **"wrap_help"**: Turns on the help text wrapping feature, based on the terminal size. (builds dependency `term-size`)
+
+### Dependencies Tree
+
+The following graphic depicts `clap`s dependency graph (generated using [cargo-graph](https://github.com/kbknapp/cargo-graph)).
+
+ * **Dashed** Line: Optional dependency
+ * **Red** Color: **NOT** included by default (must use cargo `features` to enable)
+ * **Blue** Color: Dev dependency, only used while developing.
+
+![clap dependencies](clap_dep_graph.png)
+
+### More Information
+
+You can find complete documentation on the [docs.rs](https://docs.rs/clap/) for this project.
+
+You can also find usage examples in the [examples/](examples) directory of this repo.
+
+#### Video Tutorials
+
+There's also the video tutorial series [Argument Parsing with Rust v2](https://www.youtube.com/playlist?list=PLza5oFLQGTl2Z5T8g1pRkIynR3E0_pc7U).
+
+These videos slowly trickle out as I finish them and currently a work in progress.
+
+## How to Contribute
+
+Details on how to contribute can be found in the [CONTRIBUTING.md](.github/CONTRIBUTING.md) file.
+
+### Compatibility Policy
+
+Because `clap` takes SemVer and compatibility seriously, this is the official policy regarding breaking changes and minimum required versions of Rust.
+
+`clap` will pin the minimum required version of Rust to the CI builds. Bumping the minimum version of Rust is considered a minor breaking change, meaning *at a minimum* the minor version of `clap` will be bumped.
+
+In order to keep from being surprised of breaking changes, it is **highly** recommended to use the `~major.minor.patch` style in your `Cargo.toml` only if you wish to target a version of Rust that is *older* than current stable minus two releases:
+
+```toml
+[dependencies]
+clap = "~2.33"
+```
+
+This will cause *only* the patch version to be updated upon a `cargo update` call, and therefore cannot break due to new features, or bumped minimum versions of Rust.
+
+#### Warning about '~' Dependencies
+
+Using `~` can cause issues in certain circumstances.
+
+From @alexcrichton:
+
+Right now Cargo's version resolution is pretty naive, it's just a brute-force search of the solution space, returning the first resolvable graph. This also means that it currently won't terminate until it proves there is not possible resolvable graph. This leads to situations where workspaces with multiple binaries, for example, have two different dependencies such as:
+
+```toml,no_sync
+
+# In one Cargo.toml
+[dependencies]
+clap = "~2.33.0"
+
+# In another Cargo.toml
+[dependencies]
+clap = "2.33.0"
+```
+
+This is inherently an unresolvable crate graph in Cargo right now. Cargo requires there's only one major version of a crate, and being in the same workspace these two crates must share a version. This is impossible in this location, though, as these version constraints cannot be met.
+
+#### Minimum Version of Rust
+
+`clap` will officially support current stable Rust, minus two releases, but may work with prior releases as well. For example, current stable Rust at the time of this writing is 1.32.0, meaning `clap` is guaranteed to compile with 1.30.0 and beyond.
+
+At the 1.33.0 stable release, `clap` will be guaranteed to compile with 1.31.0 and beyond, etc.
+
+Upon bumping the minimum version of Rust (assuming it's within the stable-2 range), it *must* be clearly annotated in the `CHANGELOG.md`
+
+#### Breaking Changes
+
+`clap` takes a similar policy to Rust and will bump the major version number upon breaking changes with only the following exceptions:
+
+ * The breaking change is to fix a security concern
+ * The breaking change is to be fixing a bug (i.e. relying on a bug as a feature)
+ * The breaking change is a feature isn't used in the wild, or all users of said feature have given approval *prior* to the change
+
+#### Compatibility with Wasm
+
+A best effort is made to ensure that `clap` will work on projects targeting `wasm32-unknown-unknown`. However there is no dedicated CI build
+covering this specific target.
+
+## License
+
+`clap` is licensed under the MIT license. Please read the [LICENSE-MIT](LICENSE-MIT) file in this repository for more information.
+
+## Related Crates
+
+There are several excellent crates which can be used with `clap`, I recommend checking them all out! If you've got a crate that would be a good fit to be used with `clap` open an issue and let me know, I'd love to add it!
+
+* [`structopt`](https://github.com/TeXitoi/structopt) - This crate allows you to define a struct, and build a CLI from it! No more "stringly typed" and it uses `clap` behind the scenes! (*Note*: There is work underway to pull this crate into mainline `clap`).
+* [`assert_cli`](https://github.com/assert-rs/assert_cli) - This crate allows you test your CLIs in a very intuitive and functional way!
+
+## Recent Breaking Changes
+
+`clap` follows semantic versioning, so breaking changes should only happen upon major version bumps. The only exception to this rule is breaking changes that happen due to implementation that was deemed to be a bug, security concerns, or it can be reasonably proved to affect no code. For the full details, see [CHANGELOG.md](./CHANGELOG.md).
+
+As of 2.27.0:
+
+* Argument values now take precedence over subcommand names. This only arises by using unrestrained multiple values and subcommands together where the subcommand name can coincide with one of the multiple values. Such as `$ prog <files>... <subcommand>`. The fix is to place restraints on number of values, or disallow the use of `$ prog <prog-args> <subcommand>` structure.
+
+As of 2.0.0 (From 1.x)
+
+* **Fewer lifetimes! Yay!**
+ * `App<'a, 'b, 'c, 'd, 'e, 'f>` => `App<'a, 'b>`
+ * `Arg<'a, 'b, 'c, 'd, 'e, 'f>` => `Arg<'a, 'b>`
+ * `ArgMatches<'a, 'b>` => `ArgMatches<'a>`
+* **Simply Renamed**
+ * `App::arg_group` => `App::group`
+ * `App::arg_groups` => `App::groups`
+ * `ArgGroup::add` => `ArgGroup::arg`
+ * `ArgGroup::add_all` => `ArgGroup::args`
+ * `ClapError` => `Error`
+  * struct field `ClapError::error_type` => `Error::kind`
+ * `ClapResult` => `Result`
+ * `ClapErrorType` => `ErrorKind`
+* **Removed Deprecated Functions and Methods**
+ * `App::subcommands_negate_reqs`
+ * `App::subcommand_required`
+ * `App::arg_required_else_help`
+ * `App::global_version(bool)`
+ * `App::versionless_subcommands`
+ * `App::unified_help_messages`
+ * `App::wait_on_error`
+ * `App::subcommand_required_else_help`
+ * `SubCommand::new`
+ * `App::error_on_no_subcommand`
+ * `Arg::new`
+ * `Arg::mutually_excludes`
+ * `Arg::mutually_excludes_all`
+ * `Arg::mutually_overrides_with`
+ * `simple_enum!`
+* **Renamed Error Variants**
+ * `InvalidUnicode` => `InvalidUtf8`
+ * `InvalidArgument` => `UnknownArgument`
+* **Usage Parser**
+ * Value names can now be specified inline, i.e. `-o, --option <FILE> <FILE2> 'some option which takes two files'`
+ * **There is now a priority of order to determine the name** - This is perhaps the biggest breaking change. See the documentation for full details. Prior to this change, the value name took precedence. **Ensure your args are using the proper names (i.e. typically the long or short and NOT the value name) throughout the code**
+* `ArgMatches::values_of` returns an `Values` now which implements `Iterator` (should not break any code)
+* `crate_version!` returns `&'static str` instead of `String`
+
+### Deprecations
+
+Old method names will be left around for several minor version bumps, or one major version bump.
+
+As of 2.27.0:
+
+* **AppSettings::PropagateGlobalValuesDown:**  this setting deprecated and is no longer required to propagate values down or up
diff --git a/SPONSORS.md b/SPONSORS.md
new file mode 100644
index 0000000..67f5544
--- /dev/null
+++ b/SPONSORS.md
@@ -0,0 +1,17 @@
+Below is a list of sponsors for the clap-rs project
+
+If you are interested in becoming a sponsor for this project please our [sponsorship page](https://clap.rs/sponsorship/).
+
+## Recurring Sponsors:
+
+| [<img alt="Noelia Seva-Gonzalez" src="https://clap.rs/wp-content/uploads/2017/10/noelia_sm-1.png" width="117">](https://noeliasg.com/about/)  | [<img alt="messense" src="https://clap.rs/wp-content/uploads/2018/01/messense-400x400.png" width="117">](https://github.com/messense)  | [<img alt="Josh" src="https://clap.rs/wp-content/uploads/2018/11/josh_t.jpg" width="117">](https://joshtriplett.org)  | <img alt="Stephen Oats" src="https://clap.rs/wp-content/uploads/2019/03/stephenoats.png" width="117"> |
+|:-:|:-:|:-:|:-:|
+|Noelia Seva-Gonzalez | Messense | Josh Triplett | Stephen Oats |
+
+
+## Single-Donation and Former Sponsors:
+
+| [<img alt="Rob Tsuk" src="https://clap.rs/wp-content/uploads/2017/10/robtsuk_sm.png" width="117">](https://github.com/rtsuk)| | |
+|:-:|:-:|:-:|
+|Rob Tsuk| | |
+
diff --git a/clap-test.rs b/clap-test.rs
new file mode 100644
index 0000000..7d57ac4
--- /dev/null
+++ b/clap-test.rs
@@ -0,0 +1,86 @@
+#[allow(unused_imports, dead_code)]
+mod test {
+    use std::str;
+    use std::io::{Cursor, Write};
+
+    use regex::Regex;
+
+    use clap::{App, Arg, SubCommand, ArgGroup};
+
+    fn compare<S, S2>(l: S, r: S2) -> bool
+        where S: AsRef<str>,
+              S2: AsRef<str>
+    {
+        let re = Regex::new("\x1b[^m]*m").unwrap();
+        // Strip out any mismatching \r character on windows that might sneak in on either side
+        let ls = l.as_ref().trim().replace("\r", "");
+        let rs = r.as_ref().trim().replace("\r", "");
+        let left = re.replace_all(&*ls, "");
+        let right = re.replace_all(&*rs, "");
+        let b = left == right;
+        if !b {
+            println!();
+            println!("--> left");
+            println!("{}", left);
+            println!("--> right");
+            println!("{}", right);
+            println!("--")
+        }
+        b
+    }
+
+    pub fn compare_output(l: App, args: &str, right: &str, stderr: bool) -> bool {
+        let mut buf = Cursor::new(Vec::with_capacity(50));
+        let res = l.get_matches_from_safe(args.split(' ').collect::<Vec<_>>());
+        let err = res.unwrap_err();
+        err.write_to(&mut buf).unwrap();
+        let content = buf.into_inner();
+        let left = String::from_utf8(content).unwrap();
+        assert_eq!(stderr, err.use_stderr());
+        compare(left, right)
+    }
+    pub fn compare_output2(l: App, args: &str, right1: &str, right2: &str, stderr: bool) -> bool {
+        let mut buf = Cursor::new(Vec::with_capacity(50));
+        let res = l.get_matches_from_safe(args.split(' ').collect::<Vec<_>>());
+        let err = res.unwrap_err();
+        err.write_to(&mut buf).unwrap();
+        let content = buf.into_inner();
+        let left = String::from_utf8(content).unwrap();
+        assert_eq!(stderr, err.use_stderr());
+        compare(&*left, right1) || compare(&*left, right2)
+    }
+
+    // Legacy tests from the Python script days
+
+    pub fn complex_app() -> App<'static, 'static> {
+        let args = "-o --option=[opt]... 'tests options'
+                    [positional] 'tests positionals'";
+        let opt3_vals = ["fast", "slow"];
+        let pos3_vals = ["vi", "emacs"];
+        App::new("clap-test")
+            .version("v1.4.8")
+            .about("tests clap library")
+            .author("Kevin K. <kbknapp@gmail.com>")
+            .args_from_usage(args)
+            .arg(Arg::from_usage("-f --flag... 'tests flags'")
+                .global(true))
+            .args(&[
+                Arg::from_usage("[flag2] -F 'tests flags with exclusions'").conflicts_with("flag").requires("long-option-2"),
+                Arg::from_usage("--long-option-2 [option2] 'tests long options with exclusions'").conflicts_with("option").requires("positional2"),
+                Arg::from_usage("[positional2] 'tests positionals with exclusions'"),
+                Arg::from_usage("-O --Option [option3] 'specific vals'").possible_values(&opt3_vals),
+                Arg::from_usage("[positional3]... 'tests specific values'").possible_values(&pos3_vals),
+                Arg::from_usage("--multvals [one] [two] 'Tests multiple values, not mult occs'"),
+                Arg::from_usage("--multvalsmo... [one] [two] 'Tests multiple values, and mult occs'"),
+                Arg::from_usage("--minvals2 [minvals]... 'Tests 2 min vals'").min_values(2),
+                Arg::from_usage("--maxvals3 [maxvals]... 'Tests 3 max vals'").max_values(3)
+            ])
+            .subcommand(SubCommand::with_name("subcmd")
+                                    .about("tests subcommands")
+                                    .version("0.1")
+                                    .author("Kevin K. <kbknapp@gmail.com>")
+                                    .arg_from_usage("-o --option [scoption]... 'tests options'")
+                                    .arg_from_usage("-s --subcmdarg [subcmdarg] 'tests other args'")
+                                    .arg_from_usage("[scpositional] 'tests positionals'"))
+    }
+}
diff --git a/justfile b/justfile
new file mode 100644
index 0000000..0768764
--- /dev/null
+++ b/justfile
@@ -0,0 +1,39 @@
+@update-contributors:
+	echo 'Removing old CONTRIBUTORS.md'
+	mv CONTRIBUTORS.md CONTRIBUTORS.md.bak
+	echo 'Downloading a list of new contributors'
+	echo "the following is a list of contributors:" > CONTRIBUTORS.md
+	echo "" >> CONTRIBUTORS.md
+	echo "" >> CONTRIBUTORS.md
+	githubcontrib --owner clap-rs --repo clap --sha master --cols 6 --format md --showlogin true --sortBy contributions --sortOrder desc >> CONTRIBUTORS.md
+	echo "" >> CONTRIBUTORS.md
+	echo "" >> CONTRIBUTORS.md
+	echo "This list was generated by [mgechev/github-contributors-list](https://github.com/mgechev/github-contributors-list)" >> CONTRIBUTORS.md
+	rm CONTRIBUTORS.md.bak
+
+run-test TEST:
+	cargo test --test {{TEST}}
+
+debug TEST:
+	cargo test --test {{TEST}} --features debug
+
+run-tests:
+	cargo test --features "yaml unstable"
+
+@bench: nightly
+	cargo bench && just remove-nightly
+
+nightly:
+	rustup override add nightly
+
+remove-nightly:
+	rustup override remove
+
+@lint: nightly
+	cargo build --features lints && just remove-nightly
+
+clean:
+	cargo clean
+	find . -type f -name "*.orig" -exec rm {} \;
+	find . -type f -name "*.bk" -exec rm {} \;
+	find . -type f -name ".*~" -exec rm {} \;
diff --git a/rustfmt.toml b/rustfmt.toml
new file mode 100644
index 0000000..0136d86
--- /dev/null
+++ b/rustfmt.toml
@@ -0,0 +1,4 @@
+format_strings = false
+chain_overflow_last = false
+same_line_if_else = true
+fn_single_line = true
diff --git a/src/app/help.rs b/src/app/help.rs
new file mode 100644
index 0000000..34f97ac
--- /dev/null
+++ b/src/app/help.rs
@@ -0,0 +1,1028 @@
+// Std
+use std::borrow::Cow;
+use std::cmp;
+use std::collections::BTreeMap;
+use std::fmt::Display;
+use std::io::{self, Cursor, Read, Write};
+use std::usize;
+
+// Internal
+use app::parser::Parser;
+use app::usage;
+use app::{App, AppSettings};
+use args::{AnyArg, ArgSettings, DispOrder};
+use errors::{Error, Result as ClapResult};
+use fmt::{Colorizer, ColorizerOption, Format};
+use map::VecMap;
+use INTERNAL_ERROR_MSG;
+
+// Third Party
+#[cfg(feature = "wrap_help")]
+use term_size;
+use textwrap;
+use unicode_width::UnicodeWidthStr;
+
+#[cfg(not(feature = "wrap_help"))]
+mod term_size {
+    pub fn dimensions() -> Option<(usize, usize)> {
+        None
+    }
+}
+
+fn str_width(s: &str) -> usize {
+    UnicodeWidthStr::width(s)
+}
+
+const TAB: &'static str = "    ";
+
+// These are just convenient traits to make the code easier to read.
+trait ArgWithDisplay<'b, 'c>: AnyArg<'b, 'c> + Display {}
+impl<'b, 'c, T> ArgWithDisplay<'b, 'c> for T
+where
+    T: AnyArg<'b, 'c> + Display,
+{
+}
+
+trait ArgWithOrder<'b, 'c>: ArgWithDisplay<'b, 'c> + DispOrder {
+    fn as_base(&self) -> &ArgWithDisplay<'b, 'c>;
+}
+impl<'b, 'c, T> ArgWithOrder<'b, 'c> for T
+where
+    T: ArgWithDisplay<'b, 'c> + DispOrder,
+{
+    fn as_base(&self) -> &ArgWithDisplay<'b, 'c> {
+        self
+    }
+}
+
+fn as_arg_trait<'a, 'b, T: ArgWithOrder<'a, 'b>>(x: &T) -> &ArgWithOrder<'a, 'b> {
+    x
+}
+
+impl<'b, 'c> DispOrder for App<'b, 'c> {
+    fn disp_ord(&self) -> usize {
+        999
+    }
+}
+
+macro_rules! color {
+    ($_self:ident, $s:expr, $c:ident) => {
+        if $_self.color {
+            write!($_self.writer, "{}", $_self.cizer.$c($s))
+        } else {
+            write!($_self.writer, "{}", $s)
+        }
+    };
+    ($_self:ident, $fmt_s:expr, $v:expr, $c:ident) => {
+        if $_self.color {
+            write!($_self.writer, "{}", $_self.cizer.$c(format!($fmt_s, $v)))
+        } else {
+            write!($_self.writer, $fmt_s, $v)
+        }
+    };
+}
+
+/// `clap` Help Writer.
+///
+/// Wraps a writer stream providing different methods to generate help for `clap` objects.
+pub struct Help<'a> {
+    writer: &'a mut Write,
+    next_line_help: bool,
+    hide_pv: bool,
+    term_w: usize,
+    color: bool,
+    cizer: Colorizer,
+    longest: usize,
+    force_next_line: bool,
+    use_long: bool,
+}
+
+// Public Functions
+impl<'a> Help<'a> {
+    /// Create a new `Help` instance.
+    #[cfg_attr(feature = "cargo-clippy", allow(too_many_arguments))]
+    pub fn new(
+        w: &'a mut Write,
+        next_line_help: bool,
+        hide_pv: bool,
+        color: bool,
+        cizer: Colorizer,
+        term_w: Option<usize>,
+        max_w: Option<usize>,
+        use_long: bool,
+    ) -> Self {
+        debugln!("Help::new;");
+        Help {
+            writer: w,
+            next_line_help: next_line_help,
+            hide_pv: hide_pv,
+            term_w: match term_w {
+                Some(width) => if width == 0 {
+                    usize::MAX
+                } else {
+                    width
+                },
+                None => cmp::min(
+                    term_size::dimensions().map_or(120, |(w, _)| w),
+                    match max_w {
+                        None | Some(0) => usize::MAX,
+                        Some(mw) => mw,
+                    },
+                ),
+            },
+            color: color,
+            cizer: cizer,
+            longest: 0,
+            force_next_line: false,
+            use_long: use_long,
+        }
+    }
+
+    /// Reads help settings from an App
+    /// and write its help to the wrapped stream.
+    pub fn write_app_help(w: &'a mut Write, app: &App, use_long: bool) -> ClapResult<()> {
+        debugln!("Help::write_app_help;");
+        Self::write_parser_help(w, &app.p, use_long)
+    }
+
+    /// Reads help settings from a Parser
+    /// and write its help to the wrapped stream.
+    pub fn write_parser_help(w: &'a mut Write, parser: &Parser, use_long: bool) -> ClapResult<()> {
+        debugln!("Help::write_parser_help;");
+        Self::_write_parser_help(w, parser, false, use_long)
+    }
+
+    /// Reads help settings from a Parser
+    /// and write its help to the wrapped stream which will be stderr. This method prevents
+    /// formatting when required.
+    pub fn write_parser_help_to_stderr(w: &'a mut Write, parser: &Parser) -> ClapResult<()> {
+        debugln!("Help::write_parser_help;");
+        Self::_write_parser_help(w, parser, true, false)
+    }
+
+    #[doc(hidden)]
+    pub fn _write_parser_help(
+        w: &'a mut Write,
+        parser: &Parser,
+        stderr: bool,
+        use_long: bool,
+    ) -> ClapResult<()> {
+        debugln!("Help::write_parser_help;");
+        let nlh = parser.is_set(AppSettings::NextLineHelp);
+        let hide_v = parser.is_set(AppSettings::HidePossibleValuesInHelp);
+        let color = parser.is_set(AppSettings::ColoredHelp);
+        let cizer = Colorizer::new(ColorizerOption {
+            use_stderr: stderr,
+            when: parser.color(),
+        });
+        Self::new(
+            w,
+            nlh,
+            hide_v,
+            color,
+            cizer,
+            parser.meta.term_w,
+            parser.meta.max_w,
+            use_long,
+        ).write_help(parser)
+    }
+
+    /// Writes the parser help to the wrapped stream.
+    pub fn write_help(&mut self, parser: &Parser) -> ClapResult<()> {
+        debugln!("Help::write_help;");
+        if let Some(h) = parser.meta.help_str {
+            write!(self.writer, "{}", h).map_err(Error::from)?;
+        } else if let Some(tmpl) = parser.meta.template {
+            self.write_templated_help(parser, tmpl)?;
+        } else {
+            self.write_default_help(parser)?;
+        }
+        Ok(())
+    }
+}
+
+// Methods to write AnyArg help.
+impl<'a> Help<'a> {
+    /// Writes help for each argument in the order they were declared to the wrapped stream.
+    fn write_args_unsorted<'b: 'd, 'c: 'd, 'd, I: 'd>(&mut self, args: I) -> io::Result<()>
+    where
+        I: Iterator<Item = &'d ArgWithOrder<'b, 'c>>,
+    {
+        debugln!("Help::write_args_unsorted;");
+        // The shortest an arg can legally be is 2 (i.e. '-x')
+        self.longest = 2;
+        let mut arg_v = Vec::with_capacity(10);
+        let use_long = self.use_long;
+        for arg in args.filter(|arg| should_show_arg(use_long, *arg)) {
+            if arg.longest_filter() {
+                self.longest = cmp::max(self.longest, str_width(arg.to_string().as_str()));
+            }
+            arg_v.push(arg)
+        }
+        let mut first = true;
+        for arg in arg_v {
+            if first {
+                first = false;
+            } else {
+                self.writer.write_all(b"\n")?;
+            }
+            self.write_arg(arg.as_base())?;
+        }
+        Ok(())
+    }
+
+    /// Sorts arguments by length and display order and write their help to the wrapped stream.
+    fn write_args<'b: 'd, 'c: 'd, 'd, I: 'd>(&mut self, args: I) -> io::Result<()>
+    where
+        I: Iterator<Item = &'d ArgWithOrder<'b, 'c>>,
+    {
+        debugln!("Help::write_args;");
+        // The shortest an arg can legally be is 2 (i.e. '-x')
+        self.longest = 2;
+        let mut ord_m = VecMap::new();
+        let use_long = self.use_long;
+        // Determine the longest
+        for arg in args.filter(|arg| {
+            // If it's NextLineHelp, but we don't care to compute how long because it may be
+            // NextLineHelp on purpose *because* it's so long and would throw off all other
+            // args alignment
+            should_show_arg(use_long, *arg)
+        }) {
+            if arg.longest_filter() {
+                debugln!("Help::write_args: Current Longest...{}", self.longest);
+                self.longest = cmp::max(self.longest, str_width(arg.to_string().as_str()));
+                debugln!("Help::write_args: New Longest...{}", self.longest);
+            }
+            let btm = ord_m.entry(arg.disp_ord()).or_insert(BTreeMap::new());
+            btm.insert(arg.name(), arg);
+        }
+        let mut first = true;
+        for btm in ord_m.values() {
+            for arg in btm.values() {
+                if first {
+                    first = false;
+                } else {
+                    self.writer.write_all(b"\n")?;
+                }
+                self.write_arg(arg.as_base())?;
+            }
+        }
+        Ok(())
+    }
+
+    /// Writes help for an argument to the wrapped stream.
+    fn write_arg<'b, 'c>(&mut self, arg: &ArgWithDisplay<'b, 'c>) -> io::Result<()> {
+        debugln!("Help::write_arg;");
+        self.short(arg)?;
+        self.long(arg)?;
+        let spec_vals = self.val(arg)?;
+        self.help(arg, &*spec_vals)?;
+        Ok(())
+    }
+
+    /// Writes argument's short command to the wrapped stream.
+    fn short<'b, 'c>(&mut self, arg: &ArgWithDisplay<'b, 'c>) -> io::Result<()> {
+        debugln!("Help::short;");
+        write!(self.writer, "{}", TAB)?;
+        if let Some(s) = arg.short() {
+            color!(self, "-{}", s, good)
+        } else if arg.has_switch() {
+            write!(self.writer, "{}", TAB)
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Writes argument's long command to the wrapped stream.
+    fn long<'b, 'c>(&mut self, arg: &ArgWithDisplay<'b, 'c>) -> io::Result<()> {
+        debugln!("Help::long;");
+        if !arg.has_switch() {
+            return Ok(());
+        }
+        if arg.takes_value() {
+            if let Some(l) = arg.long() {
+                if arg.short().is_some() {
+                    write!(self.writer, ", ")?;
+                }
+                color!(self, "--{}", l, good)?
+            }
+
+            let sep = if arg.is_set(ArgSettings::RequireEquals) {
+                "="
+            } else {
+                " "
+            };
+            write!(self.writer, "{}", sep)?;
+        } else if let Some(l) = arg.long() {
+            if arg.short().is_some() {
+                write!(self.writer, ", ")?;
+            }
+            color!(self, "--{}", l, good)?;
+        }
+        Ok(())
+    }
+
+    /// Writes argument's possible values to the wrapped stream.
+    fn val<'b, 'c>(&mut self, arg: &ArgWithDisplay<'b, 'c>) -> Result<String, io::Error> {
+        debugln!("Help::val: arg={}", arg);
+        if arg.takes_value() {
+            let delim = if arg.is_set(ArgSettings::RequireDelimiter) {
+                arg.val_delim().expect(INTERNAL_ERROR_MSG)
+            } else {
+                ' '
+            };
+            if let Some(vec) = arg.val_names() {
+                let mut it = vec.iter().peekable();
+                while let Some((_, val)) = it.next() {
+                    color!(self, "<{}>", val, good)?;
+                    if it.peek().is_some() {
+                        write!(self.writer, "{}", delim)?;
+                    }
+                }
+                let num = vec.len();
+                if arg.is_set(ArgSettings::Multiple) && num == 1 {
+                    color!(self, "...", good)?;
+                }
+            } else if let Some(num) = arg.num_vals() {
+                let mut it = (0..num).peekable();
+                while let Some(_) = it.next() {
+                    color!(self, "<{}>", arg.name(), good)?;
+                    if it.peek().is_some() {
+                        write!(self.writer, "{}", delim)?;
+                    }
+                }
+                if arg.is_set(ArgSettings::Multiple) && num == 1 {
+                    color!(self, "...", good)?;
+                }
+            } else if arg.has_switch() {
+                color!(self, "<{}>", arg.name(), good)?;
+                if arg.is_set(ArgSettings::Multiple) {
+                    color!(self, "...", good)?;
+                }
+            } else {
+                color!(self, "{}", arg, good)?;
+            }
+        }
+
+        let spec_vals = self.spec_vals(arg);
+        let h = arg.help().unwrap_or("");
+        let h_w = str_width(h) + str_width(&*spec_vals);
+        let nlh = self.next_line_help || arg.is_set(ArgSettings::NextLineHelp);
+        let taken = self.longest + 12;
+        self.force_next_line = !nlh && self.term_w >= taken
+            && (taken as f32 / self.term_w as f32) > 0.40
+            && h_w > (self.term_w - taken);
+
+        debug!("Help::val: Has switch...");
+        if arg.has_switch() {
+            sdebugln!("Yes");
+            debugln!("Help::val: force_next_line...{:?}", self.force_next_line);
+            debugln!("Help::val: nlh...{:?}", nlh);
+            debugln!("Help::val: taken...{}", taken);
+            debugln!(
+                "Help::val: help_width > (width - taken)...{} > ({} - {})",
+                h_w,
+                self.term_w,
+                taken
+            );
+            debugln!("Help::val: longest...{}", self.longest);
+            debug!("Help::val: next_line...");
+            if !(nlh || self.force_next_line) {
+                sdebugln!("No");
+                let self_len = str_width(arg.to_string().as_str());
+                // subtract ourself
+                let mut spcs = self.longest - self_len;
+                // Since we're writing spaces from the tab point we first need to know if we
+                // had a long and short, or just short
+                if arg.long().is_some() {
+                    // Only account 4 after the val
+                    spcs += 4;
+                } else {
+                    // Only account for ', --' + 4 after the val
+                    spcs += 8;
+                }
+
+                write_nspaces!(self.writer, spcs);
+            } else {
+                sdebugln!("Yes");
+            }
+        } else if !(nlh || self.force_next_line) {
+            sdebugln!("No, and not next_line");
+            write_nspaces!(
+                self.writer,
+                self.longest + 4 - (str_width(arg.to_string().as_str()))
+            );
+        } else {
+            sdebugln!("No");
+        }
+        Ok(spec_vals)
+    }
+
+    fn write_before_after_help(&mut self, h: &str) -> io::Result<()> {
+        debugln!("Help::write_before_after_help;");
+        let mut help = String::from(h);
+        // determine if our help fits or needs to wrap
+        debugln!(
+            "Help::write_before_after_help: Term width...{}",
+            self.term_w
+        );
+        let too_long = str_width(h) >= self.term_w;
+
+        debug!("Help::write_before_after_help: Too long...");
+        if too_long || h.contains("{n}") {
+            sdebugln!("Yes");
+            debugln!("Help::write_before_after_help: help: {}", help);
+            debugln!(
+                "Help::write_before_after_help: help width: {}",
+                str_width(&*help)
+            );
+            // Determine how many newlines we need to insert
+            debugln!(
+                "Help::write_before_after_help: Usable space: {}",
+                self.term_w
+            );
+            help = wrap_help(&help.replace("{n}", "\n"), self.term_w);
+        } else {
+            sdebugln!("No");
+        }
+        write!(self.writer, "{}", help)?;
+        Ok(())
+    }
+
+    /// Writes argument's help to the wrapped stream.
+    fn help<'b, 'c>(&mut self, arg: &ArgWithDisplay<'b, 'c>, spec_vals: &str) -> io::Result<()> {
+        debugln!("Help::help;");
+        let h = if self.use_long && arg.name() != "" {
+            arg.long_help().unwrap_or_else(|| arg.help().unwrap_or(""))
+        } else {
+            arg.help().unwrap_or_else(|| arg.long_help().unwrap_or(""))
+        };
+        let mut help = String::from(h) + spec_vals;
+        let nlh = self.next_line_help || arg.is_set(ArgSettings::NextLineHelp) || (self.use_long && arg.name() != "");
+        debugln!("Help::help: Next Line...{:?}", nlh);
+
+        let spcs = if nlh || self.force_next_line {
+            12 // "tab" * 3
+        } else {
+            self.longest + 12
+        };
+
+        let too_long = spcs + str_width(h) + str_width(&*spec_vals) >= self.term_w;
+
+        // Is help on next line, if so then indent
+        if nlh || self.force_next_line {
+            write!(self.writer, "\n{}{}{}", TAB, TAB, TAB)?;
+        }
+
+        debug!("Help::help: Too long...");
+        if too_long && spcs <= self.term_w || h.contains("{n}") {
+            sdebugln!("Yes");
+            debugln!("Help::help: help...{}", help);
+            debugln!("Help::help: help width...{}", str_width(&*help));
+            // Determine how many newlines we need to insert
+            let avail_chars = self.term_w - spcs;
+            debugln!("Help::help: Usable space...{}", avail_chars);
+            help = wrap_help(&help.replace("{n}", "\n"), avail_chars);
+        } else {
+            sdebugln!("No");
+        }
+        if let Some(part) = help.lines().next() {
+            write!(self.writer, "{}", part)?;
+        }
+        for part in help.lines().skip(1) {
+            write!(self.writer, "\n")?;
+            if nlh || self.force_next_line {
+                write!(self.writer, "{}{}{}", TAB, TAB, TAB)?;
+            } else if arg.has_switch() {
+                write_nspaces!(self.writer, self.longest + 12);
+            } else {
+                write_nspaces!(self.writer, self.longest + 8);
+            }
+            write!(self.writer, "{}", part)?;
+        }
+        if !help.contains('\n') && (nlh || self.force_next_line) {
+            write!(self.writer, "\n")?;
+        }
+        Ok(())
+    }
+
+    fn spec_vals(&self, a: &ArgWithDisplay) -> String {
+        debugln!("Help::spec_vals: a={}", a);
+        let mut spec_vals = vec![];
+        if let Some(ref env) = a.env() {
+            debugln!(
+                "Help::spec_vals: Found environment variable...[{:?}:{:?}]",
+                env.0,
+                env.1
+            );
+            let env_val = if !a.is_set(ArgSettings::HideEnvValues) {
+                format!(
+                    "={}",
+                    env.1.map_or(Cow::Borrowed(""), |val| val.to_string_lossy())
+                )
+            } else {
+                String::new()
+            };
+            let env_info = format!(" [env: {}{}]", env.0.to_string_lossy(), env_val);
+            spec_vals.push(env_info);
+        }
+        if !a.is_set(ArgSettings::HideDefaultValue) {
+            if let Some(pv) = a.default_val() {
+                debugln!("Help::spec_vals: Found default value...[{:?}]", pv);
+                spec_vals.push(format!(
+                    " [default: {}]",
+                    if self.color {
+                        self.cizer.good(pv.to_string_lossy())
+                    } else {
+                        Format::None(pv.to_string_lossy())
+                    }
+                ));
+            }
+        }
+        if let Some(ref aliases) = a.aliases() {
+            debugln!("Help::spec_vals: Found aliases...{:?}", aliases);
+            spec_vals.push(format!(
+                " [aliases: {}]",
+                if self.color {
+                    aliases
+                        .iter()
+                        .map(|v| format!("{}", self.cizer.good(v)))
+                        .collect::<Vec<_>>()
+                        .join(", ")
+                } else {
+                    aliases.join(", ")
+                }
+            ));
+        }
+        if !self.hide_pv && !a.is_set(ArgSettings::HidePossibleValues) {
+            if let Some(pv) = a.possible_vals() {
+                debugln!("Help::spec_vals: Found possible vals...{:?}", pv);
+                spec_vals.push(if self.color {
+                    format!(
+                        " [possible values: {}]",
+                        pv.iter()
+                            .map(|v| format!("{}", self.cizer.good(v)))
+                            .collect::<Vec<_>>()
+                            .join(", ")
+                    )
+                } else {
+                    format!(" [possible values: {}]", pv.join(", "))
+                });
+            }
+        }
+        spec_vals.join(" ")
+    }
+}
+
+fn should_show_arg(use_long: bool, arg: &ArgWithOrder) -> bool {
+    if arg.is_set(ArgSettings::Hidden) {
+        return false;
+    }
+
+    (!arg.is_set(ArgSettings::HiddenLongHelp) && use_long)
+        || (!arg.is_set(ArgSettings::HiddenShortHelp) && !use_long)
+        || arg.is_set(ArgSettings::NextLineHelp)
+}
+
+// Methods to write Parser help.
+impl<'a> Help<'a> {
+    /// Writes help for all arguments (options, flags, args, subcommands)
+    /// including titles of a Parser Object to the wrapped stream.
+    #[cfg_attr(feature = "lints", allow(useless_let_if_seq))]
+    #[cfg_attr(feature = "cargo-clippy", allow(useless_let_if_seq))]
+    pub fn write_all_args(&mut self, parser: &Parser) -> ClapResult<()> {
+        debugln!("Help::write_all_args;");
+        let flags = parser.has_flags();
+        let pos = parser
+            .positionals()
+            .filter(|arg| !arg.is_set(ArgSettings::Hidden))
+            .count() > 0;
+        let opts = parser.has_opts();
+        let subcmds = parser.has_visible_subcommands();
+
+        let unified_help = parser.is_set(AppSettings::UnifiedHelpMessage);
+
+        let mut first = true;
+
+        if unified_help && (flags || opts) {
+            let opts_flags = parser
+                .flags()
+                .map(as_arg_trait)
+                .chain(parser.opts().map(as_arg_trait));
+            color!(self, "OPTIONS:\n", warning)?;
+            self.write_args(opts_flags)?;
+            first = false;
+        } else {
+            if flags {
+                color!(self, "FLAGS:\n", warning)?;
+                self.write_args(parser.flags().map(as_arg_trait))?;
+                first = false;
+            }
+            if opts {
+                if !first {
+                    self.writer.write_all(b"\n\n")?;
+                }
+                color!(self, "OPTIONS:\n", warning)?;
+                self.write_args(parser.opts().map(as_arg_trait))?;
+                first = false;
+            }
+        }
+
+        if pos {
+            if !first {
+                self.writer.write_all(b"\n\n")?;
+            }
+            color!(self, "ARGS:\n", warning)?;
+            self.write_args_unsorted(parser.positionals().map(as_arg_trait))?;
+            first = false;
+        }
+
+        if subcmds {
+            if !first {
+                self.writer.write_all(b"\n\n")?;
+            }
+            color!(self, "SUBCOMMANDS:\n", warning)?;
+            self.write_subcommands(parser)?;
+        }
+
+        Ok(())
+    }
+
+    /// Writes help for subcommands of a Parser Object to the wrapped stream.
+    fn write_subcommands(&mut self, parser: &Parser) -> io::Result<()> {
+        debugln!("Help::write_subcommands;");
+        // The shortest an arg can legally be is 2 (i.e. '-x')
+        self.longest = 2;
+        let mut ord_m = VecMap::new();
+        for sc in parser
+            .subcommands
+            .iter()
+            .filter(|s| !s.p.is_set(AppSettings::Hidden))
+        {
+            let btm = ord_m.entry(sc.p.meta.disp_ord).or_insert(BTreeMap::new());
+            self.longest = cmp::max(self.longest, str_width(sc.p.meta.name.as_str()));
+            //self.longest = cmp::max(self.longest, sc.p.meta.name.len());
+            btm.insert(sc.p.meta.name.clone(), sc.clone());
+        }
+
+        let mut first = true;
+        for btm in ord_m.values() {
+            for sc in btm.values() {
+                if first {
+                    first = false;
+                } else {
+                    self.writer.write_all(b"\n")?;
+                }
+                self.write_arg(sc)?;
+            }
+        }
+        Ok(())
+    }
+
+    /// Writes version of a Parser Object to the wrapped stream.
+    fn write_version(&mut self, parser: &Parser) -> io::Result<()> {
+        debugln!("Help::write_version;");
+        write!(self.writer, "{}", parser.meta.version.unwrap_or(""))?;
+        Ok(())
+    }
+
+    /// Writes binary name of a Parser Object to the wrapped stream.
+    fn write_bin_name(&mut self, parser: &Parser) -> io::Result<()> {
+        debugln!("Help::write_bin_name;");
+        macro_rules! write_name {
+            () => {{
+                let mut name = parser.meta.name.clone();
+                name = name.replace("{n}", "\n");
+                color!(self, wrap_help(&name, self.term_w), good)?;
+            }};
+        }
+        if let Some(bn) = parser.meta.bin_name.as_ref() {
+            if bn.contains(' ') {
+                // Incase we're dealing with subcommands i.e. git mv is translated to git-mv
+                color!(self, bn.replace(" ", "-"), good)?
+            } else {
+                write_name!();
+            }
+        } else {
+            write_name!();
+        }
+        Ok(())
+    }
+
+    /// Writes default help for a Parser Object to the wrapped stream.
+    pub fn write_default_help(&mut self, parser: &Parser) -> ClapResult<()> {
+        debugln!("Help::write_default_help;");
+        if let Some(h) = parser.meta.pre_help {
+            self.write_before_after_help(h)?;
+            self.writer.write_all(b"\n\n")?;
+        }
+
+        macro_rules! write_thing {
+            ($thing:expr) => {{
+                let mut owned_thing = $thing.to_owned();
+                owned_thing = owned_thing.replace("{n}", "\n");
+                write!(self.writer, "{}\n", wrap_help(&owned_thing, self.term_w))?
+            }};
+        }
+        // Print the version
+        self.write_bin_name(parser)?;
+        self.writer.write_all(b" ")?;
+        self.write_version(parser)?;
+        self.writer.write_all(b"\n")?;
+        if let Some(author) = parser.meta.author {
+            write_thing!(author)
+        }
+        // if self.use_long {
+        //     if let Some(about) = parser.meta.long_about {
+        //         debugln!("Help::write_default_help: writing long about");
+        //         write_thing!(about)
+        //     } else if let Some(about) = parser.meta.about {
+        //         debugln!("Help::write_default_help: writing about");
+        //         write_thing!(about)
+        //     }
+        // } else
+        if let Some(about) = parser.meta.long_about {
+            debugln!("Help::write_default_help: writing long about");
+            write_thing!(about)
+        } else if let Some(about) = parser.meta.about {
+            debugln!("Help::write_default_help: writing about");
+            write_thing!(about)
+        }
+
+        color!(self, "\nUSAGE:", warning)?;
+        write!(
+            self.writer,
+            "\n{}{}\n\n",
+            TAB,
+            usage::create_usage_no_title(parser, &[])
+        )?;
+
+        let flags = parser.has_flags();
+        let pos = parser.has_positionals();
+        let opts = parser.has_opts();
+        let subcmds = parser.has_subcommands();
+
+        if flags || opts || pos || subcmds {
+            self.write_all_args(parser)?;
+        }
+
+        if let Some(h) = parser.meta.more_help {
+            if flags || opts || pos || subcmds {
+                self.writer.write_all(b"\n\n")?;
+            }
+            self.write_before_after_help(h)?;
+        }
+
+        self.writer.flush().map_err(Error::from)
+    }
+}
+
+/// Possible results for a copying function that stops when a given
+/// byte was found.
+enum CopyUntilResult {
+    DelimiterFound(usize),
+    DelimiterNotFound(usize),
+    ReaderEmpty,
+    ReadError(io::Error),
+    WriteError(io::Error),
+}
+
+/// Copies the contents of a reader into a writer until a delimiter byte is found.
+/// On success, the total number of bytes that were
+/// copied from reader to writer is returned.
+fn copy_until<R: Read, W: Write>(r: &mut R, w: &mut W, delimiter_byte: u8) -> CopyUntilResult {
+    debugln!("copy_until;");
+
+    let mut count = 0;
+    for wb in r.bytes() {
+        match wb {
+            Ok(b) => {
+                if b == delimiter_byte {
+                    return CopyUntilResult::DelimiterFound(count);
+                }
+                match w.write(&[b]) {
+                    Ok(c) => count += c,
+                    Err(e) => return CopyUntilResult::WriteError(e),
+                }
+            }
+            Err(e) => return CopyUntilResult::ReadError(e),
+        }
+    }
+    if count > 0 {
+        CopyUntilResult::DelimiterNotFound(count)
+    } else {
+        CopyUntilResult::ReaderEmpty
+    }
+}
+
+/// Copies the contents of a reader into a writer until a {tag} is found,
+/// copying the tag content to a buffer and returning its size.
+/// In addition to errors, there are three possible outputs:
+///   - `None`: The reader was consumed.
+///   - `Some(Ok(0))`: No tag was captured but the reader still contains data.
+///   - `Some(Ok(length>0))`: a tag with `length` was captured to the `tag_buffer`.
+fn copy_and_capture<R: Read, W: Write>(
+    r: &mut R,
+    w: &mut W,
+    tag_buffer: &mut Cursor<Vec<u8>>,
+) -> Option<io::Result<usize>> {
+    use self::CopyUntilResult::*;
+    debugln!("copy_and_capture;");
+
+    // Find the opening byte.
+    match copy_until(r, w, b'{') {
+        // The end of the reader was reached without finding the opening tag.
+        // (either with or without having copied data to the writer)
+        // Return None indicating that we are done.
+        ReaderEmpty | DelimiterNotFound(_) => None,
+
+        // Something went wrong.
+        ReadError(e) | WriteError(e) => Some(Err(e)),
+
+        // The opening byte was found.
+        // (either with or without having copied data to the writer)
+        DelimiterFound(_) => {
+            // Lets reset the buffer first and find out how long it is.
+            tag_buffer.set_position(0);
+            let buffer_size = tag_buffer.get_ref().len();
+
+            // Find the closing byte,limiting the reader to the length of the buffer.
+            let mut rb = r.take(buffer_size as u64);
+            match copy_until(&mut rb, tag_buffer, b'}') {
+                // We were already at the end of the reader.
+                // Return None indicating that we are done.
+                ReaderEmpty => None,
+
+                // The closing tag was found.
+                // Return the tag_length.
+                DelimiterFound(tag_length) => Some(Ok(tag_length)),
+
+                // The end of the reader was found without finding the closing tag.
+                // Write the opening byte and captured text to the writer.
+                // Return 0 indicating that nothing was captured but the reader still contains data.
+                DelimiterNotFound(not_tag_length) => match w.write(b"{") {
+                    Err(e) => Some(Err(e)),
+                    _ => match w.write(&tag_buffer.get_ref()[0..not_tag_length]) {
+                        Err(e) => Some(Err(e)),
+                        _ => Some(Ok(0)),
+                    },
+                },
+
+                ReadError(e) | WriteError(e) => Some(Err(e)),
+            }
+        }
+    }
+}
+
+// Methods to write Parser help using templates.
+impl<'a> Help<'a> {
+    /// Write help to stream for the parser in the format defined by the template.
+    ///
+    /// Tags arg given inside curly brackets:
+    /// Valid tags are:
+    ///     * `{bin}`         - Binary name.
+    ///     * `{version}`     - Version number.
+    ///     * `{author}`      - Author information.
+    ///     * `{usage}`       - Automatically generated or given usage string.
+    ///     * `{all-args}`    - Help for all arguments (options, flags, positionals arguments,
+    ///                         and subcommands) including titles.
+    ///     * `{unified}`     - Unified help for options and flags.
+    ///     * `{flags}`       - Help for flags.
+    ///     * `{options}`     - Help for options.
+    ///     * `{positionals}` - Help for positionals arguments.
+    ///     * `{subcommands}` - Help for subcommands.
+    ///     * `{after-help}`  - Info to be displayed after the help message.
+    ///     * `{before-help}` - Info to be displayed before the help message.
+    ///
+    /// The template system is, on purpose, very simple. Therefore the tags have to written
+    /// in the lowercase and without spacing.
+    fn write_templated_help(&mut self, parser: &Parser, template: &str) -> ClapResult<()> {
+        debugln!("Help::write_templated_help;");
+        let mut tmplr = Cursor::new(&template);
+        let mut tag_buf = Cursor::new(vec![0u8; 15]);
+
+        // The strategy is to copy the template from the reader to wrapped stream
+        // until a tag is found. Depending on its value, the appropriate content is copied
+        // to the wrapped stream.
+        // The copy from template is then resumed, repeating this sequence until reading
+        // the complete template.
+
+        loop {
+            let tag_length = match copy_and_capture(&mut tmplr, &mut self.writer, &mut tag_buf) {
+                None => return Ok(()),
+                Some(Err(e)) => return Err(Error::from(e)),
+                Some(Ok(val)) if val > 0 => val,
+                _ => continue,
+            };
+
+            debugln!("Help::write_template_help:iter: tag_buf={};", unsafe {
+                String::from_utf8_unchecked(
+                    tag_buf.get_ref()[0..tag_length]
+                        .iter()
+                        .map(|&i| i)
+                        .collect::<Vec<_>>(),
+                )
+            });
+            match &tag_buf.get_ref()[0..tag_length] {
+                b"?" => {
+                    self.writer.write_all(b"Could not decode tag name")?;
+                }
+                b"bin" => {
+                    self.write_bin_name(parser)?;
+                }
+                b"version" => {
+                    write!(
+                        self.writer,
+                        "{}",
+                        parser.meta.version.unwrap_or("unknown version")
+                    )?;
+                }
+                b"author" => {
+                    write!(
+                        self.writer,
+                        "{}",
+                        parser.meta.author.unwrap_or("unknown author")
+                    )?;
+                }
+                b"about" => {
+                    write!(
+                        self.writer,
+                        "{}",
+                        parser.meta.about.unwrap_or("unknown about")
+                    )?;
+                }
+                b"long-about" => {
+                    write!(
+                        self.writer,
+                        "{}",
+                        parser.meta.long_about.unwrap_or("unknown about")
+                    )?;
+                }
+                b"usage" => {
+                    write!(self.writer, "{}", usage::create_usage_no_title(parser, &[]))?;
+                }
+                b"all-args" => {
+                    self.write_all_args(parser)?;
+                }
+                b"unified" => {
+                    let opts_flags = parser
+                        .flags()
+                        .map(as_arg_trait)
+                        .chain(parser.opts().map(as_arg_trait));
+                    self.write_args(opts_flags)?;
+                }
+                b"flags" => {
+                    self.write_args(parser.flags().map(as_arg_trait))?;
+                }
+                b"options" => {
+                    self.write_args(parser.opts().map(as_arg_trait))?;
+                }
+                b"positionals" => {
+                    self.write_args(parser.positionals().map(as_arg_trait))?;
+                }
+                b"subcommands" => {
+                    self.write_subcommands(parser)?;
+                }
+                b"after-help" => {
+                    write!(
+                        self.writer,
+                        "{}",
+                        parser.meta.more_help.unwrap_or("unknown after-help")
+                    )?;
+                }
+                b"before-help" => {
+                    write!(
+                        self.writer,
+                        "{}",
+                        parser.meta.pre_help.unwrap_or("unknown before-help")
+                    )?;
+                }
+                // Unknown tag, write it back.
+                r => {
+                    self.writer.write_all(b"{")?;
+                    self.writer.write_all(r)?;
+                    self.writer.write_all(b"}")?;
+                }
+            }
+        }
+    }
+}
+
+fn wrap_help(help: &str, avail_chars: usize) -> String {
+    let wrapper = textwrap::Wrapper::new(avail_chars).break_words(false);
+    help.lines()
+        .map(|line| wrapper.fill(line))
+        .collect::<Vec<String>>()
+        .join("\n")
+}
+
+#[cfg(test)]
+mod test {
+    use super::wrap_help;
+
+    #[test]
+    fn wrap_help_last_word() {
+        let help = String::from("foo bar baz");
+        assert_eq!(wrap_help(&help, 5), "foo\nbar\nbaz");
+    }
+}
diff --git a/src/app/meta.rs b/src/app/meta.rs
new file mode 100644
index 0000000..c7f128f
--- /dev/null
+++ b/src/app/meta.rs
@@ -0,0 +1,33 @@
+#[doc(hidden)]
+#[allow(missing_debug_implementations)]
+#[derive(Default, Clone)]
+pub struct AppMeta<'b> {
+    pub name: String,
+    pub bin_name: Option<String>,
+    pub author: Option<&'b str>,
+    pub version: Option<&'b str>,
+    pub long_version: Option<&'b str>,
+    pub about: Option<&'b str>,
+    pub long_about: Option<&'b str>,
+    pub more_help: Option<&'b str>,
+    pub pre_help: Option<&'b str>,
+    pub aliases: Option<Vec<(&'b str, bool)>>, // (name, visible)
+    pub usage_str: Option<&'b str>,
+    pub usage: Option<String>,
+    pub help_str: Option<&'b str>,
+    pub disp_ord: usize,
+    pub term_w: Option<usize>,
+    pub max_w: Option<usize>,
+    pub template: Option<&'b str>,
+}
+
+impl<'b> AppMeta<'b> {
+    pub fn new() -> Self { Default::default() }
+    pub fn with_name(s: String) -> Self {
+        AppMeta {
+            name: s,
+            disp_ord: 999,
+            ..Default::default()
+        }
+    }
+}
diff --git a/src/app/mod.rs b/src/app/mod.rs
new file mode 100644
index 0000000..3a1a383
--- /dev/null
+++ b/src/app/mod.rs
@@ -0,0 +1,1839 @@
+mod settings;
+pub mod parser;
+mod meta;
+mod help;
+mod validator;
+mod usage;
+
+// Std
+use std::env;
+use std::ffi::{OsStr, OsString};
+use std::fmt;
+use std::io::{self, BufRead, BufWriter, Write};
+use std::path::Path;
+use std::process;
+use std::rc::Rc;
+use std::result::Result as StdResult;
+
+// Third Party
+#[cfg(feature = "yaml")]
+use yaml_rust::Yaml;
+
+// Internal
+use app::help::Help;
+use app::parser::Parser;
+use args::{AnyArg, Arg, ArgGroup, ArgMatcher, ArgMatches, ArgSettings};
+use errors::Result as ClapResult;
+pub use self::settings::AppSettings;
+use completions::Shell;
+use map::{self, VecMap};
+
+/// Used to create a representation of a command line program and all possible command line
+/// arguments. Application settings are set using the "builder pattern" with the
+/// [`App::get_matches`] family of methods being the terminal methods that starts the
+/// runtime-parsing process. These methods then return information about the user supplied
+/// arguments (or lack there of).
+///
+/// **NOTE:** There aren't any mandatory "options" that one must set. The "options" may
+/// also appear in any order (so long as one of the [`App::get_matches`] methods is the last method
+/// called).
+///
+/// # Examples
+///
+/// ```no_run
+/// # use clap::{App, Arg};
+/// let m = App::new("My Program")
+///     .author("Me, me@mail.com")
+///     .version("1.0.2")
+///     .about("Explains in brief what the program does")
+///     .arg(
+///         Arg::with_name("in_file").index(1)
+///     )
+///     .after_help("Longer explanation to appear after the options when \
+///                  displaying the help information from --help or -h")
+///     .get_matches();
+///
+/// // Your program logic starts here...
+/// ```
+/// [`App::get_matches`]: ./struct.App.html#method.get_matches
+#[allow(missing_debug_implementations)]
+pub struct App<'a, 'b>
+where
+    'a: 'b,
+{
+    #[doc(hidden)] pub p: Parser<'a, 'b>,
+}
+
+
+impl<'a, 'b> App<'a, 'b> {
+    /// Creates a new instance of an application requiring a name. The name may be, but doesn't
+    /// have to be same as the binary. The name will be displayed to the user when they request to
+    /// print version or help and usage information.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// let prog = App::new("My Program")
+    /// # ;
+    /// ```
+    pub fn new<S: Into<String>>(n: S) -> Self {
+        App {
+            p: Parser::with_name(n.into()),
+        }
+    }
+
+    /// Get the name of the app
+    pub fn get_name(&self) -> &str { &self.p.meta.name }
+
+    /// Get the name of the binary
+    pub fn get_bin_name(&self) -> Option<&str> { self.p.meta.bin_name.as_ref().map(|s| s.as_str()) }
+
+    /// Creates a new instance of an application requiring a name, but uses the [`crate_authors!`]
+    /// and [`crate_version!`] macros to fill in the [`App::author`] and [`App::version`] fields.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// let prog = App::with_defaults("My Program")
+    /// # ;
+    /// ```
+    /// [`crate_authors!`]: ./macro.crate_authors!.html
+    /// [`crate_version!`]: ./macro.crate_version!.html
+    /// [`App::author`]: ./struct.App.html#method.author
+    /// [`App::version`]: ./struct.App.html#method.author
+    #[deprecated(since="2.14.1", note="Can never work; use explicit App::author() and App::version() calls instead")]
+    pub fn with_defaults<S: Into<String>>(n: S) -> Self {
+        let mut a = App {
+            p: Parser::with_name(n.into()),
+        };
+        a.p.meta.author = Some("Kevin K. <kbknapp@gmail.com>");
+        a.p.meta.version = Some("2.19.2");
+        a
+    }
+
+    /// Creates a new instance of [`App`] from a .yml (YAML) file. A full example of supported YAML
+    /// objects can be found in [`examples/17_yaml.rs`] and [`examples/17_yaml.yml`]. One great use
+    /// for using YAML is when supporting multiple languages and dialects, as each language could
+    /// be a distinct YAML file and determined at compiletime via `cargo` "features" in your
+    /// `Cargo.toml`
+    ///
+    /// In order to use this function you must compile `clap` with the `features = ["yaml"]` in
+    /// your settings for the `[dependencies.clap]` table of your `Cargo.toml`
+    ///
+    /// **NOTE:** Due to how the YAML objects are built there is a convenience macro for loading
+    /// the YAML file at compile time (relative to the current file, like modules work). That YAML
+    /// object can then be passed to this function.
+    ///
+    /// # Panics
+    ///
+    /// The YAML file must be properly formatted or this function will [`panic!`]. A good way to
+    /// ensure this doesn't happen is to run your program with the `--help` switch. If this passes
+    /// without error, you needn't worry because the YAML is properly formatted.
+    ///
+    /// # Examples
+    ///
+    /// The following example shows how to load a properly formatted YAML file to build an instance
+    /// of an [`App`] struct.
+    ///
+    /// ```ignore
+    /// # #[macro_use]
+    /// # extern crate clap;
+    /// # use clap::App;
+    /// # fn main() {
+    /// let yml = load_yaml!("app.yml");
+    /// let app = App::from_yaml(yml);
+    ///
+    /// // continued logic goes here, such as `app.get_matches()` etc.
+    /// # }
+    /// ```
+    /// [`App`]: ./struct.App.html
+    /// [`examples/17_yaml.rs`]: https://github.com/clap-rs/clap/blob/master/examples/17_yaml.rs
+    /// [`examples/17_yaml.yml`]: https://github.com/clap-rs/clap/blob/master/examples/17_yaml.yml
+    /// [`panic!`]: https://doc.rust-lang.org/std/macro.panic!.html
+    #[cfg(feature = "yaml")]
+    pub fn from_yaml(yaml: &'a Yaml) -> App<'a, 'a> { App::from(yaml) }
+
+    /// Sets a string of author(s) that will be displayed to the user when they
+    /// request the help information with `--help` or `-h`.
+    ///
+    /// **Pro-tip:** Use `clap`s convenience macro [`crate_authors!`] to automatically set your
+    /// application's author(s) to the same thing as your crate at compile time. See the [`examples/`]
+    /// directory for more information
+    ///
+    /// See the [`examples/`]
+    /// directory for more information
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///      .author("Me, me@mymain.com")
+    /// # ;
+    /// ```
+    /// [`crate_authors!`]: ./macro.crate_authors!.html
+    /// [`examples/`]: https://github.com/clap-rs/clap/tree/master/examples
+    pub fn author<S: Into<&'b str>>(mut self, author: S) -> Self {
+        self.p.meta.author = Some(author.into());
+        self
+    }
+
+    /// Overrides the system-determined binary name. This should only be used when absolutely
+    /// necessary, such as when the binary name for your application is misleading, or perhaps
+    /// *not* how the user should invoke your program.
+    ///
+    /// **Pro-tip:** When building things such as third party `cargo` subcommands, this setting
+    /// **should** be used!
+    ///
+    /// **NOTE:** This command **should not** be used for [`SubCommand`]s.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("My Program")
+    ///      .bin_name("my_binary")
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    pub fn bin_name<S: Into<String>>(mut self, name: S) -> Self {
+        self.p.meta.bin_name = Some(name.into());
+        self
+    }
+
+    /// Sets a string describing what the program does. This will be displayed when displaying help
+    /// information with `-h`.
+    ///
+    /// **NOTE:** If only `about` is provided, and not [`App::long_about`] but the user requests
+    /// `--help` clap will still display the contents of `about` appropriately
+    ///
+    /// **NOTE:** Only [`App::about`] is used in completion script generation in order to be
+    /// concise
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .about("Does really amazing things to great people")
+    /// # ;
+    /// ```
+    /// [`App::long_about`]: ./struct.App.html#method.long_about
+    pub fn about<S: Into<&'b str>>(mut self, about: S) -> Self {
+        self.p.meta.about = Some(about.into());
+        self
+    }
+
+    /// Sets a string describing what the program does. This will be displayed when displaying help
+    /// information.
+    ///
+    /// **NOTE:** If only `long_about` is provided, and not [`App::about`] but the user requests
+    /// `-h` clap will still display the contents of `long_about` appropriately
+    ///
+    /// **NOTE:** Only [`App::about`] is used in completion script generation in order to be
+    /// concise
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .long_about(
+    /// "Does really amazing things to great people. Now let's talk a little
+    ///  more in depth about how this subcommand really works. It may take about
+    ///  a few lines of text, but that's ok!")
+    /// # ;
+    /// ```
+    /// [`App::about`]: ./struct.App.html#method.about
+    pub fn long_about<S: Into<&'b str>>(mut self, about: S) -> Self {
+        self.p.meta.long_about = Some(about.into());
+        self
+    }
+
+    /// Sets the program's name. This will be displayed when displaying help information.
+    ///
+    /// **Pro-top:** This function is particularly useful when configuring a program via
+    /// [`App::from_yaml`] in conjunction with the [`crate_name!`] macro to derive the program's
+    /// name from its `Cargo.toml`.
+    ///
+    /// # Examples
+    /// ```ignore
+    /// # #[macro_use]
+    /// # extern crate clap;
+    /// # use clap::App;
+    /// # fn main() {
+    /// let yml = load_yaml!("app.yml");
+    /// let app = App::from_yaml(yml)
+    ///     .name(crate_name!());
+    ///
+    /// // continued logic goes here, such as `app.get_matches()` etc.
+    /// # }
+    /// ```
+    ///
+    /// [`App::from_yaml`]: ./struct.App.html#method.from_yaml
+    /// [`crate_name!`]: ./macro.crate_name.html
+    pub fn name<S: Into<String>>(mut self, name: S) -> Self {
+        self.p.meta.name = name.into();
+        self
+    }
+
+    /// Adds additional help information to be displayed in addition to auto-generated help. This
+    /// information is displayed **after** the auto-generated help information. This is often used
+    /// to describe how to use the arguments, or caveats to be noted.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::App;
+    /// App::new("myprog")
+    ///     .after_help("Does really amazing things to great people...but be careful with -R")
+    /// # ;
+    /// ```
+    pub fn after_help<S: Into<&'b str>>(mut self, help: S) -> Self {
+        self.p.meta.more_help = Some(help.into());
+        self
+    }
+
+    /// Adds additional help information to be displayed in addition to auto-generated help. This
+    /// information is displayed **before** the auto-generated help information. This is often used
+    /// for header information.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::App;
+    /// App::new("myprog")
+    ///     .before_help("Some info I'd like to appear before the help info")
+    /// # ;
+    /// ```
+    pub fn before_help<S: Into<&'b str>>(mut self, help: S) -> Self {
+        self.p.meta.pre_help = Some(help.into());
+        self
+    }
+
+    /// Sets a string of the version number to be displayed when displaying version or help
+    /// information with `-V`.
+    ///
+    /// **NOTE:** If only `version` is provided, and not [`App::long_version`] but the user
+    /// requests `--version` clap will still display the contents of `version` appropriately
+    ///
+    /// **Pro-tip:** Use `clap`s convenience macro [`crate_version!`] to automatically set your
+    /// application's version to the same thing as your crate at compile time. See the [`examples/`]
+    /// directory for more information
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .version("v0.1.24")
+    /// # ;
+    /// ```
+    /// [`crate_version!`]: ./macro.crate_version!.html
+    /// [`examples/`]: https://github.com/clap-rs/clap/tree/master/examples
+    /// [`App::long_version`]: ./struct.App.html#method.long_version
+    pub fn version<S: Into<&'b str>>(mut self, ver: S) -> Self {
+        self.p.meta.version = Some(ver.into());
+        self
+    }
+
+    /// Sets a string of the version number to be displayed when displaying version or help
+    /// information with `--version`.
+    ///
+    /// **NOTE:** If only `long_version` is provided, and not [`App::version`] but the user
+    /// requests `-V` clap will still display the contents of `long_version` appropriately
+    ///
+    /// **Pro-tip:** Use `clap`s convenience macro [`crate_version!`] to automatically set your
+    /// application's version to the same thing as your crate at compile time. See the [`examples/`]
+    /// directory for more information
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .long_version(
+    /// "v0.1.24
+    ///  commit: abcdef89726d
+    ///  revision: 123
+    ///  release: 2
+    ///  binary: myprog")
+    /// # ;
+    /// ```
+    /// [`crate_version!`]: ./macro.crate_version!.html
+    /// [`examples/`]: https://github.com/clap-rs/clap/tree/master/examples
+    /// [`App::version`]: ./struct.App.html#method.version
+    pub fn long_version<S: Into<&'b str>>(mut self, ver: S) -> Self {
+        self.p.meta.long_version = Some(ver.into());
+        self
+    }
+
+    /// Sets a custom usage string to override the auto-generated usage string.
+    ///
+    /// This will be displayed to the user when errors are found in argument parsing, or when you
+    /// call [`ArgMatches::usage`]
+    ///
+    /// **CAUTION:** Using this setting disables `clap`s "context-aware" usage strings. After this
+    /// setting is set, this will be the only usage string displayed to the user!
+    ///
+    /// **NOTE:** You do not need to specify the "USAGE: \n\t" portion, as that will
+    /// still be applied by `clap`, you only need to specify the portion starting
+    /// with the binary name.
+    ///
+    /// **NOTE:** This will not replace the entire help message, *only* the portion
+    /// showing the usage.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .usage("myapp [-clDas] <some_file>")
+    /// # ;
+    /// ```
+    /// [`ArgMatches::usage`]: ./struct.ArgMatches.html#method.usage
+    pub fn usage<S: Into<&'b str>>(mut self, usage: S) -> Self {
+        self.p.meta.usage_str = Some(usage.into());
+        self
+    }
+
+    /// Sets a custom help message and overrides the auto-generated one. This should only be used
+    /// when the auto-generated message does not suffice.
+    ///
+    /// This will be displayed to the user when they use `--help` or `-h`
+    ///
+    /// **NOTE:** This replaces the **entire** help message, so nothing will be auto-generated.
+    ///
+    /// **NOTE:** This **only** replaces the help message for the current command, meaning if you
+    /// are using subcommands, those help messages will still be auto-generated unless you
+    /// specify a [`Arg::help`] for them as well.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myapp")
+    ///     .help("myapp v1.0\n\
+    ///            Does awesome things\n\
+    ///            (C) me@mail.com\n\n\
+    ///
+    ///            USAGE: myapp <opts> <command>\n\n\
+    ///
+    ///            Options:\n\
+    ///            -h, --help       Display this message\n\
+    ///            -V, --version    Display version info\n\
+    ///            -s <stuff>       Do something with stuff\n\
+    ///            -v               Be verbose\n\n\
+    ///
+    ///            Commmands:\n\
+    ///            help             Prints this message\n\
+    ///            work             Do some work")
+    /// # ;
+    /// ```
+    /// [`Arg::help`]: ./struct.Arg.html#method.help
+    pub fn help<S: Into<&'b str>>(mut self, help: S) -> Self {
+        self.p.meta.help_str = Some(help.into());
+        self
+    }
+
+    /// Sets the [`short`] for the auto-generated `help` argument.
+    ///
+    /// By default `clap` automatically assigns `h`, but this can be overridden if you have a
+    /// different argument which you'd prefer to use the `-h` short with. This can be done by
+    /// defining your own argument with a lowercase `h` as the [`short`].
+    ///
+    /// `clap` lazily generates these `help` arguments **after** you've defined any arguments of
+    /// your own.
+    ///
+    /// **NOTE:** Any leading `-` characters will be stripped, and only the first
+    /// non `-` character will be used as the [`short`] version
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .help_short("H") // Using an uppercase `H` instead of the default lowercase `h`
+    /// # ;
+    /// ```
+    /// [`short`]: ./struct.Arg.html#method.short
+    pub fn help_short<S: AsRef<str> + 'b>(mut self, s: S) -> Self {
+        self.p.help_short(s.as_ref());
+        self
+    }
+
+    /// Sets the [`short`] for the auto-generated `version` argument.
+    ///
+    /// By default `clap` automatically assigns `V`, but this can be overridden if you have a
+    /// different argument which you'd prefer to use the `-V` short with. This can be done by
+    /// defining your own argument with an uppercase `V` as the [`short`].
+    ///
+    /// `clap` lazily generates these `version` arguments **after** you've defined any arguments of
+    /// your own.
+    ///
+    /// **NOTE:** Any leading `-` characters will be stripped, and only the first
+    /// non `-` character will be used as the `short` version
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .version_short("v") // Using a lowercase `v` instead of the default capital `V`
+    /// # ;
+    /// ```
+    /// [`short`]: ./struct.Arg.html#method.short
+    pub fn version_short<S: AsRef<str>>(mut self, s: S) -> Self {
+        self.p.version_short(s.as_ref());
+        self
+    }
+
+    /// Sets the help text for the auto-generated `help` argument.
+    ///
+    /// By default `clap` sets this to `"Prints help information"`, but if you're using a
+    /// different convention for your help messages and would prefer a different phrasing you can
+    /// override it.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .help_message("Print help information") // Perhaps you want imperative help messages
+    ///
+    /// # ;
+    /// ```
+    pub fn help_message<S: Into<&'a str>>(mut self, s: S) -> Self {
+        self.p.help_message = Some(s.into());
+        self
+    }
+
+    /// Sets the help text for the auto-generated `version` argument.
+    ///
+    /// By default `clap` sets this to `"Prints version information"`, but if you're using a
+    /// different convention for your help messages and would prefer a different phrasing then you
+    /// can change it.
+    ///
+    /// # Examples
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .version_message("Print version information") // Perhaps you want imperative help messages
+    /// # ;
+    /// ```
+    pub fn version_message<S: Into<&'a str>>(mut self, s: S) -> Self {
+        self.p.version_message = Some(s.into());
+        self
+    }
+
+    /// Sets the help template to be used, overriding the default format.
+    ///
+    /// Tags arg given inside curly brackets.
+    ///
+    /// Valid tags are:
+    ///
+    ///   * `{bin}`         - Binary name.
+    ///   * `{version}`     - Version number.
+    ///   * `{author}`      - Author information.
+    ///   * `{about}`       - General description (from [`App::about`])
+    ///   * `{usage}`       - Automatically generated or given usage string.
+    ///   * `{all-args}`    - Help for all arguments (options, flags, positionals arguments,
+    ///                       and subcommands) including titles.
+    ///   * `{unified}`     - Unified help for options and flags. Note, you must *also* set
+    ///                       [`AppSettings::UnifiedHelpMessage`] to fully merge both options and
+    ///                       flags, otherwise the ordering is "best effort"
+    ///   * `{flags}`       - Help for flags.
+    ///   * `{options}`     - Help for options.
+    ///   * `{positionals}` - Help for positionals arguments.
+    ///   * `{subcommands}` - Help for subcommands.
+    ///   * `{after-help}`  - Help from [`App::after_help`]
+    ///   * `{before-help}`  - Help from [`App::before_help`]
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .version("1.0")
+    ///     .template("{bin} ({version}) - {usage}")
+    /// # ;
+    /// ```
+    /// **NOTE:** The template system is, on purpose, very simple. Therefore the tags have to be
+    /// written in lowercase and without spacing.
+    ///
+    /// [`App::about`]: ./struct.App.html#method.about
+    /// [`App::after_help`]: ./struct.App.html#method.after_help
+    /// [`App::before_help`]: ./struct.App.html#method.before_help
+    /// [`AppSettings::UnifiedHelpMessage`]: ./enum.AppSettings.html#variant.UnifiedHelpMessage
+    pub fn template<S: Into<&'b str>>(mut self, s: S) -> Self {
+        self.p.meta.template = Some(s.into());
+        self
+    }
+
+    /// Enables a single command, or [`SubCommand`], level settings.
+    ///
+    /// See [`AppSettings`] for a full list of possibilities and examples.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::SubcommandRequired)
+    ///     .setting(AppSettings::WaitOnError)
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`AppSettings`]: ./enum.AppSettings.html
+    pub fn setting(mut self, setting: AppSettings) -> Self {
+        self.p.set(setting);
+        self
+    }
+
+    /// Enables multiple command, or [`SubCommand`], level settings
+    ///
+    /// See [`AppSettings`] for a full list of possibilities and examples.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, AppSettings};
+    /// App::new("myprog")
+    ///     .settings(&[AppSettings::SubcommandRequired,
+    ///                  AppSettings::WaitOnError])
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`AppSettings`]: ./enum.AppSettings.html
+    pub fn settings(mut self, settings: &[AppSettings]) -> Self {
+        for s in settings {
+            self.p.set(*s);
+        }
+        self
+    }
+
+    /// Enables a single setting that is propagated down through all child [`SubCommand`]s.
+    ///
+    /// See [`AppSettings`] for a full list of possibilities and examples.
+    ///
+    /// **NOTE**: The setting is *only* propagated *down* and not up through parent commands.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, AppSettings};
+    /// App::new("myprog")
+    ///     .global_setting(AppSettings::SubcommandRequired)
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`AppSettings`]: ./enum.AppSettings.html
+    pub fn global_setting(mut self, setting: AppSettings) -> Self {
+        self.p.set(setting);
+        self.p.g_settings.set(setting);
+        self
+    }
+
+    /// Enables multiple settings which are propagated *down* through all child [`SubCommand`]s.
+    ///
+    /// See [`AppSettings`] for a full list of possibilities and examples.
+    ///
+    /// **NOTE**: The setting is *only* propagated *down* and not up through parent commands.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, AppSettings};
+    /// App::new("myprog")
+    ///     .global_settings(&[AppSettings::SubcommandRequired,
+    ///                  AppSettings::ColoredHelp])
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`AppSettings`]: ./enum.AppSettings.html
+    pub fn global_settings(mut self, settings: &[AppSettings]) -> Self {
+        for s in settings {
+            self.p.set(*s);
+            self.p.g_settings.set(*s)
+        }
+        self
+    }
+
+    /// Disables a single command, or [`SubCommand`], level setting.
+    ///
+    /// See [`AppSettings`] for a full list of possibilities and examples.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, AppSettings};
+    /// App::new("myprog")
+    ///     .unset_setting(AppSettings::ColorAuto)
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`AppSettings`]: ./enum.AppSettings.html
+    pub fn unset_setting(mut self, setting: AppSettings) -> Self {
+        self.p.unset(setting);
+        self
+    }
+
+    /// Disables multiple command, or [`SubCommand`], level settings.
+    ///
+    /// See [`AppSettings`] for a full list of possibilities and examples.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, AppSettings};
+    /// App::new("myprog")
+    ///     .unset_settings(&[AppSettings::ColorAuto,
+    ///                       AppSettings::AllowInvalidUtf8])
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`AppSettings`]: ./enum.AppSettings.html
+    pub fn unset_settings(mut self, settings: &[AppSettings]) -> Self {
+        for s in settings {
+            self.p.unset(*s);
+        }
+        self
+    }
+
+    /// Sets the terminal width at which to wrap help messages. Defaults to `120`. Using `0` will
+    /// ignore terminal widths and use source formatting.
+    ///
+    /// `clap` automatically tries to determine the terminal width on Unix, Linux, macOS and Windows
+    /// if the `wrap_help` cargo "feature" has been used while compiling. If the terminal width
+    /// cannot be determined, `clap` defaults to `120`.
+    ///
+    /// **NOTE:** This setting applies globally and *not* on a per-command basis.
+    ///
+    /// **NOTE:** This setting must be set **before** any subcommands are added!
+    ///
+    /// # Platform Specific
+    ///
+    /// Only Unix, Linux, macOS and Windows support automatic determination of terminal width.
+    /// Even on those platforms, this setting is useful if for any reason the terminal width
+    /// cannot be determined.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::App;
+    /// App::new("myprog")
+    ///     .set_term_width(80)
+    /// # ;
+    /// ```
+    pub fn set_term_width(mut self, width: usize) -> Self {
+        self.p.meta.term_w = Some(width);
+        self
+    }
+
+    /// Sets the max terminal width at which to wrap help messages. Using `0` will ignore terminal
+    /// widths and use source formatting.
+    ///
+    /// `clap` automatically tries to determine the terminal width on Unix, Linux, macOS and Windows
+    /// if the `wrap_help` cargo "feature" has been used while compiling, but one might want to
+    /// limit the size (e.g. when the terminal is running fullscreen).
+    ///
+    /// **NOTE:** This setting applies globally and *not* on a per-command basis.
+    ///
+    /// **NOTE:** This setting must be set **before** any subcommands are added!
+    ///
+    /// # Platform Specific
+    ///
+    /// Only Unix, Linux, macOS and Windows support automatic determination of terminal width.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::App;
+    /// App::new("myprog")
+    ///     .max_term_width(100)
+    /// # ;
+    /// ```
+    pub fn max_term_width(mut self, w: usize) -> Self {
+        self.p.meta.max_w = Some(w);
+        self
+    }
+
+    /// Adds an [argument] to the list of valid possibilities.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     // Adding a single "flag" argument with a short and help text, using Arg::with_name()
+    ///     .arg(
+    ///         Arg::with_name("debug")
+    ///            .short("d")
+    ///            .help("turns on debugging mode")
+    ///     )
+    ///     // Adding a single "option" argument with a short, a long, and help text using the less
+    ///     // verbose Arg::from_usage()
+    ///     .arg(
+    ///         Arg::from_usage("-c --config=[CONFIG] 'Optionally sets a config file to use'")
+    ///     )
+    /// # ;
+    /// ```
+    /// [argument]: ./struct.Arg.html
+    pub fn arg<A: Into<Arg<'a, 'b>>>(mut self, a: A) -> Self {
+        self.p.add_arg(a.into());
+        self
+    }
+
+    /// Adds multiple [arguments] to the list of valid possibilities
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .args(
+    ///         &[Arg::from_usage("[debug] -d 'turns on debugging info'"),
+    ///          Arg::with_name("input").index(1).help("the input file to use")]
+    ///     )
+    /// # ;
+    /// ```
+    /// [arguments]: ./struct.Arg.html
+    pub fn args(mut self, args: &[Arg<'a, 'b>]) -> Self {
+        for arg in args {
+            self.p.add_arg_ref(arg);
+        }
+        self
+    }
+
+    /// A convenience method for adding a single [argument] from a usage type string. The string
+    /// used follows the same rules and syntax as [`Arg::from_usage`]
+    ///
+    /// **NOTE:** The downside to using this method is that you can not set any additional
+    /// properties of the [`Arg`] other than what [`Arg::from_usage`] supports.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .arg_from_usage("-c --config=<FILE> 'Sets a configuration file to use'")
+    /// # ;
+    /// ```
+    /// [argument]: ./struct.Arg.html
+    /// [`Arg`]: ./struct.Arg.html
+    /// [`Arg::from_usage`]: ./struct.Arg.html#method.from_usage
+    pub fn arg_from_usage(mut self, usage: &'a str) -> Self {
+        self.p.add_arg(Arg::from_usage(usage));
+        self
+    }
+
+    /// Adds multiple [arguments] at once from a usage string, one per line. See
+    /// [`Arg::from_usage`] for details on the syntax and rules supported.
+    ///
+    /// **NOTE:** Like [`App::arg_from_usage`] the downside is you only set properties for the
+    /// [`Arg`]s which [`Arg::from_usage`] supports.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// App::new("myprog")
+    ///     .args_from_usage(
+    ///         "-c --config=[FILE] 'Sets a configuration file to use'
+    ///          [debug]... -d 'Sets the debugging level'
+    ///          <FILE> 'The input file to use'"
+    ///     )
+    /// # ;
+    /// ```
+    /// [arguments]: ./struct.Arg.html
+    /// [`Arg::from_usage`]: ./struct.Arg.html#method.from_usage
+    /// [`App::arg_from_usage`]: ./struct.App.html#method.arg_from_usage
+    /// [`Arg`]: ./struct.Arg.html
+    pub fn args_from_usage(mut self, usage: &'a str) -> Self {
+        for line in usage.lines() {
+            let l = line.trim();
+            if l.is_empty() {
+                continue;
+            }
+            self.p.add_arg(Arg::from_usage(l));
+        }
+        self
+    }
+
+    /// Allows adding a [`SubCommand`] alias, which function as "hidden" subcommands that
+    /// automatically dispatch as if this subcommand was used. This is more efficient, and easier
+    /// than creating multiple hidden subcommands as one only needs to check for the existence of
+    /// this command, and not all variants.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand};
+    /// let m = App::new("myprog")
+    ///             .subcommand(SubCommand::with_name("test")
+    ///                 .alias("do-stuff"))
+    ///             .get_matches_from(vec!["myprog", "do-stuff"]);
+    /// assert_eq!(m.subcommand_name(), Some("test"));
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    pub fn alias<S: Into<&'b str>>(mut self, name: S) -> Self {
+        if let Some(ref mut als) = self.p.meta.aliases {
+            als.push((name.into(), false));
+        } else {
+            self.p.meta.aliases = Some(vec![(name.into(), false)]);
+        }
+        self
+    }
+
+    /// Allows adding [`SubCommand`] aliases, which function as "hidden" subcommands that
+    /// automatically dispatch as if this subcommand was used. This is more efficient, and easier
+    /// than creating multiple hidden subcommands as one only needs to check for the existence of
+    /// this command, and not all variants.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, SubCommand};
+    /// let m = App::new("myprog")
+    ///             .subcommand(SubCommand::with_name("test")
+    ///                 .aliases(&["do-stuff", "do-tests", "tests"]))
+    ///                 .arg(Arg::with_name("input")
+    ///                             .help("the file to add")
+    ///                             .index(1)
+    ///                             .required(false))
+    ///             .get_matches_from(vec!["myprog", "do-tests"]);
+    /// assert_eq!(m.subcommand_name(), Some("test"));
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    pub fn aliases(mut self, names: &[&'b str]) -> Self {
+        if let Some(ref mut als) = self.p.meta.aliases {
+            for n in names {
+                als.push((n, false));
+            }
+        } else {
+            self.p.meta.aliases = Some(names.iter().map(|n| (*n, false)).collect::<Vec<_>>());
+        }
+        self
+    }
+
+    /// Allows adding a [`SubCommand`] alias that functions exactly like those defined with
+    /// [`App::alias`], except that they are visible inside the help message.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand};
+    /// let m = App::new("myprog")
+    ///             .subcommand(SubCommand::with_name("test")
+    ///                 .visible_alias("do-stuff"))
+    ///             .get_matches_from(vec!["myprog", "do-stuff"]);
+    /// assert_eq!(m.subcommand_name(), Some("test"));
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`App::alias`]: ./struct.App.html#method.alias
+    pub fn visible_alias<S: Into<&'b str>>(mut self, name: S) -> Self {
+        if let Some(ref mut als) = self.p.meta.aliases {
+            als.push((name.into(), true));
+        } else {
+            self.p.meta.aliases = Some(vec![(name.into(), true)]);
+        }
+        self
+    }
+
+    /// Allows adding multiple [`SubCommand`] aliases that functions exactly like those defined
+    /// with [`App::aliases`], except that they are visible inside the help message.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand};
+    /// let m = App::new("myprog")
+    ///             .subcommand(SubCommand::with_name("test")
+    ///                 .visible_aliases(&["do-stuff", "tests"]))
+    ///             .get_matches_from(vec!["myprog", "do-stuff"]);
+    /// assert_eq!(m.subcommand_name(), Some("test"));
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`App::aliases`]: ./struct.App.html#method.aliases
+    pub fn visible_aliases(mut self, names: &[&'b str]) -> Self {
+        if let Some(ref mut als) = self.p.meta.aliases {
+            for n in names {
+                als.push((n, true));
+            }
+        } else {
+            self.p.meta.aliases = Some(names.iter().map(|n| (*n, true)).collect::<Vec<_>>());
+        }
+        self
+    }
+
+    /// Adds an [`ArgGroup`] to the application. [`ArgGroup`]s are a family of related arguments.
+    /// By placing them in a logical group, you can build easier requirement and exclusion rules.
+    /// For instance, you can make an entire [`ArgGroup`] required, meaning that one (and *only*
+    /// one) argument from that group must be present at runtime.
+    ///
+    /// You can also do things such as name an [`ArgGroup`] as a conflict to another argument.
+    /// Meaning any of the arguments that belong to that group will cause a failure if present with
+    /// the conflicting argument.
+    ///
+    /// Another added benefit of [`ArgGroup`]s is that you can extract a value from a group instead
+    /// of determining exactly which argument was used.
+    ///
+    /// Finally, using [`ArgGroup`]s to ensure exclusion between arguments is another very common
+    /// use
+    ///
+    /// # Examples
+    ///
+    /// The following example demonstrates using an [`ArgGroup`] to ensure that one, and only one,
+    /// of the arguments from the specified group is present at runtime.
+    ///
+    /// ```no_run
+    /// # use clap::{App, ArgGroup};
+    /// App::new("app")
+    ///     .args_from_usage(
+    ///         "--set-ver [ver] 'set the version manually'
+    ///          --major         'auto increase major'
+    ///          --minor         'auto increase minor'
+    ///          --patch         'auto increase patch'")
+    ///     .group(ArgGroup::with_name("vers")
+    ///          .args(&["set-ver", "major", "minor","patch"])
+    ///          .required(true))
+    /// # ;
+    /// ```
+    /// [`ArgGroup`]: ./struct.ArgGroup.html
+    pub fn group(mut self, group: ArgGroup<'a>) -> Self {
+        self.p.add_group(group);
+        self
+    }
+
+    /// Adds multiple [`ArgGroup`]s to the [`App`] at once.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, ArgGroup};
+    /// App::new("app")
+    ///     .args_from_usage(
+    ///         "--set-ver [ver] 'set the version manually'
+    ///          --major         'auto increase major'
+    ///          --minor         'auto increase minor'
+    ///          --patch         'auto increase patch'
+    ///          -c [FILE]       'a config file'
+    ///          -i [IFACE]      'an interface'")
+    ///     .groups(&[
+    ///         ArgGroup::with_name("vers")
+    ///             .args(&["set-ver", "major", "minor","patch"])
+    ///             .required(true),
+    ///         ArgGroup::with_name("input")
+    ///             .args(&["c", "i"])
+    ///     ])
+    /// # ;
+    /// ```
+    /// [`ArgGroup`]: ./struct.ArgGroup.html
+    /// [`App`]: ./struct.App.html
+    pub fn groups(mut self, groups: &[ArgGroup<'a>]) -> Self {
+        for g in groups {
+            self = self.group(g.into());
+        }
+        self
+    }
+
+    /// Adds a [`SubCommand`] to the list of valid possibilities. Subcommands are effectively
+    /// sub-[`App`]s, because they can contain their own arguments, subcommands, version, usage,
+    /// etc. They also function just like [`App`]s, in that they get their own auto generated help,
+    /// version, and usage.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand};
+    /// App::new("myprog")
+    ///     .subcommand(SubCommand::with_name("config")
+    ///         .about("Controls configuration features")
+    ///         .arg_from_usage("<config> 'Required configuration file to use'"))
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`App`]: ./struct.App.html
+    pub fn subcommand(mut self, subcmd: App<'a, 'b>) -> Self {
+        self.p.add_subcommand(subcmd);
+        self
+    }
+
+    /// Adds multiple subcommands to the list of valid possibilities by iterating over an
+    /// [`IntoIterator`] of [`SubCommand`]s
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, SubCommand};
+    /// # App::new("myprog")
+    /// .subcommands( vec![
+    ///        SubCommand::with_name("config").about("Controls configuration functionality")
+    ///                                 .arg(Arg::with_name("config_file").index(1)),
+    ///        SubCommand::with_name("debug").about("Controls debug functionality")])
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`IntoIterator`]: https://doc.rust-lang.org/std/iter/trait.IntoIterator.html
+    pub fn subcommands<I>(mut self, subcmds: I) -> Self
+    where
+        I: IntoIterator<Item = App<'a, 'b>>,
+    {
+        for subcmd in subcmds {
+            self.p.add_subcommand(subcmd);
+        }
+        self
+    }
+
+    /// Allows custom ordering of [`SubCommand`]s within the help message. Subcommands with a lower
+    /// value will be displayed first in the help message. This is helpful when one would like to
+    /// emphasise frequently used subcommands, or prioritize those towards the top of the list.
+    /// Duplicate values **are** allowed. Subcommands with duplicate display orders will be
+    /// displayed in alphabetical order.
+    ///
+    /// **NOTE:** The default is 999 for all subcommands.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, SubCommand};
+    /// let m = App::new("cust-ord")
+    ///     .subcommand(SubCommand::with_name("alpha") // typically subcommands are grouped
+    ///                                                // alphabetically by name. Subcommands
+    ///                                                // without a display_order have a value of
+    ///                                                // 999 and are displayed alphabetically with
+    ///                                                // all other 999 subcommands
+    ///         .about("Some help and text"))
+    ///     .subcommand(SubCommand::with_name("beta")
+    ///         .display_order(1)   // In order to force this subcommand to appear *first*
+    ///                             // all we have to do is give it a value lower than 999.
+    ///                             // Any other subcommands with a value of 1 will be displayed
+    ///                             // alphabetically with this one...then 2 values, then 3, etc.
+    ///         .about("I should be first!"))
+    ///     .get_matches_from(vec![
+    ///         "cust-ord", "--help"
+    ///     ]);
+    /// ```
+    ///
+    /// The above example displays the following help message
+    ///
+    /// ```text
+    /// cust-ord
+    ///
+    /// USAGE:
+    ///     cust-ord [FLAGS] [OPTIONS]
+    ///
+    /// FLAGS:
+    ///     -h, --help       Prints help information
+    ///     -V, --version    Prints version information
+    ///
+    /// SUBCOMMANDS:
+    ///     beta    I should be first!
+    ///     alpha   Some help and text
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    pub fn display_order(mut self, ord: usize) -> Self {
+        self.p.meta.disp_ord = ord;
+        self
+    }
+
+    /// Prints the full help message to [`io::stdout()`] using a [`BufWriter`] using the same
+    /// method as if someone ran `-h` to request the help message
+    ///
+    /// **NOTE:** clap has the ability to distinguish between "short" and "long" help messages
+    /// depending on if the user ran [`-h` (short)] or [`--help` (long)]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::App;
+    /// let mut app = App::new("myprog");
+    /// app.print_help();
+    /// ```
+    /// [`io::stdout()`]: https://doc.rust-lang.org/std/io/fn.stdout.html
+    /// [`BufWriter`]: https://doc.rust-lang.org/std/io/struct.BufWriter.html
+    /// [`-h` (short)]: ./struct.Arg.html#method.help
+    /// [`--help` (long)]: ./struct.Arg.html#method.long_help
+    pub fn print_help(&mut self) -> ClapResult<()> {
+        // If there are global arguments, or settings we need to propagate them down to subcommands
+        // before parsing incase we run into a subcommand
+        self.p.propagate_globals();
+        self.p.propagate_settings();
+        self.p.derive_display_order();
+
+        self.p.create_help_and_version();
+        let out = io::stdout();
+        let mut buf_w = BufWriter::new(out.lock());
+        self.write_help(&mut buf_w)
+    }
+
+    /// Prints the full help message to [`io::stdout()`] using a [`BufWriter`] using the same
+    /// method as if someone ran `--help` to request the help message
+    ///
+    /// **NOTE:** clap has the ability to distinguish between "short" and "long" help messages
+    /// depending on if the user ran [`-h` (short)] or [`--help` (long)]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::App;
+    /// let mut app = App::new("myprog");
+    /// app.print_long_help();
+    /// ```
+    /// [`io::stdout()`]: https://doc.rust-lang.org/std/io/fn.stdout.html
+    /// [`BufWriter`]: https://doc.rust-lang.org/std/io/struct.BufWriter.html
+    /// [`-h` (short)]: ./struct.Arg.html#method.help
+    /// [`--help` (long)]: ./struct.Arg.html#method.long_help
+    pub fn print_long_help(&mut self) -> ClapResult<()> {
+        let out = io::stdout();
+        let mut buf_w = BufWriter::new(out.lock());
+        self.write_long_help(&mut buf_w)
+    }
+
+    /// Writes the full help message to the user to a [`io::Write`] object in the same method as if
+    /// the user ran `-h`
+    ///
+    /// **NOTE:** clap has the ability to distinguish between "short" and "long" help messages
+    /// depending on if the user ran [`-h` (short)] or [`--help` (long)]
+    ///
+    /// **NOTE:** There is a known bug where this method does not write propagated global arguments
+    /// or autogenerated arguments (i.e. the default help/version args). Prefer
+    /// [`App::write_long_help`] instead if possible!
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::App;
+    /// use std::io;
+    /// let mut app = App::new("myprog");
+    /// let mut out = io::stdout();
+    /// app.write_help(&mut out).expect("failed to write to stdout");
+    /// ```
+    /// [`io::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+    /// [`-h` (short)]: ./struct.Arg.html#method.help
+    /// [`--help` (long)]: ./struct.Arg.html#method.long_help
+    pub fn write_help<W: Write>(&self, w: &mut W) -> ClapResult<()> {
+        // PENDING ISSUE: 808
+        //      https://github.com/clap-rs/clap/issues/808
+        // If there are global arguments, or settings we need to propagate them down to subcommands
+        // before parsing incase we run into a subcommand
+        // self.p.propagate_globals();
+        // self.p.propagate_settings();
+        // self.p.derive_display_order();
+        // self.p.create_help_and_version();
+
+        Help::write_app_help(w, self, false)
+    }
+
+    /// Writes the full help message to the user to a [`io::Write`] object in the same method as if
+    /// the user ran `--help`
+    ///
+    /// **NOTE:** clap has the ability to distinguish between "short" and "long" help messages
+    /// depending on if the user ran [`-h` (short)] or [`--help` (long)]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::App;
+    /// use std::io;
+    /// let mut app = App::new("myprog");
+    /// let mut out = io::stdout();
+    /// app.write_long_help(&mut out).expect("failed to write to stdout");
+    /// ```
+    /// [`io::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+    /// [`-h` (short)]: ./struct.Arg.html#method.help
+    /// [`--help` (long)]: ./struct.Arg.html#method.long_help
+    pub fn write_long_help<W: Write>(&mut self, w: &mut W) -> ClapResult<()> {
+        // If there are global arguments, or settings we need to propagate them down to subcommands
+        // before parsing incase we run into a subcommand
+        self.p.propagate_globals();
+        self.p.propagate_settings();
+        self.p.derive_display_order();
+        self.p.create_help_and_version();
+
+        Help::write_app_help(w, self, true)
+    }
+
+    /// Writes the version message to the user to a [`io::Write`] object as if the user ran `-V`.
+    ///
+    /// **NOTE:** clap has the ability to distinguish between "short" and "long" version messages
+    /// depending on if the user ran [`-V` (short)] or [`--version` (long)]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::App;
+    /// use std::io;
+    /// let mut app = App::new("myprog");
+    /// let mut out = io::stdout();
+    /// app.write_version(&mut out).expect("failed to write to stdout");
+    /// ```
+    /// [`io::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+    /// [`-V` (short)]: ./struct.App.html#method.version
+    /// [`--version` (long)]: ./struct.App.html#method.long_version
+    pub fn write_version<W: Write>(&self, w: &mut W) -> ClapResult<()> {
+        self.p.write_version(w, false).map_err(From::from)
+    }
+
+    /// Writes the version message to the user to a [`io::Write`] object
+    ///
+    /// **NOTE:** clap has the ability to distinguish between "short" and "long" version messages
+    /// depending on if the user ran [`-V` (short)] or [`--version` (long)]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::App;
+    /// use std::io;
+    /// let mut app = App::new("myprog");
+    /// let mut out = io::stdout();
+    /// app.write_long_version(&mut out).expect("failed to write to stdout");
+    /// ```
+    /// [`io::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+    /// [`-V` (short)]: ./struct.App.html#method.version
+    /// [`--version` (long)]: ./struct.App.html#method.long_version
+    pub fn write_long_version<W: Write>(&self, w: &mut W) -> ClapResult<()> {
+        self.p.write_version(w, true).map_err(From::from)
+    }
+
+    /// Generate a completions file for a specified shell at compile time.
+    ///
+    /// **NOTE:** to generate the file at compile time you must use a `build.rs` "Build Script"
+    ///
+    /// # Examples
+    ///
+    /// The following example generates a bash completion script via a `build.rs` script. In this
+    /// simple example, we'll demo a very small application with only a single subcommand and two
+    /// args. Real applications could be many multiple levels deep in subcommands, and have tens or
+    /// potentially hundreds of arguments.
+    ///
+    /// First, it helps if we separate out our `App` definition into a separate file. Whether you
+    /// do this as a function, or bare App definition is a matter of personal preference.
+    ///
+    /// ```
+    /// // src/cli.rs
+    ///
+    /// use clap::{App, Arg, SubCommand};
+    ///
+    /// pub fn build_cli() -> App<'static, 'static> {
+    ///     App::new("compl")
+    ///         .about("Tests completions")
+    ///         .arg(Arg::with_name("file")
+    ///             .help("some input file"))
+    ///         .subcommand(SubCommand::with_name("test")
+    ///             .about("tests things")
+    ///             .arg(Arg::with_name("case")
+    ///                 .long("case")
+    ///                 .takes_value(true)
+    ///                 .help("the case to test")))
+    /// }
+    /// ```
+    ///
+    /// In our regular code, we can simply call this `build_cli()` function, then call
+    /// `get_matches()`, or any of the other normal methods directly after. For example:
+    ///
+    /// ```ignore
+    /// // src/main.rs
+    ///
+    /// mod cli;
+    ///
+    /// fn main() {
+    ///     let m = cli::build_cli().get_matches();
+    ///
+    ///     // normal logic continues...
+    /// }
+    /// ```
+    ///
+    /// Next, we set up our `Cargo.toml` to use a `build.rs` build script.
+    ///
+    /// ```toml
+    /// # Cargo.toml
+    /// build = "build.rs"
+    ///
+    /// [build-dependencies]
+    /// clap = "2.23"
+    /// ```
+    ///
+    /// Next, we place a `build.rs` in our project root.
+    ///
+    /// ```ignore
+    /// extern crate clap;
+    ///
+    /// use clap::Shell;
+    ///
+    /// include!("src/cli.rs");
+    ///
+    /// fn main() {
+    ///     let outdir = match env::var_os("OUT_DIR") {
+    ///         None => return,
+    ///         Some(outdir) => outdir,
+    ///     };
+    ///     let mut app = build_cli();
+    ///     app.gen_completions("myapp",      // We need to specify the bin name manually
+    ///                         Shell::Bash,  // Then say which shell to build completions for
+    ///                         outdir);      // Then say where write the completions to
+    /// }
+    /// ```
+    /// Now, once we compile there will be a `{bin_name}.bash` file in the directory.
+    /// Assuming we compiled with debug mode, it would be somewhere similar to
+    /// `<project>/target/debug/build/myapp-<hash>/out/myapp.bash`.
+    ///
+    /// Fish shell completions will use the file format `{bin_name}.fish`
+    pub fn gen_completions<T: Into<OsString>, S: Into<String>>(
+        &mut self,
+        bin_name: S,
+        for_shell: Shell,
+        out_dir: T,
+    ) {
+        self.p.meta.bin_name = Some(bin_name.into());
+        self.p.gen_completions(for_shell, out_dir.into());
+    }
+
+
+    /// Generate a completions file for a specified shell at runtime.  Until `cargo install` can
+    /// install extra files like a completion script, this may be used e.g. in a command that
+    /// outputs the contents of the completion script, to be redirected into a file by the user.
+    ///
+    /// # Examples
+    ///
+    /// Assuming a separate `cli.rs` like the [example above](./struct.App.html#method.gen_completions),
+    /// we can let users generate a completion script using a command:
+    ///
+    /// ```ignore
+    /// // src/main.rs
+    ///
+    /// mod cli;
+    /// use std::io;
+    ///
+    /// fn main() {
+    ///     let matches = cli::build_cli().get_matches();
+    ///
+    ///     if matches.is_present("generate-bash-completions") {
+    ///         cli::build_cli().gen_completions_to("myapp", Shell::Bash, &mut io::stdout());
+    ///     }
+    ///
+    ///     // normal logic continues...
+    /// }
+    ///
+    /// ```
+    ///
+    /// Usage:
+    ///
+    /// ```shell
+    /// $ myapp generate-bash-completions > /usr/share/bash-completion/completions/myapp.bash
+    /// ```
+    pub fn gen_completions_to<W: Write, S: Into<String>>(
+        &mut self,
+        bin_name: S,
+        for_shell: Shell,
+        buf: &mut W,
+    ) {
+        self.p.meta.bin_name = Some(bin_name.into());
+        self.p.gen_completions_to(for_shell, buf);
+    }
+
+    /// Starts the parsing process, upon a failed parse an error will be displayed to the user and
+    /// the process will exit with the appropriate error code. By default this method gets all user
+    /// provided arguments from [`env::args_os`] in order to allow for invalid UTF-8 code points,
+    /// which are legal on many platforms.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// let matches = App::new("myprog")
+    ///     // Args and options go here...
+    ///     .get_matches();
+    /// ```
+    /// [`env::args_os`]: https://doc.rust-lang.org/std/env/fn.args_os.html
+    pub fn get_matches(self) -> ArgMatches<'a> { self.get_matches_from(&mut env::args_os()) }
+
+    /// Starts the parsing process. This method will return a [`clap::Result`] type instead of exiting
+    /// the process on failed parse. By default this method gets matches from [`env::args_os`]
+    ///
+    /// **NOTE:** This method WILL NOT exit when `--help` or `--version` (or short versions) are
+    /// used. It will return a [`clap::Error`], where the [`kind`] is a
+    /// [`ErrorKind::HelpDisplayed`] or [`ErrorKind::VersionDisplayed`] respectively. You must call
+    /// [`Error::exit`] or perform a [`std::process::exit`].
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// let matches = App::new("myprog")
+    ///     // Args and options go here...
+    ///     .get_matches_safe()
+    ///     .unwrap_or_else( |e| e.exit() );
+    /// ```
+    /// [`env::args_os`]: https://doc.rust-lang.org/std/env/fn.args_os.html
+    /// [`ErrorKind::HelpDisplayed`]: ./enum.ErrorKind.html#variant.HelpDisplayed
+    /// [`ErrorKind::VersionDisplayed`]: ./enum.ErrorKind.html#variant.VersionDisplayed
+    /// [`Error::exit`]: ./struct.Error.html#method.exit
+    /// [`std::process::exit`]: https://doc.rust-lang.org/std/process/fn.exit.html
+    /// [`clap::Result`]: ./type.Result.html
+    /// [`clap::Error`]: ./struct.Error.html
+    /// [`kind`]: ./struct.Error.html
+    pub fn get_matches_safe(self) -> ClapResult<ArgMatches<'a>> {
+        // Start the parsing
+        self.get_matches_from_safe(&mut env::args_os())
+    }
+
+    /// Starts the parsing process. Like [`App::get_matches`] this method does not return a [`clap::Result`]
+    /// and will automatically exit with an error message. This method, however, lets you specify
+    /// what iterator to use when performing matches, such as a [`Vec`] of your making.
+    ///
+    /// **NOTE:** The first argument will be parsed as the binary name unless
+    /// [`AppSettings::NoBinaryName`] is used
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// let arg_vec = vec!["my_prog", "some", "args", "to", "parse"];
+    ///
+    /// let matches = App::new("myprog")
+    ///     // Args and options go here...
+    ///     .get_matches_from(arg_vec);
+    /// ```
+    /// [`App::get_matches`]: ./struct.App.html#method.get_matches
+    /// [`clap::Result`]: ./type.Result.html
+    /// [`Vec`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
+    /// [`AppSettings::NoBinaryName`]: ./enum.AppSettings.html#variant.NoBinaryName
+    pub fn get_matches_from<I, T>(mut self, itr: I) -> ArgMatches<'a>
+    where
+        I: IntoIterator<Item = T>,
+        T: Into<OsString> + Clone,
+    {
+        self.get_matches_from_safe_borrow(itr).unwrap_or_else(|e| {
+            // Otherwise, write to stderr and exit
+            if e.use_stderr() {
+                wlnerr!("{}", e.message);
+                if self.p.is_set(AppSettings::WaitOnError) {
+                    wlnerr!("\nPress [ENTER] / [RETURN] to continue...");
+                    let mut s = String::new();
+                    let i = io::stdin();
+                    i.lock().read_line(&mut s).unwrap();
+                }
+                drop(self);
+                drop(e);
+                process::exit(1);
+            }
+
+            drop(self);
+            e.exit()
+        })
+    }
+
+    /// Starts the parsing process. A combination of [`App::get_matches_from`], and
+    /// [`App::get_matches_safe`]
+    ///
+    /// **NOTE:** This method WILL NOT exit when `--help` or `--version` (or short versions) are
+    /// used. It will return a [`clap::Error`], where the [`kind`] is a [`ErrorKind::HelpDisplayed`]
+    /// or [`ErrorKind::VersionDisplayed`] respectively. You must call [`Error::exit`] or
+    /// perform a [`std::process::exit`] yourself.
+    ///
+    /// **NOTE:** The first argument will be parsed as the binary name unless
+    /// [`AppSettings::NoBinaryName`] is used
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// let arg_vec = vec!["my_prog", "some", "args", "to", "parse"];
+    ///
+    /// let matches = App::new("myprog")
+    ///     // Args and options go here...
+    ///     .get_matches_from_safe(arg_vec)
+    ///     .unwrap_or_else( |e| { panic!("An error occurs: {}", e) });
+    /// ```
+    /// [`App::get_matches_from`]: ./struct.App.html#method.get_matches_from
+    /// [`App::get_matches_safe`]: ./struct.App.html#method.get_matches_safe
+    /// [`ErrorKind::HelpDisplayed`]: ./enum.ErrorKind.html#variant.HelpDisplayed
+    /// [`ErrorKind::VersionDisplayed`]: ./enum.ErrorKind.html#variant.VersionDisplayed
+    /// [`Error::exit`]: ./struct.Error.html#method.exit
+    /// [`std::process::exit`]: https://doc.rust-lang.org/std/process/fn.exit.html
+    /// [`clap::Error`]: ./struct.Error.html
+    /// [`Error::exit`]: ./struct.Error.html#method.exit
+    /// [`kind`]: ./struct.Error.html
+    /// [`AppSettings::NoBinaryName`]: ./enum.AppSettings.html#variant.NoBinaryName
+    pub fn get_matches_from_safe<I, T>(mut self, itr: I) -> ClapResult<ArgMatches<'a>>
+    where
+        I: IntoIterator<Item = T>,
+        T: Into<OsString> + Clone,
+    {
+        self.get_matches_from_safe_borrow(itr)
+    }
+
+    /// Starts the parsing process without consuming the [`App`] struct `self`. This is normally not
+    /// the desired functionality, instead prefer [`App::get_matches_from_safe`] which *does*
+    /// consume `self`.
+    ///
+    /// **NOTE:** The first argument will be parsed as the binary name unless
+    /// [`AppSettings::NoBinaryName`] is used
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// let arg_vec = vec!["my_prog", "some", "args", "to", "parse"];
+    ///
+    /// let mut app = App::new("myprog");
+    ///     // Args and options go here...
+    /// let matches = app.get_matches_from_safe_borrow(arg_vec)
+    ///     .unwrap_or_else( |e| { panic!("An error occurs: {}", e) });
+    /// ```
+    /// [`App`]: ./struct.App.html
+    /// [`App::get_matches_from_safe`]: ./struct.App.html#method.get_matches_from_safe
+    /// [`AppSettings::NoBinaryName`]: ./enum.AppSettings.html#variant.NoBinaryName
+    pub fn get_matches_from_safe_borrow<I, T>(&mut self, itr: I) -> ClapResult<ArgMatches<'a>>
+    where
+        I: IntoIterator<Item = T>,
+        T: Into<OsString> + Clone,
+    {
+        // If there are global arguments, or settings we need to propagate them down to subcommands
+        // before parsing incase we run into a subcommand
+        if !self.p.is_set(AppSettings::Propagated) {
+            self.p.propagate_globals();
+            self.p.propagate_settings();
+            self.p.derive_display_order();
+            self.p.set(AppSettings::Propagated);
+        }
+
+        let mut matcher = ArgMatcher::new();
+
+        let mut it = itr.into_iter();
+        // Get the name of the program (argument 1 of env::args()) and determine the
+        // actual file
+        // that was used to execute the program. This is because a program called
+        // ./target/release/my_prog -a
+        // will have two arguments, './target/release/my_prog', '-a' but we don't want
+        // to display
+        // the full path when displaying help messages and such
+        if !self.p.is_set(AppSettings::NoBinaryName) {
+            if let Some(name) = it.next() {
+                let bn_os = name.into();
+                let p = Path::new(&*bn_os);
+                if let Some(f) = p.file_name() {
+                    if let Some(s) = f.to_os_string().to_str() {
+                        if self.p.meta.bin_name.is_none() {
+                            self.p.meta.bin_name = Some(s.to_owned());
+                        }
+                    }
+                }
+            }
+        }
+
+        // do the real parsing
+        if let Err(e) = self.p.get_matches_with(&mut matcher, &mut it.peekable()) {
+            return Err(e);
+        }
+
+        let global_arg_vec: Vec<&str> = (&self).p.global_args.iter().map(|ga| ga.b.name).collect();
+        matcher.propagate_globals(&global_arg_vec);
+
+        Ok(matcher.into())
+    }
+}
+
+#[cfg(feature = "yaml")]
+impl<'a> From<&'a Yaml> for App<'a, 'a> {
+    fn from(mut yaml: &'a Yaml) -> Self {
+        use args::SubCommand;
+        // We WANT this to panic on error...so expect() is good.
+        let mut is_sc = None;
+        let mut a = if let Some(name) = yaml["name"].as_str() {
+            App::new(name)
+        } else {
+            let yaml_hash = yaml.as_hash().unwrap();
+            let sc_key = yaml_hash.keys().nth(0).unwrap();
+            is_sc = Some(yaml_hash.get(sc_key).unwrap());
+            App::new(sc_key.as_str().unwrap())
+        };
+        yaml = if let Some(sc) = is_sc { sc } else { yaml };
+
+        macro_rules! yaml_str {
+            ($a:ident, $y:ident, $i:ident) => {
+                if let Some(v) = $y[stringify!($i)].as_str() {
+                    $a = $a.$i(v);
+                } else if $y[stringify!($i)] != Yaml::BadValue {
+                    panic!("Failed to convert YAML value {:?} to a string", $y[stringify!($i)]);
+                }
+            };
+        }
+
+        yaml_str!(a, yaml, version);
+        yaml_str!(a, yaml, long_version);
+        yaml_str!(a, yaml, author);
+        yaml_str!(a, yaml, bin_name);
+        yaml_str!(a, yaml, about);
+        yaml_str!(a, yaml, long_about);
+        yaml_str!(a, yaml, before_help);
+        yaml_str!(a, yaml, after_help);
+        yaml_str!(a, yaml, template);
+        yaml_str!(a, yaml, usage);
+        yaml_str!(a, yaml, help);
+        yaml_str!(a, yaml, help_short);
+        yaml_str!(a, yaml, version_short);
+        yaml_str!(a, yaml, help_message);
+        yaml_str!(a, yaml, version_message);
+        yaml_str!(a, yaml, alias);
+        yaml_str!(a, yaml, visible_alias);
+
+        if let Some(v) = yaml["display_order"].as_i64() {
+            a = a.display_order(v as usize);
+        } else if yaml["display_order"] != Yaml::BadValue {
+            panic!(
+                "Failed to convert YAML value {:?} to a u64",
+                yaml["display_order"]
+            );
+        }
+        if let Some(v) = yaml["setting"].as_str() {
+            a = a.setting(v.parse().expect("unknown AppSetting found in YAML file"));
+        } else if yaml["setting"] != Yaml::BadValue {
+            panic!(
+                "Failed to convert YAML value {:?} to an AppSetting",
+                yaml["setting"]
+            );
+        }
+        if let Some(v) = yaml["settings"].as_vec() {
+            for ys in v {
+                if let Some(s) = ys.as_str() {
+                    a = a.setting(s.parse().expect("unknown AppSetting found in YAML file"));
+                }
+            }
+        } else if let Some(v) = yaml["settings"].as_str() {
+            a = a.setting(v.parse().expect("unknown AppSetting found in YAML file"));
+        } else if yaml["settings"] != Yaml::BadValue {
+            panic!(
+                "Failed to convert YAML value {:?} to a string",
+                yaml["settings"]
+            );
+        }
+        if let Some(v) = yaml["global_setting"].as_str() {
+            a = a.setting(v.parse().expect("unknown AppSetting found in YAML file"));
+        } else if yaml["global_setting"] != Yaml::BadValue {
+            panic!(
+                "Failed to convert YAML value {:?} to an AppSetting",
+                yaml["setting"]
+            );
+        }
+        if let Some(v) = yaml["global_settings"].as_vec() {
+            for ys in v {
+                if let Some(s) = ys.as_str() {
+                    a = a.global_setting(s.parse().expect("unknown AppSetting found in YAML file"));
+                }
+            }
+        } else if let Some(v) = yaml["global_settings"].as_str() {
+            a = a.global_setting(v.parse().expect("unknown AppSetting found in YAML file"));
+        } else if yaml["global_settings"] != Yaml::BadValue {
+            panic!(
+                "Failed to convert YAML value {:?} to a string",
+                yaml["global_settings"]
+            );
+        }
+
+        macro_rules! vec_or_str {
+            ($a:ident, $y:ident, $as_vec:ident, $as_single:ident) => {{
+                    let maybe_vec = $y[stringify!($as_vec)].as_vec();
+                    if let Some(vec) = maybe_vec {
+                        for ys in vec {
+                            if let Some(s) = ys.as_str() {
+                                $a = $a.$as_single(s);
+                            } else {
+                                panic!("Failed to convert YAML value {:?} to a string", ys);
+                            }
+                        }
+                    } else {
+                        if let Some(s) = $y[stringify!($as_vec)].as_str() {
+                            $a = $a.$as_single(s);
+                        } else if $y[stringify!($as_vec)] != Yaml::BadValue {
+                            panic!("Failed to convert YAML value {:?} to either a vec or string", $y[stringify!($as_vec)]);
+                        }
+                    }
+                    $a
+                }
+            };
+        }
+
+        a = vec_or_str!(a, yaml, aliases, alias);
+        a = vec_or_str!(a, yaml, visible_aliases, visible_alias);
+
+        if let Some(v) = yaml["args"].as_vec() {
+            for arg_yaml in v {
+                a = a.arg(Arg::from_yaml(arg_yaml.as_hash().unwrap()));
+            }
+        }
+        if let Some(v) = yaml["subcommands"].as_vec() {
+            for sc_yaml in v {
+                a = a.subcommand(SubCommand::from_yaml(sc_yaml));
+            }
+        }
+        if let Some(v) = yaml["groups"].as_vec() {
+            for ag_yaml in v {
+                a = a.group(ArgGroup::from(ag_yaml.as_hash().unwrap()));
+            }
+        }
+
+        a
+    }
+}
+
+impl<'a, 'b> Clone for App<'a, 'b> {
+    fn clone(&self) -> Self { App { p: self.p.clone() } }
+}
+
+impl<'n, 'e> AnyArg<'n, 'e> for App<'n, 'e> {
+    fn name(&self) -> &'n str {
+        ""
+    }
+    fn overrides(&self) -> Option<&[&'e str]> { None }
+    fn requires(&self) -> Option<&[(Option<&'e str>, &'n str)]> { None }
+    fn blacklist(&self) -> Option<&[&'e str]> { None }
+    fn required_unless(&self) -> Option<&[&'e str]> { None }
+    fn val_names(&self) -> Option<&VecMap<&'e str>> { None }
+    fn is_set(&self, _: ArgSettings) -> bool { false }
+    fn val_terminator(&self) -> Option<&'e str> { None }
+    fn set(&mut self, _: ArgSettings) {
+        unreachable!("App struct does not support AnyArg::set, this is a bug!")
+    }
+    fn has_switch(&self) -> bool { false }
+    fn max_vals(&self) -> Option<u64> { None }
+    fn num_vals(&self) -> Option<u64> { None }
+    fn possible_vals(&self) -> Option<&[&'e str]> { None }
+    fn validator(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> { None }
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> StdResult<(), OsString>>> { None }
+    fn min_vals(&self) -> Option<u64> { None }
+    fn short(&self) -> Option<char> { None }
+    fn long(&self) -> Option<&'e str> { None }
+    fn val_delim(&self) -> Option<char> { None }
+    fn takes_value(&self) -> bool { true }
+    fn help(&self) -> Option<&'e str> { self.p.meta.about }
+    fn long_help(&self) -> Option<&'e str> { self.p.meta.long_about }
+    fn default_val(&self) -> Option<&'e OsStr> { None }
+    fn default_vals_ifs(&self) -> Option<map::Values<(&'n str, Option<&'e OsStr>, &'e OsStr)>> {
+        None
+    }
+    fn env<'s>(&'s self) -> Option<(&'n OsStr, Option<&'s OsString>)> { None }
+    fn longest_filter(&self) -> bool { true }
+    fn aliases(&self) -> Option<Vec<&'e str>> {
+        if let Some(ref aliases) = self.p.meta.aliases {
+            let vis_aliases: Vec<_> = aliases
+                .iter()
+                .filter_map(|&(n, v)| if v { Some(n) } else { None })
+                .collect();
+            if vis_aliases.is_empty() {
+                None
+            } else {
+                Some(vis_aliases)
+            }
+        } else {
+            None
+        }
+    }
+}
+
+impl<'n, 'e> fmt::Display for App<'n, 'e> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{}", self.p.meta.name) }
+}
diff --git a/src/app/parser.rs b/src/app/parser.rs
new file mode 100644
index 0000000..decfde4
--- /dev/null
+++ b/src/app/parser.rs
@@ -0,0 +1,2167 @@
+// Std
+use std::ffi::{OsStr, OsString};
+use std::fmt::Display;
+use std::fs::File;
+use std::io::{self, BufWriter, Write};
+#[cfg(all(feature = "debug", not(any(target_os = "windows", target_arch = "wasm32"))))]
+use std::os::unix::ffi::OsStrExt;
+#[cfg(all(feature = "debug", any(target_os = "windows", target_arch = "wasm32")))]
+use osstringext::OsStrExt3;
+use std::path::PathBuf;
+use std::slice::Iter;
+use std::iter::Peekable;
+use std::cell::Cell;
+
+// Internal
+use INTERNAL_ERROR_MSG;
+use INVALID_UTF8;
+use SubCommand;
+use app::App;
+use app::help::Help;
+use app::meta::AppMeta;
+use app::settings::AppFlags;
+use args::{AnyArg, Arg, ArgGroup, ArgMatcher, Base, FlagBuilder, OptBuilder, PosBuilder, Switched};
+use args::settings::ArgSettings;
+use completions::ComplGen;
+use errors::{Error, ErrorKind};
+use errors::Result as ClapResult;
+use fmt::ColorWhen;
+use osstringext::OsStrExt2;
+use completions::Shell;
+use suggestions;
+use app::settings::AppSettings as AS;
+use app::validator::Validator;
+use app::usage;
+use map::{self, VecMap};
+
+#[derive(Debug, PartialEq, Copy, Clone)]
+#[doc(hidden)]
+pub enum ParseResult<'a> {
+    Flag,
+    Opt(&'a str),
+    Pos(&'a str),
+    MaybeHyphenValue,
+    MaybeNegNum,
+    NotFound,
+    ValuesDone,
+}
+
+#[allow(missing_debug_implementations)]
+#[doc(hidden)]
+#[derive(Clone, Default)]
+pub struct Parser<'a, 'b>
+where
+    'a: 'b,
+{
+    pub meta: AppMeta<'b>,
+    settings: AppFlags,
+    pub g_settings: AppFlags,
+    pub flags: Vec<FlagBuilder<'a, 'b>>,
+    pub opts: Vec<OptBuilder<'a, 'b>>,
+    pub positionals: VecMap<PosBuilder<'a, 'b>>,
+    pub subcommands: Vec<App<'a, 'b>>,
+    pub groups: Vec<ArgGroup<'a>>,
+    pub global_args: Vec<Arg<'a, 'b>>,
+    pub required: Vec<&'a str>,
+    pub r_ifs: Vec<(&'a str, &'b str, &'a str)>,
+    pub overrides: Vec<(&'b str, &'a str)>,
+    help_short: Option<char>,
+    version_short: Option<char>,
+    cache: Option<&'a str>,
+    pub help_message: Option<&'a str>,
+    pub version_message: Option<&'a str>,
+    cur_idx: Cell<usize>,
+}
+
+impl<'a, 'b> Parser<'a, 'b>
+where
+    'a: 'b,
+{
+    pub fn with_name(n: String) -> Self {
+        Parser {
+            meta: AppMeta::with_name(n),
+            g_settings: AppFlags::zeroed(),
+            cur_idx: Cell::new(0),
+            ..Default::default()
+        }
+    }
+
+    pub fn help_short(&mut self, s: &str) {
+        let c = s.trim_left_matches(|c| c == '-')
+            .chars()
+            .nth(0)
+            .unwrap_or('h');
+        self.help_short = Some(c);
+    }
+
+    pub fn version_short(&mut self, s: &str) {
+        let c = s.trim_left_matches(|c| c == '-')
+            .chars()
+            .nth(0)
+            .unwrap_or('V');
+        self.version_short = Some(c);
+    }
+
+    pub fn gen_completions_to<W: Write>(&mut self, for_shell: Shell, buf: &mut W) {
+        if !self.is_set(AS::Propagated) {
+            self.propagate_help_version();
+            self.build_bin_names();
+            self.propagate_globals();
+            self.propagate_settings();
+            self.set(AS::Propagated);
+        }
+
+        ComplGen::new(self).generate(for_shell, buf)
+    }
+
+    pub fn gen_completions(&mut self, for_shell: Shell, od: OsString) {
+        use std::error::Error;
+
+        let out_dir = PathBuf::from(od);
+        let name = &*self.meta.bin_name.as_ref().unwrap().clone();
+        let file_name = match for_shell {
+            Shell::Bash => format!("{}.bash", name),
+            Shell::Fish => format!("{}.fish", name),
+            Shell::Zsh => format!("_{}", name),
+            Shell::PowerShell => format!("_{}.ps1", name),
+            Shell::Elvish => format!("{}.elv", name),
+        };
+
+        let mut file = match File::create(out_dir.join(file_name)) {
+            Err(why) => panic!("couldn't create completion file: {}", why.description()),
+            Ok(file) => file,
+        };
+        self.gen_completions_to(for_shell, &mut file)
+    }
+
+    #[inline]
+    fn app_debug_asserts(&self) -> bool {
+        assert!(self.verify_positionals());
+        let should_err = self.groups.iter().all(|g| {
+            g.args.iter().all(|arg| {
+                (self.flags.iter().any(|f| &f.b.name == arg)
+                    || self.opts.iter().any(|o| &o.b.name == arg)
+                    || self.positionals.values().any(|p| &p.b.name == arg)
+                    || self.groups.iter().any(|g| &g.name == arg))
+            })
+        });
+        let g = self.groups.iter().find(|g| {
+            g.args.iter().any(|arg| {
+                !(self.flags.iter().any(|f| &f.b.name == arg)
+                    || self.opts.iter().any(|o| &o.b.name == arg)
+                    || self.positionals.values().any(|p| &p.b.name == arg)
+                    || self.groups.iter().any(|g| &g.name == arg))
+            })
+        });
+        assert!(
+            should_err,
+            "The group '{}' contains the arg '{}' that doesn't actually exist.",
+            g.unwrap().name,
+            g.unwrap()
+                .args
+                .iter()
+                .find(|arg| !(self.flags.iter().any(|f| &&f.b.name == arg)
+                    || self.opts.iter().any(|o| &&o.b.name == arg)
+                    || self.positionals.values().any(|p| &&p.b.name == arg)
+                    || self.groups.iter().any(|g| &&g.name == arg)))
+                .unwrap()
+        );
+        true
+    }
+
+    #[inline]
+    fn debug_asserts(&self, a: &Arg) -> bool {
+        assert!(
+            !arg_names!(self).any(|name| name == a.b.name),
+            format!("Non-unique argument name: {} is already in use", a.b.name)
+        );
+        if let Some(l) = a.s.long {
+            assert!(
+                !self.contains_long(l),
+                "Argument long must be unique\n\n\t--{} is already in use",
+                l
+            );
+        }
+        if let Some(s) = a.s.short {
+            assert!(
+                !self.contains_short(s),
+                "Argument short must be unique\n\n\t-{} is already in use",
+                s
+            );
+        }
+        let i = if a.index.is_none() {
+            (self.positionals.len() + 1)
+        } else {
+            a.index.unwrap() as usize
+        };
+        assert!(
+            !self.positionals.contains_key(i),
+            "Argument \"{}\" has the same index as another positional \
+             argument\n\n\tPerhaps try .multiple(true) to allow one positional argument \
+             to take multiple values",
+            a.b.name
+        );
+        assert!(
+            !(a.is_set(ArgSettings::Required) && a.is_set(ArgSettings::Global)),
+            "Global arguments cannot be required.\n\n\t'{}' is marked as \
+             global and required",
+            a.b.name
+        );
+        if a.b.is_set(ArgSettings::Last) {
+            assert!(
+                !self.positionals
+                    .values()
+                    .any(|p| p.b.is_set(ArgSettings::Last)),
+                "Only one positional argument may have last(true) set. Found two."
+            );
+            assert!(a.s.long.is_none(),
+                    "Flags or Options may not have last(true) set. {} has both a long and last(true) set.",
+                    a.b.name);
+            assert!(a.s.short.is_none(),
+                    "Flags or Options may not have last(true) set. {} has both a short and last(true) set.",
+                    a.b.name);
+        }
+        true
+    }
+
+    #[inline]
+    fn add_conditional_reqs(&mut self, a: &Arg<'a, 'b>) {
+        if let Some(ref r_ifs) = a.r_ifs {
+            for &(arg, val) in r_ifs {
+                self.r_ifs.push((arg, val, a.b.name));
+            }
+        }
+    }
+
+    #[inline]
+    fn add_arg_groups(&mut self, a: &Arg<'a, 'b>) {
+        if let Some(ref grps) = a.b.groups {
+            for g in grps {
+                let mut found = false;
+                if let Some(ref mut ag) = self.groups.iter_mut().find(|grp| &grp.name == g) {
+                    ag.args.push(a.b.name);
+                    found = true;
+                }
+                if !found {
+                    let mut ag = ArgGroup::with_name(g);
+                    ag.args.push(a.b.name);
+                    self.groups.push(ag);
+                }
+            }
+        }
+    }
+
+    #[inline]
+    fn add_reqs(&mut self, a: &Arg<'a, 'b>) {
+        if a.is_set(ArgSettings::Required) {
+            // If the arg is required, add all it's requirements to master required list
+            self.required.push(a.b.name);
+            if let Some(ref areqs) = a.b.requires {
+                for name in areqs
+                    .iter()
+                    .filter(|&&(val, _)| val.is_none())
+                    .map(|&(_, name)| name)
+                {
+                    self.required.push(name);
+                }
+            }
+        }
+    }
+
+    #[inline]
+    fn implied_settings(&mut self, a: &Arg<'a, 'b>) {
+        if a.is_set(ArgSettings::Last) {
+            // if an arg has `Last` set, we need to imply DontCollapseArgsInUsage so that args
+            // in the usage string don't get confused or left out.
+            self.set(AS::DontCollapseArgsInUsage);
+            self.set(AS::ContainsLast);
+        }
+        if let Some(l) = a.s.long {
+            if l == "version" {
+                self.unset(AS::NeedsLongVersion);
+            } else if l == "help" {
+                self.unset(AS::NeedsLongHelp);
+            }
+        }
+    }
+
+    // actually adds the arguments
+    pub fn add_arg(&mut self, a: Arg<'a, 'b>) {
+        // if it's global we have to clone anyways
+        if a.is_set(ArgSettings::Global) {
+            return self.add_arg_ref(&a);
+        }
+        debug_assert!(self.debug_asserts(&a));
+        self.add_conditional_reqs(&a);
+        self.add_arg_groups(&a);
+        self.add_reqs(&a);
+        self.implied_settings(&a);
+        if a.index.is_some() || (a.s.short.is_none() && a.s.long.is_none()) {
+            let i = if a.index.is_none() {
+                (self.positionals.len() + 1)
+            } else {
+                a.index.unwrap() as usize
+            };
+            self.positionals
+                .insert(i, PosBuilder::from_arg(a, i as u64));
+        } else if a.is_set(ArgSettings::TakesValue) {
+            let mut ob = OptBuilder::from(a);
+            ob.s.unified_ord = self.flags.len() + self.opts.len();
+            self.opts.push(ob);
+        } else {
+            let mut fb = FlagBuilder::from(a);
+            fb.s.unified_ord = self.flags.len() + self.opts.len();
+            self.flags.push(fb);
+        }
+    }
+    // actually adds the arguments but from a borrow (which means we have to do some cloning)
+    pub fn add_arg_ref(&mut self, a: &Arg<'a, 'b>) {
+        debug_assert!(self.debug_asserts(a));
+        self.add_conditional_reqs(a);
+        self.add_arg_groups(a);
+        self.add_reqs(a);
+        self.implied_settings(a);
+        if a.index.is_some() || (a.s.short.is_none() && a.s.long.is_none()) {
+            let i = if a.index.is_none() {
+                (self.positionals.len() + 1)
+            } else {
+                a.index.unwrap() as usize
+            };
+            let pb = PosBuilder::from_arg_ref(a, i as u64);
+            self.positionals.insert(i, pb);
+        } else if a.is_set(ArgSettings::TakesValue) {
+            let mut ob = OptBuilder::from(a);
+            ob.s.unified_ord = self.flags.len() + self.opts.len();
+            self.opts.push(ob);
+        } else {
+            let mut fb = FlagBuilder::from(a);
+            fb.s.unified_ord = self.flags.len() + self.opts.len();
+            self.flags.push(fb);
+        }
+        if a.is_set(ArgSettings::Global) {
+            self.global_args.push(a.into());
+        }
+    }
+
+    pub fn add_group(&mut self, group: ArgGroup<'a>) {
+        if group.required {
+            self.required.push(group.name);
+            if let Some(ref reqs) = group.requires {
+                self.required.extend_from_slice(reqs);
+            }
+            //            if let Some(ref bl) = group.conflicts {
+            //                self.blacklist.extend_from_slice(bl);
+            //            }
+        }
+        if self.groups.iter().any(|g| g.name == group.name) {
+            let grp = self.groups
+                .iter_mut()
+                .find(|g| g.name == group.name)
+                .expect(INTERNAL_ERROR_MSG);
+            grp.args.extend_from_slice(&group.args);
+            grp.requires = group.requires.clone();
+            grp.conflicts = group.conflicts.clone();
+            grp.required = group.required;
+        } else {
+            self.groups.push(group);
+        }
+    }
+
+    pub fn add_subcommand(&mut self, mut subcmd: App<'a, 'b>) {
+        debugln!(
+            "Parser::add_subcommand: term_w={:?}, name={}",
+            self.meta.term_w,
+            subcmd.p.meta.name
+        );
+        subcmd.p.meta.term_w = self.meta.term_w;
+        if subcmd.p.meta.name == "help" {
+            self.unset(AS::NeedsSubcommandHelp);
+        }
+
+        self.subcommands.push(subcmd);
+    }
+
+    pub fn propagate_settings(&mut self) {
+        debugln!(
+            "Parser::propagate_settings: self={}, g_settings={:#?}",
+            self.meta.name,
+            self.g_settings
+        );
+        for sc in &mut self.subcommands {
+            debugln!(
+                "Parser::propagate_settings: sc={}, settings={:#?}, g_settings={:#?}",
+                sc.p.meta.name,
+                sc.p.settings,
+                sc.p.g_settings
+            );
+            // We have to create a new scope in order to tell rustc the borrow of `sc` is
+            // done and to recursively call this method
+            {
+                let vsc = self.settings.is_set(AS::VersionlessSubcommands);
+                let gv = self.settings.is_set(AS::GlobalVersion);
+
+                if vsc {
+                    sc.p.set(AS::DisableVersion);
+                }
+                if gv && sc.p.meta.version.is_none() && self.meta.version.is_some() {
+                    sc.p.set(AS::GlobalVersion);
+                    sc.p.meta.version = Some(self.meta.version.unwrap());
+                }
+                sc.p.settings = sc.p.settings | self.g_settings;
+                sc.p.g_settings = sc.p.g_settings | self.g_settings;
+                sc.p.meta.term_w = self.meta.term_w;
+                sc.p.meta.max_w = self.meta.max_w;
+            }
+            sc.p.propagate_settings();
+        }
+    }
+
+    #[cfg_attr(feature = "lints", allow(needless_borrow))]
+    pub fn derive_display_order(&mut self) {
+        if self.is_set(AS::DeriveDisplayOrder) {
+            let unified = self.is_set(AS::UnifiedHelpMessage);
+            for (i, o) in self.opts
+                .iter_mut()
+                .enumerate()
+                .filter(|&(_, ref o)| o.s.disp_ord == 999)
+            {
+                o.s.disp_ord = if unified { o.s.unified_ord } else { i };
+            }
+            for (i, f) in self.flags
+                .iter_mut()
+                .enumerate()
+                .filter(|&(_, ref f)| f.s.disp_ord == 999)
+            {
+                f.s.disp_ord = if unified { f.s.unified_ord } else { i };
+            }
+            for (i, sc) in &mut self.subcommands
+                .iter_mut()
+                .enumerate()
+                .filter(|&(_, ref sc)| sc.p.meta.disp_ord == 999)
+            {
+                sc.p.meta.disp_ord = i;
+            }
+        }
+        for sc in &mut self.subcommands {
+            sc.p.derive_display_order();
+        }
+    }
+
+    pub fn required(&self) -> Iter<&str> { self.required.iter() }
+
+    #[cfg_attr(feature = "lints", allow(needless_borrow))]
+    #[inline]
+    pub fn has_args(&self) -> bool {
+        !(self.flags.is_empty() && self.opts.is_empty() && self.positionals.is_empty())
+    }
+
+    #[inline]
+    pub fn has_opts(&self) -> bool { !self.opts.is_empty() }
+
+    #[inline]
+    pub fn has_flags(&self) -> bool { !self.flags.is_empty() }
+
+    #[inline]
+    pub fn has_positionals(&self) -> bool { !self.positionals.is_empty() }
+
+    #[inline]
+    pub fn has_subcommands(&self) -> bool { !self.subcommands.is_empty() }
+
+    #[inline]
+    pub fn has_visible_opts(&self) -> bool {
+        if self.opts.is_empty() {
+            return false;
+        }
+        self.opts.iter().any(|o| !o.is_set(ArgSettings::Hidden))
+    }
+
+    #[inline]
+    pub fn has_visible_flags(&self) -> bool {
+        if self.flags.is_empty() {
+            return false;
+        }
+        self.flags.iter().any(|f| !f.is_set(ArgSettings::Hidden))
+    }
+
+    #[inline]
+    pub fn has_visible_positionals(&self) -> bool {
+        if self.positionals.is_empty() {
+            return false;
+        }
+        self.positionals
+            .values()
+            .any(|p| !p.is_set(ArgSettings::Hidden))
+    }
+
+    #[inline]
+    pub fn has_visible_subcommands(&self) -> bool {
+        self.has_subcommands()
+            && self.subcommands
+                .iter()
+                .filter(|sc| sc.p.meta.name != "help")
+                .any(|sc| !sc.p.is_set(AS::Hidden))
+    }
+
+    #[inline]
+    pub fn is_set(&self, s: AS) -> bool { self.settings.is_set(s) }
+
+    #[inline]
+    pub fn set(&mut self, s: AS) { self.settings.set(s) }
+
+    #[inline]
+    pub fn unset(&mut self, s: AS) { self.settings.unset(s) }
+
+    #[cfg_attr(feature = "lints", allow(block_in_if_condition_stmt))]
+    pub fn verify_positionals(&self) -> bool {
+        // Because you must wait until all arguments have been supplied, this is the first chance
+        // to make assertions on positional argument indexes
+        //
+        // First we verify that the index highest supplied index, is equal to the number of
+        // positional arguments to verify there are no gaps (i.e. supplying an index of 1 and 3
+        // but no 2)
+        if let Some((idx, p)) = self.positionals.iter().rev().next() {
+            assert!(
+                !(idx != self.positionals.len()),
+                "Found positional argument \"{}\" whose index is {} but there \
+                 are only {} positional arguments defined",
+                p.b.name,
+                idx,
+                self.positionals.len()
+            );
+        }
+
+        // Next we verify that only the highest index has a .multiple(true) (if any)
+        if self.positionals.values().any(|a| {
+            a.b.is_set(ArgSettings::Multiple) && (a.index as usize != self.positionals.len())
+        }) {
+            let mut it = self.positionals.values().rev();
+            let last = it.next().unwrap();
+            let second_to_last = it.next().unwrap();
+            // Either the final positional is required
+            // Or the second to last has a terminator or .last(true) set
+            let ok = last.is_set(ArgSettings::Required)
+                || (second_to_last.v.terminator.is_some()
+                    || second_to_last.b.is_set(ArgSettings::Last))
+                || last.is_set(ArgSettings::Last);
+            assert!(
+                ok,
+                "When using a positional argument with .multiple(true) that is *not the \
+                 last* positional argument, the last positional argument (i.e the one \
+                 with the highest index) *must* have .required(true) or .last(true) set."
+            );
+            let ok = second_to_last.is_set(ArgSettings::Multiple) || last.is_set(ArgSettings::Last);
+            assert!(
+                ok,
+                "Only the last positional argument, or second to last positional \
+                 argument may be set to .multiple(true)"
+            );
+
+            let count = self.positionals
+                .values()
+                .filter(|p| p.b.settings.is_set(ArgSettings::Multiple) && p.v.num_vals.is_none())
+                .count();
+            let ok = count <= 1
+                || (last.is_set(ArgSettings::Last) && last.is_set(ArgSettings::Multiple)
+                    && second_to_last.is_set(ArgSettings::Multiple)
+                    && count == 2);
+            assert!(
+                ok,
+                "Only one positional argument with .multiple(true) set is allowed per \
+                 command, unless the second one also has .last(true) set"
+            );
+        }
+
+        if self.is_set(AS::AllowMissingPositional) {
+            // Check that if a required positional argument is found, all positions with a lower
+            // index are also required.
+            let mut found = false;
+            let mut foundx2 = false;
+            for p in self.positionals.values().rev() {
+                if foundx2 && !p.b.settings.is_set(ArgSettings::Required) {
+                    assert!(
+                        p.b.is_set(ArgSettings::Required),
+                        "Found positional argument which is not required with a lower \
+                         index than a required positional argument by two or more: {:?} \
+                         index {}",
+                        p.b.name,
+                        p.index
+                    );
+                } else if p.b.is_set(ArgSettings::Required) && !p.b.is_set(ArgSettings::Last) {
+                    // Args that .last(true) don't count since they can be required and have
+                    // positionals with a lower index that aren't required
+                    // Imagine: prog <req1> [opt1] -- <req2>
+                    // Both of these are valid invocations:
+                    //      $ prog r1 -- r2
+                    //      $ prog r1 o1 -- r2
+                    if found {
+                        foundx2 = true;
+                        continue;
+                    }
+                    found = true;
+                    continue;
+                } else {
+                    found = false;
+                }
+            }
+        } else {
+            // Check that if a required positional argument is found, all positions with a lower
+            // index are also required
+            let mut found = false;
+            for p in self.positionals.values().rev() {
+                if found {
+                    assert!(
+                        p.b.is_set(ArgSettings::Required),
+                        "Found positional argument which is not required with a lower \
+                         index than a required positional argument: {:?} index {}",
+                        p.b.name,
+                        p.index
+                    );
+                } else if p.b.is_set(ArgSettings::Required) && !p.b.is_set(ArgSettings::Last) {
+                    // Args that .last(true) don't count since they can be required and have
+                    // positionals with a lower index that aren't required
+                    // Imagine: prog <req1> [opt1] -- <req2>
+                    // Both of these are valid invocations:
+                    //      $ prog r1 -- r2
+                    //      $ prog r1 o1 -- r2
+                    found = true;
+                    continue;
+                }
+            }
+        }
+        if self.positionals
+            .values()
+            .any(|p| p.b.is_set(ArgSettings::Last) && p.b.is_set(ArgSettings::Required))
+            && self.has_subcommands() && !self.is_set(AS::SubcommandsNegateReqs)
+        {
+            panic!(
+                "Having a required positional argument with .last(true) set *and* child \
+                 subcommands without setting SubcommandsNegateReqs isn't compatible."
+            );
+        }
+
+        true
+    }
+
+    pub fn propagate_globals(&mut self) {
+        for sc in &mut self.subcommands {
+            // We have to create a new scope in order to tell rustc the borrow of `sc` is
+            // done and to recursively call this method
+            {
+                for a in &self.global_args {
+                    sc.p.add_arg_ref(a);
+                }
+            }
+            sc.p.propagate_globals();
+        }
+    }
+
+    // Checks if the arg matches a subcommand name, or any of it's aliases (if defined)
+    fn possible_subcommand(&self, arg_os: &OsStr) -> (bool, Option<&str>) {
+        #[cfg(not(any(target_os = "windows", target_arch = "wasm32")))]
+        use std::os::unix::ffi::OsStrExt;
+        #[cfg(any(target_os = "windows", target_arch = "wasm32"))]
+        use osstringext::OsStrExt3;
+        debugln!("Parser::possible_subcommand: arg={:?}", arg_os);
+        fn starts(h: &str, n: &OsStr) -> bool {
+            let n_bytes = n.as_bytes();
+            let h_bytes = OsStr::new(h).as_bytes();
+
+            h_bytes.starts_with(n_bytes)
+        }
+
+        if self.is_set(AS::ArgsNegateSubcommands) && self.is_set(AS::ValidArgFound) {
+            return (false, None);
+        }
+        if !self.is_set(AS::InferSubcommands) {
+            if let Some(sc) = find_subcmd!(self, arg_os) {
+                return (true, Some(&sc.p.meta.name));
+            }
+        } else {
+            let v = self.subcommands
+                .iter()
+                .filter(|s| {
+                    starts(&s.p.meta.name[..], &*arg_os)
+                        || (s.p.meta.aliases.is_some()
+                            && s.p
+                                .meta
+                                .aliases
+                                .as_ref()
+                                .unwrap()
+                                .iter()
+                                .filter(|&&(a, _)| starts(a, &*arg_os))
+                                .count() == 1)
+                })
+                .map(|sc| &sc.p.meta.name)
+                .collect::<Vec<_>>();
+
+            for sc in &v {
+                if OsStr::new(sc) == arg_os {
+                    return (true, Some(sc));
+                }
+            }
+
+            if v.len() == 1 {
+                return (true, Some(v[0]));
+            }
+        }
+        (false, None)
+    }
+
+    fn parse_help_subcommand<I, T>(&self, it: &mut I) -> ClapResult<ParseResult<'a>>
+    where
+        I: Iterator<Item = T>,
+        T: Into<OsString>,
+    {
+        debugln!("Parser::parse_help_subcommand;");
+        let cmds: Vec<OsString> = it.map(|c| c.into()).collect();
+        let mut help_help = false;
+        let mut bin_name = self.meta
+            .bin_name
+            .as_ref()
+            .unwrap_or(&self.meta.name)
+            .clone();
+        let mut sc = {
+            let mut sc: &Parser = self;
+            for (i, cmd) in cmds.iter().enumerate() {
+                if &*cmd.to_string_lossy() == "help" {
+                    // cmd help help
+                    help_help = true;
+                }
+                if let Some(c) = sc.subcommands
+                    .iter()
+                    .find(|s| &*s.p.meta.name == cmd)
+                    .map(|sc| &sc.p)
+                {
+                    sc = c;
+                    if i == cmds.len() - 1 {
+                        break;
+                    }
+                } else if let Some(c) = sc.subcommands
+                    .iter()
+                    .find(|s| {
+                        if let Some(ref als) = s.p.meta.aliases {
+                            als.iter().any(|&(a, _)| a == &*cmd.to_string_lossy())
+                        } else {
+                            false
+                        }
+                    })
+                    .map(|sc| &sc.p)
+                {
+                    sc = c;
+                    if i == cmds.len() - 1 {
+                        break;
+                    }
+                } else {
+                    return Err(Error::unrecognized_subcommand(
+                        cmd.to_string_lossy().into_owned(),
+                        self.meta.bin_name.as_ref().unwrap_or(&self.meta.name),
+                        self.color(),
+                    ));
+                }
+                bin_name = format!("{} {}", bin_name, &*sc.meta.name);
+            }
+            sc.clone()
+        };
+        if help_help {
+            let mut pb = PosBuilder::new("subcommand", 1);
+            pb.b.help = Some("The subcommand whose help message to display");
+            pb.set(ArgSettings::Multiple);
+            sc.positionals.insert(1, pb);
+            sc.settings = sc.settings | self.g_settings;
+        } else {
+            sc.create_help_and_version();
+        }
+        if sc.meta.bin_name != self.meta.bin_name {
+            sc.meta.bin_name = Some(format!("{} {}", bin_name, sc.meta.name));
+        }
+        Err(sc._help(false))
+    }
+
+    // allow wrong self convention due to self.valid_neg_num = true and it's a private method
+    #[cfg_attr(feature = "lints", allow(wrong_self_convention))]
+    fn is_new_arg(&mut self, arg_os: &OsStr, needs_val_of: ParseResult) -> bool {
+        debugln!("Parser::is_new_arg:{:?}:{:?}", arg_os, needs_val_of);
+        let app_wide_settings = if self.is_set(AS::AllowLeadingHyphen) {
+            true
+        } else if self.is_set(AS::AllowNegativeNumbers) {
+            let a = arg_os.to_string_lossy();
+            if a.parse::<i64>().is_ok() || a.parse::<f64>().is_ok() {
+                self.set(AS::ValidNegNumFound);
+                true
+            } else {
+                false
+            }
+        } else {
+            false
+        };
+        let arg_allows_tac = match needs_val_of {
+            ParseResult::Opt(name) => {
+                let o = self.opts
+                    .iter()
+                    .find(|o| o.b.name == name)
+                    .expect(INTERNAL_ERROR_MSG);
+                (o.is_set(ArgSettings::AllowLeadingHyphen) || app_wide_settings)
+            }
+            ParseResult::Pos(name) => {
+                let p = self.positionals
+                    .values()
+                    .find(|p| p.b.name == name)
+                    .expect(INTERNAL_ERROR_MSG);
+                (p.is_set(ArgSettings::AllowLeadingHyphen) || app_wide_settings)
+            }
+            ParseResult::ValuesDone => return true,
+            _ => false,
+        };
+        debugln!("Parser::is_new_arg: arg_allows_tac={:?}", arg_allows_tac);
+
+        // Is this a new argument, or values from a previous option?
+        let mut ret = if arg_os.starts_with(b"--") {
+            debugln!("Parser::is_new_arg: -- found");
+            if arg_os.len() == 2 && !arg_allows_tac {
+                return true; // We have to return true so override everything else
+            } else if arg_allows_tac {
+                return false;
+            }
+            true
+        } else if arg_os.starts_with(b"-") {
+            debugln!("Parser::is_new_arg: - found");
+            // a singe '-' by itself is a value and typically means "stdin" on unix systems
+            !(arg_os.len() == 1)
+        } else {
+            debugln!("Parser::is_new_arg: probably value");
+            false
+        };
+
+        ret = ret && !arg_allows_tac;
+
+        debugln!("Parser::is_new_arg: starts_new_arg={:?}", ret);
+        ret
+    }
+
+    // The actual parsing function
+    #[cfg_attr(feature = "lints", allow(while_let_on_iterator, collapsible_if))]
+    pub fn get_matches_with<I, T>(
+        &mut self,
+        matcher: &mut ArgMatcher<'a>,
+        it: &mut Peekable<I>,
+    ) -> ClapResult<()>
+    where
+        I: Iterator<Item = T>,
+        T: Into<OsString> + Clone,
+    {
+        debugln!("Parser::get_matches_with;");
+        // Verify all positional assertions pass
+        debug_assert!(self.app_debug_asserts());
+        if self.positionals.values().any(|a| {
+            a.b.is_set(ArgSettings::Multiple) && (a.index as usize != self.positionals.len())
+        })
+            && self.positionals
+                .values()
+                .last()
+                .map_or(false, |p| !p.is_set(ArgSettings::Last))
+        {
+            self.settings.set(AS::LowIndexMultiplePositional);
+        }
+        let has_args = self.has_args();
+
+        // Next we create the `--help` and `--version` arguments and add them if
+        // necessary
+        self.create_help_and_version();
+
+        let mut subcmd_name: Option<String> = None;
+        let mut needs_val_of: ParseResult<'a> = ParseResult::NotFound;
+        let mut pos_counter = 1;
+        let mut sc_is_external = false;
+        while let Some(arg) = it.next() {
+            let arg_os = arg.into();
+            debugln!(
+                "Parser::get_matches_with: Begin parsing '{:?}' ({:?})",
+                arg_os,
+                &*arg_os.as_bytes()
+            );
+
+            self.unset(AS::ValidNegNumFound);
+            // Is this a new argument, or values from a previous option?
+            let starts_new_arg = self.is_new_arg(&arg_os, needs_val_of);
+            if !self.is_set(AS::TrailingValues) && arg_os.starts_with(b"--") && arg_os.len() == 2
+                && starts_new_arg
+            {
+                debugln!("Parser::get_matches_with: setting TrailingVals=true");
+                self.set(AS::TrailingValues);
+                continue;
+            }
+
+            // Has the user already passed '--'? Meaning only positional args follow
+            if !self.is_set(AS::TrailingValues) {
+                // Does the arg match a subcommand name, or any of it's aliases (if defined)
+                {
+                    match needs_val_of {
+                        ParseResult::Opt(_) | ParseResult::Pos(_) => (),
+                        _ => {
+                            let (is_match, sc_name) = self.possible_subcommand(&arg_os);
+                            debugln!(
+                                "Parser::get_matches_with: possible_sc={:?}, sc={:?}",
+                                is_match,
+                                sc_name
+                            );
+                            if is_match {
+                                let sc_name = sc_name.expect(INTERNAL_ERROR_MSG);
+                                if sc_name == "help" && self.is_set(AS::NeedsSubcommandHelp) {
+                                    self.parse_help_subcommand(it)?;
+                                }
+                                subcmd_name = Some(sc_name.to_owned());
+                                break;
+                            }
+                        }
+                    }
+                }
+
+                if starts_new_arg {
+                    let check_all = self.is_set(AS::AllArgsOverrideSelf);
+                    {
+                        let any_arg = find_any_by_name!(self, self.cache.unwrap_or(""));
+                        matcher.process_arg_overrides(
+                            any_arg,
+                            &mut self.overrides,
+                            &mut self.required,
+                            check_all,
+                        );
+                    }
+
+                    if arg_os.starts_with(b"--") {
+                        needs_val_of = self.parse_long_arg(matcher, &arg_os, it)?;
+                        debugln!(
+                            "Parser:get_matches_with: After parse_long_arg {:?}",
+                            needs_val_of
+                        );
+                        match needs_val_of {
+                            ParseResult::Flag | ParseResult::Opt(..) | ParseResult::ValuesDone => {
+                                continue
+                            }
+                            _ => (),
+                        }
+                    } else if arg_os.starts_with(b"-") && arg_os.len() != 1 {
+                        // Try to parse short args like normal, if AllowLeadingHyphen or
+                        // AllowNegativeNumbers is set, parse_short_arg will *not* throw
+                        // an error, and instead return Ok(None)
+                        needs_val_of = self.parse_short_arg(matcher, &arg_os)?;
+                        // If it's None, we then check if one of those two AppSettings was set
+                        debugln!(
+                            "Parser:get_matches_with: After parse_short_arg {:?}",
+                            needs_val_of
+                        );
+                        match needs_val_of {
+                            ParseResult::MaybeNegNum => {
+                                if !(arg_os.to_string_lossy().parse::<i64>().is_ok()
+                                    || arg_os.to_string_lossy().parse::<f64>().is_ok())
+                                {
+                                    return Err(Error::unknown_argument(
+                                        &*arg_os.to_string_lossy(),
+                                        "",
+                                        &*usage::create_error_usage(self, matcher, None),
+                                        self.color(),
+                                    ));
+                                }
+                            }
+                            ParseResult::Opt(..) | ParseResult::Flag | ParseResult::ValuesDone => {
+                                continue
+                            }
+                            _ => (),
+                        }
+                    }
+                } else {
+                    if let ParseResult::Opt(name) = needs_val_of {
+                        // Check to see if parsing a value from a previous arg
+                        let arg = self.opts
+                            .iter()
+                            .find(|o| o.b.name == name)
+                            .expect(INTERNAL_ERROR_MSG);
+                        // get the OptBuilder so we can check the settings
+                        needs_val_of = self.add_val_to_arg(arg, &arg_os, matcher)?;
+                        // get the next value from the iterator
+                        continue;
+                    }
+                }
+            }
+
+            if !(self.is_set(AS::ArgsNegateSubcommands) && self.is_set(AS::ValidArgFound))
+                && !self.is_set(AS::InferSubcommands) && !self.is_set(AS::AllowExternalSubcommands)
+            {
+                if let Some(cdate) =
+                    suggestions::did_you_mean(&*arg_os.to_string_lossy(), sc_names!(self))
+                {
+                    return Err(Error::invalid_subcommand(
+                        arg_os.to_string_lossy().into_owned(),
+                        cdate,
+                        self.meta.bin_name.as_ref().unwrap_or(&self.meta.name),
+                        &*usage::create_error_usage(self, matcher, None),
+                        self.color(),
+                    ));
+                }
+            }
+
+            let low_index_mults = self.is_set(AS::LowIndexMultiplePositional)
+                && pos_counter == (self.positionals.len() - 1);
+            let missing_pos = self.is_set(AS::AllowMissingPositional)
+                && (pos_counter == (self.positionals.len() - 1)
+                    && !self.is_set(AS::TrailingValues));
+            debugln!(
+                "Parser::get_matches_with: Positional counter...{}",
+                pos_counter
+            );
+            debugln!(
+                "Parser::get_matches_with: Low index multiples...{:?}",
+                low_index_mults
+            );
+            if low_index_mults || missing_pos {
+                if let Some(na) = it.peek() {
+                    let n = (*na).clone().into();
+                    needs_val_of = if needs_val_of != ParseResult::ValuesDone {
+                        if let Some(p) = self.positionals.get(pos_counter) {
+                            ParseResult::Pos(p.b.name)
+                        } else {
+                            ParseResult::ValuesDone
+                        }
+                    } else {
+                        ParseResult::ValuesDone
+                    };
+                    let sc_match = { self.possible_subcommand(&n).0 };
+                    if self.is_new_arg(&n, needs_val_of) || sc_match
+                        || suggestions::did_you_mean(&n.to_string_lossy(), sc_names!(self))
+                            .is_some()
+                    {
+                        debugln!("Parser::get_matches_with: Bumping the positional counter...");
+                        pos_counter += 1;
+                    }
+                } else {
+                    debugln!("Parser::get_matches_with: Bumping the positional counter...");
+                    pos_counter += 1;
+                }
+            } else if (self.is_set(AS::AllowMissingPositional) && self.is_set(AS::TrailingValues))
+                || (self.is_set(AS::ContainsLast) && self.is_set(AS::TrailingValues))
+            {
+                // Came to -- and one postional has .last(true) set, so we go immediately
+                // to the last (highest index) positional
+                debugln!("Parser::get_matches_with: .last(true) and --, setting last pos");
+                pos_counter = self.positionals.len();
+            }
+            if let Some(p) = self.positionals.get(pos_counter) {
+                if p.is_set(ArgSettings::Last) && !self.is_set(AS::TrailingValues) {
+                    return Err(Error::unknown_argument(
+                        &*arg_os.to_string_lossy(),
+                        "",
+                        &*usage::create_error_usage(self, matcher, None),
+                        self.color(),
+                    ));
+                }
+                if !self.is_set(AS::TrailingValues)
+                    && (self.is_set(AS::TrailingVarArg) && pos_counter == self.positionals.len())
+                {
+                    self.settings.set(AS::TrailingValues);
+                }
+                if self.cache.map_or(true, |name| name != p.b.name) {
+                    let check_all = self.is_set(AS::AllArgsOverrideSelf);
+                    {
+                        let any_arg = find_any_by_name!(self, self.cache.unwrap_or(""));
+                        matcher.process_arg_overrides(
+                            any_arg,
+                            &mut self.overrides,
+                            &mut self.required,
+                            check_all,
+                        );
+                    }
+                    self.cache = Some(p.b.name);
+                }
+                let _ = self.add_val_to_arg(p, &arg_os, matcher)?;
+
+                matcher.inc_occurrence_of(p.b.name);
+                let _ = self.groups_for_arg(p.b.name)
+                    .and_then(|vec| Some(matcher.inc_occurrences_of(&*vec)));
+
+                self.settings.set(AS::ValidArgFound);
+                // Only increment the positional counter if it doesn't allow multiples
+                if !p.b.settings.is_set(ArgSettings::Multiple) {
+                    pos_counter += 1;
+                }
+                self.settings.set(AS::ValidArgFound);
+            } else if self.is_set(AS::AllowExternalSubcommands) {
+                // Get external subcommand name
+                let sc_name = match arg_os.to_str() {
+                    Some(s) => s.to_string(),
+                    None => {
+                        if !self.is_set(AS::StrictUtf8) {
+                            return Err(Error::invalid_utf8(
+                                &*usage::create_error_usage(self, matcher, None),
+                                self.color(),
+                            ));
+                        }
+                        arg_os.to_string_lossy().into_owned()
+                    }
+                };
+
+                // Collect the external subcommand args
+                let mut sc_m = ArgMatcher::new();
+                while let Some(v) = it.next() {
+                    let a = v.into();
+                    if a.to_str().is_none() && !self.is_set(AS::StrictUtf8) {
+                        return Err(Error::invalid_utf8(
+                            &*usage::create_error_usage(self, matcher, None),
+                            self.color(),
+                        ));
+                    }
+                    sc_m.add_val_to("", &a);
+                }
+
+                matcher.subcommand(SubCommand {
+                    name: sc_name,
+                    matches: sc_m.into(),
+                });
+                sc_is_external = true;
+            } else if !((self.is_set(AS::AllowLeadingHyphen)
+                || self.is_set(AS::AllowNegativeNumbers))
+                && arg_os.starts_with(b"-"))
+                && !self.is_set(AS::InferSubcommands)
+            {
+                return Err(Error::unknown_argument(
+                    &*arg_os.to_string_lossy(),
+                    "",
+                    &*usage::create_error_usage(self, matcher, None),
+                    self.color(),
+                ));
+            } else if !has_args || self.is_set(AS::InferSubcommands) && self.has_subcommands() {
+                if let Some(cdate) =
+                    suggestions::did_you_mean(&*arg_os.to_string_lossy(), sc_names!(self))
+                {
+                    return Err(Error::invalid_subcommand(
+                        arg_os.to_string_lossy().into_owned(),
+                        cdate,
+                        self.meta.bin_name.as_ref().unwrap_or(&self.meta.name),
+                        &*usage::create_error_usage(self, matcher, None),
+                        self.color(),
+                    ));
+                } else {
+                    return Err(Error::unrecognized_subcommand(
+                        arg_os.to_string_lossy().into_owned(),
+                        self.meta.bin_name.as_ref().unwrap_or(&self.meta.name),
+                        self.color(),
+                    ));
+                }
+            } else {
+                return Err(Error::unknown_argument(
+                    &*arg_os.to_string_lossy(),
+                    "",
+                    &*usage::create_error_usage(self, matcher, None),
+                    self.color(),
+                ));
+            }
+        }
+
+        if !sc_is_external {
+            if let Some(ref pos_sc_name) = subcmd_name {
+                let sc_name = {
+                    find_subcmd!(self, pos_sc_name)
+                        .expect(INTERNAL_ERROR_MSG)
+                        .p
+                        .meta
+                        .name
+                        .clone()
+                };
+                self.parse_subcommand(&*sc_name, matcher, it)?;
+            } else if self.is_set(AS::SubcommandRequired) {
+                let bn = self.meta.bin_name.as_ref().unwrap_or(&self.meta.name);
+                return Err(Error::missing_subcommand(
+                    bn,
+                    &usage::create_error_usage(self, matcher, None),
+                    self.color(),
+                ));
+            } else if self.is_set(AS::SubcommandRequiredElseHelp) {
+                debugln!("Parser::get_matches_with: SubcommandRequiredElseHelp=true");
+                let mut out = vec![];
+                self.write_help_err(&mut out)?;
+                return Err(Error {
+                    message: String::from_utf8_lossy(&*out).into_owned(),
+                    kind: ErrorKind::MissingArgumentOrSubcommand,
+                    info: None,
+                });
+            }
+        }
+
+        // In case the last arg was new, we  need to process it's overrides
+        let check_all = self.is_set(AS::AllArgsOverrideSelf);
+        {
+            let any_arg = find_any_by_name!(self, self.cache.unwrap_or(""));
+            matcher.process_arg_overrides(
+                any_arg,
+                &mut self.overrides,
+                &mut self.required,
+                check_all,
+            );
+        }
+
+        self.remove_overrides(matcher);
+
+        Validator::new(self).validate(needs_val_of, subcmd_name, matcher)
+    }
+
+    fn remove_overrides(&mut self, matcher: &mut ArgMatcher) {
+        debugln!("Parser::remove_overrides:{:?};", self.overrides);
+        for &(overr, name) in &self.overrides {
+            debugln!("Parser::remove_overrides:iter:({},{});", overr, name);
+            if matcher.is_present(overr) {
+                debugln!(
+                    "Parser::remove_overrides:iter:({},{}): removing {};",
+                    overr,
+                    name,
+                    name
+                );
+                matcher.remove(name);
+                for i in (0..self.required.len()).rev() {
+                    debugln!(
+                        "Parser::remove_overrides:iter:({},{}): removing required {};",
+                        overr,
+                        name,
+                        name
+                    );
+                    if self.required[i] == name {
+                        self.required.swap_remove(i);
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    fn propagate_help_version(&mut self) {
+        debugln!("Parser::propagate_help_version;");
+        self.create_help_and_version();
+        for sc in &mut self.subcommands {
+            sc.p.propagate_help_version();
+        }
+    }
+
+    fn build_bin_names(&mut self) {
+        debugln!("Parser::build_bin_names;");
+        for sc in &mut self.subcommands {
+            debug!("Parser::build_bin_names:iter: bin_name set...");
+            if sc.p.meta.bin_name.is_none() {
+                sdebugln!("No");
+                let bin_name = format!(
+                    "{}{}{}",
+                    self.meta
+                        .bin_name
+                        .as_ref()
+                        .unwrap_or(&self.meta.name.clone()),
+                    if self.meta.bin_name.is_some() {
+                        " "
+                    } else {
+                        ""
+                    },
+                    &*sc.p.meta.name
+                );
+                debugln!(
+                    "Parser::build_bin_names:iter: Setting bin_name of {} to {}",
+                    self.meta.name,
+                    bin_name
+                );
+                sc.p.meta.bin_name = Some(bin_name);
+            } else {
+                sdebugln!("yes ({:?})", sc.p.meta.bin_name);
+            }
+            debugln!(
+                "Parser::build_bin_names:iter: Calling build_bin_names from...{}",
+                sc.p.meta.name
+            );
+            sc.p.build_bin_names();
+        }
+    }
+
+    fn parse_subcommand<I, T>(
+        &mut self,
+        sc_name: &str,
+        matcher: &mut ArgMatcher<'a>,
+        it: &mut Peekable<I>,
+    ) -> ClapResult<()>
+    where
+        I: Iterator<Item = T>,
+        T: Into<OsString> + Clone,
+    {
+        use std::fmt::Write;
+        debugln!("Parser::parse_subcommand;");
+        let mut mid_string = String::new();
+        if !self.is_set(AS::SubcommandsNegateReqs) {
+            let mut hs: Vec<&str> = self.required.iter().map(|n| &**n).collect();
+            for k in matcher.arg_names() {
+                hs.push(k);
+            }
+            let reqs = usage::get_required_usage_from(self, &hs, Some(matcher), None, false);
+
+            for s in &reqs {
+                write!(&mut mid_string, " {}", s).expect(INTERNAL_ERROR_MSG);
+            }
+        }
+        mid_string.push_str(" ");
+        if let Some(ref mut sc) = self.subcommands
+            .iter_mut()
+            .find(|s| s.p.meta.name == sc_name)
+        {
+            let mut sc_matcher = ArgMatcher::new();
+            // bin_name should be parent's bin_name + [<reqs>] + the sc's name separated by
+            // a space
+            sc.p.meta.usage = Some(format!(
+                "{}{}{}",
+                self.meta.bin_name.as_ref().unwrap_or(&String::new()),
+                if self.meta.bin_name.is_some() {
+                    &*mid_string
+                } else {
+                    ""
+                },
+                &*sc.p.meta.name
+            ));
+            sc.p.meta.bin_name = Some(format!(
+                "{}{}{}",
+                self.meta.bin_name.as_ref().unwrap_or(&String::new()),
+                if self.meta.bin_name.is_some() {
+                    " "
+                } else {
+                    ""
+                },
+                &*sc.p.meta.name
+            ));
+            debugln!(
+                "Parser::parse_subcommand: About to parse sc={}",
+                sc.p.meta.name
+            );
+            debugln!("Parser::parse_subcommand: sc settings={:#?}", sc.p.settings);
+            sc.p.get_matches_with(&mut sc_matcher, it)?;
+            matcher.subcommand(SubCommand {
+                name: sc.p.meta.name.clone(),
+                matches: sc_matcher.into(),
+            });
+        }
+        Ok(())
+    }
+
+    pub fn groups_for_arg(&self, name: &str) -> Option<Vec<&'a str>> {
+        debugln!("Parser::groups_for_arg: name={}", name);
+
+        if self.groups.is_empty() {
+            debugln!("Parser::groups_for_arg: No groups defined");
+            return None;
+        }
+        let mut res = vec![];
+        debugln!("Parser::groups_for_arg: Searching through groups...");
+        for grp in &self.groups {
+            for a in &grp.args {
+                if a == &name {
+                    sdebugln!("\tFound '{}'", grp.name);
+                    res.push(&*grp.name);
+                }
+            }
+        }
+        if res.is_empty() {
+            return None;
+        }
+
+        Some(res)
+    }
+
+    pub fn args_in_group(&self, group: &str) -> Vec<String> {
+        debug_assert!(self.app_debug_asserts());
+
+        let mut g_vec = vec![];
+        let mut args = vec![];
+
+        for n in &self.groups
+            .iter()
+            .find(|g| g.name == group)
+            .expect(INTERNAL_ERROR_MSG)
+            .args
+        {
+            if let Some(f) = self.flags.iter().find(|f| &f.b.name == n) {
+                args.push(f.to_string());
+            } else if let Some(f) = self.opts.iter().find(|o| &o.b.name == n) {
+                args.push(f.to_string());
+            } else if let Some(p) = self.positionals.values().find(|p| &p.b.name == n) {
+                args.push(p.b.name.to_owned());
+            } else {
+                g_vec.push(*n);
+            }
+        }
+
+        for av in g_vec.iter().map(|g| self.args_in_group(g)) {
+            args.extend(av);
+        }
+        args.dedup();
+        args.iter().map(ToOwned::to_owned).collect()
+    }
+
+    pub fn arg_names_in_group(&self, group: &str) -> Vec<&'a str> {
+        let mut g_vec = vec![];
+        let mut args = vec![];
+
+        for n in &self.groups
+            .iter()
+            .find(|g| g.name == group)
+            .expect(INTERNAL_ERROR_MSG)
+            .args
+        {
+            if self.groups.iter().any(|g| g.name == *n) {
+                args.extend(self.arg_names_in_group(n));
+                g_vec.push(*n);
+            } else if !args.contains(n) {
+                args.push(*n);
+            }
+        }
+
+        args.iter().map(|s| *s).collect()
+    }
+
+    pub fn create_help_and_version(&mut self) {
+        debugln!("Parser::create_help_and_version;");
+        // name is "hclap_help" because flags are sorted by name
+        if !self.is_set(AS::DisableHelpFlags) && !self.contains_long("help") {
+            debugln!("Parser::create_help_and_version: Building --help");
+            if self.help_short.is_none() && !self.contains_short('h') {
+                self.help_short = Some('h');
+            }
+            let arg = FlagBuilder {
+                b: Base {
+                    name: "hclap_help",
+                    help: self.help_message.or(Some("Prints help information")),
+                    ..Default::default()
+                },
+                s: Switched {
+                    short: self.help_short,
+                    long: Some("help"),
+                    ..Default::default()
+                },
+            };
+            self.flags.push(arg);
+        }
+        if !self.is_set(AS::DisableVersion) && !self.contains_long("version") {
+            debugln!("Parser::create_help_and_version: Building --version");
+            if self.version_short.is_none() && !self.contains_short('V') {
+                self.version_short = Some('V');
+            }
+            // name is "vclap_version" because flags are sorted by name
+            let arg = FlagBuilder {
+                b: Base {
+                    name: "vclap_version",
+                    help: self.version_message.or(Some("Prints version information")),
+                    ..Default::default()
+                },
+                s: Switched {
+                    short: self.version_short,
+                    long: Some("version"),
+                    ..Default::default()
+                },
+            };
+            self.flags.push(arg);
+        }
+        if !self.subcommands.is_empty() && !self.is_set(AS::DisableHelpSubcommand)
+            && self.is_set(AS::NeedsSubcommandHelp)
+        {
+            debugln!("Parser::create_help_and_version: Building help");
+            self.subcommands.push(
+                App::new("help")
+                    .about("Prints this message or the help of the given subcommand(s)"),
+            );
+        }
+    }
+
+    // Retrieves the names of all args the user has supplied thus far, except required ones
+    // because those will be listed in self.required
+    fn check_for_help_and_version_str(&self, arg: &OsStr) -> ClapResult<()> {
+        debugln!("Parser::check_for_help_and_version_str;");
+        debug!(
+            "Parser::check_for_help_and_version_str: Checking if --{} is help or version...",
+            arg.to_str().unwrap()
+        );
+        if arg == "help" && self.is_set(AS::NeedsLongHelp) {
+            sdebugln!("Help");
+            return Err(self._help(true));
+        }
+        if arg == "version" && self.is_set(AS::NeedsLongVersion) {
+            sdebugln!("Version");
+            return Err(self._version(true));
+        }
+        sdebugln!("Neither");
+
+        Ok(())
+    }
+
+    fn check_for_help_and_version_char(&self, arg: char) -> ClapResult<()> {
+        debugln!("Parser::check_for_help_and_version_char;");
+        debug!(
+            "Parser::check_for_help_and_version_char: Checking if -{} is help or version...",
+            arg
+        );
+        if let Some(h) = self.help_short {
+            if arg == h && self.is_set(AS::NeedsLongHelp) {
+                sdebugln!("Help");
+                return Err(self._help(false));
+            }
+        }
+        if let Some(v) = self.version_short {
+            if arg == v && self.is_set(AS::NeedsLongVersion) {
+                sdebugln!("Version");
+                return Err(self._version(false));
+            }
+        }
+        sdebugln!("Neither");
+        Ok(())
+    }
+
+    fn use_long_help(&self) -> bool {
+        // In this case, both must be checked. This allows the retention of 
+        // original formatting, but also ensures that the actual -h or --help
+        // specified by the user is sent through. If HiddenShortHelp is not included,
+        // then items specified with hidden_short_help will also be hidden.
+        let should_long = |v: &Base| { 
+            v.long_help.is_some() || 
+            v.is_set(ArgSettings::HiddenLongHelp) || 
+            v.is_set(ArgSettings::HiddenShortHelp) 
+        };
+
+        self.meta.long_about.is_some() 
+            || self.flags.iter().any(|f| should_long(&f.b))
+            || self.opts.iter().any(|o| should_long(&o.b))
+            || self.positionals.values().any(|p| should_long(&p.b))
+            || self.subcommands
+                .iter()
+                .any(|s| s.p.meta.long_about.is_some())
+    }
+    
+    fn _help(&self, mut use_long: bool) -> Error {
+        debugln!("Parser::_help: use_long={:?}", use_long);
+        use_long = use_long && self.use_long_help();
+        let mut buf = vec![];
+        match Help::write_parser_help(&mut buf, self, use_long) {
+            Err(e) => e,
+            _ => Error {
+                message: String::from_utf8(buf).unwrap_or_default(),
+                kind: ErrorKind::HelpDisplayed,
+                info: None,
+            },
+        }
+    }
+
+    fn _version(&self, use_long: bool) -> Error {
+        debugln!("Parser::_version: ");
+        let out = io::stdout();
+        let mut buf_w = BufWriter::new(out.lock());
+        match self.print_version(&mut buf_w, use_long) {
+            Err(e) => e,
+            _ => Error {
+                message: String::new(),
+                kind: ErrorKind::VersionDisplayed,
+                info: None,
+            },
+        }
+    }
+
+    fn parse_long_arg<I, T>(
+        &mut self,
+        matcher: &mut ArgMatcher<'a>,
+        full_arg: &OsStr,
+        it: &mut Peekable<I>,
+    ) -> ClapResult<ParseResult<'a>>
+    where
+        I: Iterator<Item = T>,
+        T: Into<OsString> + Clone,
+    {
+        // maybe here lifetime should be 'a
+        debugln!("Parser::parse_long_arg;");
+
+        // Update the current index
+        self.cur_idx.set(self.cur_idx.get() + 1);
+
+        let mut val = None;
+        debug!("Parser::parse_long_arg: Does it contain '='...");
+        let arg = if full_arg.contains_byte(b'=') {
+            let (p0, p1) = full_arg.trim_left_matches(b'-').split_at_byte(b'=');
+            sdebugln!("Yes '{:?}'", p1);
+            val = Some(p1);
+            p0
+        } else {
+            sdebugln!("No");
+            full_arg.trim_left_matches(b'-')
+        };
+
+        if let Some(opt) = find_opt_by_long!(@os self, arg) {
+            debugln!(
+                "Parser::parse_long_arg: Found valid opt '{}'",
+                opt.to_string()
+            );
+            self.settings.set(AS::ValidArgFound);
+            let ret = self.parse_opt(val, opt, val.is_some(), matcher)?;
+            if self.cache.map_or(true, |name| name != opt.b.name) {
+                self.cache = Some(opt.b.name);
+            }
+
+            return Ok(ret);
+        } else if let Some(flag) = find_flag_by_long!(@os self, arg) {
+            debugln!(
+                "Parser::parse_long_arg: Found valid flag '{}'",
+                flag.to_string()
+            );
+            self.settings.set(AS::ValidArgFound);
+            // Only flags could be help or version, and we need to check the raw long
+            // so this is the first point to check
+            self.check_for_help_and_version_str(arg)?;
+
+            self.parse_flag(flag, matcher)?;
+
+            // Handle conflicts, requirements, etc.
+            if self.cache.map_or(true, |name| name != flag.b.name) {
+                self.cache = Some(flag.b.name);
+            }
+
+            return Ok(ParseResult::Flag);
+        } else if self.is_set(AS::AllowLeadingHyphen) {
+            return Ok(ParseResult::MaybeHyphenValue);
+        } else if self.is_set(AS::ValidNegNumFound) {
+            return Ok(ParseResult::MaybeNegNum);
+        }
+
+        debugln!("Parser::parse_long_arg: Didn't match anything");
+
+        let args_rest: Vec<_> = it.map(|x| x.clone().into()).collect();
+        let args_rest2: Vec<_> = args_rest.iter().map(|x| x.to_str().expect(INVALID_UTF8)).collect();
+        self.did_you_mean_error(
+            arg.to_str().expect(INVALID_UTF8),
+            matcher,
+            &args_rest2[..]
+        ).map(|_| ParseResult::NotFound)
+    }
+
+    #[cfg_attr(feature = "lints", allow(len_zero))]
+    fn parse_short_arg(
+        &mut self,
+        matcher: &mut ArgMatcher<'a>,
+        full_arg: &OsStr,
+    ) -> ClapResult<ParseResult<'a>> {
+        debugln!("Parser::parse_short_arg: full_arg={:?}", full_arg);
+        let arg_os = full_arg.trim_left_matches(b'-');
+        let arg = arg_os.to_string_lossy();
+
+        // If AllowLeadingHyphen is set, we want to ensure `-val` gets parsed as `-val` and not
+        // `-v` `-a` `-l` assuming `v` `a` and `l` are all, or mostly, valid shorts.
+        if self.is_set(AS::AllowLeadingHyphen) {
+            if arg.chars().any(|c| !self.contains_short(c)) {
+                debugln!(
+                    "Parser::parse_short_arg: LeadingHyphenAllowed yet -{} isn't valid",
+                    arg
+                );
+                return Ok(ParseResult::MaybeHyphenValue);
+            }
+        } else if self.is_set(AS::ValidNegNumFound) {
+            // TODO: Add docs about having AllowNegativeNumbers and `-2` as a valid short
+            // May be better to move this to *after* not finding a valid flag/opt?
+            debugln!("Parser::parse_short_arg: Valid negative num...");
+            return Ok(ParseResult::MaybeNegNum);
+        }
+
+        let mut ret = ParseResult::NotFound;
+        for c in arg.chars() {
+            debugln!("Parser::parse_short_arg:iter:{}", c);
+
+            // update each index because `-abcd` is four indices to clap
+            self.cur_idx.set(self.cur_idx.get() + 1);
+
+            // Check for matching short options, and return the name if there is no trailing
+            // concatenated value: -oval
+            // Option: -o
+            // Value: val
+            if let Some(opt) = find_opt_by_short!(self, c) {
+                debugln!("Parser::parse_short_arg:iter:{}: Found valid opt", c);
+                self.settings.set(AS::ValidArgFound);
+                // Check for trailing concatenated value
+                let p: Vec<_> = arg.splitn(2, c).collect();
+                debugln!(
+                    "Parser::parse_short_arg:iter:{}: p[0]={:?}, p[1]={:?}",
+                    c,
+                    p[0].as_bytes(),
+                    p[1].as_bytes()
+                );
+                let i = p[0].as_bytes().len() + 1;
+                let val = if p[1].as_bytes().len() > 0 {
+                    debugln!(
+                        "Parser::parse_short_arg:iter:{}: val={:?} (bytes), val={:?} (ascii)",
+                        c,
+                        arg_os.split_at(i).1.as_bytes(),
+                        arg_os.split_at(i).1
+                    );
+                    Some(arg_os.split_at(i).1)
+                } else {
+                    None
+                };
+
+                // Default to "we're expecting a value later"
+                let ret = self.parse_opt(val, opt, false, matcher)?;
+
+                if self.cache.map_or(true, |name| name != opt.b.name) {
+                    self.cache = Some(opt.b.name);
+                }
+
+                return Ok(ret);
+            } else if let Some(flag) = find_flag_by_short!(self, c) {
+                debugln!("Parser::parse_short_arg:iter:{}: Found valid flag", c);
+                self.settings.set(AS::ValidArgFound);
+                // Only flags can be help or version
+                self.check_for_help_and_version_char(c)?;
+                ret = self.parse_flag(flag, matcher)?;
+
+                // Handle conflicts, requirements, overrides, etc.
+                // Must be called here due to mutabililty
+                if self.cache.map_or(true, |name| name != flag.b.name) {
+                    self.cache = Some(flag.b.name);
+                }
+            } else {
+                let arg = format!("-{}", c);
+                return Err(Error::unknown_argument(
+                    &*arg,
+                    "",
+                    &*usage::create_error_usage(self, matcher, None),
+                    self.color(),
+                ));
+            }
+        }
+        Ok(ret)
+    }
+
+    fn parse_opt(
+        &self,
+        val: Option<&OsStr>,
+        opt: &OptBuilder<'a, 'b>,
+        had_eq: bool,
+        matcher: &mut ArgMatcher<'a>,
+    ) -> ClapResult<ParseResult<'a>> {
+        debugln!("Parser::parse_opt; opt={}, val={:?}", opt.b.name, val);
+        debugln!("Parser::parse_opt; opt.settings={:?}", opt.b.settings);
+        let mut has_eq = false;
+        let no_val = val.is_none();
+        let empty_vals = opt.is_set(ArgSettings::EmptyValues);
+        let min_vals_zero = opt.v.min_vals.unwrap_or(1) == 0;
+        let needs_eq = opt.is_set(ArgSettings::RequireEquals);
+
+        debug!("Parser::parse_opt; Checking for val...");
+        if let Some(fv) = val {
+            has_eq = fv.starts_with(&[b'=']) || had_eq;
+            let v = fv.trim_left_matches(b'=');
+            if !empty_vals && (v.len() == 0 || (needs_eq && !has_eq)) {
+                sdebugln!("Found Empty - Error");
+                return Err(Error::empty_value(
+                    opt,
+                    &*usage::create_error_usage(self, matcher, None),
+                    self.color(),
+                ));
+            }
+            sdebugln!("Found - {:?}, len: {}", v, v.len());
+            debugln!(
+                "Parser::parse_opt: {:?} contains '='...{:?}",
+                fv,
+                fv.starts_with(&[b'='])
+            );
+            self.add_val_to_arg(opt, v, matcher)?;
+        } else if needs_eq && !(empty_vals || min_vals_zero) {
+            sdebugln!("None, but requires equals...Error");
+            return Err(Error::empty_value(
+                opt,
+                &*usage::create_error_usage(self, matcher, None),
+                self.color(),
+            ));
+        } else {
+            sdebugln!("None");
+        }
+
+        matcher.inc_occurrence_of(opt.b.name);
+        // Increment or create the group "args"
+        self.groups_for_arg(opt.b.name)
+            .and_then(|vec| Some(matcher.inc_occurrences_of(&*vec)));
+
+        let needs_delim = opt.is_set(ArgSettings::RequireDelimiter);
+        let mult = opt.is_set(ArgSettings::Multiple);
+        if no_val && min_vals_zero && !has_eq && needs_eq {
+            debugln!("Parser::parse_opt: More arg vals not required...");
+            return Ok(ParseResult::ValuesDone);
+        } else if no_val || (mult && !needs_delim) && !has_eq && matcher.needs_more_vals(opt) {
+            debugln!("Parser::parse_opt: More arg vals required...");
+            return Ok(ParseResult::Opt(opt.b.name));
+        }
+        debugln!("Parser::parse_opt: More arg vals not required...");
+        Ok(ParseResult::ValuesDone)
+    }
+
+    fn add_val_to_arg<A>(
+        &self,
+        arg: &A,
+        val: &OsStr,
+        matcher: &mut ArgMatcher<'a>,
+    ) -> ClapResult<ParseResult<'a>>
+    where
+        A: AnyArg<'a, 'b> + Display,
+    {
+        debugln!("Parser::add_val_to_arg; arg={}, val={:?}", arg.name(), val);
+        debugln!(
+            "Parser::add_val_to_arg; trailing_vals={:?}, DontDelimTrailingVals={:?}",
+            self.is_set(AS::TrailingValues),
+            self.is_set(AS::DontDelimitTrailingValues)
+        );
+        if !(self.is_set(AS::TrailingValues) && self.is_set(AS::DontDelimitTrailingValues)) {
+            if let Some(delim) = arg.val_delim() {
+                if val.is_empty() {
+                    Ok(self.add_single_val_to_arg(arg, val, matcher)?)
+                } else {
+                    let mut iret = ParseResult::ValuesDone;
+                    for v in val.split(delim as u32 as u8) {
+                        iret = self.add_single_val_to_arg(arg, v, matcher)?;
+                    }
+                    // If there was a delimiter used, we're not looking for more values
+                    if val.contains_byte(delim as u32 as u8)
+                        || arg.is_set(ArgSettings::RequireDelimiter)
+                    {
+                        iret = ParseResult::ValuesDone;
+                    }
+                    Ok(iret)
+                }
+            } else {
+                self.add_single_val_to_arg(arg, val, matcher)
+            }
+        } else {
+            self.add_single_val_to_arg(arg, val, matcher)
+        }
+    }
+
+    fn add_single_val_to_arg<A>(
+        &self,
+        arg: &A,
+        v: &OsStr,
+        matcher: &mut ArgMatcher<'a>,
+    ) -> ClapResult<ParseResult<'a>>
+    where
+        A: AnyArg<'a, 'b> + Display,
+    {
+        debugln!("Parser::add_single_val_to_arg;");
+        debugln!("Parser::add_single_val_to_arg: adding val...{:?}", v);
+
+        // update the current index because each value is a distinct index to clap
+        self.cur_idx.set(self.cur_idx.get() + 1);
+
+        // @TODO @docs @p4: docs for indices should probably note that a terminator isn't a value
+        // and therefore not reported in indices
+        if let Some(t) = arg.val_terminator() {
+            if t == v {
+                return Ok(ParseResult::ValuesDone);
+            }
+        }
+
+        matcher.add_val_to(arg.name(), v);
+        matcher.add_index_to(arg.name(), self.cur_idx.get());
+
+        // Increment or create the group "args"
+        if let Some(grps) = self.groups_for_arg(arg.name()) {
+            for grp in grps {
+                matcher.add_val_to(&*grp, v);
+            }
+        }
+
+        if matcher.needs_more_vals(arg) {
+            return Ok(ParseResult::Opt(arg.name()));
+        }
+        Ok(ParseResult::ValuesDone)
+    }
+
+    fn parse_flag(
+        &self,
+        flag: &FlagBuilder<'a, 'b>,
+        matcher: &mut ArgMatcher<'a>,
+    ) -> ClapResult<ParseResult<'a>> {
+        debugln!("Parser::parse_flag;");
+
+        matcher.inc_occurrence_of(flag.b.name);
+        matcher.add_index_to(flag.b.name, self.cur_idx.get());
+
+        // Increment or create the group "args"
+        self.groups_for_arg(flag.b.name)
+            .and_then(|vec| Some(matcher.inc_occurrences_of(&*vec)));
+
+        Ok(ParseResult::Flag)
+    }
+
+    fn did_you_mean_error(&self, arg: &str, matcher: &mut ArgMatcher<'a>, args_rest: &[&str]) -> ClapResult<()> {
+        // Didn't match a flag or option
+        let suffix = suggestions::did_you_mean_flag_suffix(arg, &args_rest, longs!(self), &self.subcommands);
+
+        // Add the arg to the matches to build a proper usage string
+        if let Some(name) = suffix.1 {
+            if let Some(opt) = find_opt_by_long!(self, name) {
+                self.groups_for_arg(&*opt.b.name)
+                    .and_then(|grps| Some(matcher.inc_occurrences_of(&*grps)));
+                matcher.insert(&*opt.b.name);
+            } else if let Some(flg) = find_flag_by_long!(self, name) {
+                self.groups_for_arg(&*flg.b.name)
+                    .and_then(|grps| Some(matcher.inc_occurrences_of(&*grps)));
+                matcher.insert(&*flg.b.name);
+            }
+        }
+
+        let used_arg = format!("--{}", arg);
+        Err(Error::unknown_argument(
+            &*used_arg,
+            &*suffix.0,
+            &*usage::create_error_usage(self, matcher, None),
+            self.color(),
+        ))
+    }
+
+    // Prints the version to the user and exits if quit=true
+    fn print_version<W: Write>(&self, w: &mut W, use_long: bool) -> ClapResult<()> {
+        self.write_version(w, use_long)?;
+        w.flush().map_err(Error::from)
+    }
+
+    pub fn write_version<W: Write>(&self, w: &mut W, use_long: bool) -> io::Result<()> {
+        let ver = if use_long {
+            self.meta
+                .long_version
+                .unwrap_or_else(|| self.meta.version.unwrap_or(""))
+        } else {
+            self.meta
+                .version
+                .unwrap_or_else(|| self.meta.long_version.unwrap_or(""))
+        };
+        if let Some(bn) = self.meta.bin_name.as_ref() {
+            if bn.contains(' ') {
+                // Incase we're dealing with subcommands i.e. git mv is translated to git-mv
+                write!(w, "{} {}", bn.replace(" ", "-"), ver)
+            } else {
+                write!(w, "{} {}", &self.meta.name[..], ver)
+            }
+        } else {
+            write!(w, "{} {}", &self.meta.name[..], ver)
+        }
+    }
+
+    pub fn print_help(&self) -> ClapResult<()> {
+        let out = io::stdout();
+        let mut buf_w = BufWriter::new(out.lock());
+        self.write_help(&mut buf_w)
+    }
+
+    pub fn write_help<W: Write>(&self, w: &mut W) -> ClapResult<()> {
+        Help::write_parser_help(w, self, false)
+    }
+
+    pub fn write_long_help<W: Write>(&self, w: &mut W) -> ClapResult<()> {
+        Help::write_parser_help(w, self, true)
+    }
+
+    pub fn write_help_err<W: Write>(&self, w: &mut W) -> ClapResult<()> {
+        Help::write_parser_help_to_stderr(w, self)
+    }
+
+    pub fn add_defaults(&mut self, matcher: &mut ArgMatcher<'a>) -> ClapResult<()> {
+        debugln!("Parser::add_defaults;");
+        macro_rules! add_val {
+            (@default $_self:ident, $a:ident, $m:ident) => {
+                if let Some(ref val) = $a.v.default_val {
+                    debugln!("Parser::add_defaults:iter:{}: has default vals", $a.b.name);
+                    if $m.get($a.b.name).map(|ma| ma.vals.len()).map(|len| len == 0).unwrap_or(false) {
+                        debugln!("Parser::add_defaults:iter:{}: has no user defined vals", $a.b.name);
+                        $_self.add_val_to_arg($a, OsStr::new(val), $m)?;
+
+                        if $_self.cache.map_or(true, |name| name != $a.name()) {
+                            $_self.cache = Some($a.name());
+                        }
+                    } else if $m.get($a.b.name).is_some() {
+                        debugln!("Parser::add_defaults:iter:{}: has user defined vals", $a.b.name);
+                    } else {
+                        debugln!("Parser::add_defaults:iter:{}: wasn't used", $a.b.name);
+
+                        $_self.add_val_to_arg($a, OsStr::new(val), $m)?;
+
+                        if $_self.cache.map_or(true, |name| name != $a.name()) {
+                            $_self.cache = Some($a.name());
+                        }
+                    }
+                } else {
+                    debugln!("Parser::add_defaults:iter:{}: doesn't have default vals", $a.b.name);
+                }
+            };
+            ($_self:ident, $a:ident, $m:ident) => {
+                if let Some(ref vm) = $a.v.default_vals_ifs {
+                    sdebugln!(" has conditional defaults");
+                    let mut done = false;
+                    if $m.get($a.b.name).is_none() {
+                        for &(arg, val, default) in vm.values() {
+                            let add = if let Some(a) = $m.get(arg) {
+                                if let Some(v) = val {
+                                    a.vals.iter().any(|value| v == value)
+                                } else {
+                                    true
+                                }
+                            } else {
+                                false
+                            };
+                            if add {
+                                $_self.add_val_to_arg($a, OsStr::new(default), $m)?;
+                                if $_self.cache.map_or(true, |name| name != $a.name()) {
+                                    $_self.cache = Some($a.name());
+                                }
+                                done = true;
+                                break;
+                            }
+                        }
+                    }
+
+                    if done {
+                        continue; // outer loop (outside macro)
+                    }
+                } else {
+                    sdebugln!(" doesn't have conditional defaults");
+                }
+                add_val!(@default $_self, $a, $m)
+            };
+        }
+
+        for o in &self.opts {
+            debug!("Parser::add_defaults:iter:{}:", o.b.name);
+            add_val!(self, o, matcher);
+        }
+        for p in self.positionals.values() {
+            debug!("Parser::add_defaults:iter:{}:", p.b.name);
+            add_val!(self, p, matcher);
+        }
+        Ok(())
+    }
+
+    pub fn add_env(&mut self, matcher: &mut ArgMatcher<'a>) -> ClapResult<()> {
+        macro_rules! add_val {
+            ($_self:ident, $a:ident, $m:ident) => {
+                if let Some(ref val) = $a.v.env {
+                    if $m.get($a.b.name).map(|ma| ma.vals.len()).map(|len| len == 0).unwrap_or(false) {
+                        if let Some(ref val) = val.1 {
+                            $_self.add_val_to_arg($a, OsStr::new(val), $m)?;
+
+                            if $_self.cache.map_or(true, |name| name != $a.name()) {
+                                $_self.cache = Some($a.name());
+                            }
+                        }
+                    } else {
+                        if let Some(ref val) = val.1 {
+                            $_self.add_val_to_arg($a, OsStr::new(val), $m)?;
+
+                            if $_self.cache.map_or(true, |name| name != $a.name()) {
+                                $_self.cache = Some($a.name());
+                            }
+                        }
+                    }
+                }
+            };
+        }
+
+        for o in &self.opts {
+            add_val!(self, o, matcher);
+        }
+        for p in self.positionals.values() {
+            add_val!(self, p, matcher);
+        }
+        Ok(())
+    }
+
+    pub fn flags(&self) -> Iter<FlagBuilder<'a, 'b>> { self.flags.iter() }
+
+    pub fn opts(&self) -> Iter<OptBuilder<'a, 'b>> { self.opts.iter() }
+
+    pub fn positionals(&self) -> map::Values<PosBuilder<'a, 'b>> { self.positionals.values() }
+
+    pub fn subcommands(&self) -> Iter<App> { self.subcommands.iter() }
+
+    // Should we color the output? None=determined by output location, true=yes, false=no
+    #[doc(hidden)]
+    pub fn color(&self) -> ColorWhen {
+        debugln!("Parser::color;");
+        debug!("Parser::color: Color setting...");
+        if self.is_set(AS::ColorNever) {
+            sdebugln!("Never");
+            ColorWhen::Never
+        } else if self.is_set(AS::ColorAlways) {
+            sdebugln!("Always");
+            ColorWhen::Always
+        } else {
+            sdebugln!("Auto");
+            ColorWhen::Auto
+        }
+    }
+
+    pub fn find_any_arg(&self, name: &str) -> Option<&AnyArg<'a, 'b>> {
+        if let Some(f) = find_by_name!(self, name, flags, iter) {
+            return Some(f);
+        }
+        if let Some(o) = find_by_name!(self, name, opts, iter) {
+            return Some(o);
+        }
+        if let Some(p) = find_by_name!(self, name, positionals, values) {
+            return Some(p);
+        }
+        None
+    }
+
+    /// Check is a given string matches the binary name for this parser
+    fn is_bin_name(&self, value: &str) -> bool {
+        self.meta
+            .bin_name
+            .as_ref()
+            .and_then(|name| Some(value == name))
+            .unwrap_or(false)
+    }
+
+    /// Check is a given string is an alias for this parser
+    fn is_alias(&self, value: &str) -> bool {
+        self.meta
+            .aliases
+            .as_ref()
+            .and_then(|aliases| {
+                for alias in aliases {
+                    if alias.0 == value {
+                        return Some(true);
+                    }
+                }
+                Some(false)
+            })
+            .unwrap_or(false)
+    }
+
+    // Only used for completion scripts due to bin_name messiness
+    #[cfg_attr(feature = "lints", allow(block_in_if_condition_stmt))]
+    pub fn find_subcommand(&'b self, sc: &str) -> Option<&'b App<'a, 'b>> {
+        debugln!("Parser::find_subcommand: sc={}", sc);
+        debugln!(
+            "Parser::find_subcommand: Currently in Parser...{}",
+            self.meta.bin_name.as_ref().unwrap()
+        );
+        for s in &self.subcommands {
+            if s.p.is_bin_name(sc) {
+                return Some(s);
+            }
+            // XXX: why do we split here?
+            // isn't `sc` supposed to be single word already?
+            let last = sc.split(' ').rev().next().expect(INTERNAL_ERROR_MSG);
+            if s.p.is_alias(last) {
+                return Some(s);
+            }
+
+            if let Some(app) = s.p.find_subcommand(sc) {
+                return Some(app);
+            }
+        }
+        None
+    }
+
+    #[inline]
+    fn contains_long(&self, l: &str) -> bool { longs!(self).any(|al| al == &l) }
+
+    #[inline]
+    fn contains_short(&self, s: char) -> bool { shorts!(self).any(|arg_s| arg_s == &s) }
+}
diff --git a/src/app/settings.rs b/src/app/settings.rs
new file mode 100644
index 0000000..ec03997
--- /dev/null
+++ b/src/app/settings.rs
@@ -0,0 +1,1174 @@
+// Std
+#[allow(deprecated, unused_imports)]
+use std::ascii::AsciiExt;
+use std::str::FromStr;
+use std::ops::BitOr;
+
+bitflags! {
+    struct Flags: u64 {
+        const SC_NEGATE_REQS       = 1;
+        const SC_REQUIRED          = 1 << 1;
+        const A_REQUIRED_ELSE_HELP = 1 << 2;
+        const GLOBAL_VERSION       = 1 << 3;
+        const VERSIONLESS_SC       = 1 << 4;
+        const UNIFIED_HELP         = 1 << 5;
+        const WAIT_ON_ERROR        = 1 << 6;
+        const SC_REQUIRED_ELSE_HELP= 1 << 7;
+        const NEEDS_LONG_HELP      = 1 << 8;
+        const NEEDS_LONG_VERSION   = 1 << 9;
+        const NEEDS_SC_HELP        = 1 << 10;
+        const DISABLE_VERSION      = 1 << 11;
+        const HIDDEN               = 1 << 12;
+        const TRAILING_VARARG      = 1 << 13;
+        const NO_BIN_NAME          = 1 << 14;
+        const ALLOW_UNK_SC         = 1 << 15;
+        const UTF8_STRICT          = 1 << 16;
+        const UTF8_NONE            = 1 << 17;
+        const LEADING_HYPHEN       = 1 << 18;
+        const NO_POS_VALUES        = 1 << 19;
+        const NEXT_LINE_HELP       = 1 << 20;
+        const DERIVE_DISP_ORDER    = 1 << 21;
+        const COLORED_HELP         = 1 << 22;
+        const COLOR_ALWAYS         = 1 << 23;
+        const COLOR_AUTO           = 1 << 24;
+        const COLOR_NEVER          = 1 << 25;
+        const DONT_DELIM_TRAIL     = 1 << 26;
+        const ALLOW_NEG_NUMS       = 1 << 27;
+        const LOW_INDEX_MUL_POS    = 1 << 28;
+        const DISABLE_HELP_SC      = 1 << 29;
+        const DONT_COLLAPSE_ARGS   = 1 << 30;
+        const ARGS_NEGATE_SCS      = 1 << 31;
+        const PROPAGATE_VALS_DOWN  = 1 << 32;
+        const ALLOW_MISSING_POS    = 1 << 33;
+        const TRAILING_VALUES      = 1 << 34;
+        const VALID_NEG_NUM_FOUND  = 1 << 35;
+        const PROPAGATED           = 1 << 36;
+        const VALID_ARG_FOUND      = 1 << 37;
+        const INFER_SUBCOMMANDS    = 1 << 38;
+        const CONTAINS_LAST        = 1 << 39;
+        const ARGS_OVERRIDE_SELF   = 1 << 40;
+        const DISABLE_HELP_FLAGS   = 1 << 41;
+    }
+}
+
+#[doc(hidden)]
+#[derive(Debug, Copy, Clone, PartialEq)]
+pub struct AppFlags(Flags);
+
+impl BitOr for AppFlags {
+    type Output = Self;
+    fn bitor(self, rhs: Self) -> Self { AppFlags(self.0 | rhs.0) }
+}
+
+impl Default for AppFlags {
+    fn default() -> Self {
+        AppFlags(
+            Flags::NEEDS_LONG_VERSION | Flags::NEEDS_LONG_HELP | Flags::NEEDS_SC_HELP
+                | Flags::UTF8_NONE | Flags::COLOR_AUTO,
+        )
+    }
+}
+
+#[allow(deprecated)]
+impl AppFlags {
+    pub fn new() -> Self { AppFlags::default() }
+    pub fn zeroed() -> Self { AppFlags(Flags::empty()) }
+
+    impl_settings! { AppSettings,
+        ArgRequiredElseHelp => Flags::A_REQUIRED_ELSE_HELP,
+        ArgsNegateSubcommands => Flags::ARGS_NEGATE_SCS,
+        AllArgsOverrideSelf => Flags::ARGS_OVERRIDE_SELF,
+        AllowExternalSubcommands => Flags::ALLOW_UNK_SC,
+        AllowInvalidUtf8 => Flags::UTF8_NONE,
+        AllowLeadingHyphen => Flags::LEADING_HYPHEN,
+        AllowNegativeNumbers => Flags::ALLOW_NEG_NUMS,
+        AllowMissingPositional => Flags::ALLOW_MISSING_POS,
+        ColoredHelp => Flags::COLORED_HELP,
+        ColorAlways => Flags::COLOR_ALWAYS,
+        ColorAuto => Flags::COLOR_AUTO,
+        ColorNever => Flags::COLOR_NEVER,
+        DontDelimitTrailingValues => Flags::DONT_DELIM_TRAIL,
+        DontCollapseArgsInUsage => Flags::DONT_COLLAPSE_ARGS,
+        DeriveDisplayOrder => Flags::DERIVE_DISP_ORDER,
+        DisableHelpFlags => Flags::DISABLE_HELP_FLAGS,
+        DisableHelpSubcommand => Flags::DISABLE_HELP_SC,
+        DisableVersion => Flags::DISABLE_VERSION,
+        GlobalVersion => Flags::GLOBAL_VERSION,
+        HidePossibleValuesInHelp => Flags::NO_POS_VALUES,
+        Hidden => Flags::HIDDEN,
+        LowIndexMultiplePositional => Flags::LOW_INDEX_MUL_POS,
+        NeedsLongHelp => Flags::NEEDS_LONG_HELP,
+        NeedsLongVersion => Flags::NEEDS_LONG_VERSION,
+        NeedsSubcommandHelp => Flags::NEEDS_SC_HELP,
+        NoBinaryName => Flags::NO_BIN_NAME,
+        PropagateGlobalValuesDown=> Flags::PROPAGATE_VALS_DOWN,
+        StrictUtf8 => Flags::UTF8_STRICT,
+        SubcommandsNegateReqs => Flags::SC_NEGATE_REQS,
+        SubcommandRequired => Flags::SC_REQUIRED,
+        SubcommandRequiredElseHelp => Flags::SC_REQUIRED_ELSE_HELP,
+        TrailingVarArg => Flags::TRAILING_VARARG,
+        UnifiedHelpMessage => Flags::UNIFIED_HELP,
+        NextLineHelp => Flags::NEXT_LINE_HELP,
+        VersionlessSubcommands => Flags::VERSIONLESS_SC,
+        WaitOnError => Flags::WAIT_ON_ERROR,
+        TrailingValues => Flags::TRAILING_VALUES,
+        ValidNegNumFound => Flags::VALID_NEG_NUM_FOUND,
+        Propagated => Flags::PROPAGATED,
+        ValidArgFound => Flags::VALID_ARG_FOUND,
+        InferSubcommands => Flags::INFER_SUBCOMMANDS,
+        ContainsLast => Flags::CONTAINS_LAST
+    }
+}
+
+/// Application level settings, which affect how [`App`] operates
+///
+/// **NOTE:** When these settings are used, they apply only to current command, and are *not*
+/// propagated down or up through child or parent subcommands
+///
+/// [`App`]: ./struct.App.html
+#[derive(Debug, PartialEq, Copy, Clone)]
+pub enum AppSettings {
+    /// Specifies that any invalid UTF-8 code points should *not* be treated as an error.
+    /// This is the default behavior of `clap`.
+    ///
+    /// **NOTE:** Using argument values with invalid UTF-8 code points requires using
+    /// [`ArgMatches::os_value_of`], [`ArgMatches::os_values_of`], [`ArgMatches::lossy_value_of`],
+    /// or [`ArgMatches::lossy_values_of`] for those particular arguments which may contain invalid
+    /// UTF-8 values
+    ///
+    /// **NOTE:** This rule only applies to  argument values, as flags, options, and
+    /// [`SubCommand`]s themselves only allow valid UTF-8 code points.
+    ///
+    /// # Platform Specific
+    ///
+    /// Non Windows systems only
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(not(unix), doc = " ```ignore")]
+    #[cfg_attr(unix, doc = " ```")]
+    /// # use clap::{App, AppSettings};
+    /// use std::ffi::OsString;
+    /// use std::os::unix::ffi::{OsStrExt,OsStringExt};
+    ///
+    /// let r = App::new("myprog")
+    ///   //.setting(AppSettings::AllowInvalidUtf8)
+    ///     .arg_from_usage("<arg> 'some positional arg'")
+    ///     .get_matches_from_safe(
+    ///         vec![
+    ///             OsString::from("myprog"),
+    ///             OsString::from_vec(vec![0xe9])]);
+    ///
+    /// assert!(r.is_ok());
+    /// let m = r.unwrap();
+    /// assert_eq!(m.value_of_os("arg").unwrap().as_bytes(), &[0xe9]);
+    /// ```
+    /// [`ArgMatches::os_value_of`]: ./struct.ArgMatches.html#method.os_value_of
+    /// [`ArgMatches::os_values_of`]: ./struct.ArgMatches.html#method.os_values_of
+    /// [`ArgMatches::lossy_value_of`]: ./struct.ArgMatches.html#method.lossy_value_of
+    /// [`ArgMatches::lossy_values_of`]: ./struct.ArgMatches.html#method.lossy_values_of
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    AllowInvalidUtf8,
+
+    /// Essentially sets [`Arg::overrides_with("itself")`] for all arguments.
+    ///
+    /// **WARNING:** Positional arguments cannot override themselves (or we would never be able
+    /// to advance to the next positional). This setting ignores positional arguments.
+    /// [`Arg::overrides_with("itself")`]: ./struct.Arg.html#method.overrides_with
+    AllArgsOverrideSelf,
+
+    /// Specifies that leading hyphens are allowed in argument *values*, such as negative numbers
+    /// like `-10`. (which would otherwise be parsed as another flag or option)
+    ///
+    /// **NOTE:** Use this setting with caution as it silences certain circumstances which would
+    /// otherwise be an error (such as accidentally forgetting to specify a value for leading
+    /// option). It is preferred to set this on a per argument basis, via [`Arg::allow_hyphen_values`]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{Arg, App, AppSettings};
+    /// // Imagine you needed to represent negative numbers as well, such as -10
+    /// let m = App::new("nums")
+    ///     .setting(AppSettings::AllowLeadingHyphen)
+    ///     .arg(Arg::with_name("neg").index(1))
+    ///     .get_matches_from(vec![
+    ///         "nums", "-20"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("neg"), Some("-20"));
+    /// # ;
+    /// ```
+    /// [`Arg::allow_hyphen_values`]: ./struct.Arg.html#method.allow_hyphen_values
+    AllowLeadingHyphen,
+
+    /// Allows negative numbers to pass as values. This is similar to
+    /// `AllowLeadingHyphen` except that it only allows numbers, all
+    /// other undefined leading hyphens will fail to parse.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings};
+    /// let res = App::new("myprog")
+    ///     .version("v1.1")
+    ///     .setting(AppSettings::AllowNegativeNumbers)
+    ///     .arg(Arg::with_name("num"))
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog", "-20"
+    ///     ]);
+    /// assert!(res.is_ok());
+    /// let m = res.unwrap();
+    /// assert_eq!(m.value_of("num").unwrap(), "-20");
+    /// ```
+    /// [`AllowLeadingHyphen`]: ./enum.AppSettings.html#variant.AllowLeadingHyphen
+    AllowNegativeNumbers,
+
+    /// Allows one to implement two styles of CLIs where positionals can be used out of order.
+    ///
+    /// The first example is a CLI where the second to last positional argument is optional, but
+    /// the final positional argument is required. Such as `$ prog [optional] <required>` where one
+    /// of the two following usages is allowed:
+    ///
+    /// * `$ prog [optional] <required>`
+    /// * `$ prog <required>`
+    ///
+    /// This would otherwise not be allowed. This is useful when `[optional]` has a default value.
+    ///
+    /// **Note:** when using this style of "missing positionals" the final positional *must* be
+    /// [required] if `--` will not be used to skip to the final positional argument.
+    ///
+    /// **Note:** This style also only allows a single positional argument to be "skipped" without
+    /// the use of `--`. To skip more than one, see the second example.
+    ///
+    /// The second example is when one wants to skip multiple optional positional arguments, and use
+    /// of the `--` operator is OK (but not required if all arguments will be specified anyways).
+    ///
+    /// For example, imagine a CLI which has three positional arguments `[foo] [bar] [baz]...` where
+    /// `baz` accepts multiple values (similar to man `ARGS...` style training arguments).
+    ///
+    /// With this setting the following invocations are possible:
+    ///
+    /// * `$ prog foo bar baz1 baz2 baz3`
+    /// * `$ prog foo -- baz1 baz2 baz3`
+    /// * `$ prog -- baz1 baz2 baz3`
+    ///
+    /// # Examples
+    ///
+    /// Style number one from above:
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings};
+    /// // Assume there is an external subcommand named "subcmd"
+    /// let m = App::new("myprog")
+    ///     .setting(AppSettings::AllowMissingPositional)
+    ///     .arg(Arg::with_name("arg1"))
+    ///     .arg(Arg::with_name("arg2")
+    ///         .required(true))
+    ///     .get_matches_from(vec![
+    ///         "prog", "other"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("arg1"), None);
+    /// assert_eq!(m.value_of("arg2"), Some("other"));
+    /// ```
+    ///
+    /// Now the same example, but using a default value for the first optional positional argument
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings};
+    /// // Assume there is an external subcommand named "subcmd"
+    /// let m = App::new("myprog")
+    ///     .setting(AppSettings::AllowMissingPositional)
+    ///     .arg(Arg::with_name("arg1")
+    ///         .default_value("something"))
+    ///     .arg(Arg::with_name("arg2")
+    ///         .required(true))
+    ///     .get_matches_from(vec![
+    ///         "prog", "other"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("arg1"), Some("something"));
+    /// assert_eq!(m.value_of("arg2"), Some("other"));
+    /// ```
+    /// Style number two from above:
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings};
+    /// // Assume there is an external subcommand named "subcmd"
+    /// let m = App::new("myprog")
+    ///     .setting(AppSettings::AllowMissingPositional)
+    ///     .arg(Arg::with_name("foo"))
+    ///     .arg(Arg::with_name("bar"))
+    ///     .arg(Arg::with_name("baz").multiple(true))
+    ///     .get_matches_from(vec![
+    ///         "prog", "foo", "bar", "baz1", "baz2", "baz3"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("foo"), Some("foo"));
+    /// assert_eq!(m.value_of("bar"), Some("bar"));
+    /// assert_eq!(m.values_of("baz").unwrap().collect::<Vec<_>>(), &["baz1", "baz2", "baz3"]);
+    /// ```
+    ///
+    /// Now notice if we don't specify `foo` or `baz` but use the `--` operator.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings};
+    /// // Assume there is an external subcommand named "subcmd"
+    /// let m = App::new("myprog")
+    ///     .setting(AppSettings::AllowMissingPositional)
+    ///     .arg(Arg::with_name("foo"))
+    ///     .arg(Arg::with_name("bar"))
+    ///     .arg(Arg::with_name("baz").multiple(true))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--", "baz1", "baz2", "baz3"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("foo"), None);
+    /// assert_eq!(m.value_of("bar"), None);
+    /// assert_eq!(m.values_of("baz").unwrap().collect::<Vec<_>>(), &["baz1", "baz2", "baz3"]);
+    /// ```
+    /// [required]: ./struct.Arg.html#method.required
+    AllowMissingPositional,
+
+    /// Specifies that an unexpected positional argument,
+    /// which would otherwise cause a [`ErrorKind::UnknownArgument`] error,
+    /// should instead be treated as a [`SubCommand`] within the [`ArgMatches`] struct.
+    ///
+    /// **NOTE:** Use this setting with caution,
+    /// as a truly unexpected argument (i.e. one that is *NOT* an external subcommand)
+    /// will **not** cause an error and instead be treated as a potential subcommand.
+    /// One should check for such cases manually and inform the user appropriately.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, AppSettings};
+    /// // Assume there is an external subcommand named "subcmd"
+    /// let m = App::new("myprog")
+    ///     .setting(AppSettings::AllowExternalSubcommands)
+    ///     .get_matches_from(vec![
+    ///         "myprog", "subcmd", "--option", "value", "-fff", "--flag"
+    ///     ]);
+    ///
+    /// // All trailing arguments will be stored under the subcommand's sub-matches using an empty
+    /// // string argument name
+    /// match m.subcommand() {
+    ///     (external, Some(ext_m)) => {
+    ///          let ext_args: Vec<&str> = ext_m.values_of("").unwrap().collect();
+    ///          assert_eq!(external, "subcmd");
+    ///          assert_eq!(ext_args, ["--option", "value", "-fff", "--flag"]);
+    ///     },
+    ///     _ => {},
+    /// }
+    /// ```
+    /// [`ErrorKind::UnknownArgument`]: ./enum.ErrorKind.html#variant.UnknownArgument
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`ArgMatches`]: ./struct.ArgMatches.html
+    AllowExternalSubcommands,
+
+    /// Specifies that use of a valid [argument] negates [subcommands] being used after. By default
+    /// `clap` allows arguments between subcommands such as
+    /// `<cmd> [cmd_args] <cmd2> [cmd2_args] <cmd3> [cmd3_args]`. This setting disables that
+    /// functionality and says that arguments can only follow the *final* subcommand. For instance
+    /// using this setting makes only the following invocations possible:
+    ///
+    /// * `<cmd> <cmd2> <cmd3> [cmd3_args]`
+    /// * `<cmd> <cmd2> [cmd2_args]`
+    /// * `<cmd> [cmd_args]`
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::ArgsNegateSubcommands)
+    /// # ;
+    /// ```
+    /// [subcommands]: ./struct.SubCommand.html
+    /// [argument]: ./struct.Arg.html
+    ArgsNegateSubcommands,
+
+    /// Specifies that the help text should be displayed (and then exit gracefully),
+    /// if no arguments are present at runtime (i.e. an empty run such as, `$ myprog`.
+    ///
+    /// **NOTE:** [`SubCommand`]s count as arguments
+    ///
+    /// **NOTE:** Setting [`Arg::default_value`] effectively disables this option as it will
+    /// ensure that some argument is always present.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::ArgRequiredElseHelp)
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`Arg::default_value`]: ./struct.Arg.html#method.default_value
+    ArgRequiredElseHelp,
+
+    /// Uses colorized help messages.
+    ///
+    /// **NOTE:** Must be compiled with the `color` cargo feature
+    ///
+    /// # Platform Specific
+    ///
+    /// This setting only applies to Unix, Linux, and macOS (i.e. non-Windows platforms)
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::ColoredHelp)
+    ///     .get_matches();
+    /// ```
+    ColoredHelp,
+
+    /// Enables colored output only when the output is going to a terminal or TTY.
+    ///
+    /// **NOTE:** This is the default behavior of `clap`.
+    ///
+    /// **NOTE:** Must be compiled with the `color` cargo feature.
+    ///
+    /// # Platform Specific
+    ///
+    /// This setting only applies to Unix, Linux, and macOS (i.e. non-Windows platforms).
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::ColorAuto)
+    ///     .get_matches();
+    /// ```
+    ColorAuto,
+
+    /// Enables colored output regardless of whether or not the output is going to a terminal/TTY.
+    ///
+    /// **NOTE:** Must be compiled with the `color` cargo feature.
+    ///
+    /// # Platform Specific
+    ///
+    /// This setting only applies to Unix, Linux, and macOS (i.e. non-Windows platforms).
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::ColorAlways)
+    ///     .get_matches();
+    /// ```
+    ColorAlways,
+
+    /// Disables colored output no matter if the output is going to a terminal/TTY, or not.
+    ///
+    /// **NOTE:** Must be compiled with the `color` cargo feature
+    ///
+    /// # Platform Specific
+    ///
+    /// This setting only applies to Unix, Linux, and macOS (i.e. non-Windows platforms)
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::ColorNever)
+    ///     .get_matches();
+    /// ```
+    ColorNever,
+
+    /// Disables the automatic collapsing of positional args into `[ARGS]` inside the usage string
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::DontCollapseArgsInUsage)
+    ///     .get_matches();
+    /// ```
+    DontCollapseArgsInUsage,
+
+    /// Disables the automatic delimiting of values when `--` or [`AppSettings::TrailingVarArg`]
+    /// was used.
+    ///
+    /// **NOTE:** The same thing can be done manually by setting the final positional argument to
+    /// [`Arg::use_delimiter(false)`]. Using this setting is safer, because it's easier to locate
+    /// when making changes.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::DontDelimitTrailingValues)
+    ///     .get_matches();
+    /// ```
+    /// [`AppSettings::TrailingVarArg`]: ./enum.AppSettings.html#variant.TrailingVarArg
+    /// [`Arg::use_delimiter(false)`]: ./struct.Arg.html#method.use_delimiter
+    DontDelimitTrailingValues,
+
+    /// Disables `-h` and `--help` [`App`] without affecting any of the [`SubCommand`]s
+    /// (Defaults to `false`; application *does* have help flags)
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, AppSettings, ErrorKind};
+    /// let res = App::new("myprog")
+    ///     .setting(AppSettings::DisableHelpFlags)
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog", "-h"
+    ///     ]);
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::UnknownArgument);
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, SubCommand, AppSettings, ErrorKind};
+    /// let res = App::new("myprog")
+    ///     .setting(AppSettings::DisableHelpFlags)
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog", "test", "-h"
+    ///     ]);
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::HelpDisplayed);
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`App`]: ./struct.App.html
+    DisableHelpFlags,
+
+    /// Disables the `help` subcommand
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, AppSettings, ErrorKind, SubCommand};
+    /// let res = App::new("myprog")
+    ///     .version("v1.1")
+    ///     .setting(AppSettings::DisableHelpSubcommand)
+    ///     // Normally, creating a subcommand causes a `help` subcommand to automatically
+    ///     // be generated as well
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog", "help"
+    ///     ]);
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::UnknownArgument);
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    DisableHelpSubcommand,
+
+    /// Disables `-V` and `--version` [`App`] without affecting any of the [`SubCommand`]s
+    /// (Defaults to `false`; application *does* have a version flag)
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, AppSettings, ErrorKind};
+    /// let res = App::new("myprog")
+    ///     .version("v1.1")
+    ///     .setting(AppSettings::DisableVersion)
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog", "-V"
+    ///     ]);
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::UnknownArgument);
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, SubCommand, AppSettings, ErrorKind};
+    /// let res = App::new("myprog")
+    ///     .version("v1.1")
+    ///     .setting(AppSettings::DisableVersion)
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog", "test", "-V"
+    ///     ]);
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::VersionDisplayed);
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`App`]: ./struct.App.html
+    DisableVersion,
+
+    /// Displays the arguments and [`SubCommand`]s in the help message in the order that they were
+    /// declared in, and not alphabetically which is the default.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::DeriveDisplayOrder)
+    ///     .get_matches();
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    DeriveDisplayOrder,
+
+    /// Specifies to use the version of the current command for all child [`SubCommand`]s.
+    /// (Defaults to `false`; subcommands have independent version strings from their parents.)
+    ///
+    /// **NOTE:** The version for the current command **and** this setting must be set **prior** to
+    /// adding any child subcommands
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// App::new("myprog")
+    ///     .version("v1.1")
+    ///     .setting(AppSettings::GlobalVersion)
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches();
+    /// // running `$ myprog test --version` will display
+    /// // "myprog-test v1.1"
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    GlobalVersion,
+
+    /// Specifies that this [`SubCommand`] should be hidden from help messages
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings, SubCommand};
+    /// App::new("myprog")
+    ///     .subcommand(SubCommand::with_name("test")
+    ///     .setting(AppSettings::Hidden))
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    Hidden,
+
+    /// Tells `clap` *not* to print possible values when displaying help information.
+    /// This can be useful if there are many values, or they are explained elsewhere.
+    HidePossibleValuesInHelp,
+
+    /// Tries to match unknown args to partial [`subcommands`] or their [aliases]. For example to
+    /// match a subcommand named `test`, one could use `t`, `te`, `tes`, and `test`.
+    ///
+    /// **NOTE:** The match *must not* be ambiguous at all in order to succeed. i.e. to match `te`
+    /// to `test` there could not also be a subcommand or alias `temp` because both start with `te`
+    ///
+    /// **CAUTION:** This setting can interfere with [positional/free arguments], take care when
+    /// designing CLIs which allow inferred subcommands and have potential positional/free
+    /// arguments whose values could start with the same characters as subcommands. If this is the
+    /// case, it's recommended to use settings such as [`AppSeettings::ArgsNegateSubcommands`] in
+    /// conjunction with this setting.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// let m = App::new("prog")
+    ///     .setting(AppSettings::InferSubcommands)
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "te"
+    ///     ]);
+    /// assert_eq!(m.subcommand_name(), Some("test"));
+    /// ```
+    /// [`subcommands`]: ./struct.SubCommand.html
+    /// [positional/free arguments]: ./struct.Arg.html#method.index
+    /// [aliases]: ./struct.App.html#method.alias
+    /// [`AppSeettings::ArgsNegateSubcommands`]: ./enum.AppSettings.html#variant.ArgsNegateSubcommands
+    InferSubcommands,
+
+    /// Specifies that the parser should not assume the first argument passed is the binary name.
+    /// This is normally the case when using a "daemon" style mode, or an interactive CLI where one
+    /// one would not normally type the binary or program name for each command.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings};
+    /// let m = App::new("myprog")
+    ///     .setting(AppSettings::NoBinaryName)
+    ///     .arg(Arg::from_usage("<cmd>... 'commands to run'"))
+    ///     .get_matches_from(vec!["command", "set"]);
+    ///
+    /// let cmds: Vec<&str> = m.values_of("cmd").unwrap().collect();
+    /// assert_eq!(cmds, ["command", "set"]);
+    /// ```
+    NoBinaryName,
+
+    /// Places the help string for all arguments on the line after the argument.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::NextLineHelp)
+    ///     .get_matches();
+    /// ```
+    NextLineHelp,
+
+    /// **DEPRECATED**: This setting is no longer required in order to propagate values up or down
+    ///
+    /// Specifies that the parser should propagate global arg's values down or up through any *used*
+    /// child subcommands. Meaning, if a subcommand wasn't used, the values won't be propagated to
+    /// said subcommand.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings, SubCommand};
+    /// let m = App::new("myprog")
+    ///     .arg(Arg::from_usage("[cmd] 'command to run'")
+    ///         .global(true))
+    ///     .subcommand(SubCommand::with_name("foo"))
+    ///     .get_matches_from(vec!["myprog", "set", "foo"]);
+    ///
+    /// assert_eq!(m.value_of("cmd"), Some("set"));
+    ///
+    /// let sub_m = m.subcommand_matches("foo").unwrap();
+    /// assert_eq!(sub_m.value_of("cmd"), Some("set"));
+    /// ```
+    /// Now doing the same thing, but *not* using any subcommands will result in the value not being
+    /// propagated down.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings, SubCommand};
+    /// let m = App::new("myprog")
+    ///     .arg(Arg::from_usage("[cmd] 'command to run'")
+    ///         .global(true))
+    ///     .subcommand(SubCommand::with_name("foo"))
+    ///     .get_matches_from(vec!["myprog", "set"]);
+    ///
+    /// assert_eq!(m.value_of("cmd"), Some("set"));
+    ///
+    /// assert!(m.subcommand_matches("foo").is_none());
+    /// ```
+    #[deprecated(since = "2.27.0", note = "No longer required to propagate values")]
+    PropagateGlobalValuesDown,
+
+    /// Allows [`SubCommand`]s to override all requirements of the parent command.
+    /// For example if you had a subcommand or top level application with a required argument
+    /// that is only required as long as there is no subcommand present,
+    /// using this setting would allow you to set those arguments to [`Arg::required(true)`]
+    /// and yet receive no error so long as the user uses a valid subcommand instead.
+    ///
+    /// **NOTE:** This defaults to false (using subcommand does *not* negate requirements)
+    ///
+    /// # Examples
+    ///
+    /// This first example shows that it is an error to not use a required argument
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings, SubCommand, ErrorKind};
+    /// let err = App::new("myprog")
+    ///     .setting(AppSettings::SubcommandsNegateReqs)
+    ///     .arg(Arg::with_name("opt").required(true))
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog"
+    ///     ]);
+    /// assert!(err.is_err());
+    /// assert_eq!(err.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// # ;
+    /// ```
+    ///
+    /// This next example shows that it is no longer error to not use a required argument if a
+    /// valid subcommand is used.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings, SubCommand, ErrorKind};
+    /// let noerr = App::new("myprog")
+    ///     .setting(AppSettings::SubcommandsNegateReqs)
+    ///     .arg(Arg::with_name("opt").required(true))
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog", "test"
+    ///     ]);
+    /// assert!(noerr.is_ok());
+    /// # ;
+    /// ```
+    /// [`Arg::required(true)`]: ./struct.Arg.html#method.required
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    SubcommandsNegateReqs,
+
+    /// Specifies that the help text should be displayed (before exiting gracefully) if no
+    /// [`SubCommand`]s are present at runtime (i.e. an empty run such as `$ myprog`).
+    ///
+    /// **NOTE:** This should *not* be used with [`AppSettings::SubcommandRequired`] as they do
+    /// nearly same thing; this prints the help text, and the other prints an error.
+    ///
+    /// **NOTE:** If the user specifies arguments at runtime, but no subcommand the help text will
+    /// still be displayed and exit. If this is *not* the desired result, consider using
+    /// [`AppSettings::ArgRequiredElseHelp`] instead.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::SubcommandRequiredElseHelp)
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`AppSettings::SubcommandRequired`]: ./enum.AppSettings.html#variant.SubcommandRequired
+    /// [`AppSettings::ArgRequiredElseHelp`]: ./enum.AppSettings.html#variant.ArgRequiredElseHelp
+    SubcommandRequiredElseHelp,
+
+    /// Specifies that any invalid UTF-8 code points should be treated as an error and fail
+    /// with a [`ErrorKind::InvalidUtf8`] error.
+    ///
+    /// **NOTE:** This rule only applies to argument values; Things such as flags, options, and
+    /// [`SubCommand`]s themselves only allow valid UTF-8 code points.
+    ///
+    /// # Platform Specific
+    ///
+    /// Non Windows systems only
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(not(unix), doc = " ```ignore")]
+    #[cfg_attr(unix, doc = " ```")]
+    /// # use clap::{App, AppSettings, ErrorKind};
+    /// use std::ffi::OsString;
+    /// use std::os::unix::ffi::OsStringExt;
+    ///
+    /// let m = App::new("myprog")
+    ///     .setting(AppSettings::StrictUtf8)
+    ///     .arg_from_usage("<arg> 'some positional arg'")
+    ///     .get_matches_from_safe(
+    ///         vec![
+    ///             OsString::from("myprog"),
+    ///             OsString::from_vec(vec![0xe9])]);
+    ///
+    /// assert!(m.is_err());
+    /// assert_eq!(m.unwrap_err().kind, ErrorKind::InvalidUtf8);
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`ErrorKind::InvalidUtf8`]: ./enum.ErrorKind.html#variant.InvalidUtf8
+    StrictUtf8,
+
+    /// Allows specifying that if no [`SubCommand`] is present at runtime,
+    /// error and exit gracefully.
+    ///
+    /// **NOTE:** This defaults to `false` (subcommands do *not* need to be present)
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, AppSettings, SubCommand, ErrorKind};
+    /// let err = App::new("myprog")
+    ///     .setting(AppSettings::SubcommandRequired)
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog",
+    ///     ]);
+    /// assert!(err.is_err());
+    /// assert_eq!(err.unwrap_err().kind, ErrorKind::MissingSubcommand);
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    SubcommandRequired,
+
+    /// Specifies that the final positional argument is a "VarArg" and that `clap` should not
+    /// attempt to parse any further args.
+    ///
+    /// The values of the trailing positional argument will contain all args from itself on.
+    ///
+    /// **NOTE:** The final positional argument **must** have [`Arg::multiple(true)`] or the usage
+    /// string equivalent.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings};
+    /// let m = App::new("myprog")
+    ///     .setting(AppSettings::TrailingVarArg)
+    ///     .arg(Arg::from_usage("<cmd>... 'commands to run'"))
+    ///     .get_matches_from(vec!["myprog", "arg1", "-r", "val1"]);
+    ///
+    /// let trail: Vec<&str> = m.values_of("cmd").unwrap().collect();
+    /// assert_eq!(trail, ["arg1", "-r", "val1"]);
+    /// ```
+    /// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+    TrailingVarArg,
+
+    /// Groups flags and options together, presenting a more unified help message
+    /// (a la `getopts` or `docopt` style).
+    ///
+    /// The default is that the auto-generated help message will group flags, and options
+    /// separately.
+    ///
+    /// **NOTE:** This setting is cosmetic only and does not affect any functionality.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::UnifiedHelpMessage)
+    ///     .get_matches();
+    /// // running `myprog --help` will display a unified "docopt" or "getopts" style help message
+    /// ```
+    UnifiedHelpMessage,
+
+    /// Disables `-V` and `--version` for all [`SubCommand`]s
+    /// (Defaults to `false`; subcommands *do* have version flags.)
+    ///
+    /// **NOTE:** This setting must be set **prior** to adding any subcommands.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, SubCommand, AppSettings, ErrorKind};
+    /// let res = App::new("myprog")
+    ///     .version("v1.1")
+    ///     .setting(AppSettings::VersionlessSubcommands)
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog", "test", "-V"
+    ///     ]);
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::UnknownArgument);
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    VersionlessSubcommands,
+
+    /// Will display a message "Press \[ENTER\]/\[RETURN\] to continue..." and wait for user before
+    /// exiting
+    ///
+    /// This is most useful when writing an application which is run from a GUI shortcut, or on
+    /// Windows where a user tries to open the binary by double-clicking instead of using the
+    /// command line.
+    ///
+    /// **NOTE:** This setting is **not** recursive with [`SubCommand`]s, meaning if you wish this
+    /// behavior for all subcommands, you must set this on each command (needing this is extremely
+    /// rare)
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings};
+    /// App::new("myprog")
+    ///     .setting(AppSettings::WaitOnError)
+    /// # ;
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    WaitOnError,
+
+    #[doc(hidden)] NeedsLongVersion,
+
+    #[doc(hidden)] NeedsLongHelp,
+
+    #[doc(hidden)] NeedsSubcommandHelp,
+
+    #[doc(hidden)] LowIndexMultiplePositional,
+
+    #[doc(hidden)] TrailingValues,
+
+    #[doc(hidden)] ValidNegNumFound,
+
+    #[doc(hidden)] Propagated,
+
+    #[doc(hidden)] ValidArgFound,
+
+    #[doc(hidden)] ContainsLast,
+}
+
+impl FromStr for AppSettings {
+    type Err = String;
+    fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
+        match &*s.to_ascii_lowercase() {
+            "disablehelpflags" => Ok(AppSettings::DisableHelpFlags),
+            "argrequiredelsehelp" => Ok(AppSettings::ArgRequiredElseHelp),
+            "argsnegatesubcommands" => Ok(AppSettings::ArgsNegateSubcommands),
+            "allowinvalidutf8" => Ok(AppSettings::AllowInvalidUtf8),
+            "allowleadinghyphen" => Ok(AppSettings::AllowLeadingHyphen),
+            "allowexternalsubcommands" => Ok(AppSettings::AllowExternalSubcommands),
+            "allownegativenumbers" => Ok(AppSettings::AllowNegativeNumbers),
+            "colorauto" => Ok(AppSettings::ColorAuto),
+            "coloralways" => Ok(AppSettings::ColorAlways),
+            "colornever" => Ok(AppSettings::ColorNever),
+            "coloredhelp" => Ok(AppSettings::ColoredHelp),
+            "derivedisplayorder" => Ok(AppSettings::DeriveDisplayOrder),
+            "dontcollapseargsinusage" => Ok(AppSettings::DontCollapseArgsInUsage),
+            "dontdelimittrailingvalues" => Ok(AppSettings::DontDelimitTrailingValues),
+            "disablehelpsubcommand" => Ok(AppSettings::DisableHelpSubcommand),
+            "disableversion" => Ok(AppSettings::DisableVersion),
+            "globalversion" => Ok(AppSettings::GlobalVersion),
+            "hidden" => Ok(AppSettings::Hidden),
+            "hidepossiblevaluesinhelp" => Ok(AppSettings::HidePossibleValuesInHelp),
+            "infersubcommands" => Ok(AppSettings::InferSubcommands),
+            "lowindexmultiplepositional" => Ok(AppSettings::LowIndexMultiplePositional),
+            "nobinaryname" => Ok(AppSettings::NoBinaryName),
+            "nextlinehelp" => Ok(AppSettings::NextLineHelp),
+            "strictutf8" => Ok(AppSettings::StrictUtf8),
+            "subcommandsnegatereqs" => Ok(AppSettings::SubcommandsNegateReqs),
+            "subcommandrequired" => Ok(AppSettings::SubcommandRequired),
+            "subcommandrequiredelsehelp" => Ok(AppSettings::SubcommandRequiredElseHelp),
+            "trailingvararg" => Ok(AppSettings::TrailingVarArg),
+            "unifiedhelpmessage" => Ok(AppSettings::UnifiedHelpMessage),
+            "versionlesssubcommands" => Ok(AppSettings::VersionlessSubcommands),
+            "waitonerror" => Ok(AppSettings::WaitOnError),
+            "validnegnumfound" => Ok(AppSettings::ValidNegNumFound),
+            "validargfound" => Ok(AppSettings::ValidArgFound),
+            "propagated" => Ok(AppSettings::Propagated),
+            "trailingvalues" => Ok(AppSettings::TrailingValues),
+            _ => Err("unknown AppSetting, cannot convert from str".to_owned()),
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::AppSettings;
+
+    #[test]
+    fn app_settings_fromstr() {
+        assert_eq!(
+            "disablehelpflags".parse::<AppSettings>().unwrap(),
+            AppSettings::DisableHelpFlags
+        );
+        assert_eq!(
+            "argsnegatesubcommands".parse::<AppSettings>().unwrap(),
+            AppSettings::ArgsNegateSubcommands
+        );
+        assert_eq!(
+            "argrequiredelsehelp".parse::<AppSettings>().unwrap(),
+            AppSettings::ArgRequiredElseHelp
+        );
+        assert_eq!(
+            "allowexternalsubcommands".parse::<AppSettings>().unwrap(),
+            AppSettings::AllowExternalSubcommands
+        );
+        assert_eq!(
+            "allowinvalidutf8".parse::<AppSettings>().unwrap(),
+            AppSettings::AllowInvalidUtf8
+        );
+        assert_eq!(
+            "allowleadinghyphen".parse::<AppSettings>().unwrap(),
+            AppSettings::AllowLeadingHyphen
+        );
+        assert_eq!(
+            "allownegativenumbers".parse::<AppSettings>().unwrap(),
+            AppSettings::AllowNegativeNumbers
+        );
+        assert_eq!(
+            "coloredhelp".parse::<AppSettings>().unwrap(),
+            AppSettings::ColoredHelp
+        );
+        assert_eq!(
+            "colorauto".parse::<AppSettings>().unwrap(),
+            AppSettings::ColorAuto
+        );
+        assert_eq!(
+            "coloralways".parse::<AppSettings>().unwrap(),
+            AppSettings::ColorAlways
+        );
+        assert_eq!(
+            "colornever".parse::<AppSettings>().unwrap(),
+            AppSettings::ColorNever
+        );
+        assert_eq!(
+            "disablehelpsubcommand".parse::<AppSettings>().unwrap(),
+            AppSettings::DisableHelpSubcommand
+        );
+        assert_eq!(
+            "disableversion".parse::<AppSettings>().unwrap(),
+            AppSettings::DisableVersion
+        );
+        assert_eq!(
+            "dontcollapseargsinusage".parse::<AppSettings>().unwrap(),
+            AppSettings::DontCollapseArgsInUsage
+        );
+        assert_eq!(
+            "dontdelimittrailingvalues".parse::<AppSettings>().unwrap(),
+            AppSettings::DontDelimitTrailingValues
+        );
+        assert_eq!(
+            "derivedisplayorder".parse::<AppSettings>().unwrap(),
+            AppSettings::DeriveDisplayOrder
+        );
+        assert_eq!(
+            "globalversion".parse::<AppSettings>().unwrap(),
+            AppSettings::GlobalVersion
+        );
+        assert_eq!(
+            "hidden".parse::<AppSettings>().unwrap(),
+            AppSettings::Hidden
+        );
+        assert_eq!(
+            "hidepossiblevaluesinhelp".parse::<AppSettings>().unwrap(),
+            AppSettings::HidePossibleValuesInHelp
+        );
+        assert_eq!(
+            "lowindexmultiplePositional".parse::<AppSettings>().unwrap(),
+            AppSettings::LowIndexMultiplePositional
+        );
+        assert_eq!(
+            "nobinaryname".parse::<AppSettings>().unwrap(),
+            AppSettings::NoBinaryName
+        );
+        assert_eq!(
+            "nextlinehelp".parse::<AppSettings>().unwrap(),
+            AppSettings::NextLineHelp
+        );
+        assert_eq!(
+            "subcommandsnegatereqs".parse::<AppSettings>().unwrap(),
+            AppSettings::SubcommandsNegateReqs
+        );
+        assert_eq!(
+            "subcommandrequired".parse::<AppSettings>().unwrap(),
+            AppSettings::SubcommandRequired
+        );
+        assert_eq!(
+            "subcommandrequiredelsehelp".parse::<AppSettings>().unwrap(),
+            AppSettings::SubcommandRequiredElseHelp
+        );
+        assert_eq!(
+            "strictutf8".parse::<AppSettings>().unwrap(),
+            AppSettings::StrictUtf8
+        );
+        assert_eq!(
+            "trailingvararg".parse::<AppSettings>().unwrap(),
+            AppSettings::TrailingVarArg
+        );
+        assert_eq!(
+            "unifiedhelpmessage".parse::<AppSettings>().unwrap(),
+            AppSettings::UnifiedHelpMessage
+        );
+        assert_eq!(
+            "versionlesssubcommands".parse::<AppSettings>().unwrap(),
+            AppSettings::VersionlessSubcommands
+        );
+        assert_eq!(
+            "waitonerror".parse::<AppSettings>().unwrap(),
+            AppSettings::WaitOnError
+        );
+        assert_eq!(
+            "validnegnumfound".parse::<AppSettings>().unwrap(),
+            AppSettings::ValidNegNumFound
+        );
+        assert_eq!(
+            "validargfound".parse::<AppSettings>().unwrap(),
+            AppSettings::ValidArgFound
+        );
+        assert_eq!(
+            "propagated".parse::<AppSettings>().unwrap(),
+            AppSettings::Propagated
+        );
+        assert_eq!(
+            "trailingvalues".parse::<AppSettings>().unwrap(),
+            AppSettings::TrailingValues
+        );
+        assert_eq!(
+            "infersubcommands".parse::<AppSettings>().unwrap(),
+            AppSettings::InferSubcommands
+        );
+        assert!("hahahaha".parse::<AppSettings>().is_err());
+    }
+}
diff --git a/src/app/usage.rs b/src/app/usage.rs
new file mode 100644
index 0000000..6090588
--- /dev/null
+++ b/src/app/usage.rs
@@ -0,0 +1,479 @@
+// std
+use std::collections::{BTreeMap, VecDeque};
+
+// Internal
+use INTERNAL_ERROR_MSG;
+use args::{AnyArg, ArgMatcher, PosBuilder};
+use args::settings::ArgSettings;
+use app::settings::AppSettings as AS;
+use app::parser::Parser;
+
+// Creates a usage string for display. This happens just after all arguments were parsed, but before
+// any subcommands have been parsed (so as to give subcommands their own usage recursively)
+pub fn create_usage_with_title(p: &Parser, used: &[&str]) -> String {
+    debugln!("usage::create_usage_with_title;");
+    let mut usage = String::with_capacity(75);
+    usage.push_str("USAGE:\n    ");
+    usage.push_str(&*create_usage_no_title(p, used));
+    usage
+}
+
+// Creates a usage string to be used in error message (i.e. one with currently used args)
+pub fn create_error_usage<'a, 'b>(
+    p: &Parser<'a, 'b>,
+    matcher: &'b ArgMatcher<'a>,
+    extra: Option<&str>,
+) -> String {
+    let mut args: Vec<_> = matcher
+        .arg_names()
+        .iter()
+        .filter(|n| {
+            if let Some(o) = find_by_name!(p, **n, opts, iter) {
+                !o.b.is_set(ArgSettings::Required) && !o.b.is_set(ArgSettings::Hidden)
+            } else if let Some(p) = find_by_name!(p, **n, positionals, values) {
+                !p.b.is_set(ArgSettings::Required) && p.b.is_set(ArgSettings::Hidden)
+            } else {
+                true // flags can't be required, so they're always true
+            }
+        })
+        .map(|&n| n)
+        .collect();
+    if let Some(r) = extra {
+        args.push(r);
+    }
+    create_usage_with_title(p, &*args)
+}
+
+// Creates a usage string (*without title*) if one was not provided by the user manually.
+pub fn create_usage_no_title(p: &Parser, used: &[&str]) -> String {
+    debugln!("usage::create_usage_no_title;");
+    if let Some(u) = p.meta.usage_str {
+        String::from(&*u)
+    } else if used.is_empty() {
+        create_help_usage(p, true)
+    } else {
+        create_smart_usage(p, used)
+    }
+}
+
+// Creates a usage string for display in help messages (i.e. not for errors)
+pub fn create_help_usage(p: &Parser, incl_reqs: bool) -> String {
+    let mut usage = String::with_capacity(75);
+    let name = p.meta
+        .usage
+        .as_ref()
+        .unwrap_or_else(|| p.meta.bin_name.as_ref().unwrap_or(&p.meta.name));
+    usage.push_str(&*name);
+    let req_string = if incl_reqs {
+        let mut reqs: Vec<&str> = p.required().map(|r| &**r).collect();
+        reqs.sort();
+        reqs.dedup();
+        get_required_usage_from(p, &reqs, None, None, false)
+            .iter()
+            .fold(String::new(), |a, s| a + &format!(" {}", s)[..])
+    } else {
+        String::new()
+    };
+
+    let flags = needs_flags_tag(p);
+    if flags && !p.is_set(AS::UnifiedHelpMessage) {
+        usage.push_str(" [FLAGS]");
+    } else if flags {
+        usage.push_str(" [OPTIONS]");
+    }
+    if !p.is_set(AS::UnifiedHelpMessage) && p.opts.iter().any(|o| {
+        !o.is_set(ArgSettings::Required) && !o.is_set(ArgSettings::Hidden)
+    }) {
+        usage.push_str(" [OPTIONS]");
+    }
+
+    usage.push_str(&req_string[..]);
+
+    let has_last = p.positionals.values().any(|p| p.is_set(ArgSettings::Last));
+    // places a '--' in the usage string if there are args and options
+    // supporting multiple values
+    if p.opts.iter().any(|o| o.is_set(ArgSettings::Multiple))
+        && p.positionals
+            .values()
+            .any(|p| !p.is_set(ArgSettings::Required))
+        && !(p.has_visible_subcommands() || p.is_set(AS::AllowExternalSubcommands))
+        && !has_last
+    {
+        usage.push_str(" [--]");
+    }
+    let not_req_or_hidden = |p: &PosBuilder| {
+        (!p.is_set(ArgSettings::Required) || p.is_set(ArgSettings::Last))
+            && !p.is_set(ArgSettings::Hidden)
+    };
+    if p.has_positionals() && p.positionals.values().any(not_req_or_hidden) {
+        if let Some(args_tag) = get_args_tag(p, incl_reqs) {
+            usage.push_str(&*args_tag);
+        } else {
+            usage.push_str(" [ARGS]");
+        }
+        if has_last && incl_reqs {
+            let pos = p.positionals
+                .values()
+                .find(|p| p.b.is_set(ArgSettings::Last))
+                .expect(INTERNAL_ERROR_MSG);
+            debugln!("usage::create_help_usage: '{}' has .last(true)", pos.name());
+            let req = pos.is_set(ArgSettings::Required);
+            if req
+                && p.positionals
+                    .values()
+                    .any(|p| !p.is_set(ArgSettings::Required))
+            {
+                usage.push_str(" -- <");
+            } else if req {
+                usage.push_str(" [--] <");
+            } else {
+                usage.push_str(" [-- <");
+            }
+            usage.push_str(&*pos.name_no_brackets());
+            usage.push_str(">");
+            usage.push_str(pos.multiple_str());
+            if !req {
+                usage.push_str("]");
+            }
+        }
+    }
+
+    // incl_reqs is only false when this function is called recursively
+    if p.has_visible_subcommands() && incl_reqs || p.is_set(AS::AllowExternalSubcommands) {
+        if p.is_set(AS::SubcommandsNegateReqs) || p.is_set(AS::ArgsNegateSubcommands) {
+            if !p.is_set(AS::ArgsNegateSubcommands) {
+                usage.push_str("\n    ");
+                usage.push_str(&*create_help_usage(p, false));
+                usage.push_str(" <SUBCOMMAND>");
+            } else {
+                usage.push_str("\n    ");
+                usage.push_str(&*name);
+                usage.push_str(" <SUBCOMMAND>");
+            }
+        } else if p.is_set(AS::SubcommandRequired) || p.is_set(AS::SubcommandRequiredElseHelp) {
+            usage.push_str(" <SUBCOMMAND>");
+        } else {
+            usage.push_str(" [SUBCOMMAND]");
+        }
+    }
+    usage.shrink_to_fit();
+    debugln!("usage::create_help_usage: usage={}", usage);
+    usage
+}
+
+// Creates a context aware usage string, or "smart usage" from currently used
+// args, and requirements
+fn create_smart_usage(p: &Parser, used: &[&str]) -> String {
+    debugln!("usage::smart_usage;");
+    let mut usage = String::with_capacity(75);
+    let mut hs: Vec<&str> = p.required().map(|s| &**s).collect();
+    hs.extend_from_slice(used);
+
+    let r_string = get_required_usage_from(p, &hs, None, None, false)
+        .iter()
+        .fold(String::new(), |acc, s| acc + &format!(" {}", s)[..]);
+
+    usage.push_str(
+        &p.meta
+            .usage
+            .as_ref()
+            .unwrap_or_else(|| p.meta.bin_name.as_ref().unwrap_or(&p.meta.name))[..],
+    );
+    usage.push_str(&*r_string);
+    if p.is_set(AS::SubcommandRequired) {
+        usage.push_str(" <SUBCOMMAND>");
+    }
+    usage.shrink_to_fit();
+    usage
+}
+
+// Gets the `[ARGS]` tag for the usage string
+fn get_args_tag(p: &Parser, incl_reqs: bool) -> Option<String> {
+    debugln!("usage::get_args_tag;");
+    let mut count = 0;
+    'outer: for pos in p.positionals
+        .values()
+        .filter(|pos| !pos.is_set(ArgSettings::Required))
+        .filter(|pos| !pos.is_set(ArgSettings::Hidden))
+        .filter(|pos| !pos.is_set(ArgSettings::Last))
+    {
+        debugln!("usage::get_args_tag:iter:{}:", pos.b.name);
+        if let Some(g_vec) = p.groups_for_arg(pos.b.name) {
+            for grp_s in &g_vec {
+                debugln!("usage::get_args_tag:iter:{}:iter:{};", pos.b.name, grp_s);
+                // if it's part of a required group we don't want to count it
+                if p.groups.iter().any(|g| g.required && (&g.name == grp_s)) {
+                    continue 'outer;
+                }
+            }
+        }
+        count += 1;
+        debugln!(
+            "usage::get_args_tag:iter: {} Args not required or hidden",
+            count
+        );
+    }
+    if !p.is_set(AS::DontCollapseArgsInUsage) && count > 1 {
+        debugln!("usage::get_args_tag:iter: More than one, returning [ARGS]");
+        return None; // [ARGS]
+    } else if count == 1 && incl_reqs {
+        let pos = p.positionals
+            .values()
+            .find(|pos| {
+                !pos.is_set(ArgSettings::Required) && !pos.is_set(ArgSettings::Hidden)
+                    && !pos.is_set(ArgSettings::Last)
+            })
+            .expect(INTERNAL_ERROR_MSG);
+        debugln!(
+            "usage::get_args_tag:iter: Exactly one, returning '{}'",
+            pos.name()
+        );
+        return Some(format!(
+            " [{}]{}",
+            pos.name_no_brackets(),
+            pos.multiple_str()
+        ));
+    } else if p.is_set(AS::DontCollapseArgsInUsage) && !p.positionals.is_empty() && incl_reqs {
+        debugln!("usage::get_args_tag:iter: Don't collapse returning all");
+        return Some(
+            p.positionals
+                .values()
+                .filter(|pos| !pos.is_set(ArgSettings::Required))
+                .filter(|pos| !pos.is_set(ArgSettings::Hidden))
+                .filter(|pos| !pos.is_set(ArgSettings::Last))
+                .map(|pos| {
+                    format!(" [{}]{}", pos.name_no_brackets(), pos.multiple_str())
+                })
+                .collect::<Vec<_>>()
+                .join(""),
+        );
+    } else if !incl_reqs {
+        debugln!("usage::get_args_tag:iter: incl_reqs=false, building secondary usage string");
+        let highest_req_pos = p.positionals
+            .iter()
+            .filter_map(|(idx, pos)| {
+                if pos.b.is_set(ArgSettings::Required) && !pos.b.is_set(ArgSettings::Last) {
+                    Some(idx)
+                } else {
+                    None
+                }
+            })
+            .max()
+            .unwrap_or_else(|| p.positionals.len());
+        return Some(
+            p.positionals
+                .iter()
+                .filter_map(|(idx, pos)| {
+                    if idx <= highest_req_pos {
+                        Some(pos)
+                    } else {
+                        None
+                    }
+                })
+                .filter(|pos| !pos.is_set(ArgSettings::Required))
+                .filter(|pos| !pos.is_set(ArgSettings::Hidden))
+                .filter(|pos| !pos.is_set(ArgSettings::Last))
+                .map(|pos| {
+                    format!(" [{}]{}", pos.name_no_brackets(), pos.multiple_str())
+                })
+                .collect::<Vec<_>>()
+                .join(""),
+        );
+    }
+    Some("".into())
+}
+
+// Determines if we need the `[FLAGS]` tag in the usage string
+fn needs_flags_tag(p: &Parser) -> bool {
+    debugln!("usage::needs_flags_tag;");
+    'outer: for f in &p.flags {
+        debugln!("usage::needs_flags_tag:iter: f={};", f.b.name);
+        if let Some(l) = f.s.long {
+            if l == "help" || l == "version" {
+                // Don't print `[FLAGS]` just for help or version
+                continue;
+            }
+        }
+        if let Some(g_vec) = p.groups_for_arg(f.b.name) {
+            for grp_s in &g_vec {
+                debugln!("usage::needs_flags_tag:iter:iter: grp_s={};", grp_s);
+                if p.groups.iter().any(|g| &g.name == grp_s && g.required) {
+                    debugln!("usage::needs_flags_tag:iter:iter: Group is required");
+                    continue 'outer;
+                }
+            }
+        }
+        if f.is_set(ArgSettings::Hidden) {
+            continue;
+        }
+        debugln!("usage::needs_flags_tag:iter: [FLAGS] required");
+        return true;
+    }
+
+    debugln!("usage::needs_flags_tag: [FLAGS] not required");
+    false
+}
+
+// Returns the required args in usage string form by fully unrolling all groups
+pub fn get_required_usage_from<'a, 'b>(
+    p: &Parser<'a, 'b>,
+    reqs: &[&'a str],
+    matcher: Option<&ArgMatcher<'a>>,
+    extra: Option<&str>,
+    incl_last: bool,
+) -> VecDeque<String> {
+    debugln!(
+        "usage::get_required_usage_from: reqs={:?}, extra={:?}",
+        reqs,
+        extra
+    );
+    let mut desc_reqs: Vec<&str> = vec![];
+    desc_reqs.extend(extra);
+    let mut new_reqs: Vec<&str> = vec![];
+    macro_rules! get_requires {
+        (@group $a: ident, $v:ident, $p:ident) => {{
+            if let Some(rl) = p.groups.iter()
+                                            .filter(|g| g.requires.is_some())
+                                            .find(|g| &g.name == $a)
+                                            .map(|g| g.requires.as_ref().unwrap()) {
+                for r in rl {
+                    if !$p.contains(&r) {
+                        debugln!("usage::get_required_usage_from:iter:{}: adding group req={:?}",
+                            $a, r);
+                        $v.push(r);
+                    }
+                }
+            }
+        }};
+        ($a:ident, $what:ident, $how:ident, $v:ident, $p:ident) => {{
+            if let Some(rl) = p.$what.$how()
+                                        .filter(|a| a.b.requires.is_some())
+                                        .find(|arg| &arg.b.name == $a)
+                                        .map(|a| a.b.requires.as_ref().unwrap()) {
+                for &(_, r) in rl.iter() {
+                    if !$p.contains(&r) {
+                        debugln!("usage::get_required_usage_from:iter:{}: adding arg req={:?}",
+                            $a, r);
+                        $v.push(r);
+                    }
+                }
+            }
+        }};
+    }
+    // initialize new_reqs
+    for a in reqs {
+        get_requires!(a, flags, iter, new_reqs, reqs);
+        get_requires!(a, opts, iter, new_reqs, reqs);
+        get_requires!(a, positionals, values, new_reqs, reqs);
+        get_requires!(@group a, new_reqs, reqs);
+    }
+    desc_reqs.extend_from_slice(&*new_reqs);
+    debugln!(
+        "usage::get_required_usage_from: after init desc_reqs={:?}",
+        desc_reqs
+    );
+    loop {
+        let mut tmp = vec![];
+        for a in &new_reqs {
+            get_requires!(a, flags, iter, tmp, desc_reqs);
+            get_requires!(a, opts, iter, tmp, desc_reqs);
+            get_requires!(a, positionals, values, tmp, desc_reqs);
+            get_requires!(@group a, tmp, desc_reqs);
+        }
+        if tmp.is_empty() {
+            debugln!("usage::get_required_usage_from: no more children");
+            break;
+        } else {
+            debugln!("usage::get_required_usage_from: after iter tmp={:?}", tmp);
+            debugln!(
+                "usage::get_required_usage_from: after iter new_reqs={:?}",
+                new_reqs
+            );
+            desc_reqs.extend_from_slice(&*new_reqs);
+            new_reqs.clear();
+            new_reqs.extend_from_slice(&*tmp);
+            debugln!(
+                "usage::get_required_usage_from: after iter desc_reqs={:?}",
+                desc_reqs
+            );
+        }
+    }
+    desc_reqs.extend_from_slice(reqs);
+    desc_reqs.sort();
+    desc_reqs.dedup();
+    debugln!(
+        "usage::get_required_usage_from: final desc_reqs={:?}",
+        desc_reqs
+    );
+    let mut ret_val = VecDeque::new();
+    let args_in_groups = p.groups
+        .iter()
+        .filter(|gn| desc_reqs.contains(&gn.name))
+        .flat_map(|g| p.arg_names_in_group(g.name))
+        .collect::<Vec<_>>();
+
+    let pmap = if let Some(m) = matcher {
+        desc_reqs
+            .iter()
+            .filter(|a| p.positionals.values().any(|p| &&p.b.name == a))
+            .filter(|&pos| !m.contains(pos))
+            .filter_map(|pos| p.positionals.values().find(|x| &x.b.name == pos))
+            .filter(|&pos| incl_last || !pos.is_set(ArgSettings::Last))
+            .filter(|pos| !args_in_groups.contains(&pos.b.name))
+            .map(|pos| (pos.index, pos))
+            .collect::<BTreeMap<u64, &PosBuilder>>() // sort by index
+    } else {
+        desc_reqs
+            .iter()
+            .filter(|a| p.positionals.values().any(|pos| &&pos.b.name == a))
+            .filter_map(|pos| p.positionals.values().find(|x| &x.b.name == pos))
+            .filter(|&pos| incl_last || !pos.is_set(ArgSettings::Last))
+            .filter(|pos| !args_in_groups.contains(&pos.b.name))
+            .map(|pos| (pos.index, pos))
+            .collect::<BTreeMap<u64, &PosBuilder>>() // sort by index
+    };
+    debugln!(
+        "usage::get_required_usage_from: args_in_groups={:?}",
+        args_in_groups
+    );
+    for &p in pmap.values() {
+        let s = p.to_string();
+        if args_in_groups.is_empty() || !args_in_groups.contains(&&*s) {
+            ret_val.push_back(s);
+        }
+    }
+    for a in desc_reqs
+        .iter()
+        .filter(|name| !p.positionals.values().any(|p| &&p.b.name == name))
+        .filter(|name| !p.groups.iter().any(|g| &&g.name == name))
+        .filter(|name| !args_in_groups.contains(name))
+        .filter(|name| {
+            !(matcher.is_some() && matcher.as_ref().unwrap().contains(name))
+        }) {
+        debugln!("usage::get_required_usage_from:iter:{}:", a);
+        let arg = find_by_name!(p, *a, flags, iter)
+            .map(|f| f.to_string())
+            .unwrap_or_else(|| {
+                find_by_name!(p, *a, opts, iter)
+                    .map(|o| o.to_string())
+                    .expect(INTERNAL_ERROR_MSG)
+            });
+        ret_val.push_back(arg);
+    }
+    let mut g_vec: Vec<String> = vec![];
+    for g in desc_reqs
+        .iter()
+        .filter(|n| p.groups.iter().any(|g| &&g.name == n))
+    {
+        let g_string = p.args_in_group(g).join("|");
+        let elem = format!("<{}>", &g_string[..g_string.len()]);
+        if !g_vec.contains(&elem) {
+            g_vec.push(elem);
+        }
+    }
+    for g in g_vec {
+        ret_val.push_back(g);
+    }
+
+    ret_val
+}
diff --git a/src/app/validator.rs b/src/app/validator.rs
new file mode 100644
index 0000000..181b831
--- /dev/null
+++ b/src/app/validator.rs
@@ -0,0 +1,573 @@
+// std
+use std::fmt::Display;
+#[allow(deprecated, unused_imports)]
+use std::ascii::AsciiExt;
+
+// Internal
+use INTERNAL_ERROR_MSG;
+use INVALID_UTF8;
+use args::{AnyArg, ArgMatcher, MatchedArg};
+use args::settings::ArgSettings;
+use errors::{Error, ErrorKind};
+use errors::Result as ClapResult;
+use app::settings::AppSettings as AS;
+use app::parser::{ParseResult, Parser};
+use fmt::{Colorizer, ColorizerOption};
+use app::usage;
+
+pub struct Validator<'a, 'b, 'z>(&'z mut Parser<'a, 'b>)
+where
+    'a: 'b,
+    'b: 'z;
+
+impl<'a, 'b, 'z> Validator<'a, 'b, 'z> {
+    pub fn new(p: &'z mut Parser<'a, 'b>) -> Self { Validator(p) }
+
+    pub fn validate(
+        &mut self,
+        needs_val_of: ParseResult<'a>,
+        subcmd_name: Option<String>,
+        matcher: &mut ArgMatcher<'a>,
+    ) -> ClapResult<()> {
+        debugln!("Validator::validate;");
+        let mut reqs_validated = false;
+        self.0.add_env(matcher)?;
+        self.0.add_defaults(matcher)?;
+        if let ParseResult::Opt(a) = needs_val_of {
+            debugln!("Validator::validate: needs_val_of={:?}", a);
+            let o = {
+                self.0
+                .opts
+                .iter()
+                .find(|o| o.b.name == a)
+                .expect(INTERNAL_ERROR_MSG)
+                .clone()
+            };
+            self.validate_required(matcher)?;
+            reqs_validated = true;
+            let should_err = if let Some(v) = matcher.0.args.get(&*o.b.name) {
+                v.vals.is_empty() && !(o.v.min_vals.is_some() && o.v.min_vals.unwrap() == 0)
+            } else {
+                true
+            };
+            if should_err {
+                return Err(Error::empty_value(
+                    &o,
+                    &*usage::create_error_usage(self.0, matcher, None),
+                    self.0.color(),
+                ));
+            }
+        }
+
+        if matcher.is_empty() && matcher.subcommand_name().is_none()
+            && self.0.is_set(AS::ArgRequiredElseHelp)
+        {
+            let mut out = vec![];
+            self.0.write_help_err(&mut out)?;
+            return Err(Error {
+                message: String::from_utf8_lossy(&*out).into_owned(),
+                kind: ErrorKind::MissingArgumentOrSubcommand,
+                info: None,
+            });
+        }
+        self.validate_blacklist(matcher)?;
+        if !(self.0.is_set(AS::SubcommandsNegateReqs) && subcmd_name.is_some()) && !reqs_validated {
+            self.validate_required(matcher)?;
+        }
+        self.validate_matched_args(matcher)?;
+        matcher.usage(usage::create_usage_with_title(self.0, &[]));
+
+        Ok(())
+    }
+
+    fn validate_arg_values<A>(
+        &self,
+        arg: &A,
+        ma: &MatchedArg,
+        matcher: &ArgMatcher<'a>,
+    ) -> ClapResult<()>
+    where
+        A: AnyArg<'a, 'b> + Display,
+    {
+        debugln!("Validator::validate_arg_values: arg={:?}", arg.name());
+        for val in &ma.vals {
+            if self.0.is_set(AS::StrictUtf8) && val.to_str().is_none() {
+                debugln!(
+                    "Validator::validate_arg_values: invalid UTF-8 found in val {:?}",
+                    val
+                );
+                return Err(Error::invalid_utf8(
+                    &*usage::create_error_usage(self.0, matcher, None),
+                    self.0.color(),
+                ));
+            }
+            if let Some(p_vals) = arg.possible_vals() {
+                debugln!("Validator::validate_arg_values: possible_vals={:?}", p_vals);
+                let val_str = val.to_string_lossy();
+                let ok = if arg.is_set(ArgSettings::CaseInsensitive) {
+                    p_vals.iter().any(|pv| pv.eq_ignore_ascii_case(&*val_str))
+                } else {
+                    p_vals.contains(&&*val_str)
+                };
+                if !ok {
+                    return Err(Error::invalid_value(
+                        val_str,
+                        p_vals,
+                        arg,
+                        &*usage::create_error_usage(self.0, matcher, None),
+                        self.0.color(),
+                    ));
+                }
+            }
+            if !arg.is_set(ArgSettings::EmptyValues) && val.is_empty()
+                && matcher.contains(&*arg.name())
+            {
+                debugln!("Validator::validate_arg_values: illegal empty val found");
+                return Err(Error::empty_value(
+                    arg,
+                    &*usage::create_error_usage(self.0, matcher, None),
+                    self.0.color(),
+                ));
+            }
+            if let Some(vtor) = arg.validator() {
+                debug!("Validator::validate_arg_values: checking validator...");
+                if let Err(e) = vtor(val.to_string_lossy().into_owned()) {
+                    sdebugln!("error");
+                    return Err(Error::value_validation(Some(arg), e, self.0.color()));
+                } else {
+                    sdebugln!("good");
+                }
+            }
+            if let Some(vtor) = arg.validator_os() {
+                debug!("Validator::validate_arg_values: checking validator_os...");
+                if let Err(e) = vtor(val) {
+                    sdebugln!("error");
+                    return Err(Error::value_validation(
+                        Some(arg),
+                        (*e).to_string_lossy().to_string(),
+                        self.0.color(),
+                    ));
+                } else {
+                    sdebugln!("good");
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn build_err(&self, name: &str, matcher: &ArgMatcher) -> ClapResult<()> {
+        debugln!("build_err!: name={}", name);
+        let mut c_with = find_from!(self.0, &name, blacklist, matcher);
+        c_with = c_with.or(
+        self.0.find_any_arg(name).map_or(None, |aa| aa.blacklist())
+            .map_or(None,
+                    |bl| bl.iter().find(|arg| matcher.contains(arg)))
+            .map_or(None, |an| self.0.find_any_arg(an))
+            .map_or(None, |aa| Some(format!("{}", aa)))
+        );
+        debugln!("build_err!: '{:?}' conflicts with '{}'", c_with, &name);
+//        matcher.remove(&name);
+        let usg = usage::create_error_usage(self.0, matcher, None);
+        if let Some(f) = find_by_name!(self.0, name, flags, iter) {
+            debugln!("build_err!: It was a flag...");
+            Err(Error::argument_conflict(f, c_with, &*usg, self.0.color()))
+        } else if let Some(o) = find_by_name!(self.0, name, opts, iter) {
+            debugln!("build_err!: It was an option...");
+            Err(Error::argument_conflict(o, c_with, &*usg, self.0.color()))
+        } else {
+            match find_by_name!(self.0, name, positionals, values) {
+                Some(p) => {
+                    debugln!("build_err!: It was a positional...");
+                    Err(Error::argument_conflict(p, c_with, &*usg, self.0.color()))
+                },
+                None    => panic!(INTERNAL_ERROR_MSG)
+            }
+        }
+    }
+
+    fn validate_blacklist(&self, matcher: &mut ArgMatcher) -> ClapResult<()> {
+        debugln!("Validator::validate_blacklist;");
+        let mut conflicts: Vec<&str> = vec![];
+        for (&name, _) in matcher.iter() {
+            debugln!("Validator::validate_blacklist:iter:{};", name);
+            if let Some(grps) = self.0.groups_for_arg(name) {
+                for grp in &grps {
+                    if let Some(g) = self.0.groups.iter().find(|g| &g.name == grp) {
+                        if !g.multiple {
+                            for arg in &g.args {
+                                if arg == &name {
+                                    continue;
+                                }
+                                conflicts.push(arg);
+                            }
+                        }
+                        if let Some(ref gc) = g.conflicts {
+                            conflicts.extend(&*gc);
+                        }
+                    }
+                }
+            }
+            if let Some(arg) = find_any_by_name!(self.0, name) {
+                if let Some(bl) = arg.blacklist() {
+                    for conf in bl {
+                        if matcher.get(conf).is_some() {
+                            conflicts.push(conf);
+                        }
+                    }
+                }
+            } else {
+                debugln!("Validator::validate_blacklist:iter:{}:group;", name);
+                let args = self.0.arg_names_in_group(name);
+                for arg in &args {
+                    debugln!("Validator::validate_blacklist:iter:{}:group:iter:{};", name, arg);
+                    if let Some(bl) = find_any_by_name!(self.0, *arg).unwrap().blacklist() {
+                        for conf in bl {
+                            if matcher.get(conf).is_some() {
+                                conflicts.push(conf);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        for name in &conflicts {
+            debugln!(
+                "Validator::validate_blacklist:iter:{}: Checking blacklisted arg",
+                name
+            );
+            let mut should_err = false;
+            if self.0.groups.iter().any(|g| &g.name == name) {
+                debugln!(
+                    "Validator::validate_blacklist:iter:{}: groups contains it...",
+                    name
+                );
+                for n in self.0.arg_names_in_group(name) {
+                    debugln!(
+                        "Validator::validate_blacklist:iter:{}:iter:{}: looking in group...",
+                        name,
+                        n
+                    );
+                    if matcher.contains(n) {
+                        debugln!(
+                            "Validator::validate_blacklist:iter:{}:iter:{}: matcher contains it...",
+                            name,
+                            n
+                        );
+                        return self.build_err(n, matcher);
+                    }
+                }
+            } else if let Some(ma) = matcher.get(name) {
+                debugln!(
+                    "Validator::validate_blacklist:iter:{}: matcher contains it...",
+                    name
+                );
+                should_err = ma.occurs > 0;
+            }
+            if should_err {
+                return self.build_err(*name, matcher);
+            }
+        }
+        Ok(())
+    }
+
+    fn validate_matched_args(&self, matcher: &mut ArgMatcher<'a>) -> ClapResult<()> {
+        debugln!("Validator::validate_matched_args;");
+        for (name, ma) in matcher.iter() {
+            debugln!(
+                "Validator::validate_matched_args:iter:{}: vals={:#?}",
+                name,
+                ma.vals
+            );
+            if let Some(opt) = find_by_name!(self.0, *name, opts, iter) {
+                self.validate_arg_num_vals(opt, ma, matcher)?;
+                self.validate_arg_values(opt, ma, matcher)?;
+                self.validate_arg_requires(opt, ma, matcher)?;
+                self.validate_arg_num_occurs(opt, ma, matcher)?;
+            } else if let Some(flag) = find_by_name!(self.0, *name, flags, iter) {
+                self.validate_arg_requires(flag, ma, matcher)?;
+                self.validate_arg_num_occurs(flag, ma, matcher)?;
+            } else if let Some(pos) = find_by_name!(self.0, *name, positionals, values) {
+                self.validate_arg_num_vals(pos, ma, matcher)?;
+                self.validate_arg_num_occurs(pos, ma, matcher)?;
+                self.validate_arg_values(pos, ma, matcher)?;
+                self.validate_arg_requires(pos, ma, matcher)?;
+            } else {
+                let grp = self.0
+                    .groups
+                    .iter()
+                    .find(|g| &g.name == name)
+                    .expect(INTERNAL_ERROR_MSG);
+                if let Some(ref g_reqs) = grp.requires {
+                    if g_reqs.iter().any(|&n| !matcher.contains(n)) {
+                        return self.missing_required_error(matcher, None);
+                    }
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn validate_arg_num_occurs<A>(
+        &self,
+        a: &A,
+        ma: &MatchedArg,
+        matcher: &ArgMatcher,
+    ) -> ClapResult<()>
+    where
+        A: AnyArg<'a, 'b> + Display,
+    {
+        debugln!("Validator::validate_arg_num_occurs: a={};", a.name());
+        if ma.occurs > 1 && !a.is_set(ArgSettings::Multiple) {
+            // Not the first time, and we don't allow multiples
+            return Err(Error::unexpected_multiple_usage(
+                a,
+                &*usage::create_error_usage(self.0, matcher, None),
+                self.0.color(),
+            ));
+        }
+        Ok(())
+    }
+
+    fn validate_arg_num_vals<A>(
+        &self,
+        a: &A,
+        ma: &MatchedArg,
+        matcher: &ArgMatcher,
+    ) -> ClapResult<()>
+    where
+        A: AnyArg<'a, 'b> + Display,
+    {
+        debugln!("Validator::validate_arg_num_vals:{}", a.name());
+        if let Some(num) = a.num_vals() {
+            debugln!("Validator::validate_arg_num_vals: num_vals set...{}", num);
+            let should_err = if a.is_set(ArgSettings::Multiple) {
+                ((ma.vals.len() as u64) % num) != 0
+            } else {
+                num != (ma.vals.len() as u64)
+            };
+            if should_err {
+                debugln!("Validator::validate_arg_num_vals: Sending error WrongNumberOfValues");
+                return Err(Error::wrong_number_of_values(
+                    a,
+                    num,
+                    if a.is_set(ArgSettings::Multiple) {
+                        (ma.vals.len() % num as usize)
+                    } else {
+                        ma.vals.len()
+                    },
+                    if ma.vals.len() == 1
+                        || (a.is_set(ArgSettings::Multiple) && (ma.vals.len() % num as usize) == 1)
+                    {
+                        "as"
+                    } else {
+                        "ere"
+                    },
+                    &*usage::create_error_usage(self.0, matcher, None),
+                    self.0.color(),
+                ));
+            }
+        }
+        if let Some(num) = a.max_vals() {
+            debugln!("Validator::validate_arg_num_vals: max_vals set...{}", num);
+            if (ma.vals.len() as u64) > num {
+                debugln!("Validator::validate_arg_num_vals: Sending error TooManyValues");
+                return Err(Error::too_many_values(
+                    ma.vals
+                        .iter()
+                        .last()
+                        .expect(INTERNAL_ERROR_MSG)
+                        .to_str()
+                        .expect(INVALID_UTF8),
+                    a,
+                    &*usage::create_error_usage(self.0, matcher, None),
+                    self.0.color(),
+                ));
+            }
+        }
+        let min_vals_zero = if let Some(num) = a.min_vals() {
+            debugln!("Validator::validate_arg_num_vals: min_vals set: {}", num);
+            if (ma.vals.len() as u64) < num && num != 0 {
+                debugln!("Validator::validate_arg_num_vals: Sending error TooFewValues");
+                return Err(Error::too_few_values(
+                    a,
+                    num,
+                    ma.vals.len(),
+                    &*usage::create_error_usage(self.0, matcher, None),
+                    self.0.color(),
+                ));
+            }
+            num == 0
+        } else {
+            false
+        };
+        // Issue 665 (https://github.com/clap-rs/clap/issues/665)
+        // Issue 1105 (https://github.com/clap-rs/clap/issues/1105)
+        if a.takes_value() && !min_vals_zero && ma.vals.is_empty() {
+            return Err(Error::empty_value(
+                a,
+                &*usage::create_error_usage(self.0, matcher, None),
+                self.0.color(),
+            ));
+        }
+        Ok(())
+    }
+
+    fn validate_arg_requires<A>(
+        &self,
+        a: &A,
+        ma: &MatchedArg,
+        matcher: &ArgMatcher,
+    ) -> ClapResult<()>
+    where
+        A: AnyArg<'a, 'b> + Display,
+    {
+        debugln!("Validator::validate_arg_requires:{};", a.name());
+        if let Some(a_reqs) = a.requires() {
+            for &(val, name) in a_reqs.iter().filter(|&&(val, _)| val.is_some()) {
+                let missing_req =
+                    |v| v == val.expect(INTERNAL_ERROR_MSG) && !matcher.contains(name);
+                if ma.vals.iter().any(missing_req) {
+                    return self.missing_required_error(matcher, None);
+                }
+            }
+            for &(_, name) in a_reqs.iter().filter(|&&(val, _)| val.is_none()) {
+                if !matcher.contains(name) {
+                    return self.missing_required_error(matcher, Some(name));
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn validate_required(&mut self, matcher: &ArgMatcher) -> ClapResult<()> {
+        debugln!(
+            "Validator::validate_required: required={:?};",
+            self.0.required
+        );
+
+        let mut should_err = false;
+        let mut to_rem = Vec::new();
+        for name in &self.0.required {
+            debugln!("Validator::validate_required:iter:{}:", name);
+            if matcher.contains(name) {
+                continue;
+            }
+            if to_rem.contains(name) {
+                continue;
+            } else if let Some(a) = find_any_by_name!(self.0, *name) {
+                if self.is_missing_required_ok(a, matcher) {
+                    to_rem.push(a.name());
+                    if let Some(reqs) = a.requires() {
+                        for r in reqs
+                            .iter()
+                            .filter(|&&(val, _)| val.is_none())
+                            .map(|&(_, name)| name)
+                        {
+                            to_rem.push(r);
+                        }
+                    }
+                    continue;
+                }
+            }
+            should_err = true;
+            break;
+        }
+        if should_err {
+            for r in &to_rem {
+                'inner: for i in (0 .. self.0.required.len()).rev() {
+                    if &self.0.required[i] == r {
+                        self.0.required.swap_remove(i);
+                        break 'inner;
+                    }
+                }
+            }
+            return self.missing_required_error(matcher, None);
+        }
+
+        // Validate the conditionally required args
+        for &(a, v, r) in &self.0.r_ifs {
+            if let Some(ma) = matcher.get(a) {
+                if matcher.get(r).is_none() && ma.vals.iter().any(|val| val == v) {
+                    return self.missing_required_error(matcher, Some(r));
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn validate_arg_conflicts(&self, a: &AnyArg, matcher: &ArgMatcher) -> Option<bool> {
+        debugln!("Validator::validate_arg_conflicts: a={:?};", a.name());
+        a.blacklist().map(|bl| {
+            bl.iter().any(|conf| {
+                matcher.contains(conf)
+                    || self.0
+                        .groups
+                        .iter()
+                        .find(|g| &g.name == conf)
+                        .map_or(false, |g| g.args.iter().any(|arg| matcher.contains(arg)))
+            })
+        })
+    }
+
+    fn validate_required_unless(&self, a: &AnyArg, matcher: &ArgMatcher) -> Option<bool> {
+        debugln!("Validator::validate_required_unless: a={:?};", a.name());
+        macro_rules! check {
+            ($how:ident, $_self:expr, $a:ident, $m:ident) => {{
+                $a.required_unless().map(|ru| {
+                    ru.iter().$how(|n| {
+                        $m.contains(n) || {
+                            if let Some(grp) = $_self.groups.iter().find(|g| &g.name == n) {
+                                     grp.args.iter().any(|arg| $m.contains(arg))
+                            } else {
+                                false
+                            }
+                        }
+                    })
+                })
+            }};
+        }
+        if a.is_set(ArgSettings::RequiredUnlessAll) {
+            check!(all, self.0, a, matcher)
+        } else {
+            check!(any, self.0, a, matcher)
+        }
+    }
+
+    fn missing_required_error(&self, matcher: &ArgMatcher, extra: Option<&str>) -> ClapResult<()> {
+        debugln!("Validator::missing_required_error: extra={:?}", extra);
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: self.0.color(),
+        });
+        let mut reqs = self.0.required.iter().map(|&r| &*r).collect::<Vec<_>>();
+        if let Some(r) = extra {
+            reqs.push(r);
+        }
+        reqs.retain(|n| !matcher.contains(n));
+        reqs.dedup();
+        debugln!("Validator::missing_required_error: reqs={:#?}", reqs);
+        let req_args =
+            usage::get_required_usage_from(self.0, &reqs[..], Some(matcher), extra, true)
+                .iter()
+                .fold(String::new(), |acc, s| {
+                    acc + &format!("\n    {}", c.error(s))[..]
+                });
+        debugln!(
+            "Validator::missing_required_error: req_args={:#?}",
+            req_args
+        );
+        Err(Error::missing_required_argument(
+            &*req_args,
+            &*usage::create_error_usage(self.0, matcher, extra),
+            self.0.color(),
+        ))
+    }
+
+    #[inline]
+    fn is_missing_required_ok(&self, a: &AnyArg, matcher: &ArgMatcher) -> bool {
+        debugln!("Validator::is_missing_required_ok: a={}", a.name());
+        self.validate_arg_conflicts(a, matcher).unwrap_or(false)
+            || self.validate_required_unless(a, matcher).unwrap_or(false)
+    }
+}
diff --git a/src/args/any_arg.rs b/src/args/any_arg.rs
new file mode 100644
index 0000000..eee5228
--- /dev/null
+++ b/src/args/any_arg.rs
@@ -0,0 +1,74 @@
+// Std
+use std::rc::Rc;
+use std::fmt as std_fmt;
+use std::ffi::{OsStr, OsString};
+
+// Internal
+use args::settings::ArgSettings;
+use map::{self, VecMap};
+use INTERNAL_ERROR_MSG;
+
+#[doc(hidden)]
+pub trait AnyArg<'n, 'e>: std_fmt::Display {
+    fn name(&self) -> &'n str;
+    fn overrides(&self) -> Option<&[&'e str]>;
+    fn aliases(&self) -> Option<Vec<&'e str>>;
+    fn requires(&self) -> Option<&[(Option<&'e str>, &'n str)]>;
+    fn blacklist(&self) -> Option<&[&'e str]>;
+    fn required_unless(&self) -> Option<&[&'e str]>;
+    fn is_set(&self, ArgSettings) -> bool;
+    fn set(&mut self, ArgSettings);
+    fn has_switch(&self) -> bool;
+    fn max_vals(&self) -> Option<u64>;
+    fn min_vals(&self) -> Option<u64>;
+    fn num_vals(&self) -> Option<u64>;
+    fn possible_vals(&self) -> Option<&[&'e str]>;
+    fn validator(&self) -> Option<&Rc<Fn(String) -> Result<(), String>>>;
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> Result<(), OsString>>>;
+    fn short(&self) -> Option<char>;
+    fn long(&self) -> Option<&'e str>;
+    fn val_delim(&self) -> Option<char>;
+    fn takes_value(&self) -> bool;
+    fn val_names(&self) -> Option<&VecMap<&'e str>>;
+    fn help(&self) -> Option<&'e str>;
+    fn long_help(&self) -> Option<&'e str>;
+    fn default_val(&self) -> Option<&'e OsStr>;
+    fn default_vals_ifs(&self) -> Option<map::Values<(&'n str, Option<&'e OsStr>, &'e OsStr)>>;
+    fn env<'s>(&'s self) -> Option<(&'n OsStr, Option<&'s OsString>)>;
+    fn longest_filter(&self) -> bool;
+    fn val_terminator(&self) -> Option<&'e str>;
+}
+
+pub trait DispOrder {
+    fn disp_ord(&self) -> usize;
+}
+
+impl<'n, 'e, 'z, T: ?Sized> AnyArg<'n, 'e> for &'z T where T: AnyArg<'n, 'e> + 'z {
+    fn name(&self) -> &'n str { (*self).name() }
+    fn overrides(&self) -> Option<&[&'e str]> { (*self).overrides() }
+    fn aliases(&self) -> Option<Vec<&'e str>> { (*self).aliases() }
+    fn requires(&self) -> Option<&[(Option<&'e str>, &'n str)]> { (*self).requires() }
+    fn blacklist(&self) -> Option<&[&'e str]> { (*self).blacklist() }
+    fn required_unless(&self) -> Option<&[&'e str]> { (*self).required_unless() }
+    fn is_set(&self, a: ArgSettings) -> bool { (*self).is_set(a) }
+    fn set(&mut self, _: ArgSettings) { panic!(INTERNAL_ERROR_MSG) }
+    fn has_switch(&self) -> bool { (*self).has_switch() }
+    fn max_vals(&self) -> Option<u64> { (*self).max_vals() }
+    fn min_vals(&self) -> Option<u64> { (*self).min_vals() }
+    fn num_vals(&self) -> Option<u64> { (*self).num_vals() }
+    fn possible_vals(&self) -> Option<&[&'e str]> { (*self).possible_vals() }
+    fn validator(&self) -> Option<&Rc<Fn(String) -> Result<(), String>>> { (*self).validator() }
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> Result<(), OsString>>> { (*self).validator_os() }
+    fn short(&self) -> Option<char> { (*self).short() }
+    fn long(&self) -> Option<&'e str> { (*self).long() }
+    fn val_delim(&self) -> Option<char> { (*self).val_delim() }
+    fn takes_value(&self) -> bool { (*self).takes_value() }
+    fn val_names(&self) -> Option<&VecMap<&'e str>> { (*self).val_names() }
+    fn help(&self) -> Option<&'e str> { (*self).help() }
+    fn long_help(&self) -> Option<&'e str> { (*self).long_help() }
+    fn default_val(&self) -> Option<&'e OsStr> { (*self).default_val() }
+    fn default_vals_ifs(&self) -> Option<map::Values<(&'n str, Option<&'e OsStr>, &'e OsStr)>> { (*self).default_vals_ifs() }
+    fn env<'s>(&'s self) -> Option<(&'n OsStr, Option<&'s OsString>)> { (*self).env() }
+    fn longest_filter(&self) -> bool { (*self).longest_filter() }
+    fn val_terminator(&self) -> Option<&'e str> { (*self).val_terminator() }
+}
diff --git a/src/args/arg.rs b/src/args/arg.rs
new file mode 100644
index 0000000..50a30ab
--- /dev/null
+++ b/src/args/arg.rs
@@ -0,0 +1,3954 @@
+#[cfg(feature = "yaml")]
+use std::collections::BTreeMap;
+use std::rc::Rc;
+use std::ffi::{OsStr, OsString};
+#[cfg(any(target_os = "windows", target_arch = "wasm32"))]
+use osstringext::OsStrExt3;
+#[cfg(not(any(target_os = "windows", target_arch = "wasm32")))]
+use std::os::unix::ffi::OsStrExt;
+use std::env;
+
+#[cfg(feature = "yaml")]
+use yaml_rust::Yaml;
+use map::VecMap;
+
+use usage_parser::UsageParser;
+use args::settings::ArgSettings;
+use args::arg_builder::{Base, Switched, Valued};
+
+/// The abstract representation of a command line argument. Used to set all the options and
+/// relationships that define a valid argument for the program.
+///
+/// There are two methods for constructing [`Arg`]s, using the builder pattern and setting options
+/// manually, or using a usage string which is far less verbose but has fewer options. You can also
+/// use a combination of the two methods to achieve the best of both worlds.
+///
+/// # Examples
+///
+/// ```rust
+/// # use clap::Arg;
+/// // Using the traditional builder pattern and setting each option manually
+/// let cfg = Arg::with_name("config")
+///       .short("c")
+///       .long("config")
+///       .takes_value(true)
+///       .value_name("FILE")
+///       .help("Provides a config file to myprog");
+/// // Using a usage string (setting a similar argument to the one above)
+/// let input = Arg::from_usage("-i, --input=[FILE] 'Provides an input file to the program'");
+/// ```
+/// [`Arg`]: ./struct.Arg.html
+#[allow(missing_debug_implementations)]
+#[derive(Default, Clone)]
+pub struct Arg<'a, 'b>
+where
+    'a: 'b,
+{
+    #[doc(hidden)] pub b: Base<'a, 'b>,
+    #[doc(hidden)] pub s: Switched<'b>,
+    #[doc(hidden)] pub v: Valued<'a, 'b>,
+    #[doc(hidden)] pub index: Option<u64>,
+    #[doc(hidden)] pub r_ifs: Option<Vec<(&'a str, &'b str)>>,
+}
+
+impl<'a, 'b> Arg<'a, 'b> {
+    /// Creates a new instance of [`Arg`] using a unique string name. The name will be used to get
+    /// information about whether or not the argument was used at runtime, get values, set
+    /// relationships with other args, etc..
+    ///
+    /// **NOTE:** In the case of arguments that take values (i.e. [`Arg::takes_value(true)`])
+    /// and positional arguments (i.e. those without a preceding `-` or `--`) the name will also
+    /// be displayed when the user prints the usage/help information of the program.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("config")
+    /// # ;
+    /// ```
+    /// [`Arg::takes_value(true)`]: ./struct.Arg.html#method.takes_value
+    /// [`Arg`]: ./struct.Arg.html
+    pub fn with_name(n: &'a str) -> Self {
+        Arg {
+            b: Base::new(n),
+            ..Default::default()
+        }
+    }
+
+    /// Creates a new instance of [`Arg`] from a .yml (YAML) file.
+    ///
+    /// # Examples
+    ///
+    /// ```ignore
+    /// # #[macro_use]
+    /// # extern crate clap;
+    /// # use clap::Arg;
+    /// # fn main() {
+    /// let yml = load_yaml!("arg.yml");
+    /// let arg = Arg::from_yaml(yml);
+    /// # }
+    /// ```
+    /// [`Arg`]: ./struct.Arg.html
+    #[cfg(feature = "yaml")]
+    pub fn from_yaml(y: &BTreeMap<Yaml, Yaml>) -> Arg {
+        // We WANT this to panic on error...so expect() is good.
+        let name_yml = y.keys().nth(0).unwrap();
+        let name_str = name_yml.as_str().unwrap();
+        let mut a = Arg::with_name(name_str);
+        let arg_settings = y.get(name_yml).unwrap().as_hash().unwrap();
+
+        for (k, v) in arg_settings.iter() {
+            a = match k.as_str().unwrap() {
+                "short" => yaml_to_str!(a, v, short),
+                "long" => yaml_to_str!(a, v, long),
+                "aliases" => yaml_vec_or_str!(v, a, alias),
+                "help" => yaml_to_str!(a, v, help),
+                "long_help" => yaml_to_str!(a, v, long_help),
+                "required" => yaml_to_bool!(a, v, required),
+                "required_if" => yaml_tuple2!(a, v, required_if),
+                "required_ifs" => yaml_tuple2!(a, v, required_if),
+                "takes_value" => yaml_to_bool!(a, v, takes_value),
+                "index" => yaml_to_u64!(a, v, index),
+                "global" => yaml_to_bool!(a, v, global),
+                "multiple" => yaml_to_bool!(a, v, multiple),
+                "hidden" => yaml_to_bool!(a, v, hidden),
+                "next_line_help" => yaml_to_bool!(a, v, next_line_help),
+                "empty_values" => yaml_to_bool!(a, v, empty_values),
+                "group" => yaml_to_str!(a, v, group),
+                "number_of_values" => yaml_to_u64!(a, v, number_of_values),
+                "max_values" => yaml_to_u64!(a, v, max_values),
+                "min_values" => yaml_to_u64!(a, v, min_values),
+                "value_name" => yaml_to_str!(a, v, value_name),
+                "use_delimiter" => yaml_to_bool!(a, v, use_delimiter),
+                "allow_hyphen_values" => yaml_to_bool!(a, v, allow_hyphen_values),
+                "last" => yaml_to_bool!(a, v, last),
+                "require_delimiter" => yaml_to_bool!(a, v, require_delimiter),
+                "value_delimiter" => yaml_to_str!(a, v, value_delimiter),
+                "required_unless" => yaml_to_str!(a, v, required_unless),
+                "display_order" => yaml_to_usize!(a, v, display_order),
+                "default_value" => yaml_to_str!(a, v, default_value),
+                "default_value_if" => yaml_tuple3!(a, v, default_value_if),
+                "default_value_ifs" => yaml_tuple3!(a, v, default_value_if),
+                "env" => yaml_to_str!(a, v, env),
+                "value_names" => yaml_vec_or_str!(v, a, value_name),
+                "groups" => yaml_vec_or_str!(v, a, group),
+                "requires" => yaml_vec_or_str!(v, a, requires),
+                "requires_if" => yaml_tuple2!(a, v, requires_if),
+                "requires_ifs" => yaml_tuple2!(a, v, requires_if),
+                "conflicts_with" => yaml_vec_or_str!(v, a, conflicts_with),
+                "overrides_with" => yaml_vec_or_str!(v, a, overrides_with),
+                "possible_values" => yaml_vec_or_str!(v, a, possible_value),
+                "case_insensitive" => yaml_to_bool!(a, v, case_insensitive),
+                "required_unless_one" => yaml_vec_or_str!(v, a, required_unless),
+                "required_unless_all" => {
+                    a = yaml_vec_or_str!(v, a, required_unless);
+                    a.setb(ArgSettings::RequiredUnlessAll);
+                    a
+                }
+                s => panic!(
+                    "Unknown Arg setting '{}' in YAML file for arg '{}'",
+                    s, name_str
+                ),
+            }
+        }
+
+        a
+    }
+
+    /// Creates a new instance of [`Arg`] from a usage string. Allows creation of basic settings
+    /// for the [`Arg`]. The syntax is flexible, but there are some rules to follow.
+    ///
+    /// **NOTE**: Not all settings may be set using the usage string method. Some properties are
+    /// only available via the builder pattern.
+    ///
+    /// **NOTE**: Only ASCII values are officially supported in [`Arg::from_usage`] strings. Some
+    /// UTF-8 codepoints may work just fine, but this is not guaranteed.
+    ///
+    /// # Syntax
+    ///
+    /// Usage strings typically following the form:
+    ///
+    /// ```notrust
+    /// [explicit name] [short] [long] [value names] [help string]
+    /// ```
+    ///
+    /// This is not a hard rule as the attributes can appear in other orders. There are also
+    /// several additional sigils which denote additional settings. Below are the details of each
+    /// portion of the string.
+    ///
+    /// ### Explicit Name
+    ///
+    /// This is an optional field, if it's omitted the argument will use one of the additional
+    /// fields as the name using the following priority order:
+    ///
+    ///  * Explicit Name (This always takes precedence when present)
+    ///  * Long
+    ///  * Short
+    ///  * Value Name
+    ///
+    /// `clap` determines explicit names as the first string of characters between either `[]` or
+    /// `<>` where `[]` has the dual notation of meaning the argument is optional, and `<>` meaning
+    /// the argument is required.
+    ///
+    /// Explicit names may be followed by:
+    ///  * The multiple denotation `...`
+    ///
+    /// Example explicit names as follows (`ename` for an optional argument, and `rname` for a
+    /// required argument):
+    ///
+    /// ```notrust
+    /// [ename] -s, --long 'some flag'
+    /// <rname> -r, --longer 'some other flag'
+    /// ```
+    ///
+    /// ### Short
+    ///
+    /// This is set by placing a single character after a leading `-`.
+    ///
+    /// Shorts may be followed by
+    ///  * The multiple denotation `...`
+    ///  * An optional comma `,` which is cosmetic only
+    ///  * Value notation
+    ///
+    /// Example shorts are as follows (`-s`, and `-r`):
+    ///
+    /// ```notrust
+    /// -s, --long 'some flag'
+    /// <rname> -r [val], --longer 'some option'
+    /// ```
+    ///
+    /// ### Long
+    ///
+    /// This is set by placing a word (no spaces) after a leading `--`.
+    ///
+    /// Shorts may be followed by
+    ///  * The multiple denotation `...`
+    ///  * Value notation
+    ///
+    /// Example longs are as follows (`--some`, and `--rapid`):
+    ///
+    /// ```notrust
+    /// -s, --some 'some flag'
+    /// --rapid=[FILE] 'some option'
+    /// ```
+    ///
+    /// ### Values (Value Notation)
+    ///
+    /// This is set by placing a word(s) between `[]` or `<>` optionally after `=` (although this
+    /// is cosmetic only and does not affect functionality). If an explicit name has **not** been
+    /// set, using `<>` will denote a required argument, and `[]` will denote an optional argument
+    ///
+    /// Values may be followed by
+    ///  * The multiple denotation `...`
+    ///  * More Value notation
+    ///
+    /// More than one value will also implicitly set the arguments number of values, i.e. having
+    /// two values, `--option [val1] [val2]` specifies that in order for option to be satisified it
+    /// must receive exactly two values
+    ///
+    /// Example values are as follows (`FILE`, and `SPEED`):
+    ///
+    /// ```notrust
+    /// -s, --some [FILE] 'some option'
+    /// --rapid=<SPEED>... 'some required multiple option'
+    /// ```
+    ///
+    /// ### Help String
+    ///
+    /// The help string is denoted between a pair of single quotes `''` and may contain any
+    /// characters.
+    ///
+    /// Example help strings are as follows:
+    ///
+    /// ```notrust
+    /// -s, --some [FILE] 'some option'
+    /// --rapid=<SPEED>... 'some required multiple option'
+    /// ```
+    ///
+    /// ### Additional Sigils
+    ///
+    /// Multiple notation `...` (three consecutive dots/periods) specifies that this argument may
+    /// be used multiple times. Do not confuse multiple occurrences (`...`) with multiple values.
+    /// `--option val1 val2` is a single occurrence with multiple values. `--flag --flag` is
+    /// multiple occurrences (and then you can obviously have instances of both as well)
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// App::new("prog")
+    ///     .args(&[
+    ///         Arg::from_usage("--config <FILE> 'a required file for the configuration and no short'"),
+    ///         Arg::from_usage("-d, --debug... 'turns on debugging information and allows multiples'"),
+    ///         Arg::from_usage("[input] 'an optional input file to use'")
+    /// ])
+    /// # ;
+    /// ```
+    /// [`Arg`]: ./struct.Arg.html
+    /// [`Arg::from_usage`]: ./struct.Arg.html#method.from_usage
+    pub fn from_usage(u: &'a str) -> Self {
+        let parser = UsageParser::from_usage(u);
+        parser.parse()
+    }
+
+    /// Sets the short version of the argument without the preceding `-`.
+    ///
+    /// By default `clap` automatically assigns `V` and `h` to the auto-generated `version` and
+    /// `help` arguments respectively. You may use the uppercase `V` or lowercase `h` for your own
+    /// arguments, in which case `clap` simply will not assign those to the auto-generated
+    /// `version` or `help` arguments.
+    ///
+    /// **NOTE:** Any leading `-` characters will be stripped, and only the first
+    /// non `-` character will be used as the [`short`] version
+    ///
+    /// # Examples
+    ///
+    /// To set [`short`] use a single valid UTF-8 code point. If you supply a leading `-` such as
+    /// `-c`, the `-` will be stripped.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("config")
+    ///     .short("c")
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`short`] allows using the argument via a single hyphen (`-`) such as `-c`
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("config")
+    ///         .short("c"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-c"
+    ///     ]);
+    ///
+    /// assert!(m.is_present("config"));
+    /// ```
+    /// [`short`]: ./struct.Arg.html#method.short
+    pub fn short<S: AsRef<str>>(mut self, s: S) -> Self {
+        self.s.short = s.as_ref().trim_left_matches(|c| c == '-').chars().nth(0);
+        self
+    }
+
+    /// Sets the long version of the argument without the preceding `--`.
+    ///
+    /// By default `clap` automatically assigns `version` and `help` to the auto-generated
+    /// `version` and `help` arguments respectively. You may use the word `version` or `help` for
+    /// the long form of your own arguments, in which case `clap` simply will not assign those to
+    /// the auto-generated `version` or `help` arguments.
+    ///
+    /// **NOTE:** Any leading `-` characters will be stripped
+    ///
+    /// # Examples
+    ///
+    /// To set `long` use a word containing valid UTF-8 codepoints. If you supply a double leading
+    /// `--` such as `--config` they will be stripped. Hyphens in the middle of the word, however,
+    /// will *not* be stripped (i.e. `config-file` is allowed)
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("cfg")
+    ///     .long("config")
+    /// # ;
+    /// ```
+    ///
+    /// Setting `long` allows using the argument via a double hyphen (`--`) such as `--config`
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .long("config"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--config"
+    ///     ]);
+    ///
+    /// assert!(m.is_present("cfg"));
+    /// ```
+    pub fn long(mut self, l: &'b str) -> Self {
+        self.s.long = Some(l.trim_left_matches(|c| c == '-'));
+        self
+    }
+
+    /// Allows adding a [`Arg`] alias, which function as "hidden" arguments that
+    /// automatically dispatch as if this argument was used. This is more efficient, and easier
+    /// than creating multiple hidden arguments as one only needs to check for the existence of
+    /// this command, and not all variants.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///             .arg(Arg::with_name("test")
+    ///             .long("test")
+    ///             .alias("alias")
+    ///             .takes_value(true))
+    ///        .get_matches_from(vec![
+    ///             "prog", "--alias", "cool"
+    ///         ]);
+    /// assert!(m.is_present("test"));
+    /// assert_eq!(m.value_of("test"), Some("cool"));
+    /// ```
+    /// [`Arg`]: ./struct.Arg.html
+    pub fn alias<S: Into<&'b str>>(mut self, name: S) -> Self {
+        if let Some(ref mut als) = self.s.aliases {
+            als.push((name.into(), false));
+        } else {
+            self.s.aliases = Some(vec![(name.into(), false)]);
+        }
+        self
+    }
+
+    /// Allows adding [`Arg`] aliases, which function as "hidden" arguments that
+    /// automatically dispatch as if this argument was used. This is more efficient, and easier
+    /// than creating multiple hidden subcommands as one only needs to check for the existence of
+    /// this command, and not all variants.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///             .arg(Arg::with_name("test")
+    ///                     .long("test")
+    ///                     .aliases(&["do-stuff", "do-tests", "tests"])
+    ///                     .help("the file to add")
+    ///                     .required(false))
+    ///             .get_matches_from(vec![
+    ///                 "prog", "--do-tests"
+    ///             ]);
+    /// assert!(m.is_present("test"));
+    /// ```
+    /// [`Arg`]: ./struct.Arg.html
+    pub fn aliases(mut self, names: &[&'b str]) -> Self {
+        if let Some(ref mut als) = self.s.aliases {
+            for n in names {
+                als.push((n, false));
+            }
+        } else {
+            self.s.aliases = Some(names.iter().map(|n| (*n, false)).collect::<Vec<_>>());
+        }
+        self
+    }
+
+    /// Allows adding a [`Arg`] alias that functions exactly like those defined with
+    /// [`Arg::alias`], except that they are visible inside the help message.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///             .arg(Arg::with_name("test")
+    ///                 .visible_alias("something-awesome")
+    ///                 .long("test")
+    ///                 .takes_value(true))
+    ///        .get_matches_from(vec![
+    ///             "prog", "--something-awesome", "coffee"
+    ///         ]);
+    /// assert!(m.is_present("test"));
+    /// assert_eq!(m.value_of("test"), Some("coffee"));
+    /// ```
+    /// [`Arg`]: ./struct.Arg.html
+    /// [`App::alias`]: ./struct.Arg.html#method.alias
+    pub fn visible_alias<S: Into<&'b str>>(mut self, name: S) -> Self {
+        if let Some(ref mut als) = self.s.aliases {
+            als.push((name.into(), true));
+        } else {
+            self.s.aliases = Some(vec![(name.into(), true)]);
+        }
+        self
+    }
+
+    /// Allows adding multiple [`Arg`] aliases that functions exactly like those defined
+    /// with [`Arg::aliases`], except that they are visible inside the help message.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///             .arg(Arg::with_name("test")
+    ///                 .long("test")
+    ///                 .visible_aliases(&["something", "awesome", "cool"]))
+    ///        .get_matches_from(vec![
+    ///             "prog", "--awesome"
+    ///         ]);
+    /// assert!(m.is_present("test"));
+    /// ```
+    /// [`Arg`]: ./struct.Arg.html
+    /// [`App::aliases`]: ./struct.Arg.html#method.aliases
+    pub fn visible_aliases(mut self, names: &[&'b str]) -> Self {
+        if let Some(ref mut als) = self.s.aliases {
+            for n in names {
+                als.push((n, true));
+            }
+        } else {
+            self.s.aliases = Some(names.iter().map(|n| (*n, true)).collect::<Vec<_>>());
+        }
+        self
+    }
+
+    /// Sets the short help text of the argument that will be displayed to the user when they print
+    /// the help information with `-h`. Typically, this is a short (one line) description of the
+    /// arg.
+    ///
+    /// **NOTE:** If only `Arg::help` is provided, and not [`Arg::long_help`] but the user requests
+    /// `--help` clap will still display the contents of `help` appropriately
+    ///
+    /// **NOTE:** Only `Arg::help` is used in completion script generation in order to be concise
+    ///
+    /// # Examples
+    ///
+    /// Any valid UTF-8 is allowed in the help text. The one exception is when one wishes to
+    /// include a newline in the help text and have the following text be properly aligned with all
+    /// the other help text.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("config")
+    ///     .help("The config file used by the myprog")
+    /// # ;
+    /// ```
+    ///
+    /// Setting `help` displays a short message to the side of the argument when the user passes
+    /// `-h` or `--help` (by default).
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .long("config")
+    ///         .help("Some help text describing the --config arg"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--help"
+    ///     ]);
+    /// ```
+    ///
+    /// The above example displays
+    ///
+    /// ```notrust
+    /// helptest
+    ///
+    /// USAGE:
+    ///    helptest [FLAGS]
+    ///
+    /// FLAGS:
+    ///     --config     Some help text describing the --config arg
+    /// -h, --help       Prints help information
+    /// -V, --version    Prints version information
+    /// ```
+    /// [`Arg::long_help`]: ./struct.Arg.html#method.long_help
+    pub fn help(mut self, h: &'b str) -> Self {
+        self.b.help = Some(h);
+        self
+    }
+
+    /// Sets the long help text of the argument that will be displayed to the user when they print
+    /// the help information with `--help`. Typically this a more detailed (multi-line) message
+    /// that describes the arg.
+    ///
+    /// **NOTE:** If only `long_help` is provided, and not [`Arg::help`] but the user requests `-h`
+    /// clap will still display the contents of `long_help` appropriately
+    ///
+    /// **NOTE:** Only [`Arg::help`] is used in completion script generation in order to be concise
+    ///
+    /// # Examples
+    ///
+    /// Any valid UTF-8 is allowed in the help text. The one exception is when one wishes to
+    /// include a newline in the help text and have the following text be properly aligned with all
+    /// the other help text.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("config")
+    ///     .long_help(
+    /// "The config file used by the myprog must be in JSON format
+    /// with only valid keys and may not contain other nonsense
+    /// that cannot be read by this program. Obviously I'm going on
+    /// and on, so I'll stop now.")
+    /// # ;
+    /// ```
+    ///
+    /// Setting `help` displays a short message to the side of the argument when the user passes
+    /// `-h` or `--help` (by default).
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .long("config")
+    ///         .long_help(
+    /// "The config file used by the myprog must be in JSON format
+    /// with only valid keys and may not contain other nonsense
+    /// that cannot be read by this program. Obviously I'm going on
+    /// and on, so I'll stop now."))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--help"
+    ///     ]);
+    /// ```
+    ///
+    /// The above example displays
+    ///
+    /// ```notrust
+    /// helptest
+    ///
+    /// USAGE:
+    ///    helptest [FLAGS]
+    ///
+    /// FLAGS:
+    ///    --config
+    ///         The config file used by the myprog must be in JSON format
+    ///         with only valid keys and may not contain other nonsense
+    ///         that cannot be read by this program. Obviously I'm going on
+    ///         and on, so I'll stop now.
+    ///
+    /// -h, --help
+    ///         Prints help information
+    ///
+    /// -V, --version
+    ///         Prints version information
+    /// ```
+    /// [`Arg::help`]: ./struct.Arg.html#method.help
+    pub fn long_help(mut self, h: &'b str) -> Self {
+        self.b.long_help = Some(h);
+        self
+    }
+
+    /// Specifies that this arg is the last, or final, positional argument (i.e. has the highest
+    /// index) and is *only* able to be accessed via the `--` syntax (i.e. `$ prog args --
+    /// last_arg`). Even, if no other arguments are left to parse, if the user omits the `--` syntax
+    /// they will receive an [`UnknownArgument`] error. Setting an argument to `.last(true)` also
+    /// allows one to access this arg early using the `--` syntax. Accessing an arg early, even with
+    /// the `--` syntax is otherwise not possible.
+    ///
+    /// **NOTE:** This will change the usage string to look like `$ prog [FLAGS] [-- <ARG>]` if
+    /// `ARG` is marked as `.last(true)`.
+    ///
+    /// **NOTE:** This setting will imply [`AppSettings::DontCollapseArgsInUsage`] because failing
+    /// to set this can make the usage string very confusing.
+    ///
+    /// **NOTE**: This setting only applies to positional arguments, and has no affect on FLAGS /
+    /// OPTIONS
+    ///
+    /// **CAUTION:** Setting an argument to `.last(true)` *and* having child subcommands is not
+    /// recommended with the exception of *also* using [`AppSettings::ArgsNegateSubcommands`]
+    /// (or [`AppSettings::SubcommandsNegateReqs`] if the argument marked `.last(true)` is also
+    /// marked [`.required(true)`])
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("args")
+    ///     .last(true)
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::last(true)`] ensures the arg has the highest [index] of all positional args
+    /// and requires that the `--` syntax be used to access it early.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("first"))
+    ///     .arg(Arg::with_name("second"))
+    ///     .arg(Arg::with_name("third").last(true))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "one", "--", "three"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok());
+    /// let m = res.unwrap();
+    /// assert_eq!(m.value_of("third"), Some("three"));
+    /// assert!(m.value_of("second").is_none());
+    /// ```
+    ///
+    /// Even if the positional argument marked `.last(true)` is the only argument left to parse,
+    /// failing to use the `--` syntax results in an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("first"))
+    ///     .arg(Arg::with_name("second"))
+    ///     .arg(Arg::with_name("third").last(true))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "one", "two", "three"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::UnknownArgument);
+    /// ```
+    /// [`Arg::last(true)`]: ./struct.Arg.html#method.last
+    /// [index]: ./struct.Arg.html#method.index
+    /// [`AppSettings::DontCollapseArgsInUsage`]: ./enum.AppSettings.html#variant.DontCollapseArgsInUsage
+    /// [`AppSettings::ArgsNegateSubcommands`]: ./enum.AppSettings.html#variant.ArgsNegateSubcommands
+    /// [`AppSettings::SubcommandsNegateReqs`]: ./enum.AppSettings.html#variant.SubcommandsNegateReqs
+    /// [`.required(true)`]: ./struct.Arg.html#method.required
+    /// [`UnknownArgument`]: ./enum.ErrorKind.html#variant.UnknownArgument
+    pub fn last(self, l: bool) -> Self {
+        if l {
+            self.set(ArgSettings::Last)
+        } else {
+            self.unset(ArgSettings::Last)
+        }
+    }
+
+    /// Sets whether or not the argument is required by default. Required by default means it is
+    /// required, when no other conflicting rules have been evaluated. Conflicting rules take
+    /// precedence over being required. **Default:** `false`
+    ///
+    /// **NOTE:** Flags (i.e. not positional, or arguments that take values) cannot be required by
+    /// default. This is simply because if a flag should be required, it should simply be implied
+    /// as no additional information is required from user. Flags by their very nature are simply
+    /// yes/no, or true/false.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .required(true)
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::required(true)`] requires that the argument be used at runtime.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .required(true)
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--config", "file.conf"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok());
+    /// ```
+    ///
+    /// Setting [`Arg::required(true)`] and *not* supplying that argument is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .required(true)
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [`Arg::required(true)`]: ./struct.Arg.html#method.required
+    pub fn required(self, r: bool) -> Self {
+        if r {
+            self.set(ArgSettings::Required)
+        } else {
+            self.unset(ArgSettings::Required)
+        }
+    }
+
+    /// Requires that options use the `--option=val` syntax (i.e. an equals between the option and
+    /// associated value) **Default:** `false`
+    ///
+    /// **NOTE:** This setting also removes the default of allowing empty values and implies
+    /// [`Arg::empty_values(false)`].
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .long("config")
+    ///     .takes_value(true)
+    ///     .require_equals(true)
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::require_equals(true)`] requires that the option have an equals sign between
+    /// it and the associated value.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .require_equals(true)
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--config=file.conf"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok());
+    /// ```
+    ///
+    /// Setting [`Arg::require_equals(true)`] and *not* supplying the equals will cause an error
+    /// unless [`Arg::empty_values(true)`] is set.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .require_equals(true)
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--config", "file.conf"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::EmptyValue);
+    /// ```
+    /// [`Arg::require_equals(true)`]: ./struct.Arg.html#method.require_equals
+    /// [`Arg::empty_values(true)`]: ./struct.Arg.html#method.empty_values
+    /// [`Arg::empty_values(false)`]: ./struct.Arg.html#method.empty_values
+    pub fn require_equals(mut self, r: bool) -> Self {
+        if r {
+            self.unsetb(ArgSettings::EmptyValues);
+            self.set(ArgSettings::RequireEquals)
+        } else {
+            self.unset(ArgSettings::RequireEquals)
+        }
+    }
+
+    /// Allows values which start with a leading hyphen (`-`)
+    ///
+    /// **WARNING**: Take caution when using this setting combined with [`Arg::multiple(true)`], as
+    /// this becomes ambiguous `$ prog --arg -- -- val`. All three `--, --, val` will be values
+    /// when the user may have thought the second `--` would constitute the normal, "Only
+    /// positional args follow" idiom. To fix this, consider using [`Arg::number_of_values(1)`]
+    ///
+    /// **WARNING**: When building your CLIs, consider the effects of allowing leading hyphens and
+    /// the user passing in a value that matches a valid short. For example `prog -opt -F` where
+    /// `-F` is supposed to be a value, yet `-F` is *also* a valid short for another arg. Care should
+    /// should be taken when designing these args. This is compounded by the ability to "stack"
+    /// short args. I.e. if `-val` is supposed to be a value, but `-v`, `-a`, and `-l` are all valid
+    /// shorts.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("pattern")
+    ///     .allow_hyphen_values(true)
+    /// # ;
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("pat")
+    ///         .allow_hyphen_values(true)
+    ///         .takes_value(true)
+    ///         .long("pattern"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--pattern", "-file"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("pat"), Some("-file"));
+    /// ```
+    ///
+    /// Not setting [`Arg::allow_hyphen_values(true)`] and supplying a value which starts with a
+    /// hyphen is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("pat")
+    ///         .takes_value(true)
+    ///         .long("pattern"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--pattern", "-file"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::UnknownArgument);
+    /// ```
+    /// [`Arg::allow_hyphen_values(true)`]: ./struct.Arg.html#method.allow_hyphen_values
+    /// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+    /// [`Arg::number_of_values(1)`]: ./struct.Arg.html#method.number_of_values
+    pub fn allow_hyphen_values(self, a: bool) -> Self {
+        if a {
+            self.set(ArgSettings::AllowLeadingHyphen)
+        } else {
+            self.unset(ArgSettings::AllowLeadingHyphen)
+        }
+    }
+    /// Sets an arg that override this arg's required setting. (i.e. this arg will be required
+    /// unless this other argument is present).
+    ///
+    /// **Pro Tip:** Using [`Arg::required_unless`] implies [`Arg::required`] and is therefore not
+    /// mandatory to also set.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .required_unless("debug")
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::required_unless(name)`] requires that the argument be used at runtime
+    /// *unless* `name` is present. In the following example, the required argument is *not*
+    /// provided, but it's not an error because the `unless` arg has been supplied.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .required_unless("dbg")
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("dbg")
+    ///         .long("debug"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--debug"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok());
+    /// ```
+    ///
+    /// Setting [`Arg::required_unless(name)`] and *not* supplying `name` or this arg is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .required_unless("dbg")
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("dbg")
+    ///         .long("debug"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [`Arg::required_unless`]: ./struct.Arg.html#method.required_unless
+    /// [`Arg::required`]: ./struct.Arg.html#method.required
+    /// [`Arg::required_unless(name)`]: ./struct.Arg.html#method.required_unless
+    pub fn required_unless(mut self, name: &'a str) -> Self {
+        if let Some(ref mut vec) = self.b.r_unless {
+            vec.push(name);
+        } else {
+            self.b.r_unless = Some(vec![name]);
+        }
+        self.required(true)
+    }
+
+    /// Sets args that override this arg's required setting. (i.e. this arg will be required unless
+    /// all these other arguments are present).
+    ///
+    /// **NOTE:** If you wish for this argument to only be required if *one of* these args are
+    /// present see [`Arg::required_unless_one`]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .required_unless_all(&["cfg", "dbg"])
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::required_unless_all(names)`] requires that the argument be used at runtime
+    /// *unless* *all* the args in `names` are present. In the following example, the required
+    /// argument is *not* provided, but it's not an error because all the `unless` args have been
+    /// supplied.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .required_unless_all(&["dbg", "infile"])
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("dbg")
+    ///         .long("debug"))
+    ///     .arg(Arg::with_name("infile")
+    ///         .short("i")
+    ///         .takes_value(true))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--debug", "-i", "file"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok());
+    /// ```
+    ///
+    /// Setting [`Arg::required_unless_all(names)`] and *not* supplying *all* of `names` or this
+    /// arg is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .required_unless_all(&["dbg", "infile"])
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("dbg")
+    ///         .long("debug"))
+    ///     .arg(Arg::with_name("infile")
+    ///         .short("i")
+    ///         .takes_value(true))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [`Arg::required_unless_one`]: ./struct.Arg.html#method.required_unless_one
+    /// [`Arg::required_unless_all(names)`]: ./struct.Arg.html#method.required_unless_all
+    pub fn required_unless_all(mut self, names: &[&'a str]) -> Self {
+        if let Some(ref mut vec) = self.b.r_unless {
+            for s in names {
+                vec.push(s);
+            }
+        } else {
+            self.b.r_unless = Some(names.iter().map(|s| *s).collect::<Vec<_>>());
+        }
+        self.setb(ArgSettings::RequiredUnlessAll);
+        self.required(true)
+    }
+
+    /// Sets args that override this arg's [required] setting. (i.e. this arg will be required
+    /// unless *at least one of* these other arguments are present).
+    ///
+    /// **NOTE:** If you wish for this argument to only be required if *all of* these args are
+    /// present see [`Arg::required_unless_all`]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .required_unless_all(&["cfg", "dbg"])
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::required_unless_one(names)`] requires that the argument be used at runtime
+    /// *unless* *at least one of* the args in `names` are present. In the following example, the
+    /// required argument is *not* provided, but it's not an error because one the `unless` args
+    /// have been supplied.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .required_unless_one(&["dbg", "infile"])
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("dbg")
+    ///         .long("debug"))
+    ///     .arg(Arg::with_name("infile")
+    ///         .short("i")
+    ///         .takes_value(true))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--debug"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok());
+    /// ```
+    ///
+    /// Setting [`Arg::required_unless_one(names)`] and *not* supplying *at least one of* `names`
+    /// or this arg is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .required_unless_one(&["dbg", "infile"])
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("dbg")
+    ///         .long("debug"))
+    ///     .arg(Arg::with_name("infile")
+    ///         .short("i")
+    ///         .takes_value(true))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [required]: ./struct.Arg.html#method.required
+    /// [`Arg::required_unless_one(names)`]: ./struct.Arg.html#method.required_unless_one
+    /// [`Arg::required_unless_all`]: ./struct.Arg.html#method.required_unless_all
+    pub fn required_unless_one(mut self, names: &[&'a str]) -> Self {
+        if let Some(ref mut vec) = self.b.r_unless {
+            for s in names {
+                vec.push(s);
+            }
+        } else {
+            self.b.r_unless = Some(names.iter().map(|s| *s).collect::<Vec<_>>());
+        }
+        self.required(true)
+    }
+
+    /// Sets a conflicting argument by name. I.e. when using this argument,
+    /// the following argument can't be present and vice versa.
+    ///
+    /// **NOTE:** Conflicting rules take precedence over being required by default. Conflict rules
+    /// only need to be set for one of the two arguments, they do not need to be set for each.
+    ///
+    /// **NOTE:** Defining a conflict is two-way, but does *not* need to defined for both arguments
+    /// (i.e. if A conflicts with B, defining A.conflicts_with(B) is sufficient. You do not need
+    /// need to also do B.conflicts_with(A))
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .conflicts_with("debug")
+    /// # ;
+    /// ```
+    ///
+    /// Setting conflicting argument, and having both arguments present at runtime is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .conflicts_with("debug")
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("debug")
+    ///         .long("debug"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--debug", "--config", "file.conf"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::ArgumentConflict);
+    /// ```
+    pub fn conflicts_with(mut self, name: &'a str) -> Self {
+        if let Some(ref mut vec) = self.b.blacklist {
+            vec.push(name);
+        } else {
+            self.b.blacklist = Some(vec![name]);
+        }
+        self
+    }
+
+    /// The same as [`Arg::conflicts_with`] but allows specifying multiple two-way conlicts per
+    /// argument.
+    ///
+    /// **NOTE:** Conflicting rules take precedence over being required by default. Conflict rules
+    /// only need to be set for one of the two arguments, they do not need to be set for each.
+    ///
+    /// **NOTE:** Defining a conflict is two-way, but does *not* need to defined for both arguments
+    /// (i.e. if A conflicts with B, defining A.conflicts_with(B) is sufficient. You do not need
+    /// need to also do B.conflicts_with(A))
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .conflicts_with_all(&["debug", "input"])
+    /// # ;
+    /// ```
+    ///
+    /// Setting conflicting argument, and having any of the arguments present at runtime with a
+    /// conflicting argument is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .conflicts_with_all(&["debug", "input"])
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("debug")
+    ///         .long("debug"))
+    ///     .arg(Arg::with_name("input")
+    ///         .index(1))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--config", "file.conf", "file.txt"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::ArgumentConflict);
+    /// ```
+    /// [`Arg::conflicts_with`]: ./struct.Arg.html#method.conflicts_with
+    pub fn conflicts_with_all(mut self, names: &[&'a str]) -> Self {
+        if let Some(ref mut vec) = self.b.blacklist {
+            for s in names {
+                vec.push(s);
+            }
+        } else {
+            self.b.blacklist = Some(names.iter().map(|s| *s).collect::<Vec<_>>());
+        }
+        self
+    }
+
+    /// Sets a overridable argument by name. I.e. this argument and the following argument
+    /// will override each other in POSIX style (whichever argument was specified at runtime
+    /// **last** "wins")
+    ///
+    /// **NOTE:** When an argument is overridden it is essentially as if it never was used, any
+    /// conflicts, requirements, etc. are evaluated **after** all "overrides" have been removed
+    ///
+    /// **WARNING:** Positional arguments cannot override themselves (or we would never be able
+    /// to advance to the next positional). If a positional agument lists itself as an override,
+    /// it is simply ignored.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::from_usage("-f, --flag 'some flag'")
+    ///         .conflicts_with("debug"))
+    ///     .arg(Arg::from_usage("-d, --debug 'other flag'"))
+    ///     .arg(Arg::from_usage("-c, --color 'third flag'")
+    ///         .overrides_with("flag"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-f", "-d", "-c"]);
+    ///             //    ^~~~~~~~~~~~^~~~~ flag is overridden by color
+    ///
+    /// assert!(m.is_present("color"));
+    /// assert!(m.is_present("debug")); // even though flag conflicts with debug, it's as if flag
+    ///                                 // was never used because it was overridden with color
+    /// assert!(!m.is_present("flag"));
+    /// ```
+    /// Care must be taken when using this setting, and having an arg override with itself. This
+    /// is common practice when supporting things like shell aliases, config files, etc.
+    /// However, when combined with multiple values, it can get dicy.
+    /// Here is how clap handles such situations:
+    ///
+    /// When a flag overrides itself, it's as if the flag was only ever used once (essentially
+    /// preventing a "Unexpected multiple usage" error):
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("posix")
+    ///             .arg(Arg::from_usage("--flag  'some flag'").overrides_with("flag"))
+    ///             .get_matches_from(vec!["posix", "--flag", "--flag"]);
+    /// assert!(m.is_present("flag"));
+    /// assert_eq!(m.occurrences_of("flag"), 1);
+    /// ```
+    /// Making a arg `multiple(true)` and override itself is essentially meaningless. Therefore
+    /// clap ignores an override of self if it's a flag and it already accepts multiple occurrences.
+    ///
+    /// ```
+    /// # use clap::{App, Arg};
+    /// let m = App::new("posix")
+    ///             .arg(Arg::from_usage("--flag...  'some flag'").overrides_with("flag"))
+    ///             .get_matches_from(vec!["", "--flag", "--flag", "--flag", "--flag"]);
+    /// assert!(m.is_present("flag"));
+    /// assert_eq!(m.occurrences_of("flag"), 4);
+    /// ```
+    /// Now notice with options (which *do not* set `multiple(true)`), it's as if only the last
+    /// occurrence happened.
+    ///
+    /// ```
+    /// # use clap::{App, Arg};
+    /// let m = App::new("posix")
+    ///             .arg(Arg::from_usage("--opt [val] 'some option'").overrides_with("opt"))
+    ///             .get_matches_from(vec!["", "--opt=some", "--opt=other"]);
+    /// assert!(m.is_present("opt"));
+    /// assert_eq!(m.occurrences_of("opt"), 1);
+    /// assert_eq!(m.value_of("opt"), Some("other"));
+    /// ```
+    ///
+    /// Just like flags, options with `multiple(true)` set, will ignore the "override self" setting.
+    ///
+    /// ```
+    /// # use clap::{App, Arg};
+    /// let m = App::new("posix")
+    ///             .arg(Arg::from_usage("--opt [val]... 'some option'")
+    ///                 .overrides_with("opt"))
+    ///             .get_matches_from(vec!["", "--opt", "first", "over", "--opt", "other", "val"]);
+    /// assert!(m.is_present("opt"));
+    /// assert_eq!(m.occurrences_of("opt"), 2);
+    /// assert_eq!(m.values_of("opt").unwrap().collect::<Vec<_>>(), &["first", "over", "other", "val"]);
+    /// ```
+    ///
+    /// A safe thing to do if you'd like to support an option which supports multiple values, but
+    /// also is "overridable" by itself, is to use `use_delimiter(false)` and *not* use
+    /// `multiple(true)` while telling users to seperate values with a comma (i.e. `val1,val2`)
+    ///
+    /// ```
+    /// # use clap::{App, Arg};
+    /// let m = App::new("posix")
+    ///             .arg(Arg::from_usage("--opt [val] 'some option'")
+    ///                 .overrides_with("opt")
+    ///                 .use_delimiter(false))
+    ///             .get_matches_from(vec!["", "--opt=some,other", "--opt=one,two"]);
+    /// assert!(m.is_present("opt"));
+    /// assert_eq!(m.occurrences_of("opt"), 1);
+    /// assert_eq!(m.values_of("opt").unwrap().collect::<Vec<_>>(), &["one,two"]);
+    /// ```
+    pub fn overrides_with(mut self, name: &'a str) -> Self {
+        if let Some(ref mut vec) = self.b.overrides {
+            vec.push(name);
+        } else {
+            self.b.overrides = Some(vec![name]);
+        }
+        self
+    }
+
+    /// Sets multiple mutually overridable arguments by name. I.e. this argument and the following
+    /// argument will override each other in POSIX style (whichever argument was specified at
+    /// runtime **last** "wins")
+    ///
+    /// **NOTE:** When an argument is overridden it is essentially as if it never was used, any
+    /// conflicts, requirements, etc. are evaluated **after** all "overrides" have been removed
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::from_usage("-f, --flag 'some flag'")
+    ///         .conflicts_with("color"))
+    ///     .arg(Arg::from_usage("-d, --debug 'other flag'"))
+    ///     .arg(Arg::from_usage("-c, --color 'third flag'")
+    ///         .overrides_with_all(&["flag", "debug"]))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-f", "-d", "-c"]);
+    ///             //    ^~~~~~^~~~~~~~~ flag and debug are overridden by color
+    ///
+    /// assert!(m.is_present("color")); // even though flag conflicts with color, it's as if flag
+    ///                                 // and debug were never used because they were overridden
+    ///                                 // with color
+    /// assert!(!m.is_present("debug"));
+    /// assert!(!m.is_present("flag"));
+    /// ```
+    pub fn overrides_with_all(mut self, names: &[&'a str]) -> Self {
+        if let Some(ref mut vec) = self.b.overrides {
+            for s in names {
+                vec.push(s);
+            }
+        } else {
+            self.b.overrides = Some(names.iter().map(|s| *s).collect::<Vec<_>>());
+        }
+        self
+    }
+
+    /// Sets an argument by name that is required when this one is present I.e. when
+    /// using this argument, the following argument *must* be present.
+    ///
+    /// **NOTE:** [Conflicting] rules and [override] rules take precedence over being required
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .requires("input")
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::requires(name)`] requires that the argument be used at runtime if the
+    /// defining argument is used. If the defining argument isn't used, the other argument isn't
+    /// required
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .requires("input")
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("input")
+    ///         .index(1))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok()); // We didn't use cfg, so input wasn't required
+    /// ```
+    ///
+    /// Setting [`Arg::requires(name)`] and *not* supplying that argument is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .requires("input")
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("input")
+    ///         .index(1))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--config", "file.conf"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [`Arg::requires(name)`]: ./struct.Arg.html#method.requires
+    /// [Conflicting]: ./struct.Arg.html#method.conflicts_with
+    /// [override]: ./struct.Arg.html#method.overrides_with
+    pub fn requires(mut self, name: &'a str) -> Self {
+        if let Some(ref mut vec) = self.b.requires {
+            vec.push((None, name));
+        } else {
+            let mut vec = vec![];
+            vec.push((None, name));
+            self.b.requires = Some(vec);
+        }
+        self
+    }
+
+    /// Allows a conditional requirement. The requirement will only become valid if this arg's value
+    /// equals `val`.
+    ///
+    /// **NOTE:** If using YAML the values should be laid out as follows
+    ///
+    /// ```yaml
+    /// requires_if:
+    ///     - [val, arg]
+    /// ```
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .requires_if("val", "arg")
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::requires_if(val, arg)`] requires that the `arg` be used at runtime if the
+    /// defining argument's value is equal to `val`. If the defining argument is anything other than
+    /// `val`, the other argument isn't required.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .requires_if("my.cfg", "other")
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("other"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--config", "some.cfg"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok()); // We didn't use --config=my.cfg, so other wasn't required
+    /// ```
+    ///
+    /// Setting [`Arg::requires_if(val, arg)`] and setting the value to `val` but *not* supplying
+    /// `arg` is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .requires_if("my.cfg", "input")
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("input"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--config", "my.cfg"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [`Arg::requires(name)`]: ./struct.Arg.html#method.requires
+    /// [Conflicting]: ./struct.Arg.html#method.conflicts_with
+    /// [override]: ./struct.Arg.html#method.overrides_with
+    pub fn requires_if(mut self, val: &'b str, arg: &'a str) -> Self {
+        if let Some(ref mut vec) = self.b.requires {
+            vec.push((Some(val), arg));
+        } else {
+            self.b.requires = Some(vec![(Some(val), arg)]);
+        }
+        self
+    }
+
+    /// Allows multiple conditional requirements. The requirement will only become valid if this arg's value
+    /// equals `val`.
+    ///
+    /// **NOTE:** If using YAML the values should be laid out as follows
+    ///
+    /// ```yaml
+    /// requires_if:
+    ///     - [val, arg]
+    ///     - [val2, arg2]
+    /// ```
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .requires_ifs(&[
+    ///         ("val", "arg"),
+    ///         ("other_val", "arg2"),
+    ///     ])
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::requires_ifs(&["val", "arg"])`] requires that the `arg` be used at runtime if the
+    /// defining argument's value is equal to `val`. If the defining argument's value is anything other
+    /// than `val`, `arg` isn't required.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .requires_ifs(&[
+    ///             ("special.conf", "opt"),
+    ///             ("other.conf", "other"),
+    ///         ])
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("opt")
+    ///         .long("option")
+    ///         .takes_value(true))
+    ///     .arg(Arg::with_name("other"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--config", "special.conf"
+    ///     ]);
+    ///
+    /// assert!(res.is_err()); // We  used --config=special.conf so --option <val> is required
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [`Arg::requires(name)`]: ./struct.Arg.html#method.requires
+    /// [Conflicting]: ./struct.Arg.html#method.conflicts_with
+    /// [override]: ./struct.Arg.html#method.overrides_with
+    pub fn requires_ifs(mut self, ifs: &[(&'b str, &'a str)]) -> Self {
+        if let Some(ref mut vec) = self.b.requires {
+            for &(val, arg) in ifs {
+                vec.push((Some(val), arg));
+            }
+        } else {
+            let mut vec = vec![];
+            for &(val, arg) in ifs {
+                vec.push((Some(val), arg));
+            }
+            self.b.requires = Some(vec);
+        }
+        self
+    }
+
+    /// Allows specifying that an argument is [required] conditionally. The requirement will only
+    /// become valid if the specified `arg`'s value equals `val`.
+    ///
+    /// **NOTE:** If using YAML the values should be laid out as follows
+    ///
+    /// ```yaml
+    /// required_if:
+    ///     - [arg, val]
+    /// ```
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .required_if("other_arg", "value")
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::required_if(arg, val)`] makes this arg required if the `arg` is used at
+    /// runtime and it's value is equal to `val`. If the `arg`'s value is anything other than `val`,
+    /// this argument isn't required.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .required_if("other", "special")
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("other")
+    ///         .long("other")
+    ///         .takes_value(true))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--other", "not-special"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok()); // We didn't use --other=special, so "cfg" wasn't required
+    /// ```
+    ///
+    /// Setting [`Arg::required_if(arg, val)`] and having `arg` used with a value of `val` but *not*
+    /// using this arg is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .required_if("other", "special")
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("other")
+    ///         .long("other")
+    ///         .takes_value(true))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--other", "special"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [`Arg::requires(name)`]: ./struct.Arg.html#method.requires
+    /// [Conflicting]: ./struct.Arg.html#method.conflicts_with
+    /// [required]: ./struct.Arg.html#method.required
+    pub fn required_if(mut self, arg: &'a str, val: &'b str) -> Self {
+        if let Some(ref mut vec) = self.r_ifs {
+            vec.push((arg, val));
+        } else {
+            self.r_ifs = Some(vec![(arg, val)]);
+        }
+        self
+    }
+
+    /// Allows specifying that an argument is [required] based on multiple conditions. The
+    /// conditions are set up in a `(arg, val)` style tuple. The requirement will only become valid
+    /// if one of the specified `arg`'s value equals it's corresponding `val`.
+    ///
+    /// **NOTE:** If using YAML the values should be laid out as follows
+    ///
+    /// ```yaml
+    /// required_if:
+    ///     - [arg, val]
+    ///     - [arg2, val2]
+    /// ```
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .required_ifs(&[
+    ///         ("extra", "val"),
+    ///         ("option", "spec")
+    ///     ])
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::required_ifs(&[(arg, val)])`] makes this arg required if any of the `arg`s
+    /// are used at runtime and it's corresponding value is equal to `val`. If the `arg`'s value is
+    /// anything other than `val`, this argument isn't required.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .required_ifs(&[
+    ///             ("extra", "val"),
+    ///             ("option", "spec")
+    ///         ])
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("extra")
+    ///         .takes_value(true)
+    ///         .long("extra"))
+    ///     .arg(Arg::with_name("option")
+    ///         .takes_value(true)
+    ///         .long("option"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--option", "other"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok()); // We didn't use --option=spec, or --extra=val so "cfg" isn't required
+    /// ```
+    ///
+    /// Setting [`Arg::required_ifs(&[(arg, val)])`] and having any of the `arg`s used with it's
+    /// value of `val` but *not* using this arg is an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .required_ifs(&[
+    ///             ("extra", "val"),
+    ///             ("option", "spec")
+    ///         ])
+    ///         .takes_value(true)
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("extra")
+    ///         .takes_value(true)
+    ///         .long("extra"))
+    ///     .arg(Arg::with_name("option")
+    ///         .takes_value(true)
+    ///         .long("option"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--option", "spec"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [`Arg::requires(name)`]: ./struct.Arg.html#method.requires
+    /// [Conflicting]: ./struct.Arg.html#method.conflicts_with
+    /// [required]: ./struct.Arg.html#method.required
+    pub fn required_ifs(mut self, ifs: &[(&'a str, &'b str)]) -> Self {
+        if let Some(ref mut vec) = self.r_ifs {
+            for r_if in ifs {
+                vec.push((r_if.0, r_if.1));
+            }
+        } else {
+            let mut vec = vec![];
+            for r_if in ifs {
+                vec.push((r_if.0, r_if.1));
+            }
+            self.r_ifs = Some(vec);
+        }
+        self
+    }
+
+    /// Sets multiple arguments by names that are required when this one is present I.e. when
+    /// using this argument, the following arguments *must* be present.
+    ///
+    /// **NOTE:** [Conflicting] rules and [override] rules take precedence over being required
+    /// by default.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Arg;
+    /// Arg::with_name("config")
+    ///     .requires_all(&["input", "output"])
+    /// # ;
+    /// ```
+    ///
+    /// Setting [`Arg::requires_all(&[arg, arg2])`] requires that all the arguments be used at
+    /// runtime if the defining argument is used. If the defining argument isn't used, the other
+    /// argument isn't required
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .requires("input")
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("input")
+    ///         .index(1))
+    ///     .arg(Arg::with_name("output")
+    ///         .index(2))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok()); // We didn't use cfg, so input and output weren't required
+    /// ```
+    ///
+    /// Setting [`Arg::requires_all(&[arg, arg2])`] and *not* supplying all the arguments is an
+    /// error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .takes_value(true)
+    ///         .requires_all(&["input", "output"])
+    ///         .long("config"))
+    ///     .arg(Arg::with_name("input")
+    ///         .index(1))
+    ///     .arg(Arg::with_name("output")
+    ///         .index(2))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--config", "file.conf", "in.txt"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// // We didn't use output
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [Conflicting]: ./struct.Arg.html#method.conflicts_with
+    /// [override]: ./struct.Arg.html#method.overrides_with
+    /// [`Arg::requires_all(&[arg, arg2])`]: ./struct.Arg.html#method.requires_all
+    pub fn requires_all(mut self, names: &[&'a str]) -> Self {
+        if let Some(ref mut vec) = self.b.requires {
+            for s in names {
+                vec.push((None, s));
+            }
+        } else {
+            let mut vec = vec![];
+            for s in names {
+                vec.push((None, *s));
+            }
+            self.b.requires = Some(vec);
+        }
+        self
+    }
+
+    /// Specifies that the argument takes a value at run time.
+    ///
+    /// **NOTE:** values for arguments may be specified in any of the following methods
+    ///
+    /// * Using a space such as `-o value` or `--option value`
+    /// * Using an equals and no space such as `-o=value` or `--option=value`
+    /// * Use a short and no space such as `-ovalue`
+    ///
+    /// **NOTE:** By default, args which allow [multiple values] are delimited by commas, meaning
+    /// `--option=val1,val2,val3` is three values for the `--option` argument. If you wish to
+    /// change the delimiter to another character you can use [`Arg::value_delimiter(char)`],
+    /// alternatively you can turn delimiting values **OFF** by using [`Arg::use_delimiter(false)`]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("config")
+    ///     .takes_value(true)
+    /// # ;
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("mode")
+    ///         .long("mode")
+    ///         .takes_value(true))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--mode", "fast"
+    ///     ]);
+    ///
+    /// assert!(m.is_present("mode"));
+    /// assert_eq!(m.value_of("mode"), Some("fast"));
+    /// ```
+    /// [`Arg::value_delimiter(char)`]: ./struct.Arg.html#method.value_delimiter
+    /// [`Arg::use_delimiter(false)`]: ./struct.Arg.html#method.use_delimiter
+    /// [multiple values]: ./struct.Arg.html#method.multiple
+    pub fn takes_value(self, tv: bool) -> Self {
+        if tv {
+            self.set(ArgSettings::TakesValue)
+        } else {
+            self.unset(ArgSettings::TakesValue)
+        }
+    }
+
+    /// Specifies if the possible values of an argument should be displayed in the help text or
+    /// not. Defaults to `false` (i.e. show possible values)
+    ///
+    /// This is useful for args with many values, or ones which are explained elsewhere in the
+    /// help text.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("config")
+    ///     .hide_possible_values(true)
+    /// # ;
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("mode")
+    ///         .long("mode")
+    ///         .possible_values(&["fast", "slow"])
+    ///         .takes_value(true)
+    ///         .hide_possible_values(true));
+    ///
+    /// ```
+    ///
+    /// If we were to run the above program with `--help` the `[values: fast, slow]` portion of
+    /// the help text would be omitted.
+    pub fn hide_possible_values(self, hide: bool) -> Self {
+        if hide {
+            self.set(ArgSettings::HidePossibleValues)
+        } else {
+            self.unset(ArgSettings::HidePossibleValues)
+        }
+    }
+
+    /// Specifies if the default value of an argument should be displayed in the help text or
+    /// not. Defaults to `false` (i.e. show default value)
+    ///
+    /// This is useful when default behavior of an arg is explained elsewhere in the help text.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("config")
+    ///     .hide_default_value(true)
+    /// # ;
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("connect")
+    ///     .arg(Arg::with_name("host")
+    ///         .long("host")
+    ///         .default_value("localhost")
+    ///         .hide_default_value(true));
+    ///
+    /// ```
+    ///
+    /// If we were to run the above program with `--help` the `[default: localhost]` portion of
+    /// the help text would be omitted.
+    pub fn hide_default_value(self, hide: bool) -> Self {
+        if hide {
+            self.set(ArgSettings::HideDefaultValue)
+        } else {
+            self.unset(ArgSettings::HideDefaultValue)
+        }
+    }
+
+    /// Specifies the index of a positional argument **starting at** 1.
+    ///
+    /// **NOTE:** The index refers to position according to **other positional argument**. It does
+    /// not define position in the argument list as a whole.
+    ///
+    /// **NOTE:** If no [`Arg::short`], or [`Arg::long`] have been defined, you can optionally
+    /// leave off the `index` method, and the index will be assigned in order of evaluation.
+    /// Utilizing the `index` method allows for setting indexes out of order
+    ///
+    /// **NOTE:** When utilized with [`Arg::multiple(true)`], only the **last** positional argument
+    /// may be defined as multiple (i.e. with the highest index)
+    ///
+    /// # Panics
+    ///
+    /// Although not in this method directly, [`App`] will [`panic!`] if indexes are skipped (such
+    /// as defining `index(1)` and `index(3)` but not `index(2)`, or a positional argument is
+    /// defined as multiple and is not the highest index
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("config")
+    ///     .index(1)
+    /// # ;
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("mode")
+    ///         .index(1))
+    ///     .arg(Arg::with_name("debug")
+    ///         .long("debug"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--debug", "fast"
+    ///     ]);
+    ///
+    /// assert!(m.is_present("mode"));
+    /// assert_eq!(m.value_of("mode"), Some("fast")); // notice index(1) means "first positional"
+    ///                                               // *not* first argument
+    /// ```
+    /// [`Arg::short`]: ./struct.Arg.html#method.short
+    /// [`Arg::long`]: ./struct.Arg.html#method.long
+    /// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+    /// [`App`]: ./struct.App.html
+    /// [`panic!`]: https://doc.rust-lang.org/std/macro.panic!.html
+    pub fn index(mut self, idx: u64) -> Self {
+        self.index = Some(idx);
+        self
+    }
+
+    /// Specifies that the argument may appear more than once. For flags, this results
+    /// in the number of occurrences of the flag being recorded. For example `-ddd` or `-d -d -d`
+    /// would count as three occurrences. For options there is a distinct difference in multiple
+    /// occurrences vs multiple values.
+    ///
+    /// For example, `--opt val1 val2` is one occurrence, but two values. Whereas
+    /// `--opt val1 --opt val2` is two occurrences.
+    ///
+    /// **WARNING:**
+    ///
+    /// Setting `multiple(true)` for an [option] with no other details, allows multiple values
+    /// **and** multiple occurrences because it isn't possible to have more occurrences than values
+    /// for options. Because multiple values are allowed, `--option val1 val2 val3` is perfectly
+    /// valid, be careful when designing a CLI where positional arguments are expected after a
+    /// option which accepts multiple values, as `clap` will continue parsing *values* until it
+    /// reaches the max or specific number of values defined, or another flag or option.
+    ///
+    /// **Pro Tip**:
+    ///
+    /// It's possible to define an option which allows multiple occurrences, but only one value per
+    /// occurrence. To do this use [`Arg::number_of_values(1)`] in coordination with
+    /// [`Arg::multiple(true)`].
+    ///
+    /// **WARNING:**
+    ///
+    /// When using args with `multiple(true)` on [options] or [positionals] (i.e. those args that
+    /// accept values) and [subcommands], one needs to consider the possibility of an argument value
+    /// being the same as a valid subcommand. By default `clap` will parse the argument in question
+    /// as a value *only if* a value is possible at that moment. Otherwise it will be parsed as a
+    /// subcommand. In effect, this means using `multiple(true)` with no additional parameters and
+    /// a possible value that coincides with a subcommand name, the subcommand cannot be called
+    /// unless another argument is passed first.
+    ///
+    /// As an example, consider a CLI with an option `--ui-paths=<paths>...` and subcommand `signer`
+    ///
+    /// The following would be parsed as values to `--ui-paths`.
+    ///
+    /// ```notrust
+    /// $ program --ui-paths path1 path2 signer
+    /// ```
+    ///
+    /// This is because `--ui-paths` accepts multiple values. `clap` will continue parsing values
+    /// until another argument is reached and it knows `--ui-paths` is done.
+    ///
+    /// By adding additional parameters to `--ui-paths` we can solve this issue. Consider adding
+    /// [`Arg::number_of_values(1)`] as discussed above. The following are all valid, and `signer`
+    /// is parsed as both a subcommand and a value in the second case.
+    ///
+    /// ```notrust
+    /// $ program --ui-paths path1 signer
+    /// $ program --ui-paths path1 --ui-paths signer signer
+    /// ```
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("debug")
+    ///     .short("d")
+    ///     .multiple(true)
+    /// # ;
+    /// ```
+    /// An example with flags
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("verbose")
+    ///         .multiple(true)
+    ///         .short("v"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-v", "-v", "-v"    // note, -vvv would have same result
+    ///     ]);
+    ///
+    /// assert!(m.is_present("verbose"));
+    /// assert_eq!(m.occurrences_of("verbose"), 3);
+    /// ```
+    ///
+    /// An example with options
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .multiple(true)
+    ///         .takes_value(true)
+    ///         .short("F"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-F", "file1", "file2", "file3"
+    ///     ]);
+    ///
+    /// assert!(m.is_present("file"));
+    /// assert_eq!(m.occurrences_of("file"), 1); // notice only one occurrence
+    /// let files: Vec<_> = m.values_of("file").unwrap().collect();
+    /// assert_eq!(files, ["file1", "file2", "file3"]);
+    /// ```
+    /// This is functionally equivalent to the example above
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .multiple(true)
+    ///         .takes_value(true)
+    ///         .short("F"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-F", "file1", "-F", "file2", "-F", "file3"
+    ///     ]);
+    /// let files: Vec<_> = m.values_of("file").unwrap().collect();
+    /// assert_eq!(files, ["file1", "file2", "file3"]);
+    ///
+    /// assert!(m.is_present("file"));
+    /// assert_eq!(m.occurrences_of("file"), 3); // Notice 3 occurrences
+    /// let files: Vec<_> = m.values_of("file").unwrap().collect();
+    /// assert_eq!(files, ["file1", "file2", "file3"]);
+    /// ```
+    ///
+    /// A common mistake is to define an option which allows multiples, and a positional argument
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .multiple(true)
+    ///         .takes_value(true)
+    ///         .short("F"))
+    ///     .arg(Arg::with_name("word")
+    ///         .index(1))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-F", "file1", "file2", "file3", "word"
+    ///     ]);
+    ///
+    /// assert!(m.is_present("file"));
+    /// let files: Vec<_> = m.values_of("file").unwrap().collect();
+    /// assert_eq!(files, ["file1", "file2", "file3", "word"]); // wait...what?!
+    /// assert!(!m.is_present("word")); // but we clearly used word!
+    /// ```
+    /// The problem is clap doesn't know when to stop parsing values for "files". This is further
+    /// compounded by if we'd said `word -F file1 file2` it would have worked fine, so it would
+    /// appear to only fail sometimes...not good!
+    ///
+    /// A solution for the example above is to specify that `-F` only accepts one value, but is
+    /// allowed to appear multiple times
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .multiple(true)
+    ///         .takes_value(true)
+    ///         .number_of_values(1)
+    ///         .short("F"))
+    ///     .arg(Arg::with_name("word")
+    ///         .index(1))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-F", "file1", "-F", "file2", "-F", "file3", "word"
+    ///     ]);
+    ///
+    /// assert!(m.is_present("file"));
+    /// let files: Vec<_> = m.values_of("file").unwrap().collect();
+    /// assert_eq!(files, ["file1", "file2", "file3"]);
+    /// assert!(m.is_present("word"));
+    /// assert_eq!(m.value_of("word"), Some("word"));
+    /// ```
+    /// As a final example, notice if we define [`Arg::number_of_values(1)`] and try to run the
+    /// problem example above, it would have been a runtime error with a pretty message to the
+    /// user :)
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .multiple(true)
+    ///         .takes_value(true)
+    ///         .number_of_values(1)
+    ///         .short("F"))
+    ///     .arg(Arg::with_name("word")
+    ///         .index(1))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "-F", "file1", "file2", "file3", "word"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::UnknownArgument);
+    /// ```
+    /// [option]: ./struct.Arg.html#method.takes_value
+    /// [options]: ./struct.Arg.html#method.takes_value
+    /// [subcommands]: ./struct.SubCommand.html
+    /// [positionals]: ./struct.Arg.html#method.index
+    /// [`Arg::number_of_values(1)`]: ./struct.Arg.html#method.number_of_values
+    /// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+    pub fn multiple(self, multi: bool) -> Self {
+        if multi {
+            self.set(ArgSettings::Multiple)
+        } else {
+            self.unset(ArgSettings::Multiple)
+        }
+    }
+
+    /// Specifies a value that *stops* parsing multiple values of a give argument. By default when
+    /// one sets [`multiple(true)`] on an argument, clap will continue parsing values for that
+    /// argument until it reaches another valid argument, or one of the other more specific settings
+    /// for multiple values is used (such as [`min_values`], [`max_values`] or
+    /// [`number_of_values`]).
+    ///
+    /// **NOTE:** This setting only applies to [options] and [positional arguments]
+    ///
+    /// **NOTE:** When the terminator is passed in on the command line, it is **not** stored as one
+    /// of the values
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("vals")
+    ///     .takes_value(true)
+    ///     .multiple(true)
+    ///     .value_terminator(";")
+    /// # ;
+    /// ```
+    /// The following example uses two arguments, a sequence of commands, and the location in which
+    /// to perform them
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("cmds")
+    ///         .multiple(true)
+    ///         .allow_hyphen_values(true)
+    ///         .value_terminator(";"))
+    ///     .arg(Arg::with_name("location"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "find", "-type", "f", "-name", "special", ";", "/home/clap"
+    ///     ]);
+    /// let cmds: Vec<_> = m.values_of("cmds").unwrap().collect();
+    /// assert_eq!(&cmds, &["find", "-type", "f", "-name", "special"]);
+    /// assert_eq!(m.value_of("location"), Some("/home/clap"));
+    /// ```
+    /// [options]: ./struct.Arg.html#method.takes_value
+    /// [positional arguments]: ./struct.Arg.html#method.index
+    /// [`multiple(true)`]: ./struct.Arg.html#method.multiple
+    /// [`min_values`]: ./struct.Arg.html#method.min_values
+    /// [`number_of_values`]: ./struct.Arg.html#method.number_of_values
+    /// [`max_values`]: ./struct.Arg.html#method.max_values
+    pub fn value_terminator(mut self, term: &'b str) -> Self {
+        self.setb(ArgSettings::TakesValue);
+        self.v.terminator = Some(term);
+        self
+    }
+
+    /// Specifies that an argument can be matched to all child [`SubCommand`]s.
+    ///
+    /// **NOTE:** Global arguments *only* propagate down, **not** up (to parent commands), however
+    /// their values once a user uses them will be propagated back up to parents. In effect, this
+    /// means one should *define* all global arguments at the top level, however it doesn't matter
+    /// where the user *uses* the global argument.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("debug")
+    ///     .short("d")
+    ///     .global(true)
+    /// # ;
+    /// ```
+    ///
+    /// For example, assume an application with two subcommands, and you'd like to define a
+    /// `--verbose` flag that can be called on any of the subcommands and parent, but you don't
+    /// want to clutter the source with three duplicate [`Arg`] definitions.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, SubCommand};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("verb")
+    ///         .long("verbose")
+    ///         .short("v")
+    ///         .global(true))
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .subcommand(SubCommand::with_name("do-stuff"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "do-stuff", "--verbose"
+    ///     ]);
+    ///
+    /// assert_eq!(m.subcommand_name(), Some("do-stuff"));
+    /// let sub_m = m.subcommand_matches("do-stuff").unwrap();
+    /// assert!(sub_m.is_present("verb"));
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [required]: ./struct.Arg.html#method.required
+    /// [`ArgMatches`]: ./struct.ArgMatches.html
+    /// [`ArgMatches::is_present("flag")`]: ./struct.ArgMatches.html#method.is_present
+    /// [`Arg`]: ./struct.Arg.html
+    pub fn global(self, g: bool) -> Self {
+        if g {
+            self.set(ArgSettings::Global)
+        } else {
+            self.unset(ArgSettings::Global)
+        }
+    }
+
+    /// Allows an argument to accept explicitly empty values. An empty value must be specified at
+    /// the command line with an explicit `""`, or `''`
+    ///
+    /// **NOTE:** Defaults to `true` (Explicitly empty values are allowed)
+    ///
+    /// **NOTE:** Implicitly sets [`Arg::takes_value(true)`] when set to `false`
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("file")
+    ///     .long("file")
+    ///     .empty_values(false)
+    /// # ;
+    /// ```
+    /// The default is to allow empty values, such as `--option ""` would be an empty value. But
+    /// we can change to make empty values become an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .long("config")
+    ///         .short("v")
+    ///         .empty_values(false))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--config="
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::EmptyValue);
+    /// ```
+    /// [`Arg::takes_value(true)`]: ./struct.Arg.html#method.takes_value
+    pub fn empty_values(mut self, ev: bool) -> Self {
+        if ev {
+            self.set(ArgSettings::EmptyValues)
+        } else {
+            self = self.set(ArgSettings::TakesValue);
+            self.unset(ArgSettings::EmptyValues)
+        }
+    }
+
+    /// Hides an argument from help message output.
+    ///
+    /// **NOTE:** Implicitly sets [`Arg::hidden_short_help(true)`] and [`Arg::hidden_long_help(true)`]
+    /// when set to true
+    ///
+    /// **NOTE:** This does **not** hide the argument from usage strings on error
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("debug")
+    ///     .hidden(true)
+    /// # ;
+    /// ```
+    /// Setting `hidden(true)` will hide the argument when displaying help text
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .long("config")
+    ///         .hidden(true)
+    ///         .help("Some help text describing the --config arg"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--help"
+    ///     ]);
+    /// ```
+    ///
+    /// The above example displays
+    ///
+    /// ```notrust
+    /// helptest
+    ///
+    /// USAGE:
+    ///    helptest [FLAGS]
+    ///
+    /// FLAGS:
+    /// -h, --help       Prints help information
+    /// -V, --version    Prints version information
+    /// ```
+    /// [`Arg::hidden_short_help(true)`]: ./struct.Arg.html#method.hidden_short_help
+    /// [`Arg::hidden_long_help(true)`]: ./struct.Arg.html#method.hidden_long_help
+    pub fn hidden(self, h: bool) -> Self {
+        if h {
+            self.set(ArgSettings::Hidden)
+        } else {
+            self.unset(ArgSettings::Hidden)
+        }
+    }
+
+    /// Specifies a list of possible values for this argument. At runtime, `clap` verifies that
+    /// only one of the specified values was used, or fails with an error message.
+    ///
+    /// **NOTE:** This setting only applies to [options] and [positional arguments]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("mode")
+    ///     .takes_value(true)
+    ///     .possible_values(&["fast", "slow", "medium"])
+    /// # ;
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("mode")
+    ///         .long("mode")
+    ///         .takes_value(true)
+    ///         .possible_values(&["fast", "slow", "medium"]))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--mode", "fast"
+    ///     ]);
+    /// assert!(m.is_present("mode"));
+    /// assert_eq!(m.value_of("mode"), Some("fast"));
+    /// ```
+    ///
+    /// The next example shows a failed parse from using a value which wasn't defined as one of the
+    /// possible values.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("mode")
+    ///         .long("mode")
+    ///         .takes_value(true)
+    ///         .possible_values(&["fast", "slow", "medium"]))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--mode", "wrong"
+    ///     ]);
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::InvalidValue);
+    /// ```
+    /// [options]: ./struct.Arg.html#method.takes_value
+    /// [positional arguments]: ./struct.Arg.html#method.index
+    pub fn possible_values(mut self, names: &[&'b str]) -> Self {
+        if let Some(ref mut vec) = self.v.possible_vals {
+            for s in names {
+                vec.push(s);
+            }
+        } else {
+            self.v.possible_vals = Some(names.iter().map(|s| *s).collect::<Vec<_>>());
+        }
+        self
+    }
+
+    /// Specifies a possible value for this argument, one at a time. At runtime, `clap` verifies
+    /// that only one of the specified values was used, or fails with error message.
+    ///
+    /// **NOTE:** This setting only applies to [options] and [positional arguments]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("mode")
+    ///     .takes_value(true)
+    ///     .possible_value("fast")
+    ///     .possible_value("slow")
+    ///     .possible_value("medium")
+    /// # ;
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("mode")
+    ///         .long("mode")
+    ///         .takes_value(true)
+    ///         .possible_value("fast")
+    ///         .possible_value("slow")
+    ///         .possible_value("medium"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--mode", "fast"
+    ///     ]);
+    /// assert!(m.is_present("mode"));
+    /// assert_eq!(m.value_of("mode"), Some("fast"));
+    /// ```
+    ///
+    /// The next example shows a failed parse from using a value which wasn't defined as one of the
+    /// possible values.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("mode")
+    ///         .long("mode")
+    ///         .takes_value(true)
+    ///         .possible_value("fast")
+    ///         .possible_value("slow")
+    ///         .possible_value("medium"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "--mode", "wrong"
+    ///     ]);
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::InvalidValue);
+    /// ```
+    /// [options]: ./struct.Arg.html#method.takes_value
+    /// [positional arguments]: ./struct.Arg.html#method.index
+    pub fn possible_value(mut self, name: &'b str) -> Self {
+        if let Some(ref mut vec) = self.v.possible_vals {
+            vec.push(name);
+        } else {
+            self.v.possible_vals = Some(vec![name]);
+        }
+        self
+    }
+
+    /// When used with [`Arg::possible_values`] it allows the argument value to pass validation even if
+    /// the case differs from that of the specified `possible_value`.
+    ///
+    /// **Pro Tip:** Use this setting with [`arg_enum!`]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// # use std::ascii::AsciiExt;
+    /// let m = App::new("pv")
+    ///     .arg(Arg::with_name("option")
+    ///         .long("--option")
+    ///         .takes_value(true)
+    ///         .possible_value("test123")
+    ///         .case_insensitive(true))
+    ///     .get_matches_from(vec![
+    ///         "pv", "--option", "TeSt123",
+    ///     ]);
+    ///
+    /// assert!(m.value_of("option").unwrap().eq_ignore_ascii_case("test123"));
+    /// ```
+    ///
+    /// This setting also works when multiple values can be defined:
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("pv")
+    ///     .arg(Arg::with_name("option")
+    ///         .short("-o")
+    ///         .long("--option")
+    ///         .takes_value(true)
+    ///         .possible_value("test123")
+    ///         .possible_value("test321")
+    ///         .multiple(true)
+    ///         .case_insensitive(true))
+    ///     .get_matches_from(vec![
+    ///         "pv", "--option", "TeSt123", "teST123", "tESt321"
+    ///     ]);
+    ///
+    /// let matched_vals = m.values_of("option").unwrap().collect::<Vec<_>>();
+    /// assert_eq!(&*matched_vals, &["TeSt123", "teST123", "tESt321"]);
+    /// ```
+    /// [`Arg::case_insensitive(true)`]: ./struct.Arg.html#method.possible_values
+    /// [`arg_enum!`]: ./macro.arg_enum.html
+    pub fn case_insensitive(self, ci: bool) -> Self {
+        if ci {
+            self.set(ArgSettings::CaseInsensitive)
+        } else {
+            self.unset(ArgSettings::CaseInsensitive)
+        }
+    }
+
+    /// Specifies the name of the [`ArgGroup`] the argument belongs to.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("debug")
+    ///     .long("debug")
+    ///     .group("mode")
+    /// # ;
+    /// ```
+    ///
+    /// Multiple arguments can be a member of a single group and then the group checked as if it
+    /// was one of said arguments.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("debug")
+    ///         .long("debug")
+    ///         .group("mode"))
+    ///     .arg(Arg::with_name("verbose")
+    ///         .long("verbose")
+    ///         .group("mode"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--debug"
+    ///     ]);
+    /// assert!(m.is_present("mode"));
+    /// ```
+    /// [`ArgGroup`]: ./struct.ArgGroup.html
+    pub fn group(mut self, name: &'a str) -> Self {
+        if let Some(ref mut vec) = self.b.groups {
+            vec.push(name);
+        } else {
+            self.b.groups = Some(vec![name]);
+        }
+        self
+    }
+
+    /// Specifies the names of multiple [`ArgGroup`]'s the argument belongs to.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("debug")
+    ///     .long("debug")
+    ///     .groups(&["mode", "verbosity"])
+    /// # ;
+    /// ```
+    ///
+    /// Arguments can be members of multiple groups and then the group checked as if it
+    /// was one of said arguments.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("debug")
+    ///         .long("debug")
+    ///         .groups(&["mode", "verbosity"]))
+    ///     .arg(Arg::with_name("verbose")
+    ///         .long("verbose")
+    ///         .groups(&["mode", "verbosity"]))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--debug"
+    ///     ]);
+    /// assert!(m.is_present("mode"));
+    /// assert!(m.is_present("verbosity"));
+    /// ```
+    /// [`ArgGroup`]: ./struct.ArgGroup.html
+    pub fn groups(mut self, names: &[&'a str]) -> Self {
+        if let Some(ref mut vec) = self.b.groups {
+            for s in names {
+                vec.push(s);
+            }
+        } else {
+            self.b.groups = Some(names.into_iter().map(|s| *s).collect::<Vec<_>>());
+        }
+        self
+    }
+
+    /// Specifies how many values are required to satisfy this argument. For example, if you had a
+    /// `-f <file>` argument where you wanted exactly 3 'files' you would set
+    /// `.number_of_values(3)`, and this argument wouldn't be satisfied unless the user provided
+    /// 3 and only 3 values.
+    ///
+    /// **NOTE:** Does *not* require [`Arg::multiple(true)`] to be set. Setting
+    /// [`Arg::multiple(true)`] would allow `-f <file> <file> <file> -f <file> <file> <file>` where
+    /// as *not* setting [`Arg::multiple(true)`] would only allow one occurrence of this argument.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("file")
+    ///     .short("f")
+    ///     .number_of_values(3)
+    /// # ;
+    /// ```
+    ///
+    /// Not supplying the correct number of values is an error
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .takes_value(true)
+    ///         .number_of_values(2)
+    ///         .short("F"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "-F", "file1"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::WrongNumberOfValues);
+    /// ```
+    /// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+    pub fn number_of_values(mut self, qty: u64) -> Self {
+        self.setb(ArgSettings::TakesValue);
+        self.v.num_vals = Some(qty);
+        self
+    }
+
+    /// Allows one to perform a custom validation on the argument value. You provide a closure
+    /// which accepts a [`String`] value, and return a [`Result`] where the [`Err(String)`] is a
+    /// message displayed to the user.
+    ///
+    /// **NOTE:** The error message does *not* need to contain the `error:` portion, only the
+    /// message as all errors will appear as
+    /// `error: Invalid value for '<arg>': <YOUR MESSAGE>` where `<arg>` is replaced by the actual
+    /// arg, and `<YOUR MESSAGE>` is the `String` you return as the error.
+    ///
+    /// **NOTE:** There is a small performance hit for using validators, as they are implemented
+    /// with [`Rc`] pointers. And the value to be checked will be allocated an extra time in order
+    /// to to be passed to the closure. This performance hit is extremely minimal in the grand
+    /// scheme of things.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// fn has_at(v: String) -> Result<(), String> {
+    ///     if v.contains("@") { return Ok(()); }
+    ///     Err(String::from("The value did not contain the required @ sigil"))
+    /// }
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .index(1)
+    ///         .validator(has_at))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "some@file"
+    ///     ]);
+    /// assert!(res.is_ok());
+    /// assert_eq!(res.unwrap().value_of("file"), Some("some@file"));
+    /// ```
+    /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html
+    /// [`Result`]: https://doc.rust-lang.org/std/result/enum.Result.html
+    /// [`Err(String)`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Err
+    /// [`Rc`]: https://doc.rust-lang.org/std/rc/struct.Rc.html
+    pub fn validator<F>(mut self, f: F) -> Self
+    where
+        F: Fn(String) -> Result<(), String> + 'static,
+    {
+        self.v.validator = Some(Rc::new(f));
+        self
+    }
+
+    /// Works identically to Validator but is intended to be used with values that could
+    /// contain non UTF-8 formatted strings.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(not(unix), doc = " ```ignore")]
+    #[cfg_attr(unix, doc = " ```rust")]
+    /// # use clap::{App, Arg};
+    /// # use std::ffi::{OsStr, OsString};
+    /// # use std::os::unix::ffi::OsStrExt;
+    /// fn has_ampersand(v: &OsStr) -> Result<(), OsString> {
+    ///     if v.as_bytes().iter().any(|b| *b == b'&') { return Ok(()); }
+    ///     Err(OsString::from("The value did not contain the required & sigil"))
+    /// }
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .index(1)
+    ///         .validator_os(has_ampersand))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "Fish & chips"
+    ///     ]);
+    /// assert!(res.is_ok());
+    /// assert_eq!(res.unwrap().value_of("file"), Some("Fish & chips"));
+    /// ```
+    /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html
+    /// [`OsStr`]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html
+    /// [`OsString`]: https://doc.rust-lang.org/std/ffi/struct.OsString.html
+    /// [`Result`]: https://doc.rust-lang.org/std/result/enum.Result.html
+    /// [`Err(String)`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Err
+    /// [`Rc`]: https://doc.rust-lang.org/std/rc/struct.Rc.html
+    pub fn validator_os<F>(mut self, f: F) -> Self
+    where
+        F: Fn(&OsStr) -> Result<(), OsString> + 'static,
+    {
+        self.v.validator_os = Some(Rc::new(f));
+        self
+    }
+
+    /// Specifies the *maximum* number of values are for this argument. For example, if you had a
+    /// `-f <file>` argument where you wanted up to 3 'files' you would set `.max_values(3)`, and
+    /// this argument would be satisfied if the user provided, 1, 2, or 3 values.
+    ///
+    /// **NOTE:** This does *not* implicitly set [`Arg::multiple(true)`]. This is because
+    /// `-o val -o val` is multiple occurrences but a single value and `-o val1 val2` is a single
+    /// occurrence with multiple values. For positional arguments this **does** set
+    /// [`Arg::multiple(true)`] because there is no way to determine the difference between multiple
+    /// occurrences and multiple values.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("file")
+    ///     .short("f")
+    ///     .max_values(3)
+    /// # ;
+    /// ```
+    ///
+    /// Supplying less than the maximum number of values is allowed
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .takes_value(true)
+    ///         .max_values(3)
+    ///         .short("F"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "-F", "file1", "file2"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok());
+    /// let m = res.unwrap();
+    /// let files: Vec<_> = m.values_of("file").unwrap().collect();
+    /// assert_eq!(files, ["file1", "file2"]);
+    /// ```
+    ///
+    /// Supplying more than the maximum number of values is an error
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .takes_value(true)
+    ///         .max_values(2)
+    ///         .short("F"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "-F", "file1", "file2", "file3"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::TooManyValues);
+    /// ```
+    /// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+    pub fn max_values(mut self, qty: u64) -> Self {
+        self.setb(ArgSettings::TakesValue);
+        self.v.max_vals = Some(qty);
+        self
+    }
+
+    /// Specifies the *minimum* number of values for this argument. For example, if you had a
+    /// `-f <file>` argument where you wanted at least 2 'files' you would set
+    /// `.min_values(2)`, and this argument would be satisfied if the user provided, 2 or more
+    /// values.
+    ///
+    /// **NOTE:** This does not implicitly set [`Arg::multiple(true)`]. This is because
+    /// `-o val -o val` is multiple occurrences but a single value and `-o val1 val2` is a single
+    /// occurrence with multiple values. For positional arguments this **does** set
+    /// [`Arg::multiple(true)`] because there is no way to determine the difference between multiple
+    /// occurrences and multiple values.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("file")
+    ///     .short("f")
+    ///     .min_values(3)
+    /// # ;
+    /// ```
+    ///
+    /// Supplying more than the minimum number of values is allowed
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .takes_value(true)
+    ///         .min_values(2)
+    ///         .short("F"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "-F", "file1", "file2", "file3"
+    ///     ]);
+    ///
+    /// assert!(res.is_ok());
+    /// let m = res.unwrap();
+    /// let files: Vec<_> = m.values_of("file").unwrap().collect();
+    /// assert_eq!(files, ["file1", "file2", "file3"]);
+    /// ```
+    ///
+    /// Supplying less than the minimum number of values is an error
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("file")
+    ///         .takes_value(true)
+    ///         .min_values(2)
+    ///         .short("F"))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "-F", "file1"
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::TooFewValues);
+    /// ```
+    /// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+    pub fn min_values(mut self, qty: u64) -> Self {
+        self.v.min_vals = Some(qty);
+        self.set(ArgSettings::TakesValue)
+    }
+
+    /// Specifies whether or not an argument should allow grouping of multiple values via a
+    /// delimiter. I.e. should `--option=val1,val2,val3` be parsed as three values (`val1`, `val2`,
+    /// and `val3`) or as a single value (`val1,val2,val3`). Defaults to using `,` (comma) as the
+    /// value delimiter for all arguments that accept values (options and positional arguments)
+    ///
+    /// **NOTE:** The default is `false`. When set to `true` the default [`Arg::value_delimiter`]
+    /// is the comma `,`.
+    ///
+    /// # Examples
+    ///
+    /// The following example shows the default behavior.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let delims = App::new("prog")
+    ///     .arg(Arg::with_name("option")
+    ///         .long("option")
+    ///         .use_delimiter(true)
+    ///         .takes_value(true))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--option=val1,val2,val3",
+    ///     ]);
+    ///
+    /// assert!(delims.is_present("option"));
+    /// assert_eq!(delims.occurrences_of("option"), 1);
+    /// assert_eq!(delims.values_of("option").unwrap().collect::<Vec<_>>(), ["val1", "val2", "val3"]);
+    /// ```
+    /// The next example shows the difference when turning delimiters off. This is the default
+    /// behavior
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let nodelims = App::new("prog")
+    ///     .arg(Arg::with_name("option")
+    ///         .long("option")
+    ///         .use_delimiter(false)
+    ///         .takes_value(true))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--option=val1,val2,val3",
+    ///     ]);
+    ///
+    /// assert!(nodelims.is_present("option"));
+    /// assert_eq!(nodelims.occurrences_of("option"), 1);
+    /// assert_eq!(nodelims.value_of("option").unwrap(), "val1,val2,val3");
+    /// ```
+    /// [`Arg::value_delimiter`]: ./struct.Arg.html#method.value_delimiter
+    pub fn use_delimiter(mut self, d: bool) -> Self {
+        if d {
+            if self.v.val_delim.is_none() {
+                self.v.val_delim = Some(',');
+            }
+            self.setb(ArgSettings::TakesValue);
+            self.setb(ArgSettings::UseValueDelimiter);
+            self.unset(ArgSettings::ValueDelimiterNotSet)
+        } else {
+            self.v.val_delim = None;
+            self.unsetb(ArgSettings::UseValueDelimiter);
+            self.unset(ArgSettings::ValueDelimiterNotSet)
+        }
+    }
+
+    /// Specifies that *multiple values* may only be set using the delimiter. This means if an
+    /// if an option is encountered, and no delimiter is found, it automatically assumed that no
+    /// additional values for that option follow. This is unlike the default, where it is generally
+    /// assumed that more values will follow regardless of whether or not a delimiter is used.
+    ///
+    /// **NOTE:** The default is `false`.
+    ///
+    /// **NOTE:** Setting this to true implies [`Arg::use_delimiter(true)`]
+    ///
+    /// **NOTE:** It's a good idea to inform the user that use of a delimiter is required, either
+    /// through help text or other means.
+    ///
+    /// # Examples
+    ///
+    /// These examples demonstrate what happens when `require_delimiter(true)` is used. Notice
+    /// everything works in this first example, as we use a delimiter, as expected.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let delims = App::new("prog")
+    ///     .arg(Arg::with_name("opt")
+    ///         .short("o")
+    ///         .takes_value(true)
+    ///         .multiple(true)
+    ///         .require_delimiter(true))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-o", "val1,val2,val3",
+    ///     ]);
+    ///
+    /// assert!(delims.is_present("opt"));
+    /// assert_eq!(delims.values_of("opt").unwrap().collect::<Vec<_>>(), ["val1", "val2", "val3"]);
+    /// ```
+    /// In this next example, we will *not* use a delimiter. Notice it's now an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("opt")
+    ///         .short("o")
+    ///         .takes_value(true)
+    ///         .multiple(true)
+    ///         .require_delimiter(true))
+    ///     .get_matches_from_safe(vec![
+    ///         "prog", "-o", "val1", "val2", "val3",
+    ///     ]);
+    ///
+    /// assert!(res.is_err());
+    /// let err = res.unwrap_err();
+    /// assert_eq!(err.kind, ErrorKind::UnknownArgument);
+    /// ```
+    /// What's happening is `-o` is getting `val1`, and because delimiters are required yet none
+    /// were present, it stops parsing `-o`. At this point it reaches `val2` and because no
+    /// positional arguments have been defined, it's an error of an unexpected argument.
+    ///
+    /// In this final example, we contrast the above with `clap`'s default behavior where the above
+    /// is *not* an error.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let delims = App::new("prog")
+    ///     .arg(Arg::with_name("opt")
+    ///         .short("o")
+    ///         .takes_value(true)
+    ///         .multiple(true))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-o", "val1", "val2", "val3",
+    ///     ]);
+    ///
+    /// assert!(delims.is_present("opt"));
+    /// assert_eq!(delims.values_of("opt").unwrap().collect::<Vec<_>>(), ["val1", "val2", "val3"]);
+    /// ```
+    /// [`Arg::use_delimiter(true)`]: ./struct.Arg.html#method.use_delimiter
+    pub fn require_delimiter(mut self, d: bool) -> Self {
+        if d {
+            self = self.use_delimiter(true);
+            self.unsetb(ArgSettings::ValueDelimiterNotSet);
+            self.setb(ArgSettings::UseValueDelimiter);
+            self.set(ArgSettings::RequireDelimiter)
+        } else {
+            self = self.use_delimiter(false);
+            self.unsetb(ArgSettings::UseValueDelimiter);
+            self.unset(ArgSettings::RequireDelimiter)
+        }
+    }
+
+    /// Specifies the separator to use when values are clumped together, defaults to `,` (comma).
+    ///
+    /// **NOTE:** implicitly sets [`Arg::use_delimiter(true)`]
+    ///
+    /// **NOTE:** implicitly sets [`Arg::takes_value(true)`]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("config")
+    ///         .short("c")
+    ///         .long("config")
+    ///         .value_delimiter(";"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--config=val1;val2;val3"
+    ///     ]);
+    ///
+    /// assert_eq!(m.values_of("config").unwrap().collect::<Vec<_>>(), ["val1", "val2", "val3"])
+    /// ```
+    /// [`Arg::use_delimiter(true)`]: ./struct.Arg.html#method.use_delimiter
+    /// [`Arg::takes_value(true)`]: ./struct.Arg.html#method.takes_value
+    pub fn value_delimiter(mut self, d: &str) -> Self {
+        self.unsetb(ArgSettings::ValueDelimiterNotSet);
+        self.setb(ArgSettings::TakesValue);
+        self.setb(ArgSettings::UseValueDelimiter);
+        self.v.val_delim = Some(
+            d.chars()
+                .nth(0)
+                .expect("Failed to get value_delimiter from arg"),
+        );
+        self
+    }
+
+    /// Specify multiple names for values of option arguments. These names are cosmetic only, used
+    /// for help and usage strings only. The names are **not** used to access arguments. The values
+    /// of the arguments are accessed in numeric order (i.e. if you specify two names `one` and
+    /// `two` `one` will be the first matched value, `two` will be the second).
+    ///
+    /// This setting can be very helpful when describing the type of input the user should be
+    /// using, such as `FILE`, `INTERFACE`, etc. Although not required, it's somewhat convention to
+    /// use all capital letters for the value name.
+    ///
+    /// **Pro Tip:** It may help to use [`Arg::next_line_help(true)`] if there are long, or
+    /// multiple value names in order to not throw off the help text alignment of all options.
+    ///
+    /// **NOTE:** This implicitly sets [`Arg::number_of_values`] if the number of value names is
+    /// greater than one. I.e. be aware that the number of "names" you set for the values, will be
+    /// the *exact* number of values required to satisfy this argument
+    ///
+    /// **NOTE:** implicitly sets [`Arg::takes_value(true)`]
+    ///
+    /// **NOTE:** Does *not* require or imply [`Arg::multiple(true)`].
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("speed")
+    ///     .short("s")
+    ///     .value_names(&["fast", "slow"])
+    /// # ;
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("io")
+    ///         .long("io-files")
+    ///         .value_names(&["INFILE", "OUTFILE"]))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--help"
+    ///     ]);
+    /// ```
+    /// Running the above program produces the following output
+    ///
+    /// ```notrust
+    /// valnames
+    ///
+    /// USAGE:
+    ///    valnames [FLAGS] [OPTIONS]
+    ///
+    /// FLAGS:
+    ///     -h, --help       Prints help information
+    ///     -V, --version    Prints version information
+    ///
+    /// OPTIONS:
+    ///     --io-files <INFILE> <OUTFILE>    Some help text
+    /// ```
+    /// [`Arg::next_line_help(true)`]: ./struct.Arg.html#method.next_line_help
+    /// [`Arg::number_of_values`]: ./struct.Arg.html#method.number_of_values
+    /// [`Arg::takes_value(true)`]: ./struct.Arg.html#method.takes_value
+    /// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+    pub fn value_names(mut self, names: &[&'b str]) -> Self {
+        self.setb(ArgSettings::TakesValue);
+        if self.is_set(ArgSettings::ValueDelimiterNotSet) {
+            self.unsetb(ArgSettings::ValueDelimiterNotSet);
+            self.setb(ArgSettings::UseValueDelimiter);
+        }
+        if let Some(ref mut vals) = self.v.val_names {
+            let mut l = vals.len();
+            for s in names {
+                vals.insert(l, s);
+                l += 1;
+            }
+        } else {
+            let mut vm = VecMap::new();
+            for (i, n) in names.iter().enumerate() {
+                vm.insert(i, *n);
+            }
+            self.v.val_names = Some(vm);
+        }
+        self
+    }
+
+    /// Specifies the name for value of [option] or [positional] arguments inside of help
+    /// documentation. This name is cosmetic only, the name is **not** used to access arguments.
+    /// This setting can be very helpful when describing the type of input the user should be
+    /// using, such as `FILE`, `INTERFACE`, etc. Although not required, it's somewhat convention to
+    /// use all capital letters for the value name.
+    ///
+    /// **NOTE:** implicitly sets [`Arg::takes_value(true)`]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("cfg")
+    ///     .long("config")
+    ///     .value_name("FILE")
+    /// # ;
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("config")
+    ///         .long("config")
+    ///         .value_name("FILE"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--help"
+    ///     ]);
+    /// ```
+    /// Running the above program produces the following output
+    ///
+    /// ```notrust
+    /// valnames
+    ///
+    /// USAGE:
+    ///    valnames [FLAGS] [OPTIONS]
+    ///
+    /// FLAGS:
+    ///     -h, --help       Prints help information
+    ///     -V, --version    Prints version information
+    ///
+    /// OPTIONS:
+    ///     --config <FILE>     Some help text
+    /// ```
+    /// [option]: ./struct.Arg.html#method.takes_value
+    /// [positional]: ./struct.Arg.html#method.index
+    /// [`Arg::takes_value(true)`]: ./struct.Arg.html#method.takes_value
+    pub fn value_name(mut self, name: &'b str) -> Self {
+        self.setb(ArgSettings::TakesValue);
+        if let Some(ref mut vals) = self.v.val_names {
+            let l = vals.len();
+            vals.insert(l, name);
+        } else {
+            let mut vm = VecMap::new();
+            vm.insert(0, name);
+            self.v.val_names = Some(vm);
+        }
+        self
+    }
+
+    /// Specifies the value of the argument when *not* specified at runtime.
+    ///
+    /// **NOTE:** If the user *does not* use this argument at runtime, [`ArgMatches::occurrences_of`]
+    /// will return `0` even though the [`ArgMatches::value_of`] will return the default specified.
+    ///
+    /// **NOTE:** If the user *does not* use this argument at runtime [`ArgMatches::is_present`] will
+    /// still return `true`. If you wish to determine whether the argument was used at runtime or
+    /// not, consider [`ArgMatches::occurrences_of`] which will return `0` if the argument was *not*
+    /// used at runtime.
+    ///
+    /// **NOTE:** This setting is perfectly compatible with [`Arg::default_value_if`] but slightly
+    /// different. `Arg::default_value` *only* takes affect when the user has not provided this arg
+    /// at runtime. `Arg::default_value_if` however only takes affect when the user has not provided
+    /// a value at runtime **and** these other conditions are met as well. If you have set
+    /// `Arg::default_value` and `Arg::default_value_if`, and the user **did not** provide a this
+    /// arg at runtime, nor did were the conditions met for `Arg::default_value_if`, the
+    /// `Arg::default_value` will be applied.
+    ///
+    /// **NOTE:** This implicitly sets [`Arg::takes_value(true)`].
+    ///
+    /// **NOTE:** This setting effectively disables `AppSettings::ArgRequiredElseHelp` if used in
+    /// conjunction as it ensures that some argument will always be present.
+    ///
+    /// # Examples
+    ///
+    /// First we use the default value without providing any value at runtime.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("opt")
+    ///         .long("myopt")
+    ///         .default_value("myval"))
+    ///     .get_matches_from(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("opt"), Some("myval"));
+    /// assert!(m.is_present("opt"));
+    /// assert_eq!(m.occurrences_of("opt"), 0);
+    /// ```
+    ///
+    /// Next we provide a value at runtime to override the default.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("opt")
+    ///         .long("myopt")
+    ///         .default_value("myval"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--myopt=non_default"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("opt"), Some("non_default"));
+    /// assert!(m.is_present("opt"));
+    /// assert_eq!(m.occurrences_of("opt"), 1);
+    /// ```
+    /// [`ArgMatches::occurrences_of`]: ./struct.ArgMatches.html#method.occurrences_of
+    /// [`ArgMatches::value_of`]: ./struct.ArgMatches.html#method.value_of
+    /// [`Arg::takes_value(true)`]: ./struct.Arg.html#method.takes_value
+    /// [`ArgMatches::is_present`]: ./struct.ArgMatches.html#method.is_present
+    /// [`Arg::default_value_if`]: ./struct.Arg.html#method.default_value_if
+    pub fn default_value(self, val: &'a str) -> Self {
+        self.default_value_os(OsStr::from_bytes(val.as_bytes()))
+    }
+
+    /// Provides a default value in the exact same manner as [`Arg::default_value`]
+    /// only using [`OsStr`]s instead.
+    /// [`Arg::default_value`]: ./struct.Arg.html#method.default_value
+    /// [`OsStr`]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html
+    pub fn default_value_os(mut self, val: &'a OsStr) -> Self {
+        self.setb(ArgSettings::TakesValue);
+        self.v.default_val = Some(val);
+        self
+    }
+
+    /// Specifies the value of the argument if `arg` has been used at runtime. If `val` is set to
+    /// `None`, `arg` only needs to be present. If `val` is set to `"some-val"` then `arg` must be
+    /// present at runtime **and** have the value `val`.
+    ///
+    /// **NOTE:** This setting is perfectly compatible with [`Arg::default_value`] but slightly
+    /// different. `Arg::default_value` *only* takes affect when the user has not provided this arg
+    /// at runtime. This setting however only takes affect when the user has not provided a value at
+    /// runtime **and** these other conditions are met as well. If you have set `Arg::default_value`
+    /// and `Arg::default_value_if`, and the user **did not** provide a this arg at runtime, nor did
+    /// were the conditions met for `Arg::default_value_if`, the `Arg::default_value` will be
+    /// applied.
+    ///
+    /// **NOTE:** This implicitly sets [`Arg::takes_value(true)`].
+    ///
+    /// **NOTE:** If using YAML the values should be laid out as follows (`None` can be represented
+    /// as `null` in YAML)
+    ///
+    /// ```yaml
+    /// default_value_if:
+    ///     - [arg, val, default]
+    /// ```
+    ///
+    /// # Examples
+    ///
+    /// First we use the default value only if another arg is present at runtime.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .long("flag"))
+    ///     .arg(Arg::with_name("other")
+    ///         .long("other")
+    ///         .default_value_if("flag", None, "default"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--flag"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("other"), Some("default"));
+    /// ```
+    ///
+    /// Next we run the same test, but without providing `--flag`.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .long("flag"))
+    ///     .arg(Arg::with_name("other")
+    ///         .long("other")
+    ///         .default_value_if("flag", None, "default"))
+    ///     .get_matches_from(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("other"), None);
+    /// ```
+    ///
+    /// Now lets only use the default value if `--opt` contains the value `special`.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("opt")
+    ///         .takes_value(true)
+    ///         .long("opt"))
+    ///     .arg(Arg::with_name("other")
+    ///         .long("other")
+    ///         .default_value_if("opt", Some("special"), "default"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--opt", "special"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("other"), Some("default"));
+    /// ```
+    ///
+    /// We can run the same test and provide any value *other than* `special` and we won't get a
+    /// default value.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("opt")
+    ///         .takes_value(true)
+    ///         .long("opt"))
+    ///     .arg(Arg::with_name("other")
+    ///         .long("other")
+    ///         .default_value_if("opt", Some("special"), "default"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--opt", "hahaha"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("other"), None);
+    /// ```
+    /// [`Arg::takes_value(true)`]: ./struct.Arg.html#method.takes_value
+    /// [`Arg::default_value`]: ./struct.Arg.html#method.default_value
+    pub fn default_value_if(self, arg: &'a str, val: Option<&'b str>, default: &'b str) -> Self {
+        self.default_value_if_os(
+            arg,
+            val.map(str::as_bytes).map(OsStr::from_bytes),
+            OsStr::from_bytes(default.as_bytes()),
+        )
+    }
+
+    /// Provides a conditional default value in the exact same manner as [`Arg::default_value_if`]
+    /// only using [`OsStr`]s instead.
+    /// [`Arg::default_value_if`]: ./struct.Arg.html#method.default_value_if
+    /// [`OsStr`]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html
+    pub fn default_value_if_os(
+        mut self,
+        arg: &'a str,
+        val: Option<&'b OsStr>,
+        default: &'b OsStr,
+    ) -> Self {
+        self.setb(ArgSettings::TakesValue);
+        if let Some(ref mut vm) = self.v.default_vals_ifs {
+            let l = vm.len();
+            vm.insert(l, (arg, val, default));
+        } else {
+            let mut vm = VecMap::new();
+            vm.insert(0, (arg, val, default));
+            self.v.default_vals_ifs = Some(vm);
+        }
+        self
+    }
+
+    /// Specifies multiple values and conditions in the same manner as [`Arg::default_value_if`].
+    /// The method takes a slice of tuples in the `(arg, Option<val>, default)` format.
+    ///
+    /// **NOTE**: The conditions are stored in order and evaluated in the same order. I.e. the first
+    /// if multiple conditions are true, the first one found will be applied and the ultimate value.
+    ///
+    /// **NOTE:** If using YAML the values should be laid out as follows
+    ///
+    /// ```yaml
+    /// default_value_if:
+    ///     - [arg, val, default]
+    ///     - [arg2, null, default2]
+    /// ```
+    ///
+    /// # Examples
+    ///
+    /// First we use the default value only if another arg is present at runtime.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .long("flag"))
+    ///     .arg(Arg::with_name("opt")
+    ///         .long("opt")
+    ///         .takes_value(true))
+    ///     .arg(Arg::with_name("other")
+    ///         .long("other")
+    ///         .default_value_ifs(&[
+    ///             ("flag", None, "default"),
+    ///             ("opt", Some("channal"), "chan"),
+    ///         ]))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--opt", "channal"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("other"), Some("chan"));
+    /// ```
+    ///
+    /// Next we run the same test, but without providing `--flag`.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .long("flag"))
+    ///     .arg(Arg::with_name("other")
+    ///         .long("other")
+    ///         .default_value_ifs(&[
+    ///             ("flag", None, "default"),
+    ///             ("opt", Some("channal"), "chan"),
+    ///         ]))
+    ///     .get_matches_from(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("other"), None);
+    /// ```
+    ///
+    /// We can also see that these values are applied in order, and if more than one condition is
+    /// true, only the first evaluated "wins"
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .long("flag"))
+    ///     .arg(Arg::with_name("opt")
+    ///         .long("opt")
+    ///         .takes_value(true))
+    ///     .arg(Arg::with_name("other")
+    ///         .long("other")
+    ///         .default_value_ifs(&[
+    ///             ("flag", None, "default"),
+    ///             ("opt", Some("channal"), "chan"),
+    ///         ]))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--opt", "channal", "--flag"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("other"), Some("default"));
+    /// ```
+    /// [`Arg::takes_value(true)`]: ./struct.Arg.html#method.takes_value
+    /// [`Arg::default_value`]: ./struct.Arg.html#method.default_value
+    pub fn default_value_ifs(mut self, ifs: &[(&'a str, Option<&'b str>, &'b str)]) -> Self {
+        for &(arg, val, default) in ifs {
+            self = self.default_value_if_os(
+                arg,
+                val.map(str::as_bytes).map(OsStr::from_bytes),
+                OsStr::from_bytes(default.as_bytes()),
+            );
+        }
+        self
+    }
+
+    /// Provides multiple conditional default values in the exact same manner as
+    /// [`Arg::default_value_ifs`] only using [`OsStr`]s instead.
+    /// [`Arg::default_value_ifs`]: ./struct.Arg.html#method.default_value_ifs
+    /// [`OsStr`]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html
+    #[cfg_attr(feature = "lints", allow(explicit_counter_loop))]
+    pub fn default_value_ifs_os(mut self, ifs: &[(&'a str, Option<&'b OsStr>, &'b OsStr)]) -> Self {
+        for &(arg, val, default) in ifs {
+            self = self.default_value_if_os(arg, val, default);
+        }
+        self
+    }
+
+    /// Specifies that if the value is not passed in as an argument, that it should be retrieved
+    /// from the environment, if available. If it is not present in the environment, then default
+    /// rules will apply.
+    ///
+    /// **NOTE:** If the user *does not* use this argument at runtime, [`ArgMatches::occurrences_of`]
+    /// will return `0` even though the [`ArgMatches::value_of`] will return the default specified.
+    ///
+    /// **NOTE:** If the user *does not* use this argument at runtime [`ArgMatches::is_present`] will
+    /// return `true` if the variable is present in the environment . If you wish to determine whether
+    /// the argument was used at runtime or not, consider [`ArgMatches::occurrences_of`] which will
+    /// return `0` if the argument was *not* used at runtime.
+    ///
+    /// **NOTE:** This implicitly sets [`Arg::takes_value(true)`].
+    ///
+    /// **NOTE:** If [`Arg::multiple(true)`] is set then [`Arg::use_delimiter(true)`] should also be
+    /// set. Otherwise, only a single argument will be returned from the environment variable. The
+    /// default delimiter is `,` and follows all the other delimiter rules.
+    ///
+    /// # Examples
+    ///
+    /// In this example, we show the variable coming from the environment:
+    ///
+    /// ```rust
+    /// # use std::env;
+    /// # use clap::{App, Arg};
+    ///
+    /// env::set_var("MY_FLAG", "env");
+    ///
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .long("flag")
+    ///         .env("MY_FLAG"))
+    ///     .get_matches_from(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("flag"), Some("env"));
+    /// ```
+    ///
+    /// In this example, we show the variable coming from an option on the CLI:
+    ///
+    /// ```rust
+    /// # use std::env;
+    /// # use clap::{App, Arg};
+    ///
+    /// env::set_var("MY_FLAG", "env");
+    ///
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .long("flag")
+    ///         .env("MY_FLAG"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--flag", "opt"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("flag"), Some("opt"));
+    /// ```
+    ///
+    /// In this example, we show the variable coming from the environment even with the
+    /// presence of a default:
+    ///
+    /// ```rust
+    /// # use std::env;
+    /// # use clap::{App, Arg};
+    ///
+    /// env::set_var("MY_FLAG", "env");
+    ///
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .long("flag")
+    ///         .env("MY_FLAG")
+    ///         .default_value("default"))
+    ///     .get_matches_from(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert_eq!(m.value_of("flag"), Some("env"));
+    /// ```
+    ///
+    /// In this example, we show the use of multiple values in a single environment variable:
+    ///
+    /// ```rust
+    /// # use std::env;
+    /// # use clap::{App, Arg};
+    ///
+    /// env::set_var("MY_FLAG_MULTI", "env1,env2");
+    ///
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .long("flag")
+    ///         .env("MY_FLAG_MULTI")
+    ///         .multiple(true)
+    ///         .use_delimiter(true))
+    ///     .get_matches_from(vec![
+    ///         "prog"
+    ///     ]);
+    ///
+    /// assert_eq!(m.values_of("flag").unwrap().collect::<Vec<_>>(), vec!["env1", "env2"]);
+    /// ```
+    /// [`ArgMatches::occurrences_of`]: ./struct.ArgMatches.html#method.occurrences_of
+    /// [`ArgMatches::value_of`]: ./struct.ArgMatches.html#method.value_of
+    /// [`ArgMatches::is_present`]: ./struct.ArgMatches.html#method.is_present
+    /// [`Arg::takes_value(true)`]: ./struct.Arg.html#method.takes_value
+    /// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+    /// [`Arg::use_delimiter(true)`]: ./struct.Arg.html#method.use_delimiter
+    pub fn env(self, name: &'a str) -> Self {
+        self.env_os(OsStr::new(name))
+    }
+
+    /// Specifies that if the value is not passed in as an argument, that it should be retrieved
+    /// from the environment if available in the exact same manner as [`Arg::env`] only using
+    /// [`OsStr`]s instead.
+    pub fn env_os(mut self, name: &'a OsStr) -> Self {
+        self.setb(ArgSettings::TakesValue);
+
+        self.v.env = Some((name, env::var_os(name)));
+        self
+    }
+
+    /// @TODO @p2 @docs @release: write docs
+    pub fn hide_env_values(self, hide: bool) -> Self {
+        if hide {
+            self.set(ArgSettings::HideEnvValues)
+        } else {
+            self.unset(ArgSettings::HideEnvValues)
+        }
+    }
+
+    /// When set to `true` the help string will be displayed on the line after the argument and
+    /// indented once. This can be helpful for arguments with very long or complex help messages.
+    /// This can also be helpful for arguments with very long flag names, or many/long value names.
+    ///
+    /// **NOTE:** To apply this setting to all arguments consider using
+    /// [`AppSettings::NextLineHelp`]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("opt")
+    ///         .long("long-option-flag")
+    ///         .short("o")
+    ///         .takes_value(true)
+    ///         .value_names(&["value1", "value2"])
+    ///         .help("Some really long help and complex\n\
+    ///                help that makes more sense to be\n\
+    ///                on a line after the option")
+    ///         .next_line_help(true))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--help"
+    ///     ]);
+    /// ```
+    ///
+    /// The above example displays the following help message
+    ///
+    /// ```notrust
+    /// nlh
+    ///
+    /// USAGE:
+    ///     nlh [FLAGS] [OPTIONS]
+    ///
+    /// FLAGS:
+    ///     -h, --help       Prints help information
+    ///     -V, --version    Prints version information
+    ///
+    /// OPTIONS:
+    ///     -o, --long-option-flag <value1> <value2>
+    ///         Some really long help and complex
+    ///         help that makes more sense to be
+    ///         on a line after the option
+    /// ```
+    /// [`AppSettings::NextLineHelp`]: ./enum.AppSettings.html#variant.NextLineHelp
+    pub fn next_line_help(mut self, nlh: bool) -> Self {
+        if nlh {
+            self.setb(ArgSettings::NextLineHelp);
+        } else {
+            self.unsetb(ArgSettings::NextLineHelp);
+        }
+        self
+    }
+
+    /// Allows custom ordering of args within the help message. Args with a lower value will be
+    /// displayed first in the help message. This is helpful when one would like to emphasise
+    /// frequently used args, or prioritize those towards the top of the list. Duplicate values
+    /// **are** allowed. Args with duplicate display orders will be displayed in alphabetical
+    /// order.
+    ///
+    /// **NOTE:** The default is 999 for all arguments.
+    ///
+    /// **NOTE:** This setting is ignored for [positional arguments] which are always displayed in
+    /// [index] order.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("a") // Typically args are grouped alphabetically by name.
+    ///                              // Args without a display_order have a value of 999 and are
+    ///                              // displayed alphabetically with all other 999 valued args.
+    ///         .long("long-option")
+    ///         .short("o")
+    ///         .takes_value(true)
+    ///         .help("Some help and text"))
+    ///     .arg(Arg::with_name("b")
+    ///         .long("other-option")
+    ///         .short("O")
+    ///         .takes_value(true)
+    ///         .display_order(1)   // In order to force this arg to appear *first*
+    ///                             // all we have to do is give it a value lower than 999.
+    ///                             // Any other args with a value of 1 will be displayed
+    ///                             // alphabetically with this one...then 2 values, then 3, etc.
+    ///         .help("I should be first!"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--help"
+    ///     ]);
+    /// ```
+    ///
+    /// The above example displays the following help message
+    ///
+    /// ```notrust
+    /// cust-ord
+    ///
+    /// USAGE:
+    ///     cust-ord [FLAGS] [OPTIONS]
+    ///
+    /// FLAGS:
+    ///     -h, --help       Prints help information
+    ///     -V, --version    Prints version information
+    ///
+    /// OPTIONS:
+    ///     -O, --other-option <b>    I should be first!
+    ///     -o, --long-option <a>     Some help and text
+    /// ```
+    /// [positional arguments]: ./struct.Arg.html#method.index
+    /// [index]: ./struct.Arg.html#method.index
+    pub fn display_order(mut self, ord: usize) -> Self {
+        self.s.disp_ord = ord;
+        self
+    }
+
+    /// Indicates that all parameters passed after this should not be parsed
+    /// individually, but rather passed in their entirety. It is worth noting
+    /// that setting this requires all values to come after a `--` to indicate they
+    /// should all be captured. For example:
+    ///
+    /// ```notrust
+    /// --foo something -- -v -v -v -b -b -b --baz -q -u -x
+    /// ```
+    /// Will result in everything after `--` to be considered one raw argument. This behavior
+    /// may not be exactly what you are expecting and using [`AppSettings::TrailingVarArg`]
+    /// may be more appropriate.
+    ///
+    /// **NOTE:** Implicitly sets [`Arg::multiple(true)`], [`Arg::allow_hyphen_values(true)`], and
+    /// [`Arg::last(true)`] when set to `true`
+    ///
+    /// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+    /// [`Arg::allow_hyphen_values(true)`]: ./struct.Arg.html#method.allow_hyphen_values
+    /// [`Arg::last(true)`]: ./struct.Arg.html#method.last
+    /// [`AppSettings::TrailingVarArg`]: ./enum.AppSettings.html#variant.TrailingVarArg
+    pub fn raw(self, raw: bool) -> Self {
+        self.multiple(raw).allow_hyphen_values(raw).last(raw)
+    }
+
+    /// Hides an argument from short help message output.
+    ///
+    /// **NOTE:** This does **not** hide the argument from usage strings on error
+    ///
+    /// **NOTE:** Setting this option will cause next-line-help output style to be used
+    /// when long help (`--help`) is called.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("debug")
+    ///     .hidden_short_help(true)
+    /// # ;
+    /// ```
+    /// Setting `hidden_short_help(true)` will hide the argument when displaying short help text
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .long("config")
+    ///         .hidden_short_help(true)
+    ///         .help("Some help text describing the --config arg"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-h"
+    ///     ]);
+    /// ```
+    ///
+    /// The above example displays
+    ///
+    /// ```notrust
+    /// helptest
+    ///
+    /// USAGE:
+    ///    helptest [FLAGS]
+    ///
+    /// FLAGS:
+    /// -h, --help       Prints help information
+    /// -V, --version    Prints version information
+    /// ```
+    ///
+    /// However, when --help is called
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .long("config")
+    ///         .hidden_short_help(true)
+    ///         .help("Some help text describing the --config arg"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--help"
+    ///     ]);
+    /// ```
+    ///
+    /// Then the following would be displayed
+    ///
+    /// ```notrust
+    /// helptest
+    ///
+    /// USAGE:
+    ///    helptest [FLAGS]
+    ///
+    /// FLAGS:
+    ///     --config     Some help text describing the --config arg
+    /// -h, --help       Prints help information
+    /// -V, --version    Prints version information
+    /// ```
+    pub fn hidden_short_help(self, hide: bool) -> Self {
+        if hide {
+            self.set(ArgSettings::HiddenShortHelp)
+        } else {
+            self.unset(ArgSettings::HiddenShortHelp)
+        }
+    }
+
+    /// Hides an argument from long help message output.
+    ///
+    /// **NOTE:** This does **not** hide the argument from usage strings on error
+    ///
+    /// **NOTE:** Setting this option will cause next-line-help output style to be used
+    /// when long help (`--help`) is called.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// Arg::with_name("debug")
+    ///     .hidden_long_help(true)
+    /// # ;
+    /// ```
+    /// Setting `hidden_long_help(true)` will hide the argument when displaying long help text
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .long("config")
+    ///         .hidden_long_help(true)
+    ///         .help("Some help text describing the --config arg"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "--help"
+    ///     ]);
+    /// ```
+    ///
+    /// The above example displays
+    ///
+    /// ```notrust
+    /// helptest
+    ///
+    /// USAGE:
+    ///    helptest [FLAGS]
+    ///
+    /// FLAGS:
+    /// -h, --help       Prints help information
+    /// -V, --version    Prints version information
+    /// ```
+    ///
+    /// However, when -h is called
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("prog")
+    ///     .arg(Arg::with_name("cfg")
+    ///         .long("config")
+    ///         .hidden_long_help(true)
+    ///         .help("Some help text describing the --config arg"))
+    ///     .get_matches_from(vec![
+    ///         "prog", "-h"
+    ///     ]);
+    /// ```
+    ///
+    /// Then the following would be displayed
+    ///
+    /// ```notrust
+    /// helptest
+    ///
+    /// USAGE:
+    ///    helptest [FLAGS]
+    ///
+    /// FLAGS:
+    ///     --config     Some help text describing the --config arg
+    /// -h, --help       Prints help information
+    /// -V, --version    Prints version information
+    /// ```
+    pub fn hidden_long_help(self, hide: bool) -> Self {
+        if hide {
+            self.set(ArgSettings::HiddenLongHelp)
+        } else {
+            self.unset(ArgSettings::HiddenLongHelp)
+        }
+    }
+
+    /// Checks if one of the [`ArgSettings`] settings is set for the argument.
+    ///
+    /// [`ArgSettings`]: ./enum.ArgSettings.html
+    pub fn is_set(&self, s: ArgSettings) -> bool {
+        self.b.is_set(s)
+    }
+
+    /// Sets one of the [`ArgSettings`] settings for the argument.
+    ///
+    /// [`ArgSettings`]: ./enum.ArgSettings.html
+    pub fn set(mut self, s: ArgSettings) -> Self {
+        self.setb(s);
+        self
+    }
+
+    /// Unsets one of the [`ArgSettings`] settings for the argument.
+    ///
+    /// [`ArgSettings`]: ./enum.ArgSettings.html
+    pub fn unset(mut self, s: ArgSettings) -> Self {
+        self.unsetb(s);
+        self
+    }
+
+    #[doc(hidden)]
+    pub fn setb(&mut self, s: ArgSettings) {
+        self.b.set(s);
+    }
+
+    #[doc(hidden)]
+    pub fn unsetb(&mut self, s: ArgSettings) {
+        self.b.unset(s);
+    }
+}
+
+impl<'a, 'b, 'z> From<&'z Arg<'a, 'b>> for Arg<'a, 'b> {
+    fn from(a: &'z Arg<'a, 'b>) -> Self {
+        Arg {
+            b: a.b.clone(),
+            v: a.v.clone(),
+            s: a.s.clone(),
+            index: a.index,
+            r_ifs: a.r_ifs.clone(),
+        }
+    }
+}
+
+impl<'n, 'e> PartialEq for Arg<'n, 'e> {
+    fn eq(&self, other: &Arg<'n, 'e>) -> bool {
+        self.b == other.b
+    }
+}
diff --git a/src/args/arg_builder/base.rs b/src/args/arg_builder/base.rs
new file mode 100644
index 0000000..fef9d8a
--- /dev/null
+++ b/src/args/arg_builder/base.rs
@@ -0,0 +1,38 @@
+use args::{Arg, ArgFlags, ArgSettings};
+
+#[derive(Debug, Clone, Default)]
+pub struct Base<'a, 'b>
+where
+    'a: 'b,
+{
+    pub name: &'a str,
+    pub help: Option<&'b str>,
+    pub long_help: Option<&'b str>,
+    pub blacklist: Option<Vec<&'a str>>,
+    pub settings: ArgFlags,
+    pub r_unless: Option<Vec<&'a str>>,
+    pub overrides: Option<Vec<&'a str>>,
+    pub groups: Option<Vec<&'a str>>,
+    pub requires: Option<Vec<(Option<&'b str>, &'a str)>>,
+}
+
+impl<'n, 'e> Base<'n, 'e> {
+    pub fn new(name: &'n str) -> Self {
+        Base {
+            name: name,
+            ..Default::default()
+        }
+    }
+
+    pub fn set(&mut self, s: ArgSettings) { self.settings.set(s); }
+    pub fn unset(&mut self, s: ArgSettings) { self.settings.unset(s); }
+    pub fn is_set(&self, s: ArgSettings) -> bool { self.settings.is_set(s) }
+}
+
+impl<'n, 'e, 'z> From<&'z Arg<'n, 'e>> for Base<'n, 'e> {
+    fn from(a: &'z Arg<'n, 'e>) -> Self { a.b.clone() }
+}
+
+impl<'n, 'e> PartialEq for Base<'n, 'e> {
+    fn eq(&self, other: &Base<'n, 'e>) -> bool { self.name == other.name }
+}
diff --git a/src/args/arg_builder/flag.rs b/src/args/arg_builder/flag.rs
new file mode 100644
index 0000000..641e777
--- /dev/null
+++ b/src/args/arg_builder/flag.rs
@@ -0,0 +1,159 @@
+// Std
+use std::convert::From;
+use std::fmt::{Display, Formatter, Result};
+use std::rc::Rc;
+use std::result::Result as StdResult;
+use std::ffi::{OsStr, OsString};
+use std::mem;
+
+// Internal
+use Arg;
+use args::{AnyArg, ArgSettings, Base, DispOrder, Switched};
+use map::{self, VecMap};
+
+#[derive(Default, Clone, Debug)]
+#[doc(hidden)]
+pub struct FlagBuilder<'n, 'e>
+where
+    'n: 'e,
+{
+    pub b: Base<'n, 'e>,
+    pub s: Switched<'e>,
+}
+
+impl<'n, 'e> FlagBuilder<'n, 'e> {
+    pub fn new(name: &'n str) -> Self {
+        FlagBuilder {
+            b: Base::new(name),
+            ..Default::default()
+        }
+    }
+}
+
+impl<'a, 'b, 'z> From<&'z Arg<'a, 'b>> for FlagBuilder<'a, 'b> {
+    fn from(a: &'z Arg<'a, 'b>) -> Self {
+        FlagBuilder {
+            b: Base::from(a),
+            s: Switched::from(a),
+        }
+    }
+}
+
+impl<'a, 'b> From<Arg<'a, 'b>> for FlagBuilder<'a, 'b> {
+    fn from(mut a: Arg<'a, 'b>) -> Self {
+        FlagBuilder {
+            b: mem::replace(&mut a.b, Base::default()),
+            s: mem::replace(&mut a.s, Switched::default()),
+        }
+    }
+}
+
+impl<'n, 'e> Display for FlagBuilder<'n, 'e> {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        if let Some(l) = self.s.long {
+            write!(f, "--{}", l)?;
+        } else {
+            write!(f, "-{}", self.s.short.unwrap())?;
+        }
+
+        Ok(())
+    }
+}
+
+impl<'n, 'e> AnyArg<'n, 'e> for FlagBuilder<'n, 'e> {
+    fn name(&self) -> &'n str { self.b.name }
+    fn overrides(&self) -> Option<&[&'e str]> { self.b.overrides.as_ref().map(|o| &o[..]) }
+    fn requires(&self) -> Option<&[(Option<&'e str>, &'n str)]> {
+        self.b.requires.as_ref().map(|o| &o[..])
+    }
+    fn blacklist(&self) -> Option<&[&'e str]> { self.b.blacklist.as_ref().map(|o| &o[..]) }
+    fn required_unless(&self) -> Option<&[&'e str]> { self.b.r_unless.as_ref().map(|o| &o[..]) }
+    fn is_set(&self, s: ArgSettings) -> bool { self.b.settings.is_set(s) }
+    fn has_switch(&self) -> bool { true }
+    fn takes_value(&self) -> bool { false }
+    fn set(&mut self, s: ArgSettings) { self.b.settings.set(s) }
+    fn max_vals(&self) -> Option<u64> { None }
+    fn val_names(&self) -> Option<&VecMap<&'e str>> { None }
+    fn num_vals(&self) -> Option<u64> { None }
+    fn possible_vals(&self) -> Option<&[&'e str]> { None }
+    fn validator(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> { None }
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> StdResult<(), OsString>>> { None }
+    fn min_vals(&self) -> Option<u64> { None }
+    fn short(&self) -> Option<char> { self.s.short }
+    fn long(&self) -> Option<&'e str> { self.s.long }
+    fn val_delim(&self) -> Option<char> { None }
+    fn help(&self) -> Option<&'e str> { self.b.help }
+    fn long_help(&self) -> Option<&'e str> { self.b.long_help }
+    fn val_terminator(&self) -> Option<&'e str> { None }
+    fn default_val(&self) -> Option<&'e OsStr> { None }
+    fn default_vals_ifs(&self) -> Option<map::Values<(&'n str, Option<&'e OsStr>, &'e OsStr)>> {
+        None
+    }
+    fn env<'s>(&'s self) -> Option<(&'n OsStr, Option<&'s OsString>)> { None }
+    fn longest_filter(&self) -> bool { self.s.long.is_some() }
+    fn aliases(&self) -> Option<Vec<&'e str>> {
+        if let Some(ref aliases) = self.s.aliases {
+            let vis_aliases: Vec<_> = aliases
+                .iter()
+                .filter_map(|&(n, v)| if v { Some(n) } else { None })
+                .collect();
+            if vis_aliases.is_empty() {
+                None
+            } else {
+                Some(vis_aliases)
+            }
+        } else {
+            None
+        }
+    }
+}
+
+impl<'n, 'e> DispOrder for FlagBuilder<'n, 'e> {
+    fn disp_ord(&self) -> usize { self.s.disp_ord }
+}
+
+impl<'n, 'e> PartialEq for FlagBuilder<'n, 'e> {
+    fn eq(&self, other: &FlagBuilder<'n, 'e>) -> bool { self.b == other.b }
+}
+
+#[cfg(test)]
+mod test {
+    use args::settings::ArgSettings;
+    use super::FlagBuilder;
+
+    #[test]
+    fn flagbuilder_display() {
+        let mut f = FlagBuilder::new("flg");
+        f.b.settings.set(ArgSettings::Multiple);
+        f.s.long = Some("flag");
+
+        assert_eq!(&*format!("{}", f), "--flag");
+
+        let mut f2 = FlagBuilder::new("flg");
+        f2.s.short = Some('f');
+
+        assert_eq!(&*format!("{}", f2), "-f");
+    }
+
+    #[test]
+    fn flagbuilder_display_single_alias() {
+        let mut f = FlagBuilder::new("flg");
+        f.s.long = Some("flag");
+        f.s.aliases = Some(vec![("als", true)]);
+
+        assert_eq!(&*format!("{}", f), "--flag");
+    }
+
+    #[test]
+    fn flagbuilder_display_multiple_aliases() {
+        let mut f = FlagBuilder::new("flg");
+        f.s.short = Some('f');
+        f.s.aliases = Some(vec![
+            ("alias_not_visible", false),
+            ("f2", true),
+            ("f3", true),
+            ("f4", true),
+        ]);
+        assert_eq!(&*format!("{}", f), "-f");
+    }
+}
diff --git a/src/args/arg_builder/mod.rs b/src/args/arg_builder/mod.rs
new file mode 100644
index 0000000..d1a7a66
--- /dev/null
+++ b/src/args/arg_builder/mod.rs
@@ -0,0 +1,13 @@
+pub use self::flag::FlagBuilder;
+pub use self::option::OptBuilder;
+pub use self::positional::PosBuilder;
+pub use self::base::Base;
+pub use self::switched::Switched;
+pub use self::valued::Valued;
+
+mod flag;
+mod positional;
+mod option;
+mod base;
+mod valued;
+mod switched;
diff --git a/src/args/arg_builder/option.rs b/src/args/arg_builder/option.rs
new file mode 100644
index 0000000..4bb147a
--- /dev/null
+++ b/src/args/arg_builder/option.rs
@@ -0,0 +1,244 @@
+// Std
+use std::fmt::{Display, Formatter, Result};
+use std::rc::Rc;
+use std::result::Result as StdResult;
+use std::ffi::{OsStr, OsString};
+use std::mem;
+
+// Internal
+use args::{AnyArg, Arg, ArgSettings, Base, DispOrder, Switched, Valued};
+use map::{self, VecMap};
+use INTERNAL_ERROR_MSG;
+
+#[allow(missing_debug_implementations)]
+#[doc(hidden)]
+#[derive(Default, Clone)]
+pub struct OptBuilder<'n, 'e>
+where
+    'n: 'e,
+{
+    pub b: Base<'n, 'e>,
+    pub s: Switched<'e>,
+    pub v: Valued<'n, 'e>,
+}
+
+impl<'n, 'e> OptBuilder<'n, 'e> {
+    pub fn new(name: &'n str) -> Self {
+        OptBuilder {
+            b: Base::new(name),
+            ..Default::default()
+        }
+    }
+}
+
+impl<'n, 'e, 'z> From<&'z Arg<'n, 'e>> for OptBuilder<'n, 'e> {
+    fn from(a: &'z Arg<'n, 'e>) -> Self {
+        OptBuilder {
+            b: Base::from(a),
+            s: Switched::from(a),
+            v: Valued::from(a),
+        }
+    }
+}
+
+impl<'n, 'e> From<Arg<'n, 'e>> for OptBuilder<'n, 'e> {
+    fn from(mut a: Arg<'n, 'e>) -> Self {
+        a.v.fill_in();
+        OptBuilder {
+            b: mem::replace(&mut a.b, Base::default()),
+            s: mem::replace(&mut a.s, Switched::default()),
+            v: mem::replace(&mut a.v, Valued::default()),
+        }
+    }
+}
+
+impl<'n, 'e> Display for OptBuilder<'n, 'e> {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        debugln!("OptBuilder::fmt:{}", self.b.name);
+        let sep = if self.b.is_set(ArgSettings::RequireEquals) {
+            "="
+        } else {
+            " "
+        };
+        // Write the name such --long or -l
+        if let Some(l) = self.s.long {
+            write!(f, "--{}{}", l, sep)?;
+        } else {
+            write!(f, "-{}{}", self.s.short.unwrap(), sep)?;
+        }
+        let delim = if self.is_set(ArgSettings::RequireDelimiter) {
+            self.v.val_delim.expect(INTERNAL_ERROR_MSG)
+        } else {
+            ' '
+        };
+
+        // Write the values such as <name1> <name2>
+        if let Some(ref vec) = self.v.val_names {
+            let mut it = vec.iter().peekable();
+            while let Some((_, val)) = it.next() {
+                write!(f, "<{}>", val)?;
+                if it.peek().is_some() {
+                    write!(f, "{}", delim)?;
+                }
+            }
+            let num = vec.len();
+            if self.is_set(ArgSettings::Multiple) && num == 1 {
+                write!(f, "...")?;
+            }
+        } else if let Some(num) = self.v.num_vals {
+            let mut it = (0..num).peekable();
+            while let Some(_) = it.next() {
+                write!(f, "<{}>", self.b.name)?;
+                if it.peek().is_some() {
+                    write!(f, "{}", delim)?;
+                }
+            }
+            if self.is_set(ArgSettings::Multiple) && num == 1 {
+                write!(f, "...")?;
+            }
+        } else {
+            write!(
+                f,
+                "<{}>{}",
+                self.b.name,
+                if self.is_set(ArgSettings::Multiple) {
+                    "..."
+                } else {
+                    ""
+                }
+            )?;
+        }
+
+        Ok(())
+    }
+}
+
+impl<'n, 'e> AnyArg<'n, 'e> for OptBuilder<'n, 'e> {
+    fn name(&self) -> &'n str { self.b.name }
+    fn overrides(&self) -> Option<&[&'e str]> { self.b.overrides.as_ref().map(|o| &o[..]) }
+    fn requires(&self) -> Option<&[(Option<&'e str>, &'n str)]> {
+        self.b.requires.as_ref().map(|o| &o[..])
+    }
+    fn blacklist(&self) -> Option<&[&'e str]> { self.b.blacklist.as_ref().map(|o| &o[..]) }
+    fn required_unless(&self) -> Option<&[&'e str]> { self.b.r_unless.as_ref().map(|o| &o[..]) }
+    fn val_names(&self) -> Option<&VecMap<&'e str>> { self.v.val_names.as_ref() }
+    fn is_set(&self, s: ArgSettings) -> bool { self.b.settings.is_set(s) }
+    fn has_switch(&self) -> bool { true }
+    fn set(&mut self, s: ArgSettings) { self.b.settings.set(s) }
+    fn max_vals(&self) -> Option<u64> { self.v.max_vals }
+    fn val_terminator(&self) -> Option<&'e str> { self.v.terminator }
+    fn num_vals(&self) -> Option<u64> { self.v.num_vals }
+    fn possible_vals(&self) -> Option<&[&'e str]> { self.v.possible_vals.as_ref().map(|o| &o[..]) }
+    fn validator(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> {
+        self.v.validator.as_ref()
+    }
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> StdResult<(), OsString>>> {
+        self.v.validator_os.as_ref()
+    }
+    fn min_vals(&self) -> Option<u64> { self.v.min_vals }
+    fn short(&self) -> Option<char> { self.s.short }
+    fn long(&self) -> Option<&'e str> { self.s.long }
+    fn val_delim(&self) -> Option<char> { self.v.val_delim }
+    fn takes_value(&self) -> bool { true }
+    fn help(&self) -> Option<&'e str> { self.b.help }
+    fn long_help(&self) -> Option<&'e str> { self.b.long_help }
+    fn default_val(&self) -> Option<&'e OsStr> { self.v.default_val }
+    fn default_vals_ifs(&self) -> Option<map::Values<(&'n str, Option<&'e OsStr>, &'e OsStr)>> {
+        self.v.default_vals_ifs.as_ref().map(|vm| vm.values())
+    }
+    fn env<'s>(&'s self) -> Option<(&'n OsStr, Option<&'s OsString>)> {
+        self.v
+            .env
+            .as_ref()
+            .map(|&(key, ref value)| (key, value.as_ref()))
+    }
+    fn longest_filter(&self) -> bool { true }
+    fn aliases(&self) -> Option<Vec<&'e str>> {
+        if let Some(ref aliases) = self.s.aliases {
+            let vis_aliases: Vec<_> = aliases
+                .iter()
+                .filter_map(|&(n, v)| if v { Some(n) } else { None })
+                .collect();
+            if vis_aliases.is_empty() {
+                None
+            } else {
+                Some(vis_aliases)
+            }
+        } else {
+            None
+        }
+    }
+}
+
+impl<'n, 'e> DispOrder for OptBuilder<'n, 'e> {
+    fn disp_ord(&self) -> usize { self.s.disp_ord }
+}
+
+impl<'n, 'e> PartialEq for OptBuilder<'n, 'e> {
+    fn eq(&self, other: &OptBuilder<'n, 'e>) -> bool { self.b == other.b }
+}
+
+#[cfg(test)]
+mod test {
+    use args::settings::ArgSettings;
+    use super::OptBuilder;
+    use map::VecMap;
+
+    #[test]
+    fn optbuilder_display1() {
+        let mut o = OptBuilder::new("opt");
+        o.s.long = Some("option");
+        o.b.settings.set(ArgSettings::Multiple);
+
+        assert_eq!(&*format!("{}", o), "--option <opt>...");
+    }
+
+    #[test]
+    fn optbuilder_display2() {
+        let mut v_names = VecMap::new();
+        v_names.insert(0, "file");
+        v_names.insert(1, "name");
+
+        let mut o2 = OptBuilder::new("opt");
+        o2.s.short = Some('o');
+        o2.v.val_names = Some(v_names);
+
+        assert_eq!(&*format!("{}", o2), "-o <file> <name>");
+    }
+
+    #[test]
+    fn optbuilder_display3() {
+        let mut v_names = VecMap::new();
+        v_names.insert(0, "file");
+        v_names.insert(1, "name");
+
+        let mut o2 = OptBuilder::new("opt");
+        o2.s.short = Some('o');
+        o2.v.val_names = Some(v_names);
+        o2.b.settings.set(ArgSettings::Multiple);
+
+        assert_eq!(&*format!("{}", o2), "-o <file> <name>");
+    }
+
+    #[test]
+    fn optbuilder_display_single_alias() {
+        let mut o = OptBuilder::new("opt");
+        o.s.long = Some("option");
+        o.s.aliases = Some(vec![("als", true)]);
+
+        assert_eq!(&*format!("{}", o), "--option <opt>");
+    }
+
+    #[test]
+    fn optbuilder_display_multiple_aliases() {
+        let mut o = OptBuilder::new("opt");
+        o.s.long = Some("option");
+        o.s.aliases = Some(vec![
+            ("als_not_visible", false),
+            ("als2", true),
+            ("als3", true),
+            ("als4", true),
+        ]);
+        assert_eq!(&*format!("{}", o), "--option <opt>");
+    }
+}
diff --git a/src/args/arg_builder/positional.rs b/src/args/arg_builder/positional.rs
new file mode 100644
index 0000000..43fdca4
--- /dev/null
+++ b/src/args/arg_builder/positional.rs
@@ -0,0 +1,229 @@
+// Std
+use std::borrow::Cow;
+use std::fmt::{Display, Formatter, Result};
+use std::rc::Rc;
+use std::result::Result as StdResult;
+use std::ffi::{OsStr, OsString};
+use std::mem;
+
+// Internal
+use Arg;
+use args::{AnyArg, ArgSettings, Base, DispOrder, Valued};
+use INTERNAL_ERROR_MSG;
+use map::{self, VecMap};
+
+#[allow(missing_debug_implementations)]
+#[doc(hidden)]
+#[derive(Clone, Default)]
+pub struct PosBuilder<'n, 'e>
+where
+    'n: 'e,
+{
+    pub b: Base<'n, 'e>,
+    pub v: Valued<'n, 'e>,
+    pub index: u64,
+}
+
+impl<'n, 'e> PosBuilder<'n, 'e> {
+    pub fn new(name: &'n str, idx: u64) -> Self {
+        PosBuilder {
+            b: Base::new(name),
+            index: idx,
+            ..Default::default()
+        }
+    }
+
+    pub fn from_arg_ref(a: &Arg<'n, 'e>, idx: u64) -> Self {
+        let mut pb = PosBuilder {
+            b: Base::from(a),
+            v: Valued::from(a),
+            index: idx,
+        };
+        if a.v.max_vals.is_some() || a.v.min_vals.is_some()
+            || (a.v.num_vals.is_some() && a.v.num_vals.unwrap() > 1)
+        {
+            pb.b.settings.set(ArgSettings::Multiple);
+        }
+        pb
+    }
+
+    pub fn from_arg(mut a: Arg<'n, 'e>, idx: u64) -> Self {
+        if a.v.max_vals.is_some() || a.v.min_vals.is_some()
+            || (a.v.num_vals.is_some() && a.v.num_vals.unwrap() > 1)
+        {
+            a.b.settings.set(ArgSettings::Multiple);
+        }
+        PosBuilder {
+            b: mem::replace(&mut a.b, Base::default()),
+            v: mem::replace(&mut a.v, Valued::default()),
+            index: idx,
+        }
+    }
+
+    pub fn multiple_str(&self) -> &str {
+        let mult_vals = self.v
+            .val_names
+            .as_ref()
+            .map_or(true, |names| names.len() < 2);
+        if self.is_set(ArgSettings::Multiple) && mult_vals {
+            "..."
+        } else {
+            ""
+        }
+    }
+
+    pub fn name_no_brackets(&self) -> Cow<str> {
+        debugln!("PosBuilder::name_no_brackets;");
+        let mut delim = String::new();
+        delim.push(if self.is_set(ArgSettings::RequireDelimiter) {
+            self.v.val_delim.expect(INTERNAL_ERROR_MSG)
+        } else {
+            ' '
+        });
+        if let Some(ref names) = self.v.val_names {
+            debugln!("PosBuilder:name_no_brackets: val_names={:#?}", names);
+            if names.len() > 1 {
+                Cow::Owned(
+                    names
+                        .values()
+                        .map(|n| format!("<{}>", n))
+                        .collect::<Vec<_>>()
+                        .join(&*delim),
+                )
+            } else {
+                Cow::Borrowed(names.values().next().expect(INTERNAL_ERROR_MSG))
+            }
+        } else {
+            debugln!("PosBuilder:name_no_brackets: just name");
+            Cow::Borrowed(self.b.name)
+        }
+    }
+}
+
+impl<'n, 'e> Display for PosBuilder<'n, 'e> {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        let mut delim = String::new();
+        delim.push(if self.is_set(ArgSettings::RequireDelimiter) {
+            self.v.val_delim.expect(INTERNAL_ERROR_MSG)
+        } else {
+            ' '
+        });
+        if let Some(ref names) = self.v.val_names {
+            write!(
+                f,
+                "{}",
+                names
+                    .values()
+                    .map(|n| format!("<{}>", n))
+                    .collect::<Vec<_>>()
+                    .join(&*delim)
+            )?;
+        } else {
+            write!(f, "<{}>", self.b.name)?;
+        }
+        if self.b.settings.is_set(ArgSettings::Multiple)
+            && (self.v.val_names.is_none() || self.v.val_names.as_ref().unwrap().len() == 1)
+        {
+            write!(f, "...")?;
+        }
+
+        Ok(())
+    }
+}
+
+impl<'n, 'e> AnyArg<'n, 'e> for PosBuilder<'n, 'e> {
+    fn name(&self) -> &'n str { self.b.name }
+    fn overrides(&self) -> Option<&[&'e str]> { self.b.overrides.as_ref().map(|o| &o[..]) }
+    fn requires(&self) -> Option<&[(Option<&'e str>, &'n str)]> {
+        self.b.requires.as_ref().map(|o| &o[..])
+    }
+    fn blacklist(&self) -> Option<&[&'e str]> { self.b.blacklist.as_ref().map(|o| &o[..]) }
+    fn required_unless(&self) -> Option<&[&'e str]> { self.b.r_unless.as_ref().map(|o| &o[..]) }
+    fn val_names(&self) -> Option<&VecMap<&'e str>> { self.v.val_names.as_ref() }
+    fn is_set(&self, s: ArgSettings) -> bool { self.b.settings.is_set(s) }
+    fn set(&mut self, s: ArgSettings) { self.b.settings.set(s) }
+    fn has_switch(&self) -> bool { false }
+    fn max_vals(&self) -> Option<u64> { self.v.max_vals }
+    fn val_terminator(&self) -> Option<&'e str> { self.v.terminator }
+    fn num_vals(&self) -> Option<u64> { self.v.num_vals }
+    fn possible_vals(&self) -> Option<&[&'e str]> { self.v.possible_vals.as_ref().map(|o| &o[..]) }
+    fn validator(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> {
+        self.v.validator.as_ref()
+    }
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> StdResult<(), OsString>>> {
+        self.v.validator_os.as_ref()
+    }
+    fn min_vals(&self) -> Option<u64> { self.v.min_vals }
+    fn short(&self) -> Option<char> { None }
+    fn long(&self) -> Option<&'e str> { None }
+    fn val_delim(&self) -> Option<char> { self.v.val_delim }
+    fn takes_value(&self) -> bool { true }
+    fn help(&self) -> Option<&'e str> { self.b.help }
+    fn long_help(&self) -> Option<&'e str> { self.b.long_help }
+    fn default_vals_ifs(&self) -> Option<map::Values<(&'n str, Option<&'e OsStr>, &'e OsStr)>> {
+        self.v.default_vals_ifs.as_ref().map(|vm| vm.values())
+    }
+    fn default_val(&self) -> Option<&'e OsStr> { self.v.default_val }
+    fn env<'s>(&'s self) -> Option<(&'n OsStr, Option<&'s OsString>)> {
+        self.v
+            .env
+            .as_ref()
+            .map(|&(key, ref value)| (key, value.as_ref()))
+    }
+    fn longest_filter(&self) -> bool { true }
+    fn aliases(&self) -> Option<Vec<&'e str>> { None }
+}
+
+impl<'n, 'e> DispOrder for PosBuilder<'n, 'e> {
+    fn disp_ord(&self) -> usize { self.index as usize }
+}
+
+impl<'n, 'e> PartialEq for PosBuilder<'n, 'e> {
+    fn eq(&self, other: &PosBuilder<'n, 'e>) -> bool { self.b == other.b }
+}
+
+#[cfg(test)]
+mod test {
+    use args::settings::ArgSettings;
+    use super::PosBuilder;
+    use map::VecMap;
+
+    #[test]
+    fn display_mult() {
+        let mut p = PosBuilder::new("pos", 1);
+        p.b.settings.set(ArgSettings::Multiple);
+
+        assert_eq!(&*format!("{}", p), "<pos>...");
+    }
+
+    #[test]
+    fn display_required() {
+        let mut p2 = PosBuilder::new("pos", 1);
+        p2.b.settings.set(ArgSettings::Required);
+
+        assert_eq!(&*format!("{}", p2), "<pos>");
+    }
+
+    #[test]
+    fn display_val_names() {
+        let mut p2 = PosBuilder::new("pos", 1);
+        let mut vm = VecMap::new();
+        vm.insert(0, "file1");
+        vm.insert(1, "file2");
+        p2.v.val_names = Some(vm);
+
+        assert_eq!(&*format!("{}", p2), "<file1> <file2>");
+    }
+
+    #[test]
+    fn display_val_names_req() {
+        let mut p2 = PosBuilder::new("pos", 1);
+        p2.b.settings.set(ArgSettings::Required);
+        let mut vm = VecMap::new();
+        vm.insert(0, "file1");
+        vm.insert(1, "file2");
+        p2.v.val_names = Some(vm);
+
+        assert_eq!(&*format!("{}", p2), "<file1> <file2>");
+    }
+}
diff --git a/src/args/arg_builder/switched.rs b/src/args/arg_builder/switched.rs
new file mode 100644
index 0000000..224b2f2
--- /dev/null
+++ b/src/args/arg_builder/switched.rs
@@ -0,0 +1,38 @@
+use Arg;
+
+#[derive(Debug)]
+pub struct Switched<'b> {
+    pub short: Option<char>,
+    pub long: Option<&'b str>,
+    pub aliases: Option<Vec<(&'b str, bool)>>, // (name, visible)
+    pub disp_ord: usize,
+    pub unified_ord: usize,
+}
+
+impl<'e> Default for Switched<'e> {
+    fn default() -> Self {
+        Switched {
+            short: None,
+            long: None,
+            aliases: None,
+            disp_ord: 999,
+            unified_ord: 999,
+        }
+    }
+}
+
+impl<'n, 'e, 'z> From<&'z Arg<'n, 'e>> for Switched<'e> {
+    fn from(a: &'z Arg<'n, 'e>) -> Self { a.s.clone() }
+}
+
+impl<'e> Clone for Switched<'e> {
+    fn clone(&self) -> Self {
+        Switched {
+            short: self.short,
+            long: self.long,
+            aliases: self.aliases.clone(),
+            disp_ord: self.disp_ord,
+            unified_ord: self.unified_ord,
+        }
+    }
+}
diff --git a/src/args/arg_builder/valued.rs b/src/args/arg_builder/valued.rs
new file mode 100644
index 0000000..d70854d
--- /dev/null
+++ b/src/args/arg_builder/valued.rs
@@ -0,0 +1,67 @@
+use std::rc::Rc;
+use std::ffi::{OsStr, OsString};
+
+use map::VecMap;
+
+use Arg;
+
+#[allow(missing_debug_implementations)]
+#[derive(Clone)]
+pub struct Valued<'a, 'b>
+where
+    'a: 'b,
+{
+    pub possible_vals: Option<Vec<&'b str>>,
+    pub val_names: Option<VecMap<&'b str>>,
+    pub num_vals: Option<u64>,
+    pub max_vals: Option<u64>,
+    pub min_vals: Option<u64>,
+    pub validator: Option<Rc<Fn(String) -> Result<(), String>>>,
+    pub validator_os: Option<Rc<Fn(&OsStr) -> Result<(), OsString>>>,
+    pub val_delim: Option<char>,
+    pub default_val: Option<&'b OsStr>,
+    pub default_vals_ifs: Option<VecMap<(&'a str, Option<&'b OsStr>, &'b OsStr)>>,
+    pub env: Option<(&'a OsStr, Option<OsString>)>,
+    pub terminator: Option<&'b str>,
+}
+
+impl<'n, 'e> Default for Valued<'n, 'e> {
+    fn default() -> Self {
+        Valued {
+            possible_vals: None,
+            num_vals: None,
+            min_vals: None,
+            max_vals: None,
+            val_names: None,
+            validator: None,
+            validator_os: None,
+            val_delim: None,
+            default_val: None,
+            default_vals_ifs: None,
+            env: None,
+            terminator: None,
+        }
+    }
+}
+
+impl<'n, 'e> Valued<'n, 'e> {
+    pub fn fill_in(&mut self) {
+        if let Some(ref vec) = self.val_names {
+            if vec.len() > 1 {
+                self.num_vals = Some(vec.len() as u64);
+            }
+        }
+    }
+}
+
+impl<'n, 'e, 'z> From<&'z Arg<'n, 'e>> for Valued<'n, 'e> {
+    fn from(a: &'z Arg<'n, 'e>) -> Self {
+        let mut v = a.v.clone();
+        if let Some(ref vec) = a.v.val_names {
+            if vec.len() > 1 {
+                v.num_vals = Some(vec.len() as u64);
+            }
+        }
+        v
+    }
+}
diff --git a/src/args/arg_matcher.rs b/src/args/arg_matcher.rs
new file mode 100644
index 0000000..e1d8067
--- /dev/null
+++ b/src/args/arg_matcher.rs
@@ -0,0 +1,218 @@
+// Std
+use std::collections::hash_map::{Entry, Iter};
+use std::collections::HashMap;
+use std::ffi::OsStr;
+use std::ops::Deref;
+use std::mem;
+
+// Internal
+use args::{ArgMatches, MatchedArg, SubCommand};
+use args::AnyArg;
+use args::settings::ArgSettings;
+
+#[doc(hidden)]
+#[allow(missing_debug_implementations)]
+pub struct ArgMatcher<'a>(pub ArgMatches<'a>);
+
+impl<'a> Default for ArgMatcher<'a> {
+    fn default() -> Self { ArgMatcher(ArgMatches::default()) }
+}
+
+impl<'a> ArgMatcher<'a> {
+    pub fn new() -> Self { ArgMatcher::default() }
+
+    pub fn process_arg_overrides<'b>(&mut self, a: Option<&AnyArg<'a, 'b>>, overrides: &mut Vec<(&'b str, &'a str)>, required: &mut Vec<&'a str>, check_all: bool) {
+        debugln!("ArgMatcher::process_arg_overrides:{:?};", a.map_or(None, |a| Some(a.name())));
+        if let Some(aa) = a {
+            let mut self_done = false;
+            if let Some(a_overrides) = aa.overrides() {
+                for overr in a_overrides {
+                    debugln!("ArgMatcher::process_arg_overrides:iter:{};", overr);
+                    if overr == &aa.name() {
+                        self_done = true;
+                        self.handle_self_overrides(a);
+                    } else if self.is_present(overr) {
+                        debugln!("ArgMatcher::process_arg_overrides:iter:{}: removing from matches;", overr);
+                        self.remove(overr);
+                        for i in (0 .. required.len()).rev() {
+                            if &required[i] == overr {
+                                debugln!("ArgMatcher::process_arg_overrides:iter:{}: removing required;", overr);
+                                required.swap_remove(i);
+                                break;
+                            }
+                        }
+                        overrides.push((overr, aa.name()));
+                    } else {
+                        overrides.push((overr, aa.name()));
+                    }
+                }
+            }
+            if check_all && !self_done {
+                self.handle_self_overrides(a);
+            }
+        }
+    }
+
+    pub fn handle_self_overrides<'b>(&mut self, a: Option<&AnyArg<'a, 'b>>) {
+        debugln!("ArgMatcher::handle_self_overrides:{:?};", a.map_or(None, |a| Some(a.name())));
+        if let Some(aa) = a {
+            if !aa.has_switch() || aa.is_set(ArgSettings::Multiple) {
+                // positional args can't override self or else we would never advance to the next
+
+                // Also flags with --multiple set are ignored otherwise we could never have more
+                // than one
+                return;
+            }
+            if let Some(ma) = self.get_mut(aa.name()) {
+                if ma.vals.len() > 1 {
+                    // swap_remove(0) would be O(1) but does not preserve order, which
+                    // we need
+                    ma.vals.remove(0);
+                    ma.occurs = 1;
+                } else if !aa.takes_value() && ma.occurs > 1 {
+                    ma.occurs = 1;
+                }
+            }
+        }
+    }
+
+    pub fn is_present(&self, name: &str) -> bool {
+        self.0.is_present(name)
+    }
+
+    pub fn propagate_globals(&mut self, global_arg_vec: &[&'a str]) {
+        debugln!( "ArgMatcher::get_global_values: global_arg_vec={:?}", global_arg_vec );
+        let mut vals_map = HashMap::new();
+        self.fill_in_global_values(global_arg_vec, &mut vals_map);
+    }
+
+    fn fill_in_global_values(
+        &mut self,
+        global_arg_vec: &[&'a str],
+        vals_map: &mut HashMap<&'a str, MatchedArg>,
+    ) {
+        for global_arg in global_arg_vec {
+            if let Some(ma) = self.get(global_arg) {
+                // We have to check if the parent's global arg wasn't used but still exists
+                // such as from a default value.
+                //
+                // For example, `myprog subcommand --global-arg=value` where --global-arg defines
+                // a default value of `other` myprog would have an existing MatchedArg for
+                // --global-arg where the value is `other`, however the occurs will be 0.
+                let to_update = if let Some(parent_ma) = vals_map.get(global_arg) {
+                    if parent_ma.occurs > 0 && ma.occurs == 0 {
+                        parent_ma.clone()
+                    } else {
+                        ma.clone()
+                    }
+                } else {
+                    ma.clone()
+                };
+                vals_map.insert(global_arg, to_update);
+            }
+        }
+        if let Some(ref mut sc) = self.0.subcommand {
+            let mut am = ArgMatcher(mem::replace(&mut sc.matches, ArgMatches::new()));
+            am.fill_in_global_values(global_arg_vec, vals_map);
+            mem::swap(&mut am.0, &mut sc.matches);
+        }
+
+        for (name, matched_arg) in vals_map.into_iter() {
+            self.0.args.insert(name, matched_arg.clone());
+        }
+    }
+
+    pub fn get_mut(&mut self, arg: &str) -> Option<&mut MatchedArg> { self.0.args.get_mut(arg) }
+
+    pub fn get(&self, arg: &str) -> Option<&MatchedArg> { self.0.args.get(arg) }
+
+    pub fn remove(&mut self, arg: &str) { self.0.args.remove(arg); }
+
+    pub fn remove_all(&mut self, args: &[&str]) {
+        for &arg in args {
+            self.0.args.remove(arg);
+        }
+    }
+
+    pub fn insert(&mut self, name: &'a str) { self.0.args.insert(name, MatchedArg::new()); }
+
+    pub fn contains(&self, arg: &str) -> bool { self.0.args.contains_key(arg) }
+
+    pub fn is_empty(&self) -> bool { self.0.args.is_empty() }
+
+    pub fn usage(&mut self, usage: String) { self.0.usage = Some(usage); }
+
+    pub fn arg_names(&'a self) -> Vec<&'a str> { self.0.args.keys().map(Deref::deref).collect() }
+
+    pub fn entry(&mut self, arg: &'a str) -> Entry<&'a str, MatchedArg> { self.0.args.entry(arg) }
+
+    pub fn subcommand(&mut self, sc: SubCommand<'a>) { self.0.subcommand = Some(Box::new(sc)); }
+
+    pub fn subcommand_name(&self) -> Option<&str> { self.0.subcommand_name() }
+
+    pub fn iter(&self) -> Iter<&str, MatchedArg> { self.0.args.iter() }
+
+    pub fn inc_occurrence_of(&mut self, arg: &'a str) {
+        debugln!("ArgMatcher::inc_occurrence_of: arg={}", arg);
+        if let Some(a) = self.get_mut(arg) {
+            a.occurs += 1;
+            return;
+        }
+        debugln!("ArgMatcher::inc_occurrence_of: first instance");
+        self.insert(arg);
+    }
+
+    pub fn inc_occurrences_of(&mut self, args: &[&'a str]) {
+        debugln!("ArgMatcher::inc_occurrences_of: args={:?}", args);
+        for arg in args {
+            self.inc_occurrence_of(arg);
+        }
+    }
+
+    pub fn add_val_to(&mut self, arg: &'a str, val: &OsStr) {
+        let ma = self.entry(arg).or_insert(MatchedArg {
+            occurs: 0,
+            indices: Vec::with_capacity(1),
+            vals: Vec::with_capacity(1),
+        });
+        ma.vals.push(val.to_owned());
+    }
+
+    pub fn add_index_to(&mut self, arg: &'a str, idx: usize) {
+        let ma = self.entry(arg).or_insert(MatchedArg {
+            occurs: 0,
+            indices: Vec::with_capacity(1),
+            vals: Vec::new(),
+        });
+        ma.indices.push(idx);
+    }
+
+    pub fn needs_more_vals<'b, A>(&self, o: &A) -> bool
+    where
+        A: AnyArg<'a, 'b>,
+    {
+        debugln!("ArgMatcher::needs_more_vals: o={}", o.name());
+        if let Some(ma) = self.get(o.name()) {
+            if let Some(num) = o.num_vals() {
+                debugln!("ArgMatcher::needs_more_vals: num_vals...{}", num);
+                return if o.is_set(ArgSettings::Multiple) {
+                    ((ma.vals.len() as u64) % num) != 0
+                } else {
+                    num != (ma.vals.len() as u64)
+                };
+            } else if let Some(num) = o.max_vals() {
+                debugln!("ArgMatcher::needs_more_vals: max_vals...{}", num);
+                return !((ma.vals.len() as u64) > num);
+            } else if o.min_vals().is_some() {
+                debugln!("ArgMatcher::needs_more_vals: min_vals...true");
+                return true;
+            }
+            return o.is_set(ArgSettings::Multiple);
+        }
+        true
+    }
+}
+
+impl<'a> Into<ArgMatches<'a>> for ArgMatcher<'a> {
+    fn into(self) -> ArgMatches<'a> { self.0 }
+}
diff --git a/src/args/arg_matches.rs b/src/args/arg_matches.rs
new file mode 100644
index 0000000..6cf70a4
--- /dev/null
+++ b/src/args/arg_matches.rs
@@ -0,0 +1,963 @@
+// Std
+use std::borrow::Cow;
+use std::collections::HashMap;
+use std::ffi::{OsStr, OsString};
+use std::iter::Map;
+use std::slice::Iter;
+
+// Internal
+use INVALID_UTF8;
+use args::MatchedArg;
+use args::SubCommand;
+
+/// Used to get information about the arguments that where supplied to the program at runtime by
+/// the user. New instances of this struct are obtained by using the [`App::get_matches`] family of
+/// methods.
+///
+/// # Examples
+///
+/// ```no_run
+/// # use clap::{App, Arg};
+/// let matches = App::new("MyApp")
+///     .arg(Arg::with_name("out")
+///         .long("output")
+///         .required(true)
+///         .takes_value(true))
+///     .arg(Arg::with_name("debug")
+///         .short("d")
+///         .multiple(true))
+///     .arg(Arg::with_name("cfg")
+///         .short("c")
+///         .takes_value(true))
+///     .get_matches(); // builds the instance of ArgMatches
+///
+/// // to get information about the "cfg" argument we created, such as the value supplied we use
+/// // various ArgMatches methods, such as ArgMatches::value_of
+/// if let Some(c) = matches.value_of("cfg") {
+///     println!("Value for -c: {}", c);
+/// }
+///
+/// // The ArgMatches::value_of method returns an Option because the user may not have supplied
+/// // that argument at runtime. But if we specified that the argument was "required" as we did
+/// // with the "out" argument, we can safely unwrap because `clap` verifies that was actually
+/// // used at runtime.
+/// println!("Value for --output: {}", matches.value_of("out").unwrap());
+///
+/// // You can check the presence of an argument
+/// if matches.is_present("out") {
+///     // Another way to check if an argument was present, or if it occurred multiple times is to
+///     // use occurrences_of() which returns 0 if an argument isn't found at runtime, or the
+///     // number of times that it occurred, if it was. To allow an argument to appear more than
+///     // once, you must use the .multiple(true) method, otherwise it will only return 1 or 0.
+///     if matches.occurrences_of("debug") > 2 {
+///         println!("Debug mode is REALLY on, don't be crazy");
+///     } else {
+///         println!("Debug mode kind of on");
+///     }
+/// }
+/// ```
+/// [`App::get_matches`]: ./struct.App.html#method.get_matches
+#[derive(Debug, Clone)]
+pub struct ArgMatches<'a> {
+    #[doc(hidden)] pub args: HashMap<&'a str, MatchedArg>,
+    #[doc(hidden)] pub subcommand: Option<Box<SubCommand<'a>>>,
+    #[doc(hidden)] pub usage: Option<String>,
+}
+
+impl<'a> Default for ArgMatches<'a> {
+    fn default() -> Self {
+        ArgMatches {
+            args: HashMap::new(),
+            subcommand: None,
+            usage: None,
+        }
+    }
+}
+
+impl<'a> ArgMatches<'a> {
+    #[doc(hidden)]
+    pub fn new() -> Self {
+        ArgMatches {
+            ..Default::default()
+        }
+    }
+
+    /// Gets the value of a specific [option] or [positional] argument (i.e. an argument that takes
+    /// an additional value at runtime). If the option wasn't present at runtime
+    /// it returns `None`.
+    ///
+    /// *NOTE:* If getting a value for an option or positional argument that allows multiples,
+    /// prefer [`ArgMatches::values_of`] as `ArgMatches::value_of` will only return the *first*
+    /// value.
+    ///
+    /// # Panics
+    ///
+    /// This method will [`panic!`] if the value contains invalid UTF-8 code points.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myapp")
+    ///     .arg(Arg::with_name("output")
+    ///         .takes_value(true))
+    ///     .get_matches_from(vec!["myapp", "something"]);
+    ///
+    /// assert_eq!(m.value_of("output"), Some("something"));
+    /// ```
+    /// [option]: ./struct.Arg.html#method.takes_value
+    /// [positional]: ./struct.Arg.html#method.index
+    /// [`ArgMatches::values_of`]: ./struct.ArgMatches.html#method.values_of
+    /// [`panic!`]: https://doc.rust-lang.org/std/macro.panic!.html
+    pub fn value_of<S: AsRef<str>>(&self, name: S) -> Option<&str> {
+        if let Some(arg) = self.args.get(name.as_ref()) {
+            if let Some(v) = arg.vals.get(0) {
+                return Some(v.to_str().expect(INVALID_UTF8));
+            }
+        }
+        None
+    }
+
+    /// Gets the lossy value of a specific argument. If the argument wasn't present at runtime
+    /// it returns `None`. A lossy value is one which contains invalid UTF-8 code points, those
+    /// invalid points will be replaced with `\u{FFFD}`
+    ///
+    /// *NOTE:* If getting a value for an option or positional argument that allows multiples,
+    /// prefer [`Arg::values_of_lossy`] as `value_of_lossy()` will only return the *first* value.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(not(unix), doc = " ```ignore")]
+    #[cfg_attr(unix, doc = " ```")]
+    /// # use clap::{App, Arg};
+    /// use std::ffi::OsString;
+    /// use std::os::unix::ffi::{OsStrExt,OsStringExt};
+    ///
+    /// let m = App::new("utf8")
+    ///     .arg(Arg::from_usage("<arg> 'some arg'"))
+    ///     .get_matches_from(vec![OsString::from("myprog"),
+    ///                             // "Hi {0xe9}!"
+    ///                             OsString::from_vec(vec![b'H', b'i', b' ', 0xe9, b'!'])]);
+    /// assert_eq!(&*m.value_of_lossy("arg").unwrap(), "Hi \u{FFFD}!");
+    /// ```
+    /// [`Arg::values_of_lossy`]: ./struct.ArgMatches.html#method.values_of_lossy
+    pub fn value_of_lossy<S: AsRef<str>>(&'a self, name: S) -> Option<Cow<'a, str>> {
+        if let Some(arg) = self.args.get(name.as_ref()) {
+            if let Some(v) = arg.vals.get(0) {
+                return Some(v.to_string_lossy());
+            }
+        }
+        None
+    }
+
+    /// Gets the OS version of a string value of a specific argument. If the option wasn't present
+    /// at runtime it returns `None`. An OS value on Unix-like systems is any series of bytes,
+    /// regardless of whether or not they contain valid UTF-8 code points. Since [`String`]s in
+    /// Rust are guaranteed to be valid UTF-8, a valid filename on a Unix system as an argument
+    /// value may contain invalid UTF-8 code points.
+    ///
+    /// *NOTE:* If getting a value for an option or positional argument that allows multiples,
+    /// prefer [`ArgMatches::values_of_os`] as `Arg::value_of_os` will only return the *first*
+    /// value.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(not(unix), doc = " ```ignore")]
+    #[cfg_attr(unix, doc = " ```")]
+    /// # use clap::{App, Arg};
+    /// use std::ffi::OsString;
+    /// use std::os::unix::ffi::{OsStrExt,OsStringExt};
+    ///
+    /// let m = App::new("utf8")
+    ///     .arg(Arg::from_usage("<arg> 'some arg'"))
+    ///     .get_matches_from(vec![OsString::from("myprog"),
+    ///                             // "Hi {0xe9}!"
+    ///                             OsString::from_vec(vec![b'H', b'i', b' ', 0xe9, b'!'])]);
+    /// assert_eq!(&*m.value_of_os("arg").unwrap().as_bytes(), [b'H', b'i', b' ', 0xe9, b'!']);
+    /// ```
+    /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html
+    /// [`ArgMatches::values_of_os`]: ./struct.ArgMatches.html#method.values_of_os
+    pub fn value_of_os<S: AsRef<str>>(&self, name: S) -> Option<&OsStr> {
+        self.args
+            .get(name.as_ref())
+            .and_then(|arg| arg.vals.get(0).map(|v| v.as_os_str()))
+    }
+
+    /// Gets a [`Values`] struct which implements [`Iterator`] for values of a specific argument
+    /// (i.e. an argument that takes multiple values at runtime). If the option wasn't present at
+    /// runtime it returns `None`
+    ///
+    /// # Panics
+    ///
+    /// This method will panic if any of the values contain invalid UTF-8 code points.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myprog")
+    ///     .arg(Arg::with_name("output")
+    ///         .multiple(true)
+    ///         .short("o")
+    ///         .takes_value(true))
+    ///     .get_matches_from(vec![
+    ///         "myprog", "-o", "val1", "val2", "val3"
+    ///     ]);
+    /// let vals: Vec<&str> = m.values_of("output").unwrap().collect();
+    /// assert_eq!(vals, ["val1", "val2", "val3"]);
+    /// ```
+    /// [`Values`]: ./struct.Values.html
+    /// [`Iterator`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html
+    pub fn values_of<S: AsRef<str>>(&'a self, name: S) -> Option<Values<'a>> {
+        if let Some(arg) = self.args.get(name.as_ref()) {
+            fn to_str_slice(o: &OsString) -> &str { o.to_str().expect(INVALID_UTF8) }
+            let to_str_slice: fn(&OsString) -> &str = to_str_slice; // coerce to fn pointer
+            return Some(Values {
+                iter: arg.vals.iter().map(to_str_slice),
+            });
+        }
+        None
+    }
+
+    /// Gets the lossy values of a specific argument. If the option wasn't present at runtime
+    /// it returns `None`. A lossy value is one where if it contains invalid UTF-8 code points,
+    /// those invalid points will be replaced with `\u{FFFD}`
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(not(unix), doc = " ```ignore")]
+    #[cfg_attr(unix, doc = " ```")]
+    /// # use clap::{App, Arg};
+    /// use std::ffi::OsString;
+    /// use std::os::unix::ffi::OsStringExt;
+    ///
+    /// let m = App::new("utf8")
+    ///     .arg(Arg::from_usage("<arg>... 'some arg'"))
+    ///     .get_matches_from(vec![OsString::from("myprog"),
+    ///                             // "Hi"
+    ///                             OsString::from_vec(vec![b'H', b'i']),
+    ///                             // "{0xe9}!"
+    ///                             OsString::from_vec(vec![0xe9, b'!'])]);
+    /// let mut itr = m.values_of_lossy("arg").unwrap().into_iter();
+    /// assert_eq!(&itr.next().unwrap()[..], "Hi");
+    /// assert_eq!(&itr.next().unwrap()[..], "\u{FFFD}!");
+    /// assert_eq!(itr.next(), None);
+    /// ```
+    pub fn values_of_lossy<S: AsRef<str>>(&'a self, name: S) -> Option<Vec<String>> {
+        if let Some(arg) = self.args.get(name.as_ref()) {
+            return Some(
+                arg.vals
+                    .iter()
+                    .map(|v| v.to_string_lossy().into_owned())
+                    .collect(),
+            );
+        }
+        None
+    }
+
+    /// Gets a [`OsValues`] struct which is implements [`Iterator`] for [`OsString`] values of a
+    /// specific argument. If the option wasn't present at runtime it returns `None`. An OS value
+    /// on Unix-like systems is any series of bytes, regardless of whether or not they contain
+    /// valid UTF-8 code points. Since [`String`]s in Rust are guaranteed to be valid UTF-8, a valid
+    /// filename as an argument value on Linux (for example) may contain invalid UTF-8 code points.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(not(unix), doc = " ```ignore")]
+    #[cfg_attr(unix, doc = " ```")]
+    /// # use clap::{App, Arg};
+    /// use std::ffi::{OsStr,OsString};
+    /// use std::os::unix::ffi::{OsStrExt,OsStringExt};
+    ///
+    /// let m = App::new("utf8")
+    ///     .arg(Arg::from_usage("<arg>... 'some arg'"))
+    ///     .get_matches_from(vec![OsString::from("myprog"),
+    ///                                 // "Hi"
+    ///                                 OsString::from_vec(vec![b'H', b'i']),
+    ///                                 // "{0xe9}!"
+    ///                                 OsString::from_vec(vec![0xe9, b'!'])]);
+    ///
+    /// let mut itr = m.values_of_os("arg").unwrap().into_iter();
+    /// assert_eq!(itr.next(), Some(OsStr::new("Hi")));
+    /// assert_eq!(itr.next(), Some(OsStr::from_bytes(&[0xe9, b'!'])));
+    /// assert_eq!(itr.next(), None);
+    /// ```
+    /// [`OsValues`]: ./struct.OsValues.html
+    /// [`Iterator`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html
+    /// [`OsString`]: https://doc.rust-lang.org/std/ffi/struct.OsString.html
+    /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html
+    pub fn values_of_os<S: AsRef<str>>(&'a self, name: S) -> Option<OsValues<'a>> {
+        fn to_str_slice(o: &OsString) -> &OsStr { &*o }
+        let to_str_slice: fn(&'a OsString) -> &'a OsStr = to_str_slice; // coerce to fn pointer
+        if let Some(arg) = self.args.get(name.as_ref()) {
+            return Some(OsValues {
+                iter: arg.vals.iter().map(to_str_slice),
+            });
+        }
+        None
+    }
+
+    /// Returns `true` if an argument was present at runtime, otherwise `false`.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myprog")
+    ///     .arg(Arg::with_name("debug")
+    ///         .short("d"))
+    ///     .get_matches_from(vec![
+    ///         "myprog", "-d"
+    ///     ]);
+    ///
+    /// assert!(m.is_present("debug"));
+    /// ```
+    pub fn is_present<S: AsRef<str>>(&self, name: S) -> bool {
+        if let Some(ref sc) = self.subcommand {
+            if sc.name == name.as_ref() {
+                return true;
+            }
+        }
+        self.args.contains_key(name.as_ref())
+    }
+
+    /// Returns the number of times an argument was used at runtime. If an argument isn't present
+    /// it will return `0`.
+    ///
+    /// **NOTE:** This returns the number of times the argument was used, *not* the number of
+    /// values. For example, `-o val1 val2 val3 -o val4` would return `2` (2 occurrences, but 4
+    /// values).
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myprog")
+    ///     .arg(Arg::with_name("debug")
+    ///         .short("d")
+    ///         .multiple(true))
+    ///     .get_matches_from(vec![
+    ///         "myprog", "-d", "-d", "-d"
+    ///     ]);
+    ///
+    /// assert_eq!(m.occurrences_of("debug"), 3);
+    /// ```
+    ///
+    /// This next example shows that counts actual uses of the argument, not just `-`'s
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myprog")
+    ///     .arg(Arg::with_name("debug")
+    ///         .short("d")
+    ///         .multiple(true))
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .get_matches_from(vec![
+    ///         "myprog", "-ddfd"
+    ///     ]);
+    ///
+    /// assert_eq!(m.occurrences_of("debug"), 3);
+    /// assert_eq!(m.occurrences_of("flag"), 1);
+    /// ```
+    pub fn occurrences_of<S: AsRef<str>>(&self, name: S) -> u64 {
+        self.args.get(name.as_ref()).map_or(0, |a| a.occurs)
+    }
+
+    /// Gets the starting index of the argument in respect to all other arguments. Indices are
+    /// similar to argv indices, but are not exactly 1:1.
+    ///
+    /// For flags (i.e. those arguments which don't have an associated value), indices refer
+    /// to occurrence of the switch, such as `-f`, or `--flag`. However, for options the indices
+    /// refer to the *values* `-o val` would therefore not represent two distinct indices, only the
+    /// index for `val` would be recorded. This is by design.
+    ///
+    /// Besides the flag/option descrepancy, the primary difference between an argv index and clap
+    /// index, is that clap continues counting once all arguments have properly seperated, whereas
+    /// an argv index does not.
+    ///
+    /// The examples should clear this up.
+    ///
+    /// *NOTE:* If an argument is allowed multiple times, this method will only give the *first*
+    /// index.
+    ///
+    /// # Examples
+    ///
+    /// The argv indices are listed in the comments below. See how they correspond to the clap
+    /// indices. Note that if it's not listed in a clap index, this is becuase it's not saved in
+    /// in an `ArgMatches` struct for querying.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myapp")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("option")
+    ///         .short("o")
+    ///         .takes_value(true))
+    ///     .get_matches_from(vec!["myapp", "-f", "-o", "val"]);
+    ///             // ARGV idices: ^0       ^1    ^2    ^3
+    ///             // clap idices:          ^1          ^3
+    ///
+    /// assert_eq!(m.index_of("flag"), Some(1));
+    /// assert_eq!(m.index_of("option"), Some(3));
+    /// ```
+    ///
+    /// Now notice, if we use one of the other styles of options:
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myapp")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("option")
+    ///         .short("o")
+    ///         .takes_value(true))
+    ///     .get_matches_from(vec!["myapp", "-f", "-o=val"]);
+    ///             // ARGV idices: ^0       ^1    ^2
+    ///             // clap idices:          ^1       ^3
+    ///
+    /// assert_eq!(m.index_of("flag"), Some(1));
+    /// assert_eq!(m.index_of("option"), Some(3));
+    /// ```
+    ///
+    /// Things become much more complicated, or clear if we look at a more complex combination of
+    /// flags. Let's also throw in the final option style for good measure.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myapp")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("flag2")
+    ///         .short("F"))
+    ///     .arg(Arg::with_name("flag3")
+    ///         .short("z"))
+    ///     .arg(Arg::with_name("option")
+    ///         .short("o")
+    ///         .takes_value(true))
+    ///     .get_matches_from(vec!["myapp", "-fzF", "-oval"]);
+    ///             // ARGV idices: ^0      ^1       ^2
+    ///             // clap idices:         ^1,2,3    ^5
+    ///             //
+    ///             // clap sees the above as 'myapp -f -z -F -o val'
+    ///             //                         ^0    ^1 ^2 ^3 ^4 ^5
+    /// assert_eq!(m.index_of("flag"), Some(1));
+    /// assert_eq!(m.index_of("flag2"), Some(3));
+    /// assert_eq!(m.index_of("flag3"), Some(2));
+    /// assert_eq!(m.index_of("option"), Some(5));
+    /// ```
+    ///
+    /// One final combination of flags/options to see how they combine:
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myapp")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("flag2")
+    ///         .short("F"))
+    ///     .arg(Arg::with_name("flag3")
+    ///         .short("z"))
+    ///     .arg(Arg::with_name("option")
+    ///         .short("o")
+    ///         .takes_value(true)
+    ///         .multiple(true))
+    ///     .get_matches_from(vec!["myapp", "-fzFoval"]);
+    ///             // ARGV idices: ^0       ^1
+    ///             // clap idices:          ^1,2,3^5
+    ///             //
+    ///             // clap sees the above as 'myapp -f -z -F -o val'
+    ///             //                         ^0    ^1 ^2 ^3 ^4 ^5
+    /// assert_eq!(m.index_of("flag"), Some(1));
+    /// assert_eq!(m.index_of("flag2"), Some(3));
+    /// assert_eq!(m.index_of("flag3"), Some(2));
+    /// assert_eq!(m.index_of("option"), Some(5));
+    /// ```
+    ///
+    /// The last part to mention is when values are sent in multiple groups with a [delimiter].
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myapp")
+    ///     .arg(Arg::with_name("option")
+    ///         .short("o")
+    ///         .takes_value(true)
+    ///         .multiple(true))
+    ///     .get_matches_from(vec!["myapp", "-o=val1,val2,val3"]);
+    ///             // ARGV idices: ^0       ^1
+    ///             // clap idices:             ^2   ^3   ^4
+    ///             //
+    ///             // clap sees the above as 'myapp -o val1 val2 val3'
+    ///             //                         ^0    ^1 ^2   ^3   ^4
+    /// assert_eq!(m.index_of("option"), Some(2));
+    /// ```
+    /// [`ArgMatches`]: ./struct.ArgMatches.html
+    /// [delimiter]: ./struct.Arg.html#method.value_delimiter
+    pub fn index_of<S: AsRef<str>>(&self, name: S) -> Option<usize> {
+        if let Some(arg) = self.args.get(name.as_ref()) {
+            if let Some(i) = arg.indices.get(0) {
+                return Some(*i);
+            }
+        }
+        None
+    }
+
+    /// Gets all indices of the argument in respect to all other arguments. Indices are
+    /// similar to argv indices, but are not exactly 1:1.
+    ///
+    /// For flags (i.e. those arguments which don't have an associated value), indices refer
+    /// to occurrence of the switch, such as `-f`, or `--flag`. However, for options the indices
+    /// refer to the *values* `-o val` would therefore not represent two distinct indices, only the
+    /// index for `val` would be recorded. This is by design.
+    ///
+    /// *NOTE:* For more information about how clap indices compare to argv indices, see
+    /// [`ArgMatches::index_of`]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myapp")
+    ///     .arg(Arg::with_name("option")
+    ///         .short("o")
+    ///         .takes_value(true)
+    ///         .use_delimiter(true)
+    ///         .multiple(true))
+    ///     .get_matches_from(vec!["myapp", "-o=val1,val2,val3"]);
+    ///             // ARGV idices: ^0       ^1
+    ///             // clap idices:             ^2   ^3   ^4
+    ///             //
+    ///             // clap sees the above as 'myapp -o val1 val2 val3'
+    ///             //                         ^0    ^1 ^2   ^3   ^4
+    /// assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2, 3, 4]);
+    /// ```
+    ///
+    /// Another quick example is when flags and options are used together
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myapp")
+    ///     .arg(Arg::with_name("option")
+    ///         .short("o")
+    ///         .takes_value(true)
+    ///         .multiple(true))
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f")
+    ///         .multiple(true))
+    ///     .get_matches_from(vec!["myapp", "-o", "val1", "-f", "-o", "val2", "-f"]);
+    ///             // ARGV idices: ^0       ^1    ^2      ^3    ^4    ^5      ^6
+    ///             // clap idices:                ^2      ^3          ^5      ^6
+    ///
+    /// assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2, 5]);
+    /// assert_eq!(m.indices_of("flag").unwrap().collect::<Vec<_>>(), &[3, 6]);
+    /// ```
+    ///
+    /// One final example, which is an odd case; if we *don't* use  value delimiter as we did with
+    /// the first example above instead of `val1`, `val2` and `val3` all being distinc values, they
+    /// would all be a single value of `val1,val2,val3`, in which case case they'd only receive a
+    /// single index.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg};
+    /// let m = App::new("myapp")
+    ///     .arg(Arg::with_name("option")
+    ///         .short("o")
+    ///         .takes_value(true)
+    ///         .multiple(true))
+    ///     .get_matches_from(vec!["myapp", "-o=val1,val2,val3"]);
+    ///             // ARGV idices: ^0       ^1
+    ///             // clap idices:             ^2
+    ///             //
+    ///             // clap sees the above as 'myapp -o "val1,val2,val3"'
+    ///             //                         ^0    ^1  ^2
+    /// assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2]);
+    /// ```
+    /// [`ArgMatches`]: ./struct.ArgMatches.html
+    /// [`ArgMatches::index_of`]: ./struct.ArgMatches.html#method.index_of
+    /// [delimiter]: ./struct.Arg.html#method.value_delimiter
+    pub fn indices_of<S: AsRef<str>>(&'a self, name: S) -> Option<Indices<'a>> {
+        if let Some(arg) = self.args.get(name.as_ref()) {
+            fn to_usize(i: &usize) -> usize { *i }
+            let to_usize: fn(&usize) -> usize = to_usize; // coerce to fn pointer
+            return Some(Indices {
+                iter: arg.indices.iter().map(to_usize),
+            });
+        }
+        None
+    }
+
+    /// Because [`Subcommand`]s are essentially "sub-[`App`]s" they have their own [`ArgMatches`]
+    /// as well. This method returns the [`ArgMatches`] for a particular subcommand or `None` if
+    /// the subcommand wasn't present at runtime.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, SubCommand};
+    /// let app_m = App::new("myprog")
+    ///     .arg(Arg::with_name("debug")
+    ///         .short("d"))
+    ///     .subcommand(SubCommand::with_name("test")
+    ///         .arg(Arg::with_name("opt")
+    ///             .long("option")
+    ///             .takes_value(true)))
+    ///     .get_matches_from(vec![
+    ///         "myprog", "-d", "test", "--option", "val"
+    ///     ]);
+    ///
+    /// // Both parent commands, and child subcommands can have arguments present at the same times
+    /// assert!(app_m.is_present("debug"));
+    ///
+    /// // Get the subcommand's ArgMatches instance
+    /// if let Some(sub_m) = app_m.subcommand_matches("test") {
+    ///     // Use the struct like normal
+    ///     assert_eq!(sub_m.value_of("opt"), Some("val"));
+    /// }
+    /// ```
+    /// [`Subcommand`]: ./struct.SubCommand.html
+    /// [`App`]: ./struct.App.html
+    /// [`ArgMatches`]: ./struct.ArgMatches.html
+    pub fn subcommand_matches<S: AsRef<str>>(&self, name: S) -> Option<&ArgMatches<'a>> {
+        if let Some(ref s) = self.subcommand {
+            if s.name == name.as_ref() {
+                return Some(&s.matches);
+            }
+        }
+        None
+    }
+
+    /// Because [`Subcommand`]s are essentially "sub-[`App`]s" they have their own [`ArgMatches`]
+    /// as well.But simply getting the sub-[`ArgMatches`] doesn't help much if we don't also know
+    /// which subcommand was actually used. This method returns the name of the subcommand that was
+    /// used at runtime, or `None` if one wasn't.
+    ///
+    /// *NOTE*: Subcommands form a hierarchy, where multiple subcommands can be used at runtime,
+    /// but only a single subcommand from any group of sibling commands may used at once.
+    ///
+    /// An ASCII art depiction may help explain this better...Using a fictional version of `git` as
+    /// the demo subject. Imagine the following are all subcommands of `git` (note, the author is
+    /// aware these aren't actually all subcommands in the real `git` interface, but it makes
+    /// explanation easier)
+    ///
+    /// ```notrust
+    ///              Top Level App (git)                         TOP
+    ///                              |
+    ///       -----------------------------------------
+    ///      /             |                \          \
+    ///   clone          push              add       commit      LEVEL 1
+    ///     |           /    \            /    \       |
+    ///    url      origin   remote    ref    name   message     LEVEL 2
+    ///             /                  /\
+    ///          path            remote  local                   LEVEL 3
+    /// ```
+    ///
+    /// Given the above fictional subcommand hierarchy, valid runtime uses would be (not an all
+    /// inclusive list, and not including argument options per command for brevity and clarity):
+    ///
+    /// ```sh
+    /// $ git clone url
+    /// $ git push origin path
+    /// $ git add ref local
+    /// $ git commit message
+    /// ```
+    ///
+    /// Notice only one command per "level" may be used. You could not, for example, do `$ git
+    /// clone url push origin path`
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand};
+    ///  let app_m = App::new("git")
+    ///      .subcommand(SubCommand::with_name("clone"))
+    ///      .subcommand(SubCommand::with_name("push"))
+    ///      .subcommand(SubCommand::with_name("commit"))
+    ///      .get_matches();
+    ///
+    /// match app_m.subcommand_name() {
+    ///     Some("clone")  => {}, // clone was used
+    ///     Some("push")   => {}, // push was used
+    ///     Some("commit") => {}, // commit was used
+    ///     _              => {}, // Either no subcommand or one not tested for...
+    /// }
+    /// ```
+    /// [`Subcommand`]: ./struct.SubCommand.html
+    /// [`App`]: ./struct.App.html
+    /// [`ArgMatches`]: ./struct.ArgMatches.html
+    pub fn subcommand_name(&self) -> Option<&str> {
+        self.subcommand.as_ref().map(|sc| &sc.name[..])
+    }
+
+    /// This brings together [`ArgMatches::subcommand_matches`] and [`ArgMatches::subcommand_name`]
+    /// by returning a tuple with both pieces of information.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand};
+    ///  let app_m = App::new("git")
+    ///      .subcommand(SubCommand::with_name("clone"))
+    ///      .subcommand(SubCommand::with_name("push"))
+    ///      .subcommand(SubCommand::with_name("commit"))
+    ///      .get_matches();
+    ///
+    /// match app_m.subcommand() {
+    ///     ("clone",  Some(sub_m)) => {}, // clone was used
+    ///     ("push",   Some(sub_m)) => {}, // push was used
+    ///     ("commit", Some(sub_m)) => {}, // commit was used
+    ///     _                       => {}, // Either no subcommand or one not tested for...
+    /// }
+    /// ```
+    ///
+    /// Another useful scenario is when you want to support third party, or external, subcommands.
+    /// In these cases you can't know the subcommand name ahead of time, so use a variable instead
+    /// with pattern matching!
+    ///
+    /// ```rust
+    /// # use clap::{App, AppSettings};
+    /// // Assume there is an external subcommand named "subcmd"
+    /// let app_m = App::new("myprog")
+    ///     .setting(AppSettings::AllowExternalSubcommands)
+    ///     .get_matches_from(vec![
+    ///         "myprog", "subcmd", "--option", "value", "-fff", "--flag"
+    ///     ]);
+    ///
+    /// // All trailing arguments will be stored under the subcommand's sub-matches using an empty
+    /// // string argument name
+    /// match app_m.subcommand() {
+    ///     (external, Some(sub_m)) => {
+    ///          let ext_args: Vec<&str> = sub_m.values_of("").unwrap().collect();
+    ///          assert_eq!(external, "subcmd");
+    ///          assert_eq!(ext_args, ["--option", "value", "-fff", "--flag"]);
+    ///     },
+    ///     _ => {},
+    /// }
+    /// ```
+    /// [`ArgMatches::subcommand_matches`]: ./struct.ArgMatches.html#method.subcommand_matches
+    /// [`ArgMatches::subcommand_name`]: ./struct.ArgMatches.html#method.subcommand_name
+    pub fn subcommand(&self) -> (&str, Option<&ArgMatches<'a>>) {
+        self.subcommand
+            .as_ref()
+            .map_or(("", None), |sc| (&sc.name[..], Some(&sc.matches)))
+    }
+
+    /// Returns a string slice of the usage statement for the [`App`] or [`SubCommand`]
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg, SubCommand};
+    /// let app_m = App::new("myprog")
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches();
+    ///
+    /// println!("{}", app_m.usage());
+    /// ```
+    /// [`Subcommand`]: ./struct.SubCommand.html
+    /// [`App`]: ./struct.App.html
+    pub fn usage(&self) -> &str { self.usage.as_ref().map_or("", |u| &u[..]) }
+}
+
+
+// The following were taken and adapated from vec_map source
+// repo: https://github.com/contain-rs/vec-map
+// commit: be5e1fa3c26e351761b33010ddbdaf5f05dbcc33
+// license: MIT - Copyright (c) 2015 The Rust Project Developers
+
+/// An iterator for getting multiple values out of an argument via the [`ArgMatches::values_of`]
+/// method.
+///
+/// # Examples
+///
+/// ```rust
+/// # use clap::{App, Arg};
+/// let m = App::new("myapp")
+///     .arg(Arg::with_name("output")
+///         .short("o")
+///         .multiple(true)
+///         .takes_value(true))
+///     .get_matches_from(vec!["myapp", "-o", "val1", "val2"]);
+///
+/// let mut values = m.values_of("output").unwrap();
+///
+/// assert_eq!(values.next(), Some("val1"));
+/// assert_eq!(values.next(), Some("val2"));
+/// assert_eq!(values.next(), None);
+/// ```
+/// [`ArgMatches::values_of`]: ./struct.ArgMatches.html#method.values_of
+#[derive(Debug, Clone)]
+pub struct Values<'a> {
+    iter: Map<Iter<'a, OsString>, fn(&'a OsString) -> &'a str>,
+}
+
+impl<'a> Iterator for Values<'a> {
+    type Item = &'a str;
+
+    fn next(&mut self) -> Option<&'a str> { self.iter.next() }
+    fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
+}
+
+impl<'a> DoubleEndedIterator for Values<'a> {
+    fn next_back(&mut self) -> Option<&'a str> { self.iter.next_back() }
+}
+
+impl<'a> ExactSizeIterator for Values<'a> {}
+
+/// Creates an empty iterator.
+impl<'a> Default for Values<'a> {
+    fn default() -> Self {
+        static EMPTY: [OsString; 0] = [];
+        // This is never called because the iterator is empty:
+        fn to_str_slice(_: &OsString) -> &str { unreachable!() };
+        Values {
+            iter: EMPTY[..].iter().map(to_str_slice),
+        }
+    }
+}
+
+/// An iterator for getting multiple values out of an argument via the [`ArgMatches::values_of_os`]
+/// method. Usage of this iterator allows values which contain invalid UTF-8 code points unlike
+/// [`Values`].
+///
+/// # Examples
+///
+#[cfg_attr(not(unix), doc = " ```ignore")]
+#[cfg_attr(unix, doc = " ```")]
+/// # use clap::{App, Arg};
+/// use std::ffi::OsString;
+/// use std::os::unix::ffi::{OsStrExt,OsStringExt};
+///
+/// let m = App::new("utf8")
+///     .arg(Arg::from_usage("<arg> 'some arg'"))
+///     .get_matches_from(vec![OsString::from("myprog"),
+///                             // "Hi {0xe9}!"
+///                             OsString::from_vec(vec![b'H', b'i', b' ', 0xe9, b'!'])]);
+/// assert_eq!(&*m.value_of_os("arg").unwrap().as_bytes(), [b'H', b'i', b' ', 0xe9, b'!']);
+/// ```
+/// [`ArgMatches::values_of_os`]: ./struct.ArgMatches.html#method.values_of_os
+/// [`Values`]: ./struct.Values.html
+#[derive(Debug, Clone)]
+pub struct OsValues<'a> {
+    iter: Map<Iter<'a, OsString>, fn(&'a OsString) -> &'a OsStr>,
+}
+
+impl<'a> Iterator for OsValues<'a> {
+    type Item = &'a OsStr;
+
+    fn next(&mut self) -> Option<&'a OsStr> { self.iter.next() }
+    fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
+}
+
+impl<'a> DoubleEndedIterator for OsValues<'a> {
+    fn next_back(&mut self) -> Option<&'a OsStr> { self.iter.next_back() }
+}
+
+impl<'a> ExactSizeIterator for OsValues<'a> {}
+
+/// Creates an empty iterator.
+impl<'a> Default for OsValues<'a> {
+    fn default() -> Self {
+        static EMPTY: [OsString; 0] = [];
+        // This is never called because the iterator is empty:
+        fn to_str_slice(_: &OsString) -> &OsStr { unreachable!() };
+        OsValues {
+            iter: EMPTY[..].iter().map(to_str_slice),
+        }
+    }
+}
+
+/// An iterator for getting multiple indices out of an argument via the [`ArgMatches::indices_of`]
+/// method.
+///
+/// # Examples
+///
+/// ```rust
+/// # use clap::{App, Arg};
+/// let m = App::new("myapp")
+///     .arg(Arg::with_name("output")
+///         .short("o")
+///         .multiple(true)
+///         .takes_value(true))
+///     .get_matches_from(vec!["myapp", "-o", "val1", "val2"]);
+///
+/// let mut indices = m.indices_of("output").unwrap();
+///
+/// assert_eq!(indices.next(), Some(2));
+/// assert_eq!(indices.next(), Some(3));
+/// assert_eq!(indices.next(), None);
+/// ```
+/// [`ArgMatches::indices_of`]: ./struct.ArgMatches.html#method.indices_of
+#[derive(Debug, Clone)]
+pub struct Indices<'a> { // would rather use '_, but: https://github.com/rust-lang/rust/issues/48469
+    iter: Map<Iter<'a, usize>, fn(&'a usize) -> usize>,
+}
+
+impl<'a> Iterator for Indices<'a> {
+    type Item = usize;
+
+    fn next(&mut self) -> Option<usize> { self.iter.next() }
+    fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
+}
+
+impl<'a> DoubleEndedIterator for Indices<'a> {
+    fn next_back(&mut self) -> Option<usize> { self.iter.next_back() }
+}
+
+impl<'a> ExactSizeIterator for Indices<'a> {}
+
+/// Creates an empty iterator.
+impl<'a> Default for Indices<'a> {
+    fn default() -> Self {
+        static EMPTY: [usize; 0] = [];
+        // This is never called because the iterator is empty:
+        fn to_usize(_: &usize) -> usize { unreachable!() };
+        Indices {
+            iter: EMPTY[..].iter().map(to_usize),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_default_values() {
+        let mut values: Values = Values::default();
+        assert_eq!(values.next(), None);
+    }
+
+    #[test]
+    fn test_default_values_with_shorter_lifetime() {
+        let matches = ArgMatches::new();
+        let mut values = matches.values_of("").unwrap_or_default();
+        assert_eq!(values.next(), None);
+    }
+
+    #[test]
+    fn test_default_osvalues() {
+        let mut values: OsValues = OsValues::default();
+        assert_eq!(values.next(), None);
+    }
+
+    #[test]
+    fn test_default_osvalues_with_shorter_lifetime() {
+        let matches = ArgMatches::new();
+        let mut values = matches.values_of_os("").unwrap_or_default();
+        assert_eq!(values.next(), None);
+    }
+
+    #[test]
+    fn test_default_indices() {
+        let mut indices: Indices = Indices::default();
+        assert_eq!(indices.next(), None);
+    }
+
+    #[test]
+    fn test_default_indices_with_shorter_lifetime() {
+        let matches = ArgMatches::new();
+        let mut indices = matches.indices_of("").unwrap_or_default();
+        assert_eq!(indices.next(), None);
+    }
+}
diff --git a/src/args/group.rs b/src/args/group.rs
new file mode 100644
index 0000000..f8bfb7a
--- /dev/null
+++ b/src/args/group.rs
@@ -0,0 +1,635 @@
+#[cfg(feature = "yaml")]
+use std::collections::BTreeMap;
+use std::fmt::{Debug, Formatter, Result};
+
+#[cfg(feature = "yaml")]
+use yaml_rust::Yaml;
+
+/// `ArgGroup`s are a family of related [arguments] and way for you to express, "Any of these
+/// arguments". By placing arguments in a logical group, you can create easier requirement and
+/// exclusion rules instead of having to list each argument individually, or when you want a rule
+/// to apply "any but not all" arguments.
+///
+/// For instance, you can make an entire `ArgGroup` required. If [`ArgGroup::multiple(true)`] is
+/// set, this means that at least one argument from that group must be present. If
+/// [`ArgGroup::multiple(false)`] is set (the default), one and *only* one must be present.
+///
+/// You can also do things such as name an entire `ArgGroup` as a [conflict] or [requirement] for
+/// another argument, meaning any of the arguments that belong to that group will cause a failure
+/// if present, or must present respectively.
+///
+/// Perhaps the most common use of `ArgGroup`s is to require one and *only* one argument to be
+/// present out of a given set. Imagine that you had multiple arguments, and you want one of them
+/// to be required, but making all of them required isn't feasible because perhaps they conflict
+/// with each other. For example, lets say that you were building an application where one could
+/// set a given version number by supplying a string with an option argument, i.e.
+/// `--set-ver v1.2.3`, you also wanted to support automatically using a previous version number
+/// and simply incrementing one of the three numbers. So you create three flags `--major`,
+/// `--minor`, and `--patch`. All of these arguments shouldn't be used at one time but you want to
+/// specify that *at least one* of them is used. For this, you can create a group.
+///
+/// Finally, you may use `ArgGroup`s to pull a value from a group of arguments when you don't care
+/// exactly which argument was actually used at runtime.
+///
+/// # Examples
+///
+/// The following example demonstrates using an `ArgGroup` to ensure that one, and only one, of
+/// the arguments from the specified group is present at runtime.
+///
+/// ```rust
+/// # use clap::{App, ArgGroup, ErrorKind};
+/// let result = App::new("app")
+///     .args_from_usage(
+///         "--set-ver [ver] 'set the version manually'
+///          --major         'auto increase major'
+///          --minor         'auto increase minor'
+///          --patch         'auto increase patch'")
+///     .group(ArgGroup::with_name("vers")
+///          .args(&["set-ver", "major", "minor", "patch"])
+///          .required(true))
+///     .get_matches_from_safe(vec!["app", "--major", "--patch"]);
+/// // Because we used two args in the group it's an error
+/// assert!(result.is_err());
+/// let err = result.unwrap_err();
+/// assert_eq!(err.kind, ErrorKind::ArgumentConflict);
+/// ```
+/// This next example shows a passing parse of the same scenario
+///
+/// ```rust
+/// # use clap::{App, ArgGroup};
+/// let result = App::new("app")
+///     .args_from_usage(
+///         "--set-ver [ver] 'set the version manually'
+///          --major         'auto increase major'
+///          --minor         'auto increase minor'
+///          --patch         'auto increase patch'")
+///     .group(ArgGroup::with_name("vers")
+///          .args(&["set-ver", "major", "minor","patch"])
+///          .required(true))
+///     .get_matches_from_safe(vec!["app", "--major"]);
+/// assert!(result.is_ok());
+/// let matches = result.unwrap();
+/// // We may not know which of the args was used, so we can test for the group...
+/// assert!(matches.is_present("vers"));
+/// // we could also alternatively check each arg individually (not shown here)
+/// ```
+/// [`ArgGroup::multiple(true)`]: ./struct.ArgGroup.html#method.multiple
+/// [arguments]: ./struct.Arg.html
+/// [conflict]: ./struct.Arg.html#method.conflicts_with
+/// [requirement]: ./struct.Arg.html#method.requires
+#[derive(Default)]
+pub struct ArgGroup<'a> {
+    #[doc(hidden)] pub name: &'a str,
+    #[doc(hidden)] pub args: Vec<&'a str>,
+    #[doc(hidden)] pub required: bool,
+    #[doc(hidden)] pub requires: Option<Vec<&'a str>>,
+    #[doc(hidden)] pub conflicts: Option<Vec<&'a str>>,
+    #[doc(hidden)] pub multiple: bool,
+}
+
+impl<'a> ArgGroup<'a> {
+    /// Creates a new instance of `ArgGroup` using a unique string name. The name will be used to
+    /// get values from the group or refer to the group inside of conflict and requirement rules.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, ArgGroup};
+    /// ArgGroup::with_name("config")
+    /// # ;
+    /// ```
+    pub fn with_name(n: &'a str) -> Self {
+        ArgGroup {
+            name: n,
+            required: false,
+            args: vec![],
+            requires: None,
+            conflicts: None,
+            multiple: false,
+        }
+    }
+
+    /// Creates a new instance of `ArgGroup` from a .yml (YAML) file.
+    ///
+    /// # Examples
+    ///
+    /// ```ignore
+    /// # #[macro_use]
+    /// # extern crate clap;
+    /// # use clap::ArgGroup;
+    /// # fn main() {
+    /// let yml = load_yaml!("group.yml");
+    /// let ag = ArgGroup::from_yaml(yml);
+    /// # }
+    /// ```
+    #[cfg(feature = "yaml")]
+    pub fn from_yaml(y: &'a Yaml) -> ArgGroup<'a> { ArgGroup::from(y.as_hash().unwrap()) }
+
+    /// Adds an [argument] to this group by name
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ArgGroup};
+    /// let m = App::new("myprog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("color")
+    ///         .short("c"))
+    ///     .group(ArgGroup::with_name("req_flags")
+    ///         .arg("flag")
+    ///         .arg("color"))
+    ///     .get_matches_from(vec!["myprog", "-f"]);
+    /// // maybe we don't know which of the two flags was used...
+    /// assert!(m.is_present("req_flags"));
+    /// // but we can also check individually if needed
+    /// assert!(m.is_present("flag"));
+    /// ```
+    /// [argument]: ./struct.Arg.html
+    #[cfg_attr(feature = "lints", allow(should_assert_eq))]
+    pub fn arg(mut self, n: &'a str) -> Self {
+        assert!(
+            self.name != n,
+            "ArgGroup '{}' can not have same name as arg inside it",
+            &*self.name
+        );
+        self.args.push(n);
+        self
+    }
+
+    /// Adds multiple [arguments] to this group by name
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ArgGroup};
+    /// let m = App::new("myprog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("color")
+    ///         .short("c"))
+    ///     .group(ArgGroup::with_name("req_flags")
+    ///         .args(&["flag", "color"]))
+    ///     .get_matches_from(vec!["myprog", "-f"]);
+    /// // maybe we don't know which of the two flags was used...
+    /// assert!(m.is_present("req_flags"));
+    /// // but we can also check individually if needed
+    /// assert!(m.is_present("flag"));
+    /// ```
+    /// [arguments]: ./struct.Arg.html
+    pub fn args(mut self, ns: &[&'a str]) -> Self {
+        for n in ns {
+            self = self.arg(n);
+        }
+        self
+    }
+
+    /// Allows more than one of the ['Arg']s in this group to be used. (Default: `false`)
+    ///
+    /// # Examples
+    ///
+    /// Notice in this example we use *both* the `-f` and `-c` flags which are both part of the
+    /// group
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ArgGroup};
+    /// let m = App::new("myprog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("color")
+    ///         .short("c"))
+    ///     .group(ArgGroup::with_name("req_flags")
+    ///         .args(&["flag", "color"])
+    ///         .multiple(true))
+    ///     .get_matches_from(vec!["myprog", "-f", "-c"]);
+    /// // maybe we don't know which of the two flags was used...
+    /// assert!(m.is_present("req_flags"));
+    /// ```
+    /// In this next example, we show the default behavior (i.e. `multiple(false)) which will throw
+    /// an error if more than one of the args in the group was used.
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ArgGroup, ErrorKind};
+    /// let result = App::new("myprog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("color")
+    ///         .short("c"))
+    ///     .group(ArgGroup::with_name("req_flags")
+    ///         .args(&["flag", "color"]))
+    ///     .get_matches_from_safe(vec!["myprog", "-f", "-c"]);
+    /// // Because we used both args in the group it's an error
+    /// assert!(result.is_err());
+    /// let err = result.unwrap_err();
+    /// assert_eq!(err.kind, ErrorKind::ArgumentConflict);
+    /// ```
+    /// ['Arg']: ./struct.Arg.html
+    pub fn multiple(mut self, m: bool) -> Self {
+        self.multiple = m;
+        self
+    }
+
+    /// Sets the group as required or not. A required group will be displayed in the usage string
+    /// of the application in the format `<arg|arg2|arg3>`. A required `ArgGroup` simply states
+    /// that one argument from this group *must* be present at runtime (unless
+    /// conflicting with another argument).
+    ///
+    /// **NOTE:** This setting only applies to the current [`App`] / [`SubCommand`], and not
+    /// globally.
+    ///
+    /// **NOTE:** By default, [`ArgGroup::multiple`] is set to `false` which when combined with
+    /// `ArgGroup::required(true)` states, "One and *only one* arg must be used from this group.
+    /// Use of more than one arg is an error." Vice setting `ArgGroup::multiple(true)` which
+    /// states, '*At least* one arg from this group must be used. Using multiple is OK."
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ArgGroup, ErrorKind};
+    /// let result = App::new("myprog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("color")
+    ///         .short("c"))
+    ///     .group(ArgGroup::with_name("req_flags")
+    ///         .args(&["flag", "color"])
+    ///         .required(true))
+    ///     .get_matches_from_safe(vec!["myprog"]);
+    /// // Because we didn't use any of the args in the group, it's an error
+    /// assert!(result.is_err());
+    /// let err = result.unwrap_err();
+    /// assert_eq!(err.kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [`App`]: ./struct.App.html
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`ArgGroup::multiple`]: ./struct.ArgGroup.html#method.multiple
+    pub fn required(mut self, r: bool) -> Self {
+        self.required = r;
+        self
+    }
+
+    /// Sets the requirement rules of this group. This is not to be confused with a
+    /// [required group]. Requirement rules function just like [argument requirement rules], you
+    /// can name other arguments or groups that must be present when any one of the arguments from
+    /// this group is used.
+    ///
+    /// **NOTE:** The name provided may be an argument, or group name
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ArgGroup, ErrorKind};
+    /// let result = App::new("myprog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("color")
+    ///         .short("c"))
+    ///     .arg(Arg::with_name("debug")
+    ///         .short("d"))
+    ///     .group(ArgGroup::with_name("req_flags")
+    ///         .args(&["flag", "color"])
+    ///         .requires("debug"))
+    ///     .get_matches_from_safe(vec!["myprog", "-c"]);
+    /// // because we used an arg from the group, and the group requires "-d" to be used, it's an
+    /// // error
+    /// assert!(result.is_err());
+    /// let err = result.unwrap_err();
+    /// assert_eq!(err.kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [required group]: ./struct.ArgGroup.html#method.required
+    /// [argument requirement rules]: ./struct.Arg.html#method.requires
+    pub fn requires(mut self, n: &'a str) -> Self {
+        if let Some(ref mut reqs) = self.requires {
+            reqs.push(n);
+        } else {
+            self.requires = Some(vec![n]);
+        }
+        self
+    }
+
+    /// Sets the requirement rules of this group. This is not to be confused with a
+    /// [required group]. Requirement rules function just like [argument requirement rules], you
+    /// can name other arguments or groups that must be present when one of the arguments from this
+    /// group is used.
+    ///
+    /// **NOTE:** The names provided may be an argument, or group name
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ArgGroup, ErrorKind};
+    /// let result = App::new("myprog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("color")
+    ///         .short("c"))
+    ///     .arg(Arg::with_name("debug")
+    ///         .short("d"))
+    ///     .arg(Arg::with_name("verb")
+    ///         .short("v"))
+    ///     .group(ArgGroup::with_name("req_flags")
+    ///         .args(&["flag", "color"])
+    ///         .requires_all(&["debug", "verb"]))
+    ///     .get_matches_from_safe(vec!["myprog", "-c", "-d"]);
+    /// // because we used an arg from the group, and the group requires "-d" and "-v" to be used,
+    /// // yet we only used "-d" it's an error
+    /// assert!(result.is_err());
+    /// let err = result.unwrap_err();
+    /// assert_eq!(err.kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    /// [required group]: ./struct.ArgGroup.html#method.required
+    /// [argument requirement rules]: ./struct.Arg.html#method.requires_all
+    pub fn requires_all(mut self, ns: &[&'a str]) -> Self {
+        for n in ns {
+            self = self.requires(n);
+        }
+        self
+    }
+
+    /// Sets the exclusion rules of this group. Exclusion (aka conflict) rules function just like
+    /// [argument exclusion rules], you can name other arguments or groups that must *not* be
+    /// present when one of the arguments from this group are used.
+    ///
+    /// **NOTE:** The name provided may be an argument, or group name
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ArgGroup, ErrorKind};
+    /// let result = App::new("myprog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("color")
+    ///         .short("c"))
+    ///     .arg(Arg::with_name("debug")
+    ///         .short("d"))
+    ///     .group(ArgGroup::with_name("req_flags")
+    ///         .args(&["flag", "color"])
+    ///         .conflicts_with("debug"))
+    ///     .get_matches_from_safe(vec!["myprog", "-c", "-d"]);
+    /// // because we used an arg from the group, and the group conflicts with "-d", it's an error
+    /// assert!(result.is_err());
+    /// let err = result.unwrap_err();
+    /// assert_eq!(err.kind, ErrorKind::ArgumentConflict);
+    /// ```
+    /// [argument exclusion rules]: ./struct.Arg.html#method.conflicts_with
+    pub fn conflicts_with(mut self, n: &'a str) -> Self {
+        if let Some(ref mut confs) = self.conflicts {
+            confs.push(n);
+        } else {
+            self.conflicts = Some(vec![n]);
+        }
+        self
+    }
+
+    /// Sets the exclusion rules of this group. Exclusion rules function just like
+    /// [argument exclusion rules], you can name other arguments or groups that must *not* be
+    /// present when one of the arguments from this group are used.
+    ///
+    /// **NOTE:** The names provided may be an argument, or group name
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ArgGroup, ErrorKind};
+    /// let result = App::new("myprog")
+    ///     .arg(Arg::with_name("flag")
+    ///         .short("f"))
+    ///     .arg(Arg::with_name("color")
+    ///         .short("c"))
+    ///     .arg(Arg::with_name("debug")
+    ///         .short("d"))
+    ///     .arg(Arg::with_name("verb")
+    ///         .short("v"))
+    ///     .group(ArgGroup::with_name("req_flags")
+    ///         .args(&["flag", "color"])
+    ///         .conflicts_with_all(&["debug", "verb"]))
+    ///     .get_matches_from_safe(vec!["myprog", "-c", "-v"]);
+    /// // because we used an arg from the group, and the group conflicts with either "-v" or "-d"
+    /// // it's an error
+    /// assert!(result.is_err());
+    /// let err = result.unwrap_err();
+    /// assert_eq!(err.kind, ErrorKind::ArgumentConflict);
+    /// ```
+    /// [argument exclusion rules]: ./struct.Arg.html#method.conflicts_with_all
+    pub fn conflicts_with_all(mut self, ns: &[&'a str]) -> Self {
+        for n in ns {
+            self = self.conflicts_with(n);
+        }
+        self
+    }
+}
+
+impl<'a> Debug for ArgGroup<'a> {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        write!(
+            f,
+            "{{\n\
+             \tname: {:?},\n\
+             \targs: {:?},\n\
+             \trequired: {:?},\n\
+             \trequires: {:?},\n\
+             \tconflicts: {:?},\n\
+             }}",
+            self.name,
+            self.args,
+            self.required,
+            self.requires,
+            self.conflicts
+        )
+    }
+}
+
+impl<'a, 'z> From<&'z ArgGroup<'a>> for ArgGroup<'a> {
+    fn from(g: &'z ArgGroup<'a>) -> Self {
+        ArgGroup {
+            name: g.name,
+            required: g.required,
+            args: g.args.clone(),
+            requires: g.requires.clone(),
+            conflicts: g.conflicts.clone(),
+            multiple: g.multiple,
+        }
+    }
+}
+
+#[cfg(feature = "yaml")]
+impl<'a> From<&'a BTreeMap<Yaml, Yaml>> for ArgGroup<'a> {
+    fn from(b: &'a BTreeMap<Yaml, Yaml>) -> Self {
+        // We WANT this to panic on error...so expect() is good.
+        let mut a = ArgGroup::default();
+        let group_settings = if b.len() == 1 {
+            let name_yml = b.keys().nth(0).expect("failed to get name");
+            let name_str = name_yml
+                .as_str()
+                .expect("failed to convert arg YAML name to str");
+            a.name = name_str;
+            b.get(name_yml)
+                .expect("failed to get name_str")
+                .as_hash()
+                .expect("failed to convert to a hash")
+        } else {
+            b
+        };
+
+        for (k, v) in group_settings {
+            a = match k.as_str().unwrap() {
+                "required" => a.required(v.as_bool().unwrap()),
+                "multiple" => a.multiple(v.as_bool().unwrap()),
+                "args" => yaml_vec_or_str!(v, a, arg),
+                "arg" => {
+                    if let Some(ys) = v.as_str() {
+                        a = a.arg(ys);
+                    }
+                    a
+                }
+                "requires" => yaml_vec_or_str!(v, a, requires),
+                "conflicts_with" => yaml_vec_or_str!(v, a, conflicts_with),
+                "name" => {
+                    if let Some(ys) = v.as_str() {
+                        a.name = ys;
+                    }
+                    a
+                }
+                s => panic!(
+                    "Unknown ArgGroup setting '{}' in YAML file for \
+                     ArgGroup '{}'",
+                    s,
+                    a.name
+                ),
+            }
+        }
+
+        a
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::ArgGroup;
+    #[cfg(feature = "yaml")]
+    use yaml_rust::YamlLoader;
+
+    #[test]
+    fn groups() {
+        let g = ArgGroup::with_name("test")
+            .arg("a1")
+            .arg("a4")
+            .args(&["a2", "a3"])
+            .required(true)
+            .conflicts_with("c1")
+            .conflicts_with_all(&["c2", "c3"])
+            .conflicts_with("c4")
+            .requires("r1")
+            .requires_all(&["r2", "r3"])
+            .requires("r4");
+
+        let args = vec!["a1", "a4", "a2", "a3"];
+        let reqs = vec!["r1", "r2", "r3", "r4"];
+        let confs = vec!["c1", "c2", "c3", "c4"];
+
+        assert_eq!(g.args, args);
+        assert_eq!(g.requires, Some(reqs));
+        assert_eq!(g.conflicts, Some(confs));
+    }
+
+    #[test]
+    fn test_debug() {
+        let g = ArgGroup::with_name("test")
+            .arg("a1")
+            .arg("a4")
+            .args(&["a2", "a3"])
+            .required(true)
+            .conflicts_with("c1")
+            .conflicts_with_all(&["c2", "c3"])
+            .conflicts_with("c4")
+            .requires("r1")
+            .requires_all(&["r2", "r3"])
+            .requires("r4");
+
+        let args = vec!["a1", "a4", "a2", "a3"];
+        let reqs = vec!["r1", "r2", "r3", "r4"];
+        let confs = vec!["c1", "c2", "c3", "c4"];
+
+        let debug_str = format!(
+            "{{\n\
+             \tname: \"test\",\n\
+             \targs: {:?},\n\
+             \trequired: {:?},\n\
+             \trequires: {:?},\n\
+             \tconflicts: {:?},\n\
+             }}",
+            args,
+            true,
+            Some(reqs),
+            Some(confs)
+        );
+        assert_eq!(&*format!("{:?}", g), &*debug_str);
+    }
+
+    #[test]
+    fn test_from() {
+        let g = ArgGroup::with_name("test")
+            .arg("a1")
+            .arg("a4")
+            .args(&["a2", "a3"])
+            .required(true)
+            .conflicts_with("c1")
+            .conflicts_with_all(&["c2", "c3"])
+            .conflicts_with("c4")
+            .requires("r1")
+            .requires_all(&["r2", "r3"])
+            .requires("r4");
+
+        let args = vec!["a1", "a4", "a2", "a3"];
+        let reqs = vec!["r1", "r2", "r3", "r4"];
+        let confs = vec!["c1", "c2", "c3", "c4"];
+
+        let g2 = ArgGroup::from(&g);
+        assert_eq!(g2.args, args);
+        assert_eq!(g2.requires, Some(reqs));
+        assert_eq!(g2.conflicts, Some(confs));
+    }
+
+    #[cfg(feature = "yaml")]
+    #[cfg_attr(feature = "yaml", test)]
+    fn test_yaml() {
+        let g_yaml = "name: test
+args:
+- a1
+- a4
+- a2
+- a3
+conflicts_with:
+- c1
+- c2
+- c3
+- c4
+requires:
+- r1
+- r2
+- r3
+- r4";
+        let yml = &YamlLoader::load_from_str(g_yaml).expect("failed to load YAML file")[0];
+        let g = ArgGroup::from_yaml(yml);
+        let args = vec!["a1", "a4", "a2", "a3"];
+        let reqs = vec!["r1", "r2", "r3", "r4"];
+        let confs = vec!["c1", "c2", "c3", "c4"];
+        assert_eq!(g.args, args);
+        assert_eq!(g.requires, Some(reqs));
+        assert_eq!(g.conflicts, Some(confs));
+    }
+}
+
+impl<'a> Clone for ArgGroup<'a> {
+    fn clone(&self) -> Self {
+        ArgGroup {
+            name: self.name,
+            required: self.required,
+            args: self.args.clone(),
+            requires: self.requires.clone(),
+            conflicts: self.conflicts.clone(),
+            multiple: self.multiple,
+        }
+    }
+}
diff --git a/src/args/macros.rs b/src/args/macros.rs
new file mode 100644
index 0000000..1de12f4
--- /dev/null
+++ b/src/args/macros.rs
@@ -0,0 +1,109 @@
+#[cfg(feature = "yaml")]
+macro_rules! yaml_tuple2 {
+    ($a:ident, $v:ident, $c:ident) => {{
+            if let Some(vec) = $v.as_vec() {
+                for ys in vec {
+                    if let Some(tup) = ys.as_vec() {
+                        debug_assert_eq!(2, tup.len());
+                        $a = $a.$c(yaml_str!(tup[0]), yaml_str!(tup[1]));
+                    } else {
+                        panic!("Failed to convert YAML value to vec");
+                    }
+                }
+            } else {
+                panic!("Failed to convert YAML value to vec");
+            }
+            $a
+        }
+    };
+}
+
+#[cfg(feature = "yaml")]
+macro_rules! yaml_tuple3 {
+    ($a:ident, $v:ident, $c:ident) => {{
+            if let Some(vec) = $v.as_vec() {
+                for ys in vec {
+                    if let Some(tup) = ys.as_vec() {
+                        debug_assert_eq!(3, tup.len());
+                        $a = $a.$c(yaml_str!(tup[0]), yaml_opt_str!(tup[1]), yaml_str!(tup[2]));
+                    } else {
+                        panic!("Failed to convert YAML value to vec");
+                    }
+                }
+            } else {
+                panic!("Failed to convert YAML value to vec");
+            }
+            $a
+        }
+    };
+}
+
+#[cfg(feature = "yaml")]
+macro_rules! yaml_vec_or_str {
+    ($v:ident, $a:ident, $c:ident) => {{
+            let maybe_vec = $v.as_vec();
+            if let Some(vec) = maybe_vec {
+                for ys in vec {
+                    if let Some(s) = ys.as_str() {
+                        $a = $a.$c(s);
+                    } else {
+                        panic!("Failed to convert YAML value {:?} to a string", ys);
+                    }
+                }
+            } else {
+                if let Some(s) = $v.as_str() {
+                    $a = $a.$c(s);
+                } else {
+                    panic!("Failed to convert YAML value {:?} to either a vec or string", $v);
+                }
+            }
+            $a
+        }
+    };
+}
+
+#[cfg(feature = "yaml")]
+macro_rules! yaml_opt_str {
+    ($v:expr) => {{
+        if $v.is_null() {
+            Some($v.as_str().unwrap_or_else(|| panic!("failed to convert YAML {:?} value to a string", $v)))
+        } else {
+            None
+        }
+    }};
+}
+
+#[cfg(feature = "yaml")]
+macro_rules! yaml_str {
+    ($v:expr) => {{
+        $v.as_str().unwrap_or_else(|| panic!("failed to convert YAML {:?} value to a string", $v))
+    }};
+}
+
+#[cfg(feature = "yaml")]
+macro_rules! yaml_to_str {
+    ($a:ident, $v:ident, $c:ident) => {{
+        $a.$c(yaml_str!($v))
+    }};
+}
+
+#[cfg(feature = "yaml")]
+macro_rules! yaml_to_bool {
+    ($a:ident, $v:ident, $c:ident) => {{
+        $a.$c($v.as_bool().unwrap_or_else(|| panic!("failed to convert YAML {:?} value to a string", $v)))
+    }};
+}
+
+#[cfg(feature = "yaml")]
+macro_rules! yaml_to_u64 {
+    ($a:ident, $v:ident, $c:ident) => {{
+        $a.$c($v.as_i64().unwrap_or_else(|| panic!("failed to convert YAML {:?} value to a string", $v)) as u64)
+    }};
+}
+
+#[cfg(feature = "yaml")]
+macro_rules! yaml_to_usize {
+    ($a:ident, $v:ident, $c:ident) => {{
+        $a.$c($v.as_i64().unwrap_or_else(|| panic!("failed to convert YAML {:?} value to a string", $v)) as usize)
+    }};
+}
diff --git a/src/args/matched_arg.rs b/src/args/matched_arg.rs
new file mode 100644
index 0000000..eeda261
--- /dev/null
+++ b/src/args/matched_arg.rs
@@ -0,0 +1,24 @@
+// Std
+use std::ffi::OsString;
+
+#[doc(hidden)]
+#[derive(Debug, Clone)]
+pub struct MatchedArg {
+    #[doc(hidden)] pub occurs: u64,
+    #[doc(hidden)] pub indices: Vec<usize>,
+    #[doc(hidden)] pub vals: Vec<OsString>,
+}
+
+impl Default for MatchedArg {
+    fn default() -> Self {
+        MatchedArg {
+            occurs: 1,
+            indices: Vec::new(),
+            vals: Vec::new(),
+        }
+    }
+}
+
+impl MatchedArg {
+    pub fn new() -> Self { MatchedArg::default() }
+}
diff --git a/src/args/mod.rs b/src/args/mod.rs
new file mode 100644
index 0000000..21f9b85
--- /dev/null
+++ b/src/args/mod.rs
@@ -0,0 +1,21 @@
+pub use self::any_arg::{AnyArg, DispOrder};
+pub use self::arg::Arg;
+pub use self::arg_builder::{Base, FlagBuilder, OptBuilder, PosBuilder, Switched, Valued};
+pub use self::arg_matcher::ArgMatcher;
+pub use self::arg_matches::{ArgMatches, OsValues, Values};
+pub use self::group::ArgGroup;
+pub use self::matched_arg::MatchedArg;
+pub use self::settings::{ArgFlags, ArgSettings};
+pub use self::subcommand::SubCommand;
+
+#[macro_use]
+mod macros;
+mod arg;
+pub mod any_arg;
+mod arg_matches;
+mod arg_matcher;
+mod subcommand;
+mod arg_builder;
+mod matched_arg;
+mod group;
+pub mod settings;
diff --git a/src/args/settings.rs b/src/args/settings.rs
new file mode 100644
index 0000000..7b0e0a2
--- /dev/null
+++ b/src/args/settings.rs
@@ -0,0 +1,231 @@
+// Std
+#[allow(deprecated, unused_imports)]
+use std::ascii::AsciiExt;
+use std::str::FromStr;
+
+bitflags! {
+    struct Flags: u32 {
+        const REQUIRED         = 1;
+        const MULTIPLE         = 1 << 1;
+        const EMPTY_VALS       = 1 << 2;
+        const GLOBAL           = 1 << 3;
+        const HIDDEN           = 1 << 4;
+        const TAKES_VAL        = 1 << 5;
+        const USE_DELIM        = 1 << 6;
+        const NEXT_LINE_HELP   = 1 << 7;
+        const R_UNLESS_ALL     = 1 << 8;
+        const REQ_DELIM        = 1 << 9;
+        const DELIM_NOT_SET    = 1 << 10;
+        const HIDE_POS_VALS    = 1 << 11;
+        const ALLOW_TAC_VALS   = 1 << 12;
+        const REQUIRE_EQUALS   = 1 << 13;
+        const LAST             = 1 << 14;
+        const HIDE_DEFAULT_VAL = 1 << 15;
+        const CASE_INSENSITIVE = 1 << 16;
+        const HIDE_ENV_VALS    = 1 << 17;
+        const HIDDEN_SHORT_H   = 1 << 18;
+        const HIDDEN_LONG_H    = 1 << 19;
+    }
+}
+
+#[doc(hidden)]
+#[derive(Debug, Clone, Copy)]
+pub struct ArgFlags(Flags);
+
+impl ArgFlags {
+    pub fn new() -> Self { ArgFlags::default() }
+
+    impl_settings!{ArgSettings,
+        Required => Flags::REQUIRED,
+        Multiple => Flags::MULTIPLE,
+        EmptyValues => Flags::EMPTY_VALS,
+        Global => Flags::GLOBAL,
+        Hidden => Flags::HIDDEN,
+        TakesValue => Flags::TAKES_VAL,
+        UseValueDelimiter => Flags::USE_DELIM,
+        NextLineHelp => Flags::NEXT_LINE_HELP,
+        RequiredUnlessAll => Flags::R_UNLESS_ALL,
+        RequireDelimiter => Flags::REQ_DELIM,
+        ValueDelimiterNotSet => Flags::DELIM_NOT_SET,
+        HidePossibleValues => Flags::HIDE_POS_VALS,
+        AllowLeadingHyphen => Flags::ALLOW_TAC_VALS,
+        RequireEquals => Flags::REQUIRE_EQUALS,
+        Last => Flags::LAST,
+        CaseInsensitive => Flags::CASE_INSENSITIVE,
+        HideEnvValues => Flags::HIDE_ENV_VALS,
+        HideDefaultValue => Flags::HIDE_DEFAULT_VAL,
+        HiddenShortHelp => Flags::HIDDEN_SHORT_H,
+        HiddenLongHelp => Flags::HIDDEN_LONG_H
+    }
+}
+
+impl Default for ArgFlags {
+    fn default() -> Self { ArgFlags(Flags::EMPTY_VALS | Flags::DELIM_NOT_SET) }
+}
+
+/// Various settings that apply to arguments and may be set, unset, and checked via getter/setter
+/// methods [`Arg::set`], [`Arg::unset`], and [`Arg::is_set`]
+///
+/// [`Arg::set`]: ./struct.Arg.html#method.set
+/// [`Arg::unset`]: ./struct.Arg.html#method.unset
+/// [`Arg::is_set`]: ./struct.Arg.html#method.is_set
+#[derive(Debug, PartialEq, Copy, Clone)]
+pub enum ArgSettings {
+    /// The argument must be used
+    Required,
+    /// The argument may be used multiple times such as `--flag --flag`
+    Multiple,
+    /// The argument allows empty values such as `--option ""`
+    EmptyValues,
+    /// The argument should be propagated down through all child [`SubCommand`]s
+    ///
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    Global,
+    /// The argument should **not** be shown in help text
+    Hidden,
+    /// The argument accepts a value, such as `--option <value>`
+    TakesValue,
+    /// Determines if the argument allows values to be grouped via a delimiter
+    UseValueDelimiter,
+    /// Prints the help text on the line after the argument
+    NextLineHelp,
+    /// Requires the use of a value delimiter for all multiple values
+    RequireDelimiter,
+    /// Hides the possible values from the help string
+    HidePossibleValues,
+    /// Allows vals that start with a '-'
+    AllowLeadingHyphen,
+    /// Require options use `--option=val` syntax
+    RequireEquals,
+    /// Specifies that the arg is the last positional argument and may be accessed early via `--`
+    /// syntax
+    Last,
+    /// Hides the default value from the help string
+    HideDefaultValue,
+    /// Makes `Arg::possible_values` case insensitive
+    CaseInsensitive,
+    /// Hides ENV values in the help message
+    HideEnvValues,
+    /// The argument should **not** be shown in short help text
+    HiddenShortHelp,
+    /// The argument should **not** be shown in long help text
+    HiddenLongHelp,
+    #[doc(hidden)] RequiredUnlessAll,
+    #[doc(hidden)] ValueDelimiterNotSet,
+}
+
+impl FromStr for ArgSettings {
+    type Err = String;
+    fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
+        match &*s.to_ascii_lowercase() {
+            "required" => Ok(ArgSettings::Required),
+            "multiple" => Ok(ArgSettings::Multiple),
+            "global" => Ok(ArgSettings::Global),
+            "emptyvalues" => Ok(ArgSettings::EmptyValues),
+            "hidden" => Ok(ArgSettings::Hidden),
+            "takesvalue" => Ok(ArgSettings::TakesValue),
+            "usevaluedelimiter" => Ok(ArgSettings::UseValueDelimiter),
+            "nextlinehelp" => Ok(ArgSettings::NextLineHelp),
+            "requiredunlessall" => Ok(ArgSettings::RequiredUnlessAll),
+            "requiredelimiter" => Ok(ArgSettings::RequireDelimiter),
+            "valuedelimiternotset" => Ok(ArgSettings::ValueDelimiterNotSet),
+            "hidepossiblevalues" => Ok(ArgSettings::HidePossibleValues),
+            "allowleadinghyphen" => Ok(ArgSettings::AllowLeadingHyphen),
+            "requireequals" => Ok(ArgSettings::RequireEquals),
+            "last" => Ok(ArgSettings::Last),
+            "hidedefaultvalue" => Ok(ArgSettings::HideDefaultValue),
+            "caseinsensitive" => Ok(ArgSettings::CaseInsensitive),
+            "hideenvvalues" => Ok(ArgSettings::HideEnvValues),
+            "hiddenshorthelp" => Ok(ArgSettings::HiddenShortHelp),
+            "hiddenlonghelp" => Ok(ArgSettings::HiddenLongHelp),
+            _ => Err("unknown ArgSetting, cannot convert from str".to_owned()),
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::ArgSettings;
+
+    #[test]
+    fn arg_settings_fromstr() {
+        assert_eq!(
+            "allowleadinghyphen".parse::<ArgSettings>().unwrap(),
+            ArgSettings::AllowLeadingHyphen
+        );
+        assert_eq!(
+            "emptyvalues".parse::<ArgSettings>().unwrap(),
+            ArgSettings::EmptyValues
+        );
+        assert_eq!(
+            "global".parse::<ArgSettings>().unwrap(),
+            ArgSettings::Global
+        );
+        assert_eq!(
+            "hidepossiblevalues".parse::<ArgSettings>().unwrap(),
+            ArgSettings::HidePossibleValues
+        );
+        assert_eq!(
+            "hidden".parse::<ArgSettings>().unwrap(),
+            ArgSettings::Hidden
+        );
+        assert_eq!(
+            "multiple".parse::<ArgSettings>().unwrap(),
+            ArgSettings::Multiple
+        );
+        assert_eq!(
+            "nextlinehelp".parse::<ArgSettings>().unwrap(),
+            ArgSettings::NextLineHelp
+        );
+        assert_eq!(
+            "requiredunlessall".parse::<ArgSettings>().unwrap(),
+            ArgSettings::RequiredUnlessAll
+        );
+        assert_eq!(
+            "requiredelimiter".parse::<ArgSettings>().unwrap(),
+            ArgSettings::RequireDelimiter
+        );
+        assert_eq!(
+            "required".parse::<ArgSettings>().unwrap(),
+            ArgSettings::Required
+        );
+        assert_eq!(
+            "takesvalue".parse::<ArgSettings>().unwrap(),
+            ArgSettings::TakesValue
+        );
+        assert_eq!(
+            "usevaluedelimiter".parse::<ArgSettings>().unwrap(),
+            ArgSettings::UseValueDelimiter
+        );
+        assert_eq!(
+            "valuedelimiternotset".parse::<ArgSettings>().unwrap(),
+            ArgSettings::ValueDelimiterNotSet
+        );
+        assert_eq!(
+            "requireequals".parse::<ArgSettings>().unwrap(),
+            ArgSettings::RequireEquals
+        );
+        assert_eq!("last".parse::<ArgSettings>().unwrap(), ArgSettings::Last);
+        assert_eq!(
+            "hidedefaultvalue".parse::<ArgSettings>().unwrap(),
+            ArgSettings::HideDefaultValue
+        );
+        assert_eq!(
+            "caseinsensitive".parse::<ArgSettings>().unwrap(),
+            ArgSettings::CaseInsensitive
+        );
+        assert_eq!(
+            "hideenvvalues".parse::<ArgSettings>().unwrap(),
+            ArgSettings::HideEnvValues
+        );
+        assert_eq!(
+            "hiddenshorthelp".parse::<ArgSettings>().unwrap(),
+            ArgSettings::HiddenShortHelp
+        );
+        assert_eq!(
+            "hiddenlonghelp".parse::<ArgSettings>().unwrap(),
+            ArgSettings::HiddenLongHelp
+        );
+        assert!("hahahaha".parse::<ArgSettings>().is_err());
+    }
+}
diff --git a/src/args/subcommand.rs b/src/args/subcommand.rs
new file mode 100644
index 0000000..eebbf82
--- /dev/null
+++ b/src/args/subcommand.rs
@@ -0,0 +1,66 @@
+// Third Party
+#[cfg(feature = "yaml")]
+use yaml_rust::Yaml;
+
+// Internal
+use App;
+use ArgMatches;
+
+/// The abstract representation of a command line subcommand.
+///
+/// This struct describes all the valid options of the subcommand for the program. Subcommands are
+/// essentially "sub-[`App`]s" and contain all the same possibilities (such as their own
+/// [arguments], subcommands, and settings).
+///
+/// # Examples
+///
+/// ```rust
+/// # use clap::{App, Arg, SubCommand};
+/// App::new("myprog")
+///     .subcommand(
+///         SubCommand::with_name("config")
+///             .about("Used for configuration")
+///             .arg(Arg::with_name("config_file")
+///                 .help("The configuration file to use")
+///                 .index(1)))
+/// # ;
+/// ```
+/// [`App`]: ./struct.App.html
+/// [arguments]: ./struct.Arg.html
+#[derive(Debug, Clone)]
+pub struct SubCommand<'a> {
+    #[doc(hidden)] pub name: String,
+    #[doc(hidden)] pub matches: ArgMatches<'a>,
+}
+
+impl<'a> SubCommand<'a> {
+    /// Creates a new instance of a subcommand requiring a name. The name will be displayed
+    /// to the user when they print version or help and usage information.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, SubCommand};
+    /// App::new("myprog")
+    ///     .subcommand(
+    ///         SubCommand::with_name("config"))
+    /// # ;
+    /// ```
+    pub fn with_name<'b>(name: &str) -> App<'a, 'b> { App::new(name) }
+
+    /// Creates a new instance of a subcommand from a YAML (.yml) document
+    ///
+    /// # Examples
+    ///
+    /// ```ignore
+    /// # #[macro_use]
+    /// # extern crate clap;
+    /// # use clap::Subcommand;
+    /// # fn main() {
+    /// let sc_yaml = load_yaml!("test_subcommand.yml");
+    /// let sc = SubCommand::from_yaml(sc_yaml);
+    /// # }
+    /// ```
+    #[cfg(feature = "yaml")]
+    pub fn from_yaml(yaml: &Yaml) -> App { App::from_yaml(yaml) }
+}
diff --git a/src/completions/bash.rs b/src/completions/bash.rs
new file mode 100644
index 0000000..37dfa66
--- /dev/null
+++ b/src/completions/bash.rs
@@ -0,0 +1,219 @@
+// Std
+use std::io::Write;
+
+// Internal
+use app::parser::Parser;
+use args::OptBuilder;
+use completions;
+
+pub struct BashGen<'a, 'b>
+where
+    'a: 'b,
+{
+    p: &'b Parser<'a, 'b>,
+}
+
+impl<'a, 'b> BashGen<'a, 'b> {
+    pub fn new(p: &'b Parser<'a, 'b>) -> Self { BashGen { p: p } }
+
+    pub fn generate_to<W: Write>(&self, buf: &mut W) {
+        w!(
+            buf,
+            format!(
+                r#"_{name}() {{
+    local i cur prev opts cmds
+    COMPREPLY=()
+    cur="${{COMP_WORDS[COMP_CWORD]}}"
+    prev="${{COMP_WORDS[COMP_CWORD-1]}}"
+    cmd=""
+    opts=""
+
+    for i in ${{COMP_WORDS[@]}}
+    do
+        case "${{i}}" in
+            {name})
+                cmd="{name}"
+                ;;
+            {subcmds}
+            *)
+                ;;
+        esac
+    done
+
+    case "${{cmd}}" in
+        {name})
+            opts="{name_opts}"
+            if [[ ${{cur}} == -* || ${{COMP_CWORD}} -eq 1 ]] ; then
+                COMPREPLY=( $(compgen -W "${{opts}}" -- "${{cur}}") )
+                return 0
+            fi
+            case "${{prev}}" in
+                {name_opts_details}
+                *)
+                    COMPREPLY=()
+                    ;;
+            esac
+            COMPREPLY=( $(compgen -W "${{opts}}" -- "${{cur}}") )
+            return 0
+            ;;
+        {subcmd_details}
+    esac
+}}
+
+complete -F _{name} -o bashdefault -o default {name}
+"#,
+                name = self.p.meta.bin_name.as_ref().unwrap(),
+                name_opts = self.all_options_for_path(self.p.meta.bin_name.as_ref().unwrap()),
+                name_opts_details =
+                    self.option_details_for_path(self.p.meta.bin_name.as_ref().unwrap()),
+                subcmds = self.all_subcommands(),
+                subcmd_details = self.subcommand_details()
+            ).as_bytes()
+        );
+    }
+
+    fn all_subcommands(&self) -> String {
+        debugln!("BashGen::all_subcommands;");
+        let mut subcmds = String::new();
+        let scs = completions::all_subcommand_names(self.p);
+
+        for sc in &scs {
+            subcmds = format!(
+                r#"{}
+            {name})
+                cmd+="__{fn_name}"
+                ;;"#,
+                subcmds,
+                name = sc,
+                fn_name = sc.replace("-", "__")
+            );
+        }
+
+        subcmds
+    }
+
+    fn subcommand_details(&self) -> String {
+        debugln!("BashGen::subcommand_details;");
+        let mut subcmd_dets = String::new();
+        let mut scs = completions::get_all_subcommand_paths(self.p, true);
+        scs.sort();
+        scs.dedup();
+
+        for sc in &scs {
+            subcmd_dets = format!(
+                r#"{}
+        {subcmd})
+            opts="{sc_opts}"
+            if [[ ${{cur}} == -* || ${{COMP_CWORD}} -eq {level} ]] ; then
+                COMPREPLY=( $(compgen -W "${{opts}}" -- "${{cur}}") )
+                return 0
+            fi
+            case "${{prev}}" in
+                {opts_details}
+                *)
+                    COMPREPLY=()
+                    ;;
+            esac
+            COMPREPLY=( $(compgen -W "${{opts}}" -- "${{cur}}") )
+            return 0
+            ;;"#,
+                subcmd_dets,
+                subcmd = sc.replace("-", "__"),
+                sc_opts = self.all_options_for_path(&*sc),
+                level = sc.split("__").map(|_| 1).fold(0, |acc, n| acc + n),
+                opts_details = self.option_details_for_path(&*sc)
+            );
+        }
+
+        subcmd_dets
+    }
+
+    fn option_details_for_path(&self, path: &str) -> String {
+        debugln!("BashGen::option_details_for_path: path={}", path);
+        let mut p = self.p;
+        for sc in path.split("__").skip(1) {
+            debugln!("BashGen::option_details_for_path:iter: sc={}", sc);
+            p = &find_subcmd!(p, sc).unwrap().p;
+        }
+        let mut opts = String::new();
+        for o in p.opts() {
+            if let Some(l) = o.s.long {
+                opts = format!(
+                    "{}
+                --{})
+                    COMPREPLY=({})
+                    return 0
+                    ;;",
+                    opts,
+                    l,
+                    self.vals_for(o)
+                );
+            }
+            if let Some(s) = o.s.short {
+                opts = format!(
+                    "{}
+                    -{})
+                    COMPREPLY=({})
+                    return 0
+                    ;;",
+                    opts,
+                    s,
+                    self.vals_for(o)
+                );
+            }
+        }
+        opts
+    }
+
+    fn vals_for(&self, o: &OptBuilder) -> String {
+        debugln!("BashGen::vals_for: o={}", o.b.name);
+        use args::AnyArg;
+        if let Some(vals) = o.possible_vals() {
+            format!(r#"$(compgen -W "{}" -- "${{cur}}")"#, vals.join(" "))
+        } else {
+            String::from(r#"$(compgen -f "${cur}")"#)
+        }
+    }
+
+    fn all_options_for_path(&self, path: &str) -> String {
+        debugln!("BashGen::all_options_for_path: path={}", path);
+        let mut p = self.p;
+        for sc in path.split("__").skip(1) {
+            debugln!("BashGen::all_options_for_path:iter: sc={}", sc);
+            p = &find_subcmd!(p, sc).unwrap().p;
+        }
+        let mut opts = shorts!(p).fold(String::new(), |acc, s| format!("{} -{}", acc, s));
+        opts = format!(
+            "{} {}",
+            opts,
+            longs!(p).fold(String::new(), |acc, l| format!("{} --{}", acc, l))
+        );
+        opts = format!(
+            "{} {}",
+            opts,
+            p.positionals
+                .values()
+                .fold(String::new(), |acc, p| format!("{} {}", acc, p))
+        );
+        opts = format!(
+            "{} {}",
+            opts,
+            p.subcommands
+                .iter()
+                .fold(String::new(), |acc, s| format!("{} {}", acc, s.p.meta.name))
+        );
+        for sc in &p.subcommands {
+            if let Some(ref aliases) = sc.p.meta.aliases {
+                opts = format!(
+                    "{} {}",
+                    opts,
+                    aliases
+                        .iter()
+                        .map(|&(n, _)| n)
+                        .fold(String::new(), |acc, a| format!("{} {}", acc, a))
+                );
+            }
+        }
+        opts
+    }
+}
diff --git a/src/completions/elvish.rs b/src/completions/elvish.rs
new file mode 100644
index 0000000..9a5f21a
--- /dev/null
+++ b/src/completions/elvish.rs
@@ -0,0 +1,126 @@
+// Std
+use std::io::Write;
+
+// Internal
+use app::parser::Parser;
+use INTERNAL_ERROR_MSG;
+
+pub struct ElvishGen<'a, 'b>
+where
+    'a: 'b,
+{
+    p: &'b Parser<'a, 'b>,
+}
+
+impl<'a, 'b> ElvishGen<'a, 'b> {
+    pub fn new(p: &'b Parser<'a, 'b>) -> Self { ElvishGen { p: p } }
+
+    pub fn generate_to<W: Write>(&self, buf: &mut W) {
+        let bin_name = self.p.meta.bin_name.as_ref().unwrap();
+
+        let mut names = vec![];
+        let subcommands_cases =
+            generate_inner(self.p, "", &mut names);
+
+        let result = format!(r#"
+edit:completion:arg-completer[{bin_name}] = [@words]{{
+    fn spaces [n]{{
+        repeat $n ' ' | joins ''
+    }}
+    fn cand [text desc]{{
+        edit:complex-candidate $text &display-suffix=' '(spaces (- 14 (wcswidth $text)))$desc
+    }}
+    command = '{bin_name}'
+    for word $words[1:-1] {{
+        if (has-prefix $word '-') {{
+            break
+        }}
+        command = $command';'$word
+    }}
+    completions = [{subcommands_cases}
+    ]
+    $completions[$command]
+}}
+"#,
+            bin_name = bin_name,
+            subcommands_cases = subcommands_cases
+        );
+
+        w!(buf, result.as_bytes());
+    }
+}
+
+// Escape string inside single quotes
+fn escape_string(string: &str) -> String { string.replace("'", "''") }
+
+fn get_tooltip<T : ToString>(help: Option<&str>, data: T) -> String {
+    match help {
+        Some(help) => escape_string(help),
+        _ => data.to_string()
+    }
+}
+
+fn generate_inner<'a, 'b, 'p>(
+    p: &'p Parser<'a, 'b>,
+    previous_command_name: &str,
+    names: &mut Vec<&'p str>,
+) -> String {
+    debugln!("ElvishGen::generate_inner;");
+    let command_name = if previous_command_name.is_empty() {
+        p.meta.bin_name.as_ref().expect(INTERNAL_ERROR_MSG).clone()
+    } else {
+        format!("{};{}", previous_command_name, &p.meta.name)
+    };
+
+    let mut completions = String::new();
+    let preamble = String::from("\n            cand ");
+
+    for option in p.opts() {
+        if let Some(data) = option.s.short {
+            let tooltip = get_tooltip(option.b.help, data);
+            completions.push_str(&preamble);
+            completions.push_str(format!("-{} '{}'", data, tooltip).as_str());
+        }
+        if let Some(data) = option.s.long {
+            let tooltip = get_tooltip(option.b.help, data);
+            completions.push_str(&preamble);
+            completions.push_str(format!("--{} '{}'", data, tooltip).as_str());
+        }
+    }
+
+    for flag in p.flags() {
+        if let Some(data) = flag.s.short {
+            let tooltip = get_tooltip(flag.b.help, data);
+            completions.push_str(&preamble);
+            completions.push_str(format!("-{} '{}'", data, tooltip).as_str());
+        }
+        if let Some(data) = flag.s.long {
+            let tooltip = get_tooltip(flag.b.help, data);
+            completions.push_str(&preamble);
+            completions.push_str(format!("--{} '{}'", data, tooltip).as_str());
+        }
+    }
+
+    for subcommand in &p.subcommands {
+        let data = &subcommand.p.meta.name;
+        let tooltip = get_tooltip(subcommand.p.meta.about, data);
+        completions.push_str(&preamble);
+        completions.push_str(format!("{} '{}'", data, tooltip).as_str());
+    }
+
+    let mut subcommands_cases = format!(
+        r"
+        &'{}'= {{{}
+        }}",
+        &command_name,
+        completions
+    );
+
+    for subcommand in &p.subcommands {
+        let subcommand_subcommands_cases =
+            generate_inner(&subcommand.p, &command_name, names);
+        subcommands_cases.push_str(&subcommand_subcommands_cases);
+    }
+
+    subcommands_cases
+}
diff --git a/src/completions/fish.rs b/src/completions/fish.rs
new file mode 100644
index 0000000..c2c5a5e
--- /dev/null
+++ b/src/completions/fish.rs
@@ -0,0 +1,99 @@
+// Std
+use std::io::Write;
+
+// Internal
+use app::parser::Parser;
+
+pub struct FishGen<'a, 'b>
+where
+    'a: 'b,
+{
+    p: &'b Parser<'a, 'b>,
+}
+
+impl<'a, 'b> FishGen<'a, 'b> {
+    pub fn new(p: &'b Parser<'a, 'b>) -> Self { FishGen { p: p } }
+
+    pub fn generate_to<W: Write>(&self, buf: &mut W) {
+        let command = self.p.meta.bin_name.as_ref().unwrap();
+        let mut buffer = String::new();
+        gen_fish_inner(command, self, command, &mut buffer);
+        w!(buf, buffer.as_bytes());
+    }
+}
+
+// Escape string inside single quotes
+fn escape_string(string: &str) -> String { string.replace("\\", "\\\\").replace("'", "\\'") }
+
+fn gen_fish_inner(root_command: &str, comp_gen: &FishGen, subcommand: &str, buffer: &mut String) {
+    debugln!("FishGen::gen_fish_inner;");
+    // example :
+    //
+    // complete
+    //      -c {command}
+    //      -d "{description}"
+    //      -s {short}
+    //      -l {long}
+    //      -a "{possible_arguments}"
+    //      -r # if require parameter
+    //      -f # don't use file completion
+    //      -n "__fish_use_subcommand"               # complete for command "myprog"
+    //      -n "__fish_seen_subcommand_from subcmd1" # complete for command "myprog subcmd1"
+
+    let mut basic_template = format!("complete -c {} -n ", root_command);
+    if root_command == subcommand {
+        basic_template.push_str("\"__fish_use_subcommand\"");
+    } else {
+        basic_template.push_str(format!("\"__fish_seen_subcommand_from {}\"", subcommand).as_str());
+    }
+
+    for option in comp_gen.p.opts() {
+        let mut template = basic_template.clone();
+        if let Some(data) = option.s.short {
+            template.push_str(format!(" -s {}", data).as_str());
+        }
+        if let Some(data) = option.s.long {
+            template.push_str(format!(" -l {}", data).as_str());
+        }
+        if let Some(data) = option.b.help {
+            template.push_str(format!(" -d '{}'", escape_string(data)).as_str());
+        }
+        if let Some(ref data) = option.v.possible_vals {
+            template.push_str(format!(" -r -f -a \"{}\"", data.join(" ")).as_str());
+        }
+        buffer.push_str(template.as_str());
+        buffer.push_str("\n");
+    }
+
+    for flag in comp_gen.p.flags() {
+        let mut template = basic_template.clone();
+        if let Some(data) = flag.s.short {
+            template.push_str(format!(" -s {}", data).as_str());
+        }
+        if let Some(data) = flag.s.long {
+            template.push_str(format!(" -l {}", data).as_str());
+        }
+        if let Some(data) = flag.b.help {
+            template.push_str(format!(" -d '{}'", escape_string(data)).as_str());
+        }
+        buffer.push_str(template.as_str());
+        buffer.push_str("\n");
+    }
+
+    for subcommand in &comp_gen.p.subcommands {
+        let mut template = basic_template.clone();
+        template.push_str(" -f");
+        template.push_str(format!(" -a \"{}\"", &subcommand.p.meta.name).as_str());
+        if let Some(data) = subcommand.p.meta.about {
+            template.push_str(format!(" -d '{}'", escape_string(data)).as_str())
+        }
+        buffer.push_str(template.as_str());
+        buffer.push_str("\n");
+    }
+
+    // generate options of subcommands
+    for subcommand in &comp_gen.p.subcommands {
+        let sub_comp_gen = FishGen::new(&subcommand.p);
+        gen_fish_inner(root_command, &sub_comp_gen, &subcommand.to_string(), buffer);
+    }
+}
diff --git a/src/completions/macros.rs b/src/completions/macros.rs
new file mode 100644
index 0000000..653c72c
--- /dev/null
+++ b/src/completions/macros.rs
@@ -0,0 +1,28 @@
+macro_rules! w {
+    ($buf:expr, $to_w:expr) => {
+        match $buf.write_all($to_w) {
+            Ok(..) => (),
+            Err(..) => panic!("Failed to write to completions file"),
+        }
+    };
+}
+
+macro_rules! get_zsh_arg_conflicts {
+    ($p:ident, $arg:ident, $msg:ident) => {
+        if let Some(conf_vec) = $arg.blacklist() {
+            let mut v = vec![];
+            for arg_name in conf_vec {
+                let arg = $p.find_any_arg(arg_name).expect($msg);
+                if let Some(s) = arg.short() {
+                    v.push(format!("-{}", s));
+                }
+                if let Some(l) = arg.long() {
+                    v.push(format!("--{}", l));
+                }
+            }
+            v.join(" ")
+        } else {
+            String::new()
+        }
+    }
+}
diff --git a/src/completions/mod.rs b/src/completions/mod.rs
new file mode 100644
index 0000000..a3306d7
--- /dev/null
+++ b/src/completions/mod.rs
@@ -0,0 +1,179 @@
+#[macro_use]
+mod macros;
+mod bash;
+mod fish;
+mod zsh;
+mod powershell;
+mod elvish;
+mod shell;
+
+// Std
+use std::io::Write;
+
+// Internal
+use app::parser::Parser;
+use self::bash::BashGen;
+use self::fish::FishGen;
+use self::zsh::ZshGen;
+use self::powershell::PowerShellGen;
+use self::elvish::ElvishGen;
+pub use self::shell::Shell;
+
+pub struct ComplGen<'a, 'b>
+where
+    'a: 'b,
+{
+    p: &'b Parser<'a, 'b>,
+}
+
+impl<'a, 'b> ComplGen<'a, 'b> {
+    pub fn new(p: &'b Parser<'a, 'b>) -> Self { ComplGen { p: p } }
+
+    pub fn generate<W: Write>(&self, for_shell: Shell, buf: &mut W) {
+        match for_shell {
+            Shell::Bash => BashGen::new(self.p).generate_to(buf),
+            Shell::Fish => FishGen::new(self.p).generate_to(buf),
+            Shell::Zsh => ZshGen::new(self.p).generate_to(buf),
+            Shell::PowerShell => PowerShellGen::new(self.p).generate_to(buf),
+            Shell::Elvish => ElvishGen::new(self.p).generate_to(buf),
+        }
+    }
+}
+
+// Gets all subcommands including child subcommands in the form of 'name' where the name
+// is a single word (i.e. "install")  of the path to said subcommand (i.e.
+// "rustup toolchain install")
+//
+// Also note, aliases are treated as their own subcommands but duplicates of whatever they're
+// aliasing.
+pub fn all_subcommand_names(p: &Parser) -> Vec<String> {
+    debugln!("all_subcommand_names;");
+    let mut subcmds: Vec<_> = subcommands_of(p)
+        .iter()
+        .map(|&(ref n, _)| n.clone())
+        .collect();
+    for sc_v in p.subcommands.iter().map(|s| all_subcommand_names(&s.p)) {
+        subcmds.extend(sc_v);
+    }
+    subcmds.sort();
+    subcmds.dedup();
+    subcmds
+}
+
+// Gets all subcommands including child subcommands in the form of ('name', 'bin_name') where the name
+// is a single word (i.e. "install") of the path and full bin_name of said subcommand (i.e.
+// "rustup toolchain install")
+//
+// Also note, aliases are treated as their own subcommands but duplicates of whatever they're
+// aliasing.
+pub fn all_subcommands(p: &Parser) -> Vec<(String, String)> {
+    debugln!("all_subcommands;");
+    let mut subcmds: Vec<_> = subcommands_of(p);
+    for sc_v in p.subcommands.iter().map(|s| all_subcommands(&s.p)) {
+        subcmds.extend(sc_v);
+    }
+    subcmds
+}
+
+// Gets all subcommands excluding child subcommands in the form of (name, bin_name) where the name
+// is a single word (i.e. "install") and the bin_name is a space delineated list of the path to said
+// subcommand (i.e. "rustup toolchain install")
+//
+// Also note, aliases are treated as their own subcommands but duplicates of whatever they're
+// aliasing.
+pub fn subcommands_of(p: &Parser) -> Vec<(String, String)> {
+    debugln!(
+        "subcommands_of: name={}, bin_name={}",
+        p.meta.name,
+        p.meta.bin_name.as_ref().unwrap()
+    );
+    let mut subcmds = vec![];
+
+    debugln!(
+        "subcommands_of: Has subcommands...{:?}",
+        p.has_subcommands()
+    );
+    if !p.has_subcommands() {
+        let mut ret = vec![];
+        debugln!("subcommands_of: Looking for aliases...");
+        if let Some(ref aliases) = p.meta.aliases {
+            for &(n, _) in aliases {
+                debugln!("subcommands_of:iter:iter: Found alias...{}", n);
+                let mut als_bin_name: Vec<_> =
+                    p.meta.bin_name.as_ref().unwrap().split(' ').collect();
+                als_bin_name.push(n);
+                let old = als_bin_name.len() - 2;
+                als_bin_name.swap_remove(old);
+                ret.push((n.to_owned(), als_bin_name.join(" ")));
+            }
+        }
+        return ret;
+    }
+    for sc in &p.subcommands {
+        debugln!(
+            "subcommands_of:iter: name={}, bin_name={}",
+            sc.p.meta.name,
+            sc.p.meta.bin_name.as_ref().unwrap()
+        );
+
+        debugln!("subcommands_of:iter: Looking for aliases...");
+        if let Some(ref aliases) = sc.p.meta.aliases {
+            for &(n, _) in aliases {
+                debugln!("subcommands_of:iter:iter: Found alias...{}", n);
+                let mut als_bin_name: Vec<_> =
+                    p.meta.bin_name.as_ref().unwrap().split(' ').collect();
+                als_bin_name.push(n);
+                let old = als_bin_name.len() - 2;
+                als_bin_name.swap_remove(old);
+                subcmds.push((n.to_owned(), als_bin_name.join(" ")));
+            }
+        }
+        subcmds.push((
+            sc.p.meta.name.clone(),
+            sc.p.meta.bin_name.as_ref().unwrap().clone(),
+        ));
+    }
+    subcmds
+}
+
+pub fn get_all_subcommand_paths(p: &Parser, first: bool) -> Vec<String> {
+    debugln!("get_all_subcommand_paths;");
+    let mut subcmds = vec![];
+    if !p.has_subcommands() {
+        if !first {
+            let name = &*p.meta.name;
+            let path = p.meta.bin_name.as_ref().unwrap().clone().replace(" ", "__");
+            let mut ret = vec![path.clone()];
+            if let Some(ref aliases) = p.meta.aliases {
+                for &(n, _) in aliases {
+                    ret.push(path.replace(name, n));
+                }
+            }
+            return ret;
+        }
+        return vec![];
+    }
+    for sc in &p.subcommands {
+        let name = &*sc.p.meta.name;
+        let path = sc.p
+            .meta
+            .bin_name
+            .as_ref()
+            .unwrap()
+            .clone()
+            .replace(" ", "__");
+        subcmds.push(path.clone());
+        if let Some(ref aliases) = sc.p.meta.aliases {
+            for &(n, _) in aliases {
+                subcmds.push(path.replace(name, n));
+            }
+        }
+    }
+    for sc_v in p.subcommands
+        .iter()
+        .map(|s| get_all_subcommand_paths(&s.p, false))
+    {
+        subcmds.extend(sc_v);
+    }
+    subcmds
+}
diff --git a/src/completions/powershell.rs b/src/completions/powershell.rs
new file mode 100644
index 0000000..9fc77c7
--- /dev/null
+++ b/src/completions/powershell.rs
@@ -0,0 +1,139 @@
+// Std
+use std::io::Write;
+
+// Internal
+use app::parser::Parser;
+use INTERNAL_ERROR_MSG;
+
+pub struct PowerShellGen<'a, 'b>
+where
+    'a: 'b,
+{
+    p: &'b Parser<'a, 'b>,
+}
+
+impl<'a, 'b> PowerShellGen<'a, 'b> {
+    pub fn new(p: &'b Parser<'a, 'b>) -> Self { PowerShellGen { p: p } }
+
+    pub fn generate_to<W: Write>(&self, buf: &mut W) {
+        let bin_name = self.p.meta.bin_name.as_ref().unwrap();
+
+        let mut names = vec![];
+        let subcommands_cases =
+            generate_inner(self.p, "", &mut names);
+
+        let result = format!(r#"
+using namespace System.Management.Automation
+using namespace System.Management.Automation.Language
+
+Register-ArgumentCompleter -Native -CommandName '{bin_name}' -ScriptBlock {{
+    param($wordToComplete, $commandAst, $cursorPosition)
+
+    $commandElements = $commandAst.CommandElements
+    $command = @(
+        '{bin_name}'
+        for ($i = 1; $i -lt $commandElements.Count; $i++) {{
+            $element = $commandElements[$i]
+            if ($element -isnot [StringConstantExpressionAst] -or
+                $element.StringConstantType -ne [StringConstantType]::BareWord -or
+                $element.Value.StartsWith('-')) {{
+                break
+        }}
+        $element.Value
+    }}) -join ';'
+
+    $completions = @(switch ($command) {{{subcommands_cases}
+    }})
+
+    $completions.Where{{ $_.CompletionText -like "$wordToComplete*" }} |
+        Sort-Object -Property ListItemText
+}}
+"#,
+            bin_name = bin_name,
+            subcommands_cases = subcommands_cases
+        );
+
+        w!(buf, result.as_bytes());
+    }
+}
+
+// Escape string inside single quotes
+fn escape_string(string: &str) -> String { string.replace("'", "''") }
+
+fn get_tooltip<T : ToString>(help: Option<&str>, data: T) -> String {
+    match help {
+        Some(help) => escape_string(help),
+        _ => data.to_string()
+    }
+}
+
+fn generate_inner<'a, 'b, 'p>(
+    p: &'p Parser<'a, 'b>,
+    previous_command_name: &str,
+    names: &mut Vec<&'p str>,
+) -> String {
+    debugln!("PowerShellGen::generate_inner;");
+    let command_name = if previous_command_name.is_empty() {
+        p.meta.bin_name.as_ref().expect(INTERNAL_ERROR_MSG).clone()
+    } else {
+        format!("{};{}", previous_command_name, &p.meta.name)
+    };
+
+    let mut completions = String::new();
+    let preamble = String::from("\n            [CompletionResult]::new(");
+
+    for option in p.opts() {
+        if let Some(data) = option.s.short {
+            let tooltip = get_tooltip(option.b.help, data);
+            completions.push_str(&preamble);
+            completions.push_str(format!("'-{}', '{}', {}, '{}')",
+                                         data, data, "[CompletionResultType]::ParameterName", tooltip).as_str());
+        }
+        if let Some(data) = option.s.long {
+            let tooltip = get_tooltip(option.b.help, data);
+            completions.push_str(&preamble);
+            completions.push_str(format!("'--{}', '{}', {}, '{}')",
+                                         data, data, "[CompletionResultType]::ParameterName", tooltip).as_str());
+        }
+    }
+
+    for flag in p.flags() {
+        if let Some(data) = flag.s.short {
+            let tooltip = get_tooltip(flag.b.help, data);
+            completions.push_str(&preamble);
+            completions.push_str(format!("'-{}', '{}', {}, '{}')",
+                                         data, data, "[CompletionResultType]::ParameterName", tooltip).as_str());
+        }
+        if let Some(data) = flag.s.long {
+            let tooltip = get_tooltip(flag.b.help, data);
+            completions.push_str(&preamble);
+            completions.push_str(format!("'--{}', '{}', {}, '{}')",
+                                         data, data, "[CompletionResultType]::ParameterName", tooltip).as_str());
+        }
+    }
+
+    for subcommand in &p.subcommands {
+        let data = &subcommand.p.meta.name;
+        let tooltip = get_tooltip(subcommand.p.meta.about, data);
+        completions.push_str(&preamble);
+        completions.push_str(format!("'{}', '{}', {}, '{}')",
+                                     data, data, "[CompletionResultType]::ParameterValue", tooltip).as_str());
+    }
+
+    let mut subcommands_cases = format!(
+        r"
+        '{}' {{{}
+            break
+        }}",
+        &command_name,
+        completions
+    );
+
+    for subcommand in &p.subcommands {
+        let subcommand_subcommands_cases =
+            generate_inner(&subcommand.p, &command_name, names);
+        subcommands_cases.push_str(&subcommand_subcommands_cases);
+    }
+
+    subcommands_cases
+}
diff --git a/src/completions/shell.rs b/src/completions/shell.rs
new file mode 100644
index 0000000..19aab86
--- /dev/null
+++ b/src/completions/shell.rs
@@ -0,0 +1,52 @@
+#[allow(deprecated, unused_imports)]
+use std::ascii::AsciiExt;
+use std::str::FromStr;
+use std::fmt;
+
+/// Describes which shell to produce a completions file for
+#[cfg_attr(feature = "lints", allow(enum_variant_names))]
+#[derive(Debug, Copy, Clone)]
+pub enum Shell {
+    /// Generates a .bash completion file for the Bourne Again SHell (BASH)
+    Bash,
+    /// Generates a .fish completion file for the Friendly Interactive SHell (fish)
+    Fish,
+    /// Generates a completion file for the Z SHell (ZSH)
+    Zsh,
+    /// Generates a completion file for PowerShell
+    PowerShell,
+    /// Generates a completion file for Elvish
+    Elvish,
+}
+
+impl Shell {
+    /// A list of possible variants in `&'static str` form
+    pub fn variants() -> [&'static str; 5] { ["zsh", "bash", "fish", "powershell", "elvish"] }
+}
+
+impl FromStr for Shell {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "ZSH" | _ if s.eq_ignore_ascii_case("zsh") => Ok(Shell::Zsh),
+            "FISH" | _ if s.eq_ignore_ascii_case("fish") => Ok(Shell::Fish),
+            "BASH" | _ if s.eq_ignore_ascii_case("bash") => Ok(Shell::Bash),
+            "POWERSHELL" | _ if s.eq_ignore_ascii_case("powershell") => Ok(Shell::PowerShell),
+            "ELVISH" | _ if s.eq_ignore_ascii_case("elvish") => Ok(Shell::Elvish),
+            _ => Err(String::from("[valid values: bash, fish, zsh, powershell, elvish]")),
+        }
+    }
+}
+
+impl fmt::Display for Shell {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Shell::Bash => write!(f, "BASH"),
+            Shell::Fish => write!(f, "FISH"),
+            Shell::Zsh => write!(f, "ZSH"),
+            Shell::PowerShell => write!(f, "POWERSHELL"),
+            Shell::Elvish => write!(f, "ELVISH"),
+        }
+    }
+}
diff --git a/src/completions/zsh.rs b/src/completions/zsh.rs
new file mode 100644
index 0000000..5d23fd2
--- /dev/null
+++ b/src/completions/zsh.rs
@@ -0,0 +1,472 @@
+// Std
+use std::io::Write;
+#[allow(deprecated, unused_imports)]
+use std::ascii::AsciiExt;
+
+// Internal
+use app::App;
+use app::parser::Parser;
+use args::{AnyArg, ArgSettings};
+use completions;
+use INTERNAL_ERROR_MSG;
+
+pub struct ZshGen<'a, 'b>
+where
+    'a: 'b,
+{
+    p: &'b Parser<'a, 'b>,
+}
+
+impl<'a, 'b> ZshGen<'a, 'b> {
+    pub fn new(p: &'b Parser<'a, 'b>) -> Self {
+        debugln!("ZshGen::new;");
+        ZshGen { p: p }
+    }
+
+    pub fn generate_to<W: Write>(&self, buf: &mut W) {
+        debugln!("ZshGen::generate_to;");
+        w!(
+            buf,
+            format!(
+                "\
+#compdef {name}
+
+autoload -U is-at-least
+
+_{name}() {{
+    typeset -A opt_args
+    typeset -a _arguments_options
+    local ret=1
+
+    if is-at-least 5.2; then
+        _arguments_options=(-s -S -C)
+    else
+        _arguments_options=(-s -C)
+    fi
+
+    local context curcontext=\"$curcontext\" state line
+    {initial_args}
+    {subcommands}
+}}
+
+{subcommand_details}
+
+_{name} \"$@\"",
+                name = self.p.meta.bin_name.as_ref().unwrap(),
+                initial_args = get_args_of(self.p),
+                subcommands = get_subcommands_of(self.p),
+                subcommand_details = subcommand_details(self.p)
+            ).as_bytes()
+        );
+    }
+}
+
+// Displays the commands of a subcommand
+// (( $+functions[_[bin_name_underscore]_commands] )) ||
+// _[bin_name_underscore]_commands() {
+// 	local commands; commands=(
+// 		'[arg_name]:[arg_help]'
+// 	)
+// 	_describe -t commands '[bin_name] commands' commands "$@"
+//
+// Where the following variables are present:
+//    [bin_name_underscore]: The full space delineated bin_name, where spaces have been replaced by
+//                           underscore characters
+//    [arg_name]: The name of the subcommand
+//    [arg_help]: The help message of the subcommand
+//    [bin_name]: The full space delineated bin_name
+//
+// Here's a snippet from rustup:
+//
+// (( $+functions[_rustup_commands] )) ||
+// _rustup_commands() {
+// 	local commands; commands=(
+// 		'show:Show the active and installed toolchains'
+//      'update:Update Rust toolchains'
+//      # ... snip for brevity
+//      'help:Prints this message or the help of the given subcommand(s)'
+// 	)
+// 	_describe -t commands 'rustup commands' commands "$@"
+//
+fn subcommand_details(p: &Parser) -> String {
+    debugln!("ZshGen::subcommand_details;");
+    // First we do ourself
+    let mut ret = vec![
+        format!(
+            "\
+(( $+functions[_{bin_name_underscore}_commands] )) ||
+_{bin_name_underscore}_commands() {{
+    local commands; commands=(
+        {subcommands_and_args}
+    )
+    _describe -t commands '{bin_name} commands' commands \"$@\"
+}}",
+            bin_name_underscore = p.meta.bin_name.as_ref().unwrap().replace(" ", "__"),
+            bin_name = p.meta.bin_name.as_ref().unwrap(),
+            subcommands_and_args = subcommands_of(p)
+        ),
+    ];
+
+    // Next we start looping through all the children, grandchildren, etc.
+    let mut all_subcommands = completions::all_subcommands(p);
+    all_subcommands.sort();
+    all_subcommands.dedup();
+    for &(_, ref bin_name) in &all_subcommands {
+        debugln!("ZshGen::subcommand_details:iter: bin_name={}", bin_name);
+        ret.push(format!(
+            "\
+(( $+functions[_{bin_name_underscore}_commands] )) ||
+_{bin_name_underscore}_commands() {{
+    local commands; commands=(
+        {subcommands_and_args}
+    )
+    _describe -t commands '{bin_name} commands' commands \"$@\"
+}}",
+            bin_name_underscore = bin_name.replace(" ", "__"),
+            bin_name = bin_name,
+            subcommands_and_args = subcommands_of(parser_of(p, bin_name))
+        ));
+    }
+
+    ret.join("\n")
+}
+
+// Generates subcommand completions in form of
+//
+// 		'[arg_name]:[arg_help]'
+//
+// Where:
+//    [arg_name]: the subcommand's name
+//    [arg_help]: the help message of the subcommand
+//
+// A snippet from rustup:
+// 		'show:Show the active and installed toolchains'
+//      'update:Update Rust toolchains'
+fn subcommands_of(p: &Parser) -> String {
+    debugln!("ZshGen::subcommands_of;");
+    let mut ret = vec![];
+    fn add_sc(sc: &App, n: &str, ret: &mut Vec<String>) {
+        debugln!("ZshGen::add_sc;");
+        let s = format!(
+            "\"{name}:{help}\" \\",
+            name = n,
+            help = sc.p
+                .meta
+                .about
+                .unwrap_or("")
+                .replace("[", "\\[")
+                .replace("]", "\\]")
+        );
+        if !s.is_empty() {
+            ret.push(s);
+        }
+    }
+
+    // The subcommands
+    for sc in p.subcommands() {
+        debugln!(
+            "ZshGen::subcommands_of:iter: subcommand={}",
+            sc.p.meta.name
+        );
+        add_sc(sc, &sc.p.meta.name, &mut ret);
+        if let Some(ref v) = sc.p.meta.aliases {
+            for alias in v.iter().filter(|&&(_, vis)| vis).map(|&(n, _)| n) {
+                add_sc(sc, alias, &mut ret);
+            }
+        }
+    }
+
+    ret.join("\n")
+}
+
+// Get's the subcommand section of a completion file
+// This looks roughly like:
+//
+// case $state in
+// ([bin_name]_args)
+//     curcontext=\"${curcontext%:*:*}:[name_hyphen]-command-$words[1]:\"
+//     case $line[1] in
+//
+//         ([name])
+//         _arguments -C -s -S \
+//             [subcommand_args]
+//         && ret=0
+//
+//         [RECURSIVE_CALLS]
+//
+//         ;;",
+//
+//         [repeat]
+//
+//     esac
+// ;;
+// esac",
+//
+// Where the following variables are present:
+//    [name] = The subcommand name in the form of "install" for "rustup toolchain install"
+//    [bin_name] = The full space delineated bin_name such as "rustup toolchain install"
+//    [name_hyphen] = The full space delineated bin_name, but replace spaces with hyphens
+//    [repeat] = From the same recursive calls, but for all subcommands
+//    [subcommand_args] = The same as zsh::get_args_of
+fn get_subcommands_of(p: &Parser) -> String {
+    debugln!("get_subcommands_of;");
+
+    debugln!(
+        "get_subcommands_of: Has subcommands...{:?}",
+        p.has_subcommands()
+    );
+    if !p.has_subcommands() {
+        return String::new();
+    }
+
+    let sc_names = completions::subcommands_of(p);
+
+    let mut subcmds = vec![];
+    for &(ref name, ref bin_name) in &sc_names {
+        let mut v = vec![format!("({})", name)];
+        let subcommand_args = get_args_of(parser_of(p, &*bin_name));
+        if !subcommand_args.is_empty() {
+            v.push(subcommand_args);
+        }
+        let subcommands = get_subcommands_of(parser_of(p, &*bin_name));
+        if !subcommands.is_empty() {
+            v.push(subcommands);
+        }
+        v.push(String::from(";;"));
+        subcmds.push(v.join("\n"));
+    }
+
+    format!(
+        "case $state in
+    ({name})
+        words=($line[{pos}] \"${{words[@]}}\")
+        (( CURRENT += 1 ))
+        curcontext=\"${{curcontext%:*:*}}:{name_hyphen}-command-$line[{pos}]:\"
+        case $line[{pos}] in
+            {subcommands}
+        esac
+    ;;
+esac",
+        name = p.meta.name,
+        name_hyphen = p.meta.bin_name.as_ref().unwrap().replace(" ", "-"),
+        subcommands = subcmds.join("\n"),
+        pos = p.positionals().len() + 1
+    )
+}
+
+fn parser_of<'a, 'b>(p: &'b Parser<'a, 'b>, sc: &str) -> &'b Parser<'a, 'b> {
+    debugln!("parser_of: sc={}", sc);
+    if sc == p.meta.bin_name.as_ref().unwrap_or(&String::new()) {
+        return p;
+    }
+    &p.find_subcommand(sc).expect(INTERNAL_ERROR_MSG).p
+}
+
+// Writes out the args section, which ends up being the flags, opts and postionals, and a jump to
+// another ZSH function if there are subcommands.
+// The structer works like this:
+//    ([conflicting_args]) [multiple] arg [takes_value] [[help]] [: :(possible_values)]
+//       ^-- list '-v -h'    ^--'*'          ^--'+'                   ^-- list 'one two three'
+//
+// An example from the rustup command:
+//
+// _arguments -C -s -S \
+// 		'(-h --help --verbose)-v[Enable verbose output]' \
+// 		'(-V -v --version --verbose --help)-h[Prints help information]' \
+//      # ... snip for brevity
+// 		':: :_rustup_commands' \    # <-- displays subcommands
+// 		'*::: :->rustup' \          # <-- displays subcommand args and child subcommands
+// 	&& ret=0
+//
+// The args used for _arguments are as follows:
+//    -C: modify the $context internal variable
+//    -s: Allow stacking of short args (i.e. -a -b -c => -abc)
+//    -S: Do not complete anything after '--' and treat those as argument values
+fn get_args_of(p: &Parser) -> String {
+    debugln!("get_args_of;");
+    let mut ret = vec![String::from("_arguments \"${_arguments_options[@]}\" \\")];
+    let opts = write_opts_of(p);
+    let flags = write_flags_of(p);
+    let positionals = write_positionals_of(p);
+    let sc_or_a = if p.has_subcommands() {
+        format!(
+            "\":: :_{name}_commands\" \\",
+            name = p.meta.bin_name.as_ref().unwrap().replace(" ", "__")
+        )
+    } else {
+        String::new()
+    };
+    let sc = if p.has_subcommands() {
+        format!("\"*::: :->{name}\" \\", name = p.meta.name)
+    } else {
+        String::new()
+    };
+
+    if !opts.is_empty() {
+        ret.push(opts);
+    }
+    if !flags.is_empty() {
+        ret.push(flags);
+    }
+    if !positionals.is_empty() {
+        ret.push(positionals);
+    }
+    if !sc_or_a.is_empty() {
+        ret.push(sc_or_a);
+    }
+    if !sc.is_empty() {
+        ret.push(sc);
+    }
+    ret.push(String::from("&& ret=0"));
+
+    ret.join("\n")
+}
+
+// Escape help string inside single quotes and brackets
+fn escape_help(string: &str) -> String {
+    string
+        .replace("\\", "\\\\")
+        .replace("'", "'\\''")
+        .replace("[", "\\[")
+        .replace("]", "\\]")
+}
+
+// Escape value string inside single quotes and parentheses
+fn escape_value(string: &str) -> String {
+    string
+        .replace("\\", "\\\\")
+        .replace("'", "'\\''")
+        .replace("(", "\\(")
+        .replace(")", "\\)")
+        .replace(" ", "\\ ")
+}
+
+fn write_opts_of(p: &Parser) -> String {
+    debugln!("write_opts_of;");
+    let mut ret = vec![];
+    for o in p.opts() {
+        debugln!("write_opts_of:iter: o={}", o.name());
+        let help = o.help().map_or(String::new(), escape_help);
+        let mut conflicts = get_zsh_arg_conflicts!(p, o, INTERNAL_ERROR_MSG);
+        conflicts = if conflicts.is_empty() {
+            String::new()
+        } else {
+            format!("({})", conflicts)
+        };
+
+        let multiple = if o.is_set(ArgSettings::Multiple) {
+            "*"
+        } else {
+            ""
+        };
+        let pv = if let Some(pv_vec) = o.possible_vals() {
+            format!(": :({})", pv_vec.iter().map(
+                |v| escape_value(*v)).collect::<Vec<String>>().join(" "))
+        } else {
+            String::new()
+        };
+        if let Some(short) = o.short() {
+            let s = format!(
+                "'{conflicts}{multiple}-{arg}+[{help}]{possible_values}' \\",
+                conflicts = conflicts,
+                multiple = multiple,
+                arg = short,
+                possible_values = pv,
+                help = help
+            );
+
+            debugln!("write_opts_of:iter: Wrote...{}", &*s);
+            ret.push(s);
+        }
+        if let Some(long) = o.long() {
+            let l = format!(
+                "'{conflicts}{multiple}--{arg}=[{help}]{possible_values}' \\",
+                conflicts = conflicts,
+                multiple = multiple,
+                arg = long,
+                possible_values = pv,
+                help = help
+            );
+
+            debugln!("write_opts_of:iter: Wrote...{}", &*l);
+            ret.push(l);
+        }
+    }
+
+    ret.join("\n")
+}
+
+fn write_flags_of(p: &Parser) -> String {
+    debugln!("write_flags_of;");
+    let mut ret = vec![];
+    for f in p.flags() {
+        debugln!("write_flags_of:iter: f={}", f.name());
+        let help = f.help().map_or(String::new(), escape_help);
+        let mut conflicts = get_zsh_arg_conflicts!(p, f, INTERNAL_ERROR_MSG);
+        conflicts = if conflicts.is_empty() {
+            String::new()
+        } else {
+            format!("({})", conflicts)
+        };
+
+        let multiple = if f.is_set(ArgSettings::Multiple) {
+            "*"
+        } else {
+            ""
+        };
+        if let Some(short) = f.short() {
+            let s = format!(
+                "'{conflicts}{multiple}-{arg}[{help}]' \\",
+                multiple = multiple,
+                conflicts = conflicts,
+                arg = short,
+                help = help
+            );
+
+            debugln!("write_flags_of:iter: Wrote...{}", &*s);
+            ret.push(s);
+        }
+
+        if let Some(long) = f.long() {
+            let l = format!(
+                "'{conflicts}{multiple}--{arg}[{help}]' \\",
+                conflicts = conflicts,
+                multiple = multiple,
+                arg = long,
+                help = help
+            );
+
+            debugln!("write_flags_of:iter: Wrote...{}", &*l);
+            ret.push(l);
+        }
+    }
+
+    ret.join("\n")
+}
+
+fn write_positionals_of(p: &Parser) -> String {
+    debugln!("write_positionals_of;");
+    let mut ret = vec![];
+    for arg in p.positionals() {
+        debugln!("write_positionals_of:iter: arg={}", arg.b.name);
+        let a = format!(
+            "'{optional}:{name}{help}:{action}' \\",
+            optional = if !arg.b.is_set(ArgSettings::Required) { ":" } else { "" },
+            name = arg.b.name,
+            help = arg.b
+                .help
+                .map_or("".to_owned(), |v| " -- ".to_owned() + v)
+                .replace("[", "\\[")
+                .replace("]", "\\]"),
+            action = arg.possible_vals().map_or("_files".to_owned(), |values| {
+                format!("({})",
+                    values.iter().map(|v| escape_value(*v)).collect::<Vec<String>>().join(" "))
+            })
+        );
+
+        debugln!("write_positionals_of:iter: Wrote...{}", a);
+        ret.push(a);
+    }
+
+    ret.join("\n")
+}
diff --git a/src/errors.rs b/src/errors.rs
new file mode 100644
index 0000000..c6087c0
--- /dev/null
+++ b/src/errors.rs
@@ -0,0 +1,912 @@
+// Std
+use std::convert::From;
+use std::error::Error as StdError;
+use std::fmt as std_fmt;
+use std::fmt::Display;
+use std::io::{self, Write};
+use std::process;
+use std::result::Result as StdResult;
+
+// Internal
+use args::AnyArg;
+use fmt::{ColorWhen, Colorizer, ColorizerOption};
+use suggestions;
+
+/// Short hand for [`Result`] type
+///
+/// [`Result`]: https://doc.rust-lang.org/std/result/enum.Result.html
+pub type Result<T> = StdResult<T, Error>;
+
+/// Command line argument parser kind of error
+#[derive(Debug, Copy, Clone, PartialEq)]
+pub enum ErrorKind {
+    /// Occurs when an [`Arg`] has a set of possible values,
+    /// and the user provides a value which isn't in that set.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let result = App::new("prog")
+    ///     .arg(Arg::with_name("speed")
+    ///         .possible_value("fast")
+    ///         .possible_value("slow"))
+    ///     .get_matches_from_safe(vec!["prog", "other"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::InvalidValue);
+    /// ```
+    /// [`Arg`]: ./struct.Arg.html
+    InvalidValue,
+
+    /// Occurs when a user provides a flag, option, argument or subcommand which isn't defined.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let result = App::new("prog")
+    ///     .arg(Arg::from_usage("--flag 'some flag'"))
+    ///     .get_matches_from_safe(vec!["prog", "--other"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::UnknownArgument);
+    /// ```
+    UnknownArgument,
+
+    /// Occurs when the user provides an unrecognized [`SubCommand`] which meets the threshold for
+    /// being similar enough to an existing subcommand.
+    /// If it doesn't meet the threshold, or the 'suggestions' feature is disabled,
+    /// the more general [`UnknownArgument`] error is returned.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(not(feature = "suggestions"), doc = " ```no_run")]
+    #[cfg_attr(feature = "suggestions", doc = " ```")]
+    /// # use clap::{App, Arg, ErrorKind, SubCommand};
+    /// let result = App::new("prog")
+    ///     .subcommand(SubCommand::with_name("config")
+    ///         .about("Used for configuration")
+    ///         .arg(Arg::with_name("config_file")
+    ///             .help("The configuration file to use")
+    ///             .index(1)))
+    ///     .get_matches_from_safe(vec!["prog", "confi"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::InvalidSubcommand);
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`UnknownArgument`]: ./enum.ErrorKind.html#variant.UnknownArgument
+    InvalidSubcommand,
+
+    /// Occurs when the user provides an unrecognized [`SubCommand`] which either
+    /// doesn't meet the threshold for being similar enough to an existing subcommand,
+    /// or the 'suggestions' feature is disabled.
+    /// Otherwise the more detailed [`InvalidSubcommand`] error is returned.
+    ///
+    /// This error typically happens when passing additional subcommand names to the `help`
+    /// subcommand. Otherwise, the more general [`UnknownArgument`] error is used.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind, SubCommand};
+    /// let result = App::new("prog")
+    ///     .subcommand(SubCommand::with_name("config")
+    ///         .about("Used for configuration")
+    ///         .arg(Arg::with_name("config_file")
+    ///             .help("The configuration file to use")
+    ///             .index(1)))
+    ///     .get_matches_from_safe(vec!["prog", "help", "nothing"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::UnrecognizedSubcommand);
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`InvalidSubcommand`]: ./enum.ErrorKind.html#variant.InvalidSubcommand
+    /// [`UnknownArgument`]: ./enum.ErrorKind.html#variant.UnknownArgument
+    UnrecognizedSubcommand,
+
+    /// Occurs when the user provides an empty value for an option that does not allow empty
+    /// values.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let res = App::new("prog")
+    ///     .arg(Arg::with_name("color")
+    ///          .long("color")
+    ///          .empty_values(false))
+    ///     .get_matches_from_safe(vec!["prog", "--color="]);
+    /// assert!(res.is_err());
+    /// assert_eq!(res.unwrap_err().kind, ErrorKind::EmptyValue);
+    /// ```
+    EmptyValue,
+
+    /// Occurs when the user provides a value for an argument with a custom validation and the
+    /// value fails that validation.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// fn is_numeric(val: String) -> Result<(), String> {
+    ///     match val.parse::<i64>() {
+    ///         Ok(..) => Ok(()),
+    ///         Err(..) => Err(String::from("Value wasn't a number!")),
+    ///     }
+    /// }
+    ///
+    /// let result = App::new("prog")
+    ///     .arg(Arg::with_name("num")
+    ///          .validator(is_numeric))
+    ///     .get_matches_from_safe(vec!["prog", "NotANumber"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::ValueValidation);
+    /// ```
+    ValueValidation,
+
+    /// Occurs when a user provides more values for an argument than were defined by setting
+    /// [`Arg::max_values`].
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let result = App::new("prog")
+    ///     .arg(Arg::with_name("arg")
+    ///         .multiple(true)
+    ///         .max_values(2))
+    ///     .get_matches_from_safe(vec!["prog", "too", "many", "values"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::TooManyValues);
+    /// ```
+    /// [`Arg::max_values`]: ./struct.Arg.html#method.max_values
+    TooManyValues,
+
+    /// Occurs when the user provides fewer values for an argument than were defined by setting
+    /// [`Arg::min_values`].
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let result = App::new("prog")
+    ///     .arg(Arg::with_name("some_opt")
+    ///         .long("opt")
+    ///         .min_values(3))
+    ///     .get_matches_from_safe(vec!["prog", "--opt", "too", "few"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::TooFewValues);
+    /// ```
+    /// [`Arg::min_values`]: ./struct.Arg.html#method.min_values
+    TooFewValues,
+
+    /// Occurs when the user provides a different number of values for an argument than what's
+    /// been defined by setting [`Arg::number_of_values`] or than was implicitly set by
+    /// [`Arg::value_names`].
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let result = App::new("prog")
+    ///     .arg(Arg::with_name("some_opt")
+    ///         .long("opt")
+    ///         .takes_value(true)
+    ///         .number_of_values(2))
+    ///     .get_matches_from_safe(vec!["prog", "--opt", "wrong"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::WrongNumberOfValues);
+    /// ```
+    ///
+    /// [`Arg::number_of_values`]: ./struct.Arg.html#method.number_of_values
+    /// [`Arg::value_names`]: ./struct.Arg.html#method.value_names
+    WrongNumberOfValues,
+
+    /// Occurs when the user provides two values which conflict with each other and can't be used
+    /// together.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let result = App::new("prog")
+    ///     .arg(Arg::with_name("debug")
+    ///         .long("debug")
+    ///         .conflicts_with("color"))
+    ///     .arg(Arg::with_name("color")
+    ///         .long("color"))
+    ///     .get_matches_from_safe(vec!["prog", "--debug", "--color"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::ArgumentConflict);
+    /// ```
+    ArgumentConflict,
+
+    /// Occurs when the user does not provide one or more required arguments.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let result = App::new("prog")
+    ///     .arg(Arg::with_name("debug")
+    ///         .required(true))
+    ///     .get_matches_from_safe(vec!["prog"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::MissingRequiredArgument);
+    /// ```
+    MissingRequiredArgument,
+
+    /// Occurs when a subcommand is required (as defined by [`AppSettings::SubcommandRequired`]),
+    /// but the user does not provide one.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, AppSettings, SubCommand, ErrorKind};
+    /// let err = App::new("prog")
+    ///     .setting(AppSettings::SubcommandRequired)
+    ///     .subcommand(SubCommand::with_name("test"))
+    ///     .get_matches_from_safe(vec![
+    ///         "myprog",
+    ///     ]);
+    /// assert!(err.is_err());
+    /// assert_eq!(err.unwrap_err().kind, ErrorKind::MissingSubcommand);
+    /// # ;
+    /// ```
+    /// [`AppSettings::SubcommandRequired`]: ./enum.AppSettings.html#variant.SubcommandRequired
+    MissingSubcommand,
+
+    /// Occurs when either an argument or [`SubCommand`] is required, as defined by
+    /// [`AppSettings::ArgRequiredElseHelp`], but the user did not provide one.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, AppSettings, ErrorKind, SubCommand};
+    /// let result = App::new("prog")
+    ///     .setting(AppSettings::ArgRequiredElseHelp)
+    ///     .subcommand(SubCommand::with_name("config")
+    ///         .about("Used for configuration")
+    ///         .arg(Arg::with_name("config_file")
+    ///             .help("The configuration file to use")))
+    ///     .get_matches_from_safe(vec!["prog"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::MissingArgumentOrSubcommand);
+    /// ```
+    /// [`SubCommand`]: ./struct.SubCommand.html
+    /// [`AppSettings::ArgRequiredElseHelp`]: ./enum.AppSettings.html#variant.ArgRequiredElseHelp
+    MissingArgumentOrSubcommand,
+
+    /// Occurs when the user provides multiple values to an argument which doesn't allow that.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let result = App::new("prog")
+    ///     .arg(Arg::with_name("debug")
+    ///         .long("debug")
+    ///         .multiple(false))
+    ///     .get_matches_from_safe(vec!["prog", "--debug", "--debug"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::UnexpectedMultipleUsage);
+    /// ```
+    UnexpectedMultipleUsage,
+
+    /// Occurs when the user provides a value containing invalid UTF-8 for an argument and
+    /// [`AppSettings::StrictUtf8`] is set.
+    ///
+    /// # Platform Specific
+    ///
+    /// Non-Windows platforms only (such as Linux, Unix, macOS, etc.)
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(not(unix), doc = " ```ignore")]
+    #[cfg_attr(unix, doc = " ```")]
+    /// # use clap::{App, Arg, ErrorKind, AppSettings};
+    /// # use std::os::unix::ffi::OsStringExt;
+    /// # use std::ffi::OsString;
+    /// let result = App::new("prog")
+    ///     .setting(AppSettings::StrictUtf8)
+    ///     .arg(Arg::with_name("utf8")
+    ///         .short("u")
+    ///         .takes_value(true))
+    ///     .get_matches_from_safe(vec![OsString::from("myprog"),
+    ///                                 OsString::from("-u"),
+    ///                                 OsString::from_vec(vec![0xE9])]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::InvalidUtf8);
+    /// ```
+    /// [`AppSettings::StrictUtf8`]: ./enum.AppSettings.html#variant.StrictUtf8
+    InvalidUtf8,
+
+    /// Not a true "error" as it means `--help` or similar was used.
+    /// The help message will be sent to `stdout`.
+    ///
+    /// **Note**: If the help is displayed due to an error (such as missing subcommands) it will
+    /// be sent to `stderr` instead of `stdout`.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let result = App::new("prog")
+    ///     .get_matches_from_safe(vec!["prog", "--help"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::HelpDisplayed);
+    /// ```
+    HelpDisplayed,
+
+    /// Not a true "error" as it means `--version` or similar was used.
+    /// The message will be sent to `stdout`.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::{App, Arg, ErrorKind};
+    /// let result = App::new("prog")
+    ///     .get_matches_from_safe(vec!["prog", "--version"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().kind, ErrorKind::VersionDisplayed);
+    /// ```
+    VersionDisplayed,
+
+    /// Occurs when using the [`value_t!`] and [`values_t!`] macros to convert an argument value
+    /// into type `T`, but the argument you requested wasn't used. I.e. you asked for an argument
+    /// with name `config` to be converted, but `config` wasn't used by the user.
+    /// [`value_t!`]: ./macro.value_t!.html
+    /// [`values_t!`]: ./macro.values_t!.html
+    ArgumentNotFound,
+
+    /// Represents an [I/O error].
+    /// Can occur when writing to `stderr` or `stdout` or reading a configuration file.
+    /// [I/O error]: https://doc.rust-lang.org/std/io/struct.Error.html
+    Io,
+
+    /// Represents a [Format error] (which is a part of [`Display`]).
+    /// Typically caused by writing to `stderr` or `stdout`.
+    ///
+    /// [`Display`]: https://doc.rust-lang.org/std/fmt/trait.Display.html
+    /// [Format error]: https://doc.rust-lang.org/std/fmt/struct.Error.html
+    Format,
+}
+
+/// Command Line Argument Parser Error
+#[derive(Debug)]
+pub struct Error {
+    /// Formatted error message
+    pub message: String,
+    /// The type of error
+    pub kind: ErrorKind,
+    /// Any additional information passed along, such as the argument name that caused the error
+    pub info: Option<Vec<String>>,
+}
+
+impl Error {
+    /// Should the message be written to `stdout` or not
+    pub fn use_stderr(&self) -> bool {
+        match self.kind {
+            ErrorKind::HelpDisplayed | ErrorKind::VersionDisplayed => false,
+            _ => true,
+        }
+    }
+
+    /// Prints the error to `stderr` and exits with a status of `1`
+    pub fn exit(&self) -> ! {
+        if self.use_stderr() {
+            wlnerr!("{}", self.message);
+            process::exit(1);
+        }
+        let out = io::stdout();
+        writeln!(&mut out.lock(), "{}", self.message).expect("Error writing Error to stdout");
+        process::exit(0);
+    }
+
+    #[doc(hidden)]
+    pub fn write_to<W: Write>(&self, w: &mut W) -> io::Result<()> { write!(w, "{}", self.message) }
+
+    #[doc(hidden)]
+    pub fn argument_conflict<O, U>(
+        arg: &AnyArg,
+        other: Option<O>,
+        usage: U,
+        color: ColorWhen,
+    ) -> Self
+    where
+        O: Into<String>,
+        U: Display,
+    {
+        let mut v = vec![arg.name().to_owned()];
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} The argument '{}' cannot be used with {}\n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(&*arg.to_string()),
+                match other {
+                    Some(name) => {
+                        let n = name.into();
+                        v.push(n.clone());
+                        c.warning(format!("'{}'", n))
+                    }
+                    None => c.none("one or more of the other specified arguments".to_owned()),
+                },
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::ArgumentConflict,
+            info: Some(v),
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn empty_value<U>(arg: &AnyArg, usage: U, color: ColorWhen) -> Self
+    where
+        U: Display,
+    {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} The argument '{}' requires a value but none was supplied\
+                 \n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(arg.to_string()),
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::EmptyValue,
+            info: Some(vec![arg.name().to_owned()]),
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn invalid_value<B, G, U>(
+        bad_val: B,
+        good_vals: &[G],
+        arg: &AnyArg,
+        usage: U,
+        color: ColorWhen,
+    ) -> Self
+    where
+        B: AsRef<str>,
+        G: AsRef<str> + Display,
+        U: Display,
+    {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        let suffix = suggestions::did_you_mean_value_suffix(bad_val.as_ref(), good_vals.iter());
+
+        let mut sorted = vec![];
+        for v in good_vals {
+            let val = format!("{}", c.good(v));
+            sorted.push(val);
+        }
+        sorted.sort();
+        let valid_values = sorted.join(", ");
+        Error {
+            message: format!(
+                "{} '{}' isn't a valid value for '{}'\n\t\
+                 [possible values: {}]\n\
+                 {}\n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(bad_val.as_ref()),
+                c.warning(arg.to_string()),
+                valid_values,
+                suffix.0,
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::InvalidValue,
+            info: Some(vec![arg.name().to_owned(), bad_val.as_ref().to_owned()]),
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn invalid_subcommand<S, D, N, U>(
+        subcmd: S,
+        did_you_mean: D,
+        name: N,
+        usage: U,
+        color: ColorWhen,
+    ) -> Self
+    where
+        S: Into<String>,
+        D: AsRef<str> + Display,
+        N: Display,
+        U: Display,
+    {
+        let s = subcmd.into();
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} The subcommand '{}' wasn't recognized\n\t\
+                 Did you mean '{}'?\n\n\
+                 If you believe you received this message in error, try \
+                 re-running with '{} {} {}'\n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(&*s),
+                c.good(did_you_mean.as_ref()),
+                name,
+                c.good("--"),
+                &*s,
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::InvalidSubcommand,
+            info: Some(vec![s]),
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn unrecognized_subcommand<S, N>(subcmd: S, name: N, color: ColorWhen) -> Self
+    where
+        S: Into<String>,
+        N: Display,
+    {
+        let s = subcmd.into();
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} The subcommand '{}' wasn't recognized\n\n\
+                 {}\n\t\
+                 {} help <subcommands>...\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(&*s),
+                c.warning("USAGE:"),
+                name,
+                c.good("--help")
+            ),
+            kind: ErrorKind::UnrecognizedSubcommand,
+            info: Some(vec![s]),
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn missing_required_argument<R, U>(required: R, usage: U, color: ColorWhen) -> Self
+    where
+        R: Display,
+        U: Display,
+    {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} The following required arguments were not provided:{}\n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                required,
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::MissingRequiredArgument,
+            info: None,
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn missing_subcommand<N, U>(name: N, usage: U, color: ColorWhen) -> Self
+    where
+        N: AsRef<str> + Display,
+        U: Display,
+    {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} '{}' requires a subcommand, but one was not provided\n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(name),
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::MissingSubcommand,
+            info: None,
+        }
+    }
+
+
+    #[doc(hidden)]
+    pub fn invalid_utf8<U>(usage: U, color: ColorWhen) -> Self
+    where
+        U: Display,
+    {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} Invalid UTF-8 was detected in one or more arguments\n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::InvalidUtf8,
+            info: None,
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn too_many_values<V, U>(val: V, arg: &AnyArg, usage: U, color: ColorWhen) -> Self
+    where
+        V: AsRef<str> + Display + ToOwned,
+        U: Display,
+    {
+        let v = val.as_ref();
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} The value '{}' was provided to '{}', but it wasn't expecting \
+                 any more values\n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(v),
+                c.warning(arg.to_string()),
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::TooManyValues,
+            info: Some(vec![arg.name().to_owned(), v.to_owned()]),
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn too_few_values<U>(
+        arg: &AnyArg,
+        min_vals: u64,
+        curr_vals: usize,
+        usage: U,
+        color: ColorWhen,
+    ) -> Self
+    where
+        U: Display,
+    {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} The argument '{}' requires at least {} values, but only {} w{} \
+                 provided\n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(arg.to_string()),
+                c.warning(min_vals.to_string()),
+                c.warning(curr_vals.to_string()),
+                if curr_vals > 1 { "ere" } else { "as" },
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::TooFewValues,
+            info: Some(vec![arg.name().to_owned()]),
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn value_validation(arg: Option<&AnyArg>, err: String, color: ColorWhen) -> Self
+    {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} Invalid value{}: {}",
+                c.error("error:"),
+                if let Some(a) = arg {
+                    format!(" for '{}'", c.warning(a.to_string()))
+                } else {
+                    "".to_string()
+                },
+                err
+            ),
+            kind: ErrorKind::ValueValidation,
+            info: None,
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn value_validation_auto(err: String) -> Self {
+        let n: Option<&AnyArg> = None;
+        Error::value_validation(n, err, ColorWhen::Auto)
+    }
+
+    #[doc(hidden)]
+    pub fn wrong_number_of_values<S, U>(
+        arg: &AnyArg,
+        num_vals: u64,
+        curr_vals: usize,
+        suffix: S,
+        usage: U,
+        color: ColorWhen,
+    ) -> Self
+    where
+        S: Display,
+        U: Display,
+    {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} The argument '{}' requires {} values, but {} w{} \
+                 provided\n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(arg.to_string()),
+                c.warning(num_vals.to_string()),
+                c.warning(curr_vals.to_string()),
+                suffix,
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::WrongNumberOfValues,
+            info: Some(vec![arg.name().to_owned()]),
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn unexpected_multiple_usage<U>(arg: &AnyArg, usage: U, color: ColorWhen) -> Self
+    where
+        U: Display,
+    {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} The argument '{}' was provided more than once, but cannot \
+                 be used multiple times\n\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(arg.to_string()),
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::UnexpectedMultipleUsage,
+            info: Some(vec![arg.name().to_owned()]),
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn unknown_argument<A, U>(arg: A, did_you_mean: &str, usage: U, color: ColorWhen) -> Self
+    where
+        A: Into<String>,
+        U: Display,
+    {
+        let a = arg.into();
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!(
+                "{} Found argument '{}' which wasn't expected, or isn't valid in \
+                 this context{}\n\
+                 {}\n\n\
+                 For more information try {}",
+                c.error("error:"),
+                c.warning(&*a),
+                if did_you_mean.is_empty() {
+                    "\n".to_owned()
+                } else {
+                    format!("{}\n", did_you_mean)
+                },
+                usage,
+                c.good("--help")
+            ),
+            kind: ErrorKind::UnknownArgument,
+            info: Some(vec![a]),
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn io_error(e: &Error, color: ColorWhen) -> Self {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: color,
+        });
+        Error {
+            message: format!("{} {}", c.error("error:"), e.description()),
+            kind: ErrorKind::Io,
+            info: None,
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn argument_not_found_auto<A>(arg: A) -> Self
+    where
+        A: Into<String>,
+    {
+        let a = arg.into();
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: ColorWhen::Auto,
+        });
+        Error {
+            message: format!(
+                "{} The argument '{}' wasn't found",
+                c.error("error:"),
+                a.clone()
+            ),
+            kind: ErrorKind::ArgumentNotFound,
+            info: Some(vec![a]),
+        }
+    }
+
+    /// Create an error with a custom description.
+    ///
+    /// This can be used in combination with `Error::exit` to exit your program
+    /// with a custom error message.
+    pub fn with_description(description: &str, kind: ErrorKind) -> Self {
+        let c = Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: ColorWhen::Auto,
+        });
+        Error {
+            message: format!("{} {}", c.error("error:"), description),
+            kind: kind,
+            info: None,
+        }
+    }
+}
+
+impl StdError for Error {
+    fn description(&self) -> &str { &*self.message }
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut std_fmt::Formatter) -> std_fmt::Result { writeln!(f, "{}", self.message) }
+}
+
+impl From<io::Error> for Error {
+    fn from(e: io::Error) -> Self { Error::with_description(e.description(), ErrorKind::Io) }
+}
+
+impl From<std_fmt::Error> for Error {
+    fn from(e: std_fmt::Error) -> Self {
+        Error::with_description(e.description(), ErrorKind::Format)
+    }
+}
diff --git a/src/fmt.rs b/src/fmt.rs
new file mode 100644
index 0000000..108a635
--- /dev/null
+++ b/src/fmt.rs
@@ -0,0 +1,189 @@
+#[cfg(all(feature = "color", not(target_os = "windows")))]
+use ansi_term::ANSIString;
+
+#[cfg(all(feature = "color", not(target_os = "windows")))]
+use ansi_term::Colour::{Green, Red, Yellow};
+
+#[cfg(feature = "color")]
+use atty;
+use std::fmt;
+use std::env;
+
+#[doc(hidden)]
+#[derive(Debug, Copy, Clone, PartialEq)]
+pub enum ColorWhen {
+    Auto,
+    Always,
+    Never,
+}
+
+#[cfg(feature = "color")]
+pub fn is_a_tty(stderr: bool) -> bool {
+    debugln!("is_a_tty: stderr={:?}", stderr);
+    let stream = if stderr {
+        atty::Stream::Stderr
+    } else {
+        atty::Stream::Stdout
+    };
+    atty::is(stream)
+}
+
+#[cfg(not(feature = "color"))]
+pub fn is_a_tty(_: bool) -> bool {
+    debugln!("is_a_tty;");
+    false
+}
+
+pub fn is_term_dumb() -> bool { env::var("TERM").ok() == Some(String::from("dumb")) }
+
+#[doc(hidden)]
+pub struct ColorizerOption {
+    pub use_stderr: bool,
+    pub when: ColorWhen,
+}
+
+#[doc(hidden)]
+pub struct Colorizer {
+    when: ColorWhen,
+}
+
+macro_rules! color {
+    ($_self:ident, $c:ident, $m:expr) => {
+        match $_self.when {
+            ColorWhen::Auto => Format::$c($m),
+            ColorWhen::Always => Format::$c($m),
+            ColorWhen::Never => Format::None($m),
+        }
+    };
+}
+
+impl Colorizer {
+    pub fn new(option: ColorizerOption) -> Colorizer {
+        let is_a_tty = is_a_tty(option.use_stderr);
+        let is_term_dumb = is_term_dumb();
+        Colorizer {
+            when: match option.when {
+                ColorWhen::Auto if is_a_tty && !is_term_dumb => ColorWhen::Auto,
+                ColorWhen::Auto => ColorWhen::Never,
+                when => when,
+            }
+        }
+    }
+
+    pub fn good<T>(&self, msg: T) -> Format<T>
+    where
+        T: fmt::Display + AsRef<str>,
+    {
+        debugln!("Colorizer::good;");
+        color!(self, Good, msg)
+    }
+
+    pub fn warning<T>(&self, msg: T) -> Format<T>
+    where
+        T: fmt::Display + AsRef<str>,
+    {
+        debugln!("Colorizer::warning;");
+        color!(self, Warning, msg)
+    }
+
+    pub fn error<T>(&self, msg: T) -> Format<T>
+    where
+        T: fmt::Display + AsRef<str>,
+    {
+        debugln!("Colorizer::error;");
+        color!(self, Error, msg)
+    }
+
+    pub fn none<T>(&self, msg: T) -> Format<T>
+    where
+        T: fmt::Display + AsRef<str>,
+    {
+        debugln!("Colorizer::none;");
+        Format::None(msg)
+    }
+}
+
+impl Default for Colorizer {
+    fn default() -> Self {
+        Colorizer::new(ColorizerOption {
+            use_stderr: true,
+            when: ColorWhen::Auto,
+        })
+    }
+}
+
+/// Defines styles for different types of error messages. Defaults to Error=Red, Warning=Yellow,
+/// and Good=Green
+#[derive(Debug)]
+#[doc(hidden)]
+pub enum Format<T> {
+    /// Defines the style used for errors, defaults to Red
+    Error(T),
+    /// Defines the style used for warnings, defaults to Yellow
+    Warning(T),
+    /// Defines the style used for good values, defaults to Green
+    Good(T),
+    /// Defines no formatting style
+    None(T),
+}
+
+#[cfg(all(feature = "color", not(target_os = "windows")))]
+impl<T: AsRef<str>> Format<T> {
+    fn format(&self) -> ANSIString {
+        match *self {
+            Format::Error(ref e) => Red.bold().paint(e.as_ref()),
+            Format::Warning(ref e) => Yellow.paint(e.as_ref()),
+            Format::Good(ref e) => Green.paint(e.as_ref()),
+            Format::None(ref e) => ANSIString::from(e.as_ref()),
+        }
+    }
+}
+
+#[cfg(any(not(feature = "color"), target_os = "windows"))]
+#[cfg_attr(feature = "lints", allow(match_same_arms))]
+impl<T: fmt::Display> Format<T> {
+    fn format(&self) -> &T {
+        match *self {
+            Format::Error(ref e) => e,
+            Format::Warning(ref e) => e,
+            Format::Good(ref e) => e,
+            Format::None(ref e) => e,
+        }
+    }
+}
+
+
+#[cfg(all(feature = "color", not(target_os = "windows")))]
+impl<T: AsRef<str>> fmt::Display for Format<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{}", &self.format()) }
+}
+
+#[cfg(any(not(feature = "color"), target_os = "windows"))]
+impl<T: fmt::Display> fmt::Display for Format<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{}", &self.format()) }
+}
+
+#[cfg(all(test, feature = "color", not(target_os = "windows")))]
+mod test {
+    use ansi_term::ANSIString;
+    use ansi_term::Colour::{Green, Red, Yellow};
+    use super::Format;
+
+    #[test]
+    fn colored_output() {
+        let err = Format::Error("error");
+        assert_eq!(
+            &*format!("{}", err),
+            &*format!("{}", Red.bold().paint("error"))
+        );
+        let good = Format::Good("good");
+        assert_eq!(&*format!("{}", good), &*format!("{}", Green.paint("good")));
+        let warn = Format::Warning("warn");
+        assert_eq!(&*format!("{}", warn), &*format!("{}", Yellow.paint("warn")));
+        let none = Format::None("none");
+        assert_eq!(
+            &*format!("{}", none),
+            &*format!("{}", ANSIString::from("none"))
+        );
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..0a3e1bb
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,629 @@
+// Copyright ⓒ 2015-2016 Kevin B. Knapp and [`clap-rs` contributors](https://github.com/clap-rs/clap/blob/master/CONTRIBUTORS.md).
+// Licensed under the MIT license
+// (see LICENSE or <http://opensource.org/licenses/MIT>) All files in the project carrying such
+// notice may not be copied, modified, or distributed except according to those terms.
+
+//! `clap` is a simple-to-use, efficient, and full-featured library for parsing command line
+//! arguments and subcommands when writing console/terminal applications.
+//!
+//! ## About
+//!
+//! `clap` is used to parse *and validate* the string of command line arguments provided by the user
+//! at runtime. You provide the list of valid possibilities, and `clap` handles the rest. This means
+//! you focus on your *applications* functionality, and less on the parsing and validating of
+//! arguments.
+//!
+//! `clap` also provides the traditional version and help switches (or flags) 'for free' meaning
+//! automatically with no configuration. It does this by checking list of valid possibilities you
+//! supplied and adding only the ones you haven't already defined. If you are using subcommands,
+//! `clap` will also auto-generate a `help` subcommand for you in addition to the traditional flags.
+//!
+//! Once `clap` parses the user provided string of arguments, it returns the matches along with any
+//! applicable values. If the user made an error or typo, `clap` informs them of the mistake and
+//! exits gracefully (or returns a `Result` type and allows you to perform any clean up prior to
+//! exit). Because of this, you can make reasonable assumptions in your code about the validity of
+//! the arguments.
+//!
+//!
+//! ## Quick Example
+//!
+//! The following examples show a quick example of some of the very basic functionality of `clap`.
+//! For more advanced usage, such as requirements, conflicts, groups, multiple values and
+//! occurrences see the [documentation](https://docs.rs/clap/), [examples/] directory of
+//! this repository or the [video tutorials].
+//!
+//! **NOTE:** All of these examples are functionally the same, but show different styles in which to
+//! use `clap`
+//!
+//! The first example shows a method that allows more advanced configuration options (not shown in
+//! this small example), or even dynamically generating arguments when desired. The downside is it's
+//! more verbose.
+//!
+//! ```no_run
+//! // (Full example with detailed comments in examples/01b_quick_example.rs)
+//! //
+//! // This example demonstrates clap's full 'builder pattern' style of creating arguments which is
+//! // more verbose, but allows easier editing, and at times more advanced options, or the possibility
+//! // to generate arguments dynamically.
+//! extern crate clap;
+//! use clap::{Arg, App, SubCommand};
+//!
+//! fn main() {
+//!     let matches = App::new("My Super Program")
+//!                           .version("1.0")
+//!                           .author("Kevin K. <kbknapp@gmail.com>")
+//!                           .about("Does awesome things")
+//!                           .arg(Arg::with_name("config")
+//!                                .short("c")
+//!                                .long("config")
+//!                                .value_name("FILE")
+//!                                .help("Sets a custom config file")
+//!                                .takes_value(true))
+//!                           .arg(Arg::with_name("INPUT")
+//!                                .help("Sets the input file to use")
+//!                                .required(true)
+//!                                .index(1))
+//!                           .arg(Arg::with_name("v")
+//!                                .short("v")
+//!                                .multiple(true)
+//!                                .help("Sets the level of verbosity"))
+//!                           .subcommand(SubCommand::with_name("test")
+//!                                       .about("controls testing features")
+//!                                       .version("1.3")
+//!                                       .author("Someone E. <someone_else@other.com>")
+//!                                       .arg(Arg::with_name("debug")
+//!                                           .short("d")
+//!                                           .help("print debug information verbosely")))
+//!                           .get_matches();
+//!
+//!     // Gets a value for config if supplied by user, or defaults to "default.conf"
+//!     let config = matches.value_of("config").unwrap_or("default.conf");
+//!     println!("Value for config: {}", config);
+//!
+//!     // Calling .unwrap() is safe here because "INPUT" is required (if "INPUT" wasn't
+//!     // required we could have used an 'if let' to conditionally get the value)
+//!     println!("Using input file: {}", matches.value_of("INPUT").unwrap());
+//!
+//!     // Vary the output based on how many times the user used the "verbose" flag
+//!     // (i.e. 'myprog -v -v -v' or 'myprog -vvv' vs 'myprog -v'
+//!     match matches.occurrences_of("v") {
+//!         0 => println!("No verbose info"),
+//!         1 => println!("Some verbose info"),
+//!         2 => println!("Tons of verbose info"),
+//!         3 | _ => println!("Don't be crazy"),
+//!     }
+//!
+//!     // You can handle information about subcommands by requesting their matches by name
+//!     // (as below), requesting just the name used, or both at the same time
+//!     if let Some(matches) = matches.subcommand_matches("test") {
+//!         if matches.is_present("debug") {
+//!             println!("Printing debug info...");
+//!         } else {
+//!             println!("Printing normally...");
+//!         }
+//!     }
+//!
+//!     // more program logic goes here...
+//! }
+//! ```
+//!
+//! The next example shows a far less verbose method, but sacrifices some of the advanced
+//! configuration options (not shown in this small example). This method also takes a *very* minor
+//! runtime penalty.
+//!
+//! ```no_run
+//! // (Full example with detailed comments in examples/01a_quick_example.rs)
+//! //
+//! // This example demonstrates clap's "usage strings" method of creating arguments
+//! // which is less verbose
+//! extern crate clap;
+//! use clap::{Arg, App, SubCommand};
+//!
+//! fn main() {
+//!     let matches = App::new("myapp")
+//!                           .version("1.0")
+//!                           .author("Kevin K. <kbknapp@gmail.com>")
+//!                           .about("Does awesome things")
+//!                           .args_from_usage(
+//!                               "-c, --config=[FILE] 'Sets a custom config file'
+//!                               <INPUT>              'Sets the input file to use'
+//!                               -v...                'Sets the level of verbosity'")
+//!                           .subcommand(SubCommand::with_name("test")
+//!                                       .about("controls testing features")
+//!                                       .version("1.3")
+//!                                       .author("Someone E. <someone_else@other.com>")
+//!                                       .arg_from_usage("-d, --debug 'Print debug information'"))
+//!                           .get_matches();
+//!
+//!     // Same as previous example...
+//! }
+//! ```
+//!
+//! This third method shows how you can use a YAML file to build your CLI and keep your Rust source
+//! tidy or support multiple localized translations by having different YAML files for each
+//! localization.
+//!
+//! First, create the `cli.yml` file to hold your CLI options, but it could be called anything we
+//! like:
+//!
+//! ```yaml
+//! name: myapp
+//! version: "1.0"
+//! author: Kevin K. <kbknapp@gmail.com>
+//! about: Does awesome things
+//! args:
+//!     - config:
+//!         short: c
+//!         long: config
+//!         value_name: FILE
+//!         help: Sets a custom config file
+//!         takes_value: true
+//!     - INPUT:
+//!         help: Sets the input file to use
+//!         required: true
+//!         index: 1
+//!     - verbose:
+//!         short: v
+//!         multiple: true
+//!         help: Sets the level of verbosity
+//! subcommands:
+//!     - test:
+//!         about: controls testing features
+//!         version: "1.3"
+//!         author: Someone E. <someone_else@other.com>
+//!         args:
+//!             - debug:
+//!                 short: d
+//!                 help: print debug information
+//! ```
+//!
+//! Since this feature requires additional dependencies that not everyone may want, it is *not*
+//! compiled in by default and we need to enable a feature flag in Cargo.toml:
+//!
+//! Simply change your `clap = "~2.27.0"` to `clap = {version = "~2.27.0", features = ["yaml"]}`.
+//!
+//! At last we create our `main.rs` file just like we would have with the previous two examples:
+//!
+//! ```ignore
+//! // (Full example with detailed comments in examples/17_yaml.rs)
+//! //
+//! // This example demonstrates clap's building from YAML style of creating arguments which is far
+//! // more clean, but takes a very small performance hit compared to the other two methods.
+//! #[macro_use]
+//! extern crate clap;
+//! use clap::App;
+//!
+//! fn main() {
+//!     // The YAML file is found relative to the current file, similar to how modules are found
+//!     let yaml = load_yaml!("cli.yml");
+//!     let matches = App::from_yaml(yaml).get_matches();
+//!
+//!     // Same as previous examples...
+//! }
+//! ```
+//!
+//! Finally there is a macro version, which is like a hybrid approach offering the speed of the
+//! builder pattern (the first example), but without all the verbosity.
+//!
+//! ```no_run
+//! #[macro_use]
+//! extern crate clap;
+//!
+//! fn main() {
+//!     let matches = clap_app!(myapp =>
+//!         (version: "1.0")
+//!         (author: "Kevin K. <kbknapp@gmail.com>")
+//!         (about: "Does awesome things")
+//!         (@arg CONFIG: -c --config +takes_value "Sets a custom config file")
+//!         (@arg INPUT: +required "Sets the input file to use")
+//!         (@arg debug: -d ... "Sets the level of debugging information")
+//!         (@subcommand test =>
+//!             (about: "controls testing features")
+//!             (version: "1.3")
+//!             (author: "Someone E. <someone_else@other.com>")
+//!             (@arg verbose: -v --verbose "Print test information verbosely")
+//!         )
+//!     ).get_matches();
+//!
+//!     // Same as before...
+//! }
+//! ```
+//!
+//! If you were to compile any of the above programs and run them with the flag `--help` or `-h` (or
+//! `help` subcommand, since we defined `test` as a subcommand) the following would be output
+//!
+//! ```text
+//! $ myprog --help
+//! My Super Program 1.0
+//! Kevin K. <kbknapp@gmail.com>
+//! Does awesome things
+//!
+//! USAGE:
+//!     MyApp [FLAGS] [OPTIONS] <INPUT> [SUBCOMMAND]
+//!
+//! FLAGS:
+//!     -h, --help       Prints this message
+//!     -v               Sets the level of verbosity
+//!     -V, --version    Prints version information
+//!
+//! OPTIONS:
+//!     -c, --config <FILE>    Sets a custom config file
+//!
+//! ARGS:
+//!     INPUT    The input file to use
+//!
+//! SUBCOMMANDS:
+//!     help    Prints this message
+//!     test    Controls testing features
+//! ```
+//!
+//! **NOTE:** You could also run `myapp test --help` to see similar output and options for the
+//! `test` subcommand.
+//!
+//! ## Try it!
+//!
+//! ### Pre-Built Test
+//!
+//! To try out the pre-built example, use the following steps:
+//!
+//! * Clone the repository `$ git clone https://github.com/clap-rs/clap && cd clap-rs/tests`
+//! * Compile the example `$ cargo build --release`
+//! * Run the help info `$ ./target/release/claptests --help`
+//! * Play with the arguments!
+//!
+//! ### BYOB (Build Your Own Binary)
+//!
+//! To test out `clap`'s default auto-generated help/version follow these steps:
+//!
+//! * Create a new cargo project `$ cargo new fake --bin && cd fake`
+//! * Add `clap` to your `Cargo.toml`
+//!
+//! ```toml
+//! [dependencies]
+//! clap = "2"
+//! ```
+//!
+//! * Add the following to your `src/main.rs`
+//!
+//! ```no_run
+//! extern crate clap;
+//! use clap::App;
+//!
+//! fn main() {
+//!   App::new("fake").version("v1.0-beta").get_matches();
+//! }
+//! ```
+//!
+//! * Build your program `$ cargo build --release`
+//! * Run with help or version `$ ./target/release/fake --help` or `$ ./target/release/fake
+//! --version`
+//!
+//! ## Usage
+//!
+//! For full usage, add `clap` as a dependency in your `Cargo.toml` (it is **highly** recommended to
+//! use the `~major.minor.patch` style versions in your `Cargo.toml`, for more information see
+//! [Compatibility Policy](#compatibility-policy)) to use from crates.io:
+//!
+//! ```toml
+//! [dependencies]
+//! clap = "~2.27.0"
+//! ```
+//!
+//! Or get the latest changes from the master branch at github:
+//!
+//! ```toml
+//! [dependencies.clap]
+//! git = "https://github.com/clap-rs/clap.git"
+//! ```
+//!
+//! Add `extern crate clap;` to your crate root.
+//!
+//! Define a list of valid arguments for your program (see the
+//! [documentation](https://docs.rs/clap/) or [examples/] directory of this repo)
+//!
+//! Then run `cargo build` or `cargo update && cargo build` for your project.
+//!
+//! ### Optional Dependencies / Features
+//!
+//! #### Features enabled by default
+//!
+//! * `suggestions`: Turns on the `Did you mean '--myoption'?` feature for when users make typos. (builds dependency `strsim`)
+//! * `color`: Turns on colored error messages. This feature only works on non-Windows OSs. (builds dependency `ansi-term` and `atty`)
+//! * `wrap_help`: Wraps the help at the actual terminal width when
+//!  available, instead of 120 characters. (builds dependency `textwrap`
+//! with feature `term_size`)
+//!
+//! To disable these, add this to your `Cargo.toml`:
+//!
+//! ```toml
+//! [dependencies.clap]
+//! version = "~2.27.0"
+//! default-features = false
+//! ```
+//!
+//! You can also selectively enable only the features you'd like to include, by adding:
+//!
+//! ```toml
+//! [dependencies.clap]
+//! version = "~2.27.0"
+//! default-features = false
+//!
+//! # Cherry-pick the features you'd like to use
+//! features = [ "suggestions", "color" ]
+//! ```
+//!
+//! #### Opt-in features
+//!
+//! * **"yaml"**: Enables building CLIs from YAML documents. (builds dependency `yaml-rust`)
+//! * **"unstable"**: Enables unstable `clap` features that may change from release to release
+//!
+//! ### Dependencies Tree
+//!
+//! The following graphic depicts `clap`s dependency graph (generated using
+//! [cargo-graph](https://github.com/kbknapp/cargo-graph)).
+//!
+//!  * **Dashed** Line: Optional dependency
+//!  * **Red** Color: **NOT** included by default (must use cargo `features` to enable)
+//!  * **Blue** Color: Dev dependency, only used while developing.
+//!
+//! ![clap dependencies](https://raw.githubusercontent.com/clap-rs/clap/master/clap_dep_graph.png)
+//!
+//! ### More Information
+//!
+//! You can find complete documentation on the [docs.rs](https://docs.rs/clap/) for this project.
+//!
+//! You can also find usage examples in the [examples/] directory of this repo.
+//!
+//! #### Video Tutorials
+//!
+//! There's also the video tutorial series [Argument Parsing with Rust v2][video tutorials].
+//!
+//! These videos slowly trickle out as I finish them and currently a work in progress.
+//!
+//! ## How to Contribute
+//!
+//! Contributions are always welcome! And there is a multitude of ways in which you can help
+//! depending on what you like to do, or are good at. Anything from documentation, code cleanup,
+//! issue completion, new features, you name it, even filing issues is contributing and greatly
+//! appreciated!
+//!
+//! Another really great way to help is if you find an interesting, or helpful way in which to use
+//! `clap`. You can either add it to the [examples/] directory, or file an issue and tell
+//! me. I'm all about giving credit where credit is due :)
+//!
+//! Please read [CONTRIBUTING.md](https://raw.githubusercontent.com/clap-rs/clap/master/.github/CONTRIBUTING.md) before you start contributing.
+//!
+//!
+//! ### Testing Code
+//!
+//! To test with all features both enabled and disabled, you can run theese commands:
+//!
+//! ```text
+//! $ cargo test --no-default-features
+//! $ cargo test --features "yaml unstable"
+//! ```
+//!
+//! Alternatively, if you have [`just`](https://github.com/casey/just) installed you can run the
+//! prebuilt recipes. *Not* using `just` is perfectly fine as well, it simply bundles commands
+//! automatically.
+//!
+//! For example, to test the code, as above simply run:
+//!
+//! ```text
+//! $ just run-tests
+//! ```
+//!
+//! From here on, I will list the appropriate `cargo` command as well as the `just` command.
+//!
+//! Sometimes it's helpful to only run a subset of the tests, which can be done via:
+//!
+//! ```text
+//! $ cargo test --test <test_name>
+//!
+//! # Or
+//!
+//! $ just run-test <test_name>
+//! ```
+//!
+//! ### Linting Code
+//!
+//! During the CI process `clap` runs against many different lints using
+//! [`clippy`](https://github.com/Manishearth/rust-clippy). In order to check if these lints pass on
+//! your own computer prior to submitting a PR you'll need a nightly compiler.
+//!
+//! In order to check the code for lints run either:
+//!
+//! ```text
+//! $ rustup override add nightly
+//! $ cargo build --features lints
+//! $ rustup override remove
+//!
+//! # Or
+//!
+//! $ just lint
+//! ```
+//!
+//! ### Debugging Code
+//!
+//! Another helpful technique is to see the `clap` debug output while developing features. In order
+//! to see the debug output while running the full test suite or individual tests, run:
+//!
+//! ```text
+//! $ cargo test --features debug
+//!
+//! # Or for individual tests
+//! $ cargo test --test <test_name> --features debug
+//!
+//! # The corresponding just command for individual debugging tests is:
+//! $ just debug <test_name>
+//! ```
+//!
+//! ### Goals
+//!
+//! There are a few goals of `clap` that I'd like to maintain throughout contributions. If your
+//! proposed changes break, or go against any of these goals we'll discuss the changes further
+//! before merging (but will *not* be ignored, all contributes are welcome!). These are by no means
+//! hard-and-fast rules, as I'm no expert and break them myself from time to time (even if by
+//! mistake or ignorance).
+//!
+//! * Remain backwards compatible when possible
+//!   - If backwards compatibility *must* be broken, use deprecation warnings if at all possible before
+//!   removing legacy code - This does not apply for security concerns
+//! * Parse arguments quickly
+//!   - Parsing of arguments shouldn't slow down usage of the main program - This is also true of
+//!   generating help and usage information (although *slightly* less stringent, as the program is about
+//!   to exit)
+//! * Try to be cognizant of memory usage
+//!   - Once parsing is complete, the memory footprint of `clap` should be low since the  main program
+//!   is the star of the show
+//! * `panic!` on *developer* error, exit gracefully on *end-user* error
+//!
+//! ### Compatibility Policy
+//!
+//! Because `clap` takes `SemVer` and compatibility seriously, this is the official policy regarding
+//! breaking changes and previous versions of Rust.
+//!
+//! `clap` will pin the minimum required version of Rust to the CI builds. Bumping the minimum
+//! version of Rust is considered a minor breaking change, meaning *at a minimum* the minor version
+//! of `clap` will be bumped.
+//!
+//! In order to keep from being surprised by breaking changes, it is **highly** recommended to use
+//! the `~major.minor.patch` style in your `Cargo.toml`:
+//!
+//! ```toml
+//! [dependencies] clap = "~2.27.0"
+//! ```
+//!
+//! This will cause *only* the patch version to be updated upon a `cargo update` call, and therefore
+//! cannot break due to new features, or bumped minimum versions of Rust.
+//!
+//! #### Minimum Version of Rust
+//!
+//! `clap` will officially support current stable Rust, minus two releases, but may work with prior
+//! releases as well. For example, current stable Rust at the time of this writing is 1.21.0,
+//! meaning `clap` is guaranteed to compile with 1.19.0 and beyond. At the 1.22.0 release, `clap`
+//! will be guaranteed to compile with 1.20.0 and beyond, etc.
+//!
+//! Upon bumping the minimum version of Rust (assuming it's within the stable-2 range), it *must* be
+//! clearly annotated in the `CHANGELOG.md`
+//!
+//! ## License
+//!
+//! `clap` is licensed under the MIT license. Please read the [LICENSE-MIT][license] file in
+//! this repository for more information.
+//!
+//! [examples/]: https://github.com/clap-rs/clap/tree/master/examples
+//! [video tutorials]: https://www.youtube.com/playlist?list=PLza5oFLQGTl2Z5T8g1pRkIynR3E0_pc7U
+//! [license]: https://raw.githubusercontent.com/clap-rs/clap/master/LICENSE-MIT
+
+#![crate_type = "lib"]
+#![doc(html_root_url = "https://docs.rs/clap/2.33.0")]
+#![deny(missing_docs, missing_debug_implementations, missing_copy_implementations, trivial_casts,
+        unused_import_braces, unused_allocation)]
+// Lints we'd like to deny but are currently failing for upstream crates
+//      unused_qualifications       (bitflags, clippy)
+//      trivial_numeric_casts       (bitflags)
+#![cfg_attr(not(any(feature = "lints", feature = "nightly")), forbid(unstable_features))]
+#![cfg_attr(feature = "lints", feature(plugin))]
+#![cfg_attr(feature = "lints", plugin(clippy))]
+// Need to disable deny(warnings) while deprecations are active
+// #![cfg_attr(feature = "lints", deny(warnings))]
+#![cfg_attr(feature = "lints", allow(cyclomatic_complexity))]
+#![cfg_attr(feature = "lints", allow(doc_markdown))]
+#![cfg_attr(feature = "lints", allow(explicit_iter_loop))]
+
+#[cfg(all(feature = "color", not(target_os = "windows")))]
+extern crate ansi_term;
+#[cfg(feature = "color")]
+extern crate atty;
+#[macro_use]
+extern crate bitflags;
+#[cfg(feature = "suggestions")]
+extern crate strsim;
+#[cfg(feature = "wrap_help")]
+extern crate term_size;
+extern crate textwrap;
+extern crate unicode_width;
+#[cfg(feature = "vec_map")]
+extern crate vec_map;
+#[cfg(feature = "yaml")]
+extern crate yaml_rust;
+
+#[cfg(feature = "yaml")]
+pub use yaml_rust::YamlLoader;
+pub use args::{Arg, ArgGroup, ArgMatches, ArgSettings, OsValues, SubCommand, Values};
+pub use app::{App, AppSettings};
+pub use fmt::Format;
+pub use errors::{Error, ErrorKind, Result};
+pub use completions::Shell;
+
+#[macro_use]
+mod macros;
+mod app;
+mod args;
+mod usage_parser;
+mod fmt;
+mod suggestions;
+mod errors;
+mod osstringext;
+mod strext;
+mod completions;
+mod map;
+
+const INTERNAL_ERROR_MSG: &'static str = "Fatal internal error. Please consider filing a bug \
+                                          report at https://github.com/clap-rs/clap/issues";
+const INVALID_UTF8: &'static str = "unexpected invalid UTF-8 code point";
+
+#[cfg(unstable)]
+pub use derive::{ArgEnum, ClapApp, FromArgMatches, IntoApp};
+
+#[cfg(unstable)]
+mod derive {
+    /// @TODO @release @docs
+    pub trait ClapApp: IntoApp + FromArgMatches + Sized {
+        /// @TODO @release @docs
+        fn parse() -> Self { Self::from_argmatches(Self::into_app().get_matches()) }
+
+        /// @TODO @release @docs
+        fn parse_from<I, T>(argv: I) -> Self
+        where
+            I: IntoIterator<Item = T>,
+            T: Into<OsString> + Clone,
+        {
+            Self::from_argmatches(Self::into_app().get_matches_from(argv))
+        }
+
+        /// @TODO @release @docs
+        fn try_parse() -> Result<Self, clap::Error> {
+            Self::try_from_argmatches(Self::into_app().get_matches_safe()?)
+        }
+
+
+        /// @TODO @release @docs
+        fn try_parse_from<I, T>(argv: I) -> Result<Self, clap::Error>
+        where
+            I: IntoIterator<Item = T>,
+            T: Into<OsString> + Clone,
+        {
+            Self::try_from_argmatches(Self::into_app().get_matches_from_safe(argv)?)
+        }
+    }
+
+    /// @TODO @release @docs
+    pub trait IntoApp {
+        /// @TODO @release @docs
+        fn into_app<'a, 'b>() -> clap::App<'a, 'b>;
+    }
+
+    /// @TODO @release @docs
+    pub trait FromArgMatches: Sized {
+        /// @TODO @release @docs
+        fn from_argmatches<'a>(matches: clap::ArgMatches<'a>) -> Self;
+
+        /// @TODO @release @docs
+        fn try_from_argmatches<'a>(matches: clap::ArgMatches<'a>) -> Result<Self, clap::Error>;
+    }
+
+    /// @TODO @release @docs
+    pub trait ArgEnum {}
+}
diff --git a/src/macros.rs b/src/macros.rs
new file mode 100644
index 0000000..8198e19
--- /dev/null
+++ b/src/macros.rs
@@ -0,0 +1,1108 @@
+/// A convenience macro for loading the YAML file at compile time (relative to the current file,
+/// like modules work). That YAML object can then be passed to this function.
+///
+/// # Panics
+///
+/// The YAML file must be properly formatted or this function will panic!(). A good way to
+/// ensure this doesn't happen is to run your program with the `--help` switch. If this passes
+/// without error, you needn't worry because the YAML is properly formatted.
+///
+/// # Examples
+///
+/// The following example shows how to load a properly formatted YAML file to build an instance
+/// of an `App` struct.
+///
+/// ```ignore
+/// # #[macro_use]
+/// # extern crate clap;
+/// # use clap::App;
+/// # fn main() {
+/// let yml = load_yaml!("app.yml");
+/// let app = App::from_yaml(yml);
+///
+/// // continued logic goes here, such as `app.get_matches()` etc.
+/// # }
+/// ```
+#[cfg(feature = "yaml")]
+#[macro_export]
+macro_rules! load_yaml {
+    ($yml:expr) => (
+        &::clap::YamlLoader::load_from_str(include_str!($yml)).expect("failed to load YAML file")[0]
+    );
+}
+
+/// Convenience macro getting a typed value `T` where `T` implements [`std::str::FromStr`] from an
+/// argument value. This macro returns a `Result<T,String>` which allows you as the developer to
+/// decide what you'd like to do on a failed parse. There are two types of errors, parse failures
+/// and those where the argument wasn't present (such as a non-required argument). You can use
+/// it to get a single value, or a iterator as with the [`ArgMatches::values_of`]
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[macro_use]
+/// # extern crate clap;
+/// # use clap::App;
+/// # fn main() {
+/// let matches = App::new("myapp")
+///               .arg_from_usage("[length] 'Set the length to use as a pos whole num, i.e. 20'")
+///               .get_matches();
+///
+/// let len      = value_t!(matches.value_of("length"), u32).unwrap_or_else(|e| e.exit());
+/// let also_len = value_t!(matches, "length", u32).unwrap_or_else(|e| e.exit());
+///
+/// println!("{} + 2: {}", len, len + 2);
+/// # }
+/// ```
+/// [`std::str::FromStr`]: https://doc.rust-lang.org/std/str/trait.FromStr.html
+/// [`ArgMatches::values_of`]: ./struct.ArgMatches.html#method.values_of
+/// [`Result<T,String>`]: https://doc.rust-lang.org/std/result/enum.Result.html
+#[macro_export]
+macro_rules! value_t {
+    ($m:ident, $v:expr, $t:ty) => {
+        value_t!($m.value_of($v), $t)
+    };
+    ($m:ident.value_of($v:expr), $t:ty) => {
+        if let Some(v) = $m.value_of($v) {
+            match v.parse::<$t>() {
+                Ok(val) => Ok(val),
+                Err(_)  =>
+                    Err(::clap::Error::value_validation_auto(
+                        format!("The argument '{}' isn't a valid value", v))),
+            }
+        } else {
+            Err(::clap::Error::argument_not_found_auto($v))
+        }
+    };
+}
+
+/// Convenience macro getting a typed value `T` where `T` implements [`std::str::FromStr`] or
+/// exiting upon error, instead of returning a [`Result`] type.
+///
+/// **NOTE:** This macro is for backwards compatibility sake. Prefer
+/// [`value_t!(/* ... */).unwrap_or_else(|e| e.exit())`]
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[macro_use]
+/// # extern crate clap;
+/// # use clap::App;
+/// # fn main() {
+/// let matches = App::new("myapp")
+///               .arg_from_usage("[length] 'Set the length to use as a pos whole num, i.e. 20'")
+///               .get_matches();
+///
+/// let len      = value_t_or_exit!(matches.value_of("length"), u32);
+/// let also_len = value_t_or_exit!(matches, "length", u32);
+///
+/// println!("{} + 2: {}", len, len + 2);
+/// # }
+/// ```
+/// [`std::str::FromStr`]: https://doc.rust-lang.org/std/str/trait.FromStr.html
+/// [`Result`]: https://doc.rust-lang.org/std/result/enum.Result.html
+/// [`value_t!(/* ... */).unwrap_or_else(|e| e.exit())`]: ./macro.value_t!.html
+#[macro_export]
+macro_rules! value_t_or_exit {
+    ($m:ident, $v:expr, $t:ty) => {
+        value_t_or_exit!($m.value_of($v), $t)
+    };
+    ($m:ident.value_of($v:expr), $t:ty) => {
+        if let Some(v) = $m.value_of($v) {
+            match v.parse::<$t>() {
+                Ok(val) => val,
+                Err(_)  =>
+                    ::clap::Error::value_validation_auto(
+                        format!("The argument '{}' isn't a valid value", v)).exit(),
+            }
+        } else {
+            ::clap::Error::argument_not_found_auto($v).exit()
+        }
+    };
+}
+
+/// Convenience macro getting a typed value [`Vec<T>`] where `T` implements [`std::str::FromStr`]
+/// This macro returns a [`clap::Result<Vec<T>>`] which allows you as the developer to decide
+/// what you'd like to do on a failed parse.
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[macro_use]
+/// # extern crate clap;
+/// # use clap::App;
+/// # fn main() {
+/// let matches = App::new("myapp")
+///               .arg_from_usage("[seq]... 'A sequence of pos whole nums, i.e. 20 45'")
+///               .get_matches();
+///
+/// let vals = values_t!(matches.values_of("seq"), u32).unwrap_or_else(|e| e.exit());
+/// for v in &vals {
+///     println!("{} + 2: {}", v, v + 2);
+/// }
+///
+/// let vals = values_t!(matches, "seq", u32).unwrap_or_else(|e| e.exit());
+/// for v in &vals {
+///     println!("{} + 2: {}", v, v + 2);
+/// }
+/// # }
+/// ```
+/// [`std::str::FromStr`]: https://doc.rust-lang.org/std/str/trait.FromStr.html
+/// [`Vec<T>`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
+/// [`clap::Result<Vec<T>>`]: ./type.Result.html
+#[macro_export]
+macro_rules! values_t {
+    ($m:ident, $v:expr, $t:ty) => {
+        values_t!($m.values_of($v), $t)
+    };
+    ($m:ident.values_of($v:expr), $t:ty) => {
+        if let Some(vals) = $m.values_of($v) {
+            let mut tmp = vec![];
+            let mut err = None;
+            for pv in vals {
+                match pv.parse::<$t>() {
+                    Ok(rv) => tmp.push(rv),
+                    Err(..) => {
+                        err = Some(::clap::Error::value_validation_auto(
+                                format!("The argument '{}' isn't a valid value", pv)));
+                        break
+                    }
+                }
+            }
+            match err {
+                Some(e) => Err(e),
+                None => Ok(tmp),
+            }
+        } else {
+            Err(::clap::Error::argument_not_found_auto($v))
+        }
+    };
+}
+
+/// Convenience macro getting a typed value [`Vec<T>`] where `T` implements [`std::str::FromStr`]
+/// or exiting upon error.
+///
+/// **NOTE:** This macro is for backwards compatibility sake. Prefer
+/// [`values_t!(/* ... */).unwrap_or_else(|e| e.exit())`]
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[macro_use]
+/// # extern crate clap;
+/// # use clap::App;
+/// # fn main() {
+/// let matches = App::new("myapp")
+///               .arg_from_usage("[seq]... 'A sequence of pos whole nums, i.e. 20 45'")
+///               .get_matches();
+///
+/// let vals = values_t_or_exit!(matches.values_of("seq"), u32);
+/// for v in &vals {
+///     println!("{} + 2: {}", v, v + 2);
+/// }
+///
+/// // type for example only
+/// let vals: Vec<u32> = values_t_or_exit!(matches, "seq", u32);
+/// for v in &vals {
+///     println!("{} + 2: {}", v, v + 2);
+/// }
+/// # }
+/// ```
+/// [`values_t!(/* ... */).unwrap_or_else(|e| e.exit())`]: ./macro.values_t!.html
+/// [`std::str::FromStr`]: https://doc.rust-lang.org/std/str/trait.FromStr.html
+/// [`Vec<T>`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
+#[macro_export]
+macro_rules! values_t_or_exit {
+    ($m:ident, $v:expr, $t:ty) => {
+        values_t_or_exit!($m.values_of($v), $t)
+    };
+    ($m:ident.values_of($v:expr), $t:ty) => {
+        if let Some(vals) = $m.values_of($v) {
+            vals.map(|v| v.parse::<$t>().unwrap_or_else(|_|{
+                ::clap::Error::value_validation_auto(
+                    format!("One or more arguments aren't valid values")).exit()
+            })).collect::<Vec<$t>>()
+        } else {
+            ::clap::Error::argument_not_found_auto($v).exit()
+        }
+    };
+}
+
+// _clap_count_exprs! is derived from https://github.com/DanielKeep/rust-grabbag
+// commit: 82a35ca5d9a04c3b920622d542104e3310ee5b07
+// License: MIT
+// Copyright ⓒ 2015 grabbag contributors.
+// Licensed under the MIT license (see LICENSE or <http://opensource.org
+// /licenses/MIT>) or the Apache License, Version 2.0 (see LICENSE of
+// <http://www.apache.org/licenses/LICENSE-2.0>), at your option. All
+// files in the project carrying such notice may not be copied, modified,
+// or distributed except according to those terms.
+//
+/// Counts the number of comma-delimited expressions passed to it.  The result is a compile-time
+/// evaluable expression, suitable for use as a static array size, or the value of a `const`.
+///
+/// # Examples
+///
+/// ```
+/// # #[macro_use] extern crate clap;
+/// # fn main() {
+/// const COUNT: usize = _clap_count_exprs!(a, 5+1, "hi there!".into_string());
+/// assert_eq!(COUNT, 3);
+/// # }
+/// ```
+#[macro_export]
+macro_rules! _clap_count_exprs {
+    () => { 0 };
+    ($e:expr) => { 1 };
+    ($e:expr, $($es:expr),+) => { 1 + $crate::_clap_count_exprs!($($es),*) };
+}
+
+/// Convenience macro to generate more complete enums with variants to be used as a type when
+/// parsing arguments. This enum also provides a `variants()` function which can be used to
+/// retrieve a `Vec<&'static str>` of the variant names, as well as implementing [`FromStr`] and
+/// [`Display`] automatically.
+///
+/// **NOTE:** Case insensitivity is supported for ASCII characters only. It's highly recommended to
+/// use [`Arg::case_insensitive(true)`] for args that will be used with these enums
+///
+/// **NOTE:** This macro automatically implements [`std::str::FromStr`] and [`std::fmt::Display`]
+///
+/// **NOTE:** These enums support pub (or not) and uses of the `#[derive()]` traits
+///
+/// # Examples
+///
+/// ```rust
+/// # #[macro_use]
+/// # extern crate clap;
+/// # use clap::{App, Arg};
+/// arg_enum!{
+///     #[derive(PartialEq, Debug)]
+///     pub enum Foo {
+///         Bar,
+///         Baz,
+///         Qux
+///     }
+/// }
+/// // Foo enum can now be used via Foo::Bar, or Foo::Baz, etc
+/// // and implements std::str::FromStr to use with the value_t! macros
+/// fn main() {
+///     let m = App::new("app")
+///                 .arg(Arg::from_usage("<foo> 'the foo'")
+///                     .possible_values(&Foo::variants())
+///                     .case_insensitive(true))
+///                 .get_matches_from(vec![
+///                     "app", "baz"
+///                 ]);
+///     let f = value_t!(m, "foo", Foo).unwrap_or_else(|e| e.exit());
+///
+///     assert_eq!(f, Foo::Baz);
+/// }
+/// ```
+/// [`FromStr`]: https://doc.rust-lang.org/std/str/trait.FromStr.html
+/// [`std::str::FromStr`]: https://doc.rust-lang.org/std/str/trait.FromStr.html
+/// [`Display`]: https://doc.rust-lang.org/std/fmt/trait.Display.html
+/// [`std::fmt::Display`]: https://doc.rust-lang.org/std/fmt/trait.Display.html
+/// [`Arg::case_insensitive(true)`]: ./struct.Arg.html#method.case_insensitive
+#[macro_export]
+macro_rules! arg_enum {
+    (@as_item $($i:item)*) => ($($i)*);
+    (@impls ( $($tts:tt)* ) -> ($e:ident, $($v:ident),+)) => {
+        arg_enum!(@as_item
+        $($tts)*
+
+        impl ::std::str::FromStr for $e {
+            type Err = String;
+
+            fn from_str(s: &str) -> ::std::result::Result<Self,Self::Err> {
+                #[allow(deprecated, unused_imports)]
+                use ::std::ascii::AsciiExt;
+                match s {
+                    $(stringify!($v) |
+                    _ if s.eq_ignore_ascii_case(stringify!($v)) => Ok($e::$v)),+,
+                    _ => Err({
+                        let v = vec![
+                            $(stringify!($v),)+
+                        ];
+                        format!("valid values: {}",
+                            v.join(", "))
+                    }),
+                }
+            }
+        }
+        impl ::std::fmt::Display for $e {
+            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+                match *self {
+                    $($e::$v => write!(f, stringify!($v)),)+
+                }
+            }
+        }
+        impl $e {
+            #[allow(dead_code)]
+            pub fn variants() -> [&'static str; $crate::_clap_count_exprs!($(stringify!($v)),+)] {
+                [
+                    $(stringify!($v),)+
+                ]
+            }
+        });
+    };
+    ($(#[$($m:meta),+])+ pub enum $e:ident { $($v:ident $(=$val:expr)*,)+ } ) => {
+        arg_enum!(@impls
+            ($(#[$($m),+])+
+            pub enum $e {
+                $($v$(=$val)*),+
+            }) -> ($e, $($v),+)
+        );
+    };
+    ($(#[$($m:meta),+])+ pub enum $e:ident { $($v:ident $(=$val:expr)*),+ } ) => {
+        arg_enum!(@impls
+            ($(#[$($m),+])+
+            pub enum $e {
+                $($v$(=$val)*),+
+            }) -> ($e, $($v),+)
+        );
+    };
+    ($(#[$($m:meta),+])+ enum $e:ident { $($v:ident $(=$val:expr)*,)+ } ) => {
+        arg_enum!(@impls
+            ($(#[$($m),+])+
+             enum $e {
+                 $($v$(=$val)*),+
+             }) -> ($e, $($v),+)
+        );
+    };
+    ($(#[$($m:meta),+])+ enum $e:ident { $($v:ident $(=$val:expr)*),+ } ) => {
+        arg_enum!(@impls
+            ($(#[$($m),+])+
+            enum $e {
+                $($v$(=$val)*),+
+            }) -> ($e, $($v),+)
+        );
+    };
+    (pub enum $e:ident { $($v:ident $(=$val:expr)*,)+ } ) => {
+        arg_enum!(@impls
+            (pub enum $e {
+                $($v$(=$val)*),+
+            }) -> ($e, $($v),+)
+        );
+    };
+    (pub enum $e:ident { $($v:ident $(=$val:expr)*),+ } ) => {
+        arg_enum!(@impls
+            (pub enum $e {
+                $($v$(=$val)*),+
+            }) -> ($e, $($v),+)
+        );
+    };
+    (enum $e:ident { $($v:ident $(=$val:expr)*,)+ } ) => {
+        arg_enum!(@impls
+            (enum $e {
+                $($v$(=$val)*),+
+            }) -> ($e, $($v),+)
+        );
+    };
+    (enum $e:ident { $($v:ident $(=$val:expr)*),+ } ) => {
+        arg_enum!(@impls
+            (enum $e {
+                $($v$(=$val)*),+
+            }) -> ($e, $($v),+)
+        );
+    };
+}
+
+/// Allows you to pull the version from your Cargo.toml at compile time as
+/// `MAJOR.MINOR.PATCH_PKGVERSION_PRE`
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[macro_use]
+/// # extern crate clap;
+/// # use clap::App;
+/// # fn main() {
+/// let m = App::new("app")
+///             .version(crate_version!())
+///             .get_matches();
+/// # }
+/// ```
+#[cfg(not(feature = "no_cargo"))]
+#[macro_export]
+macro_rules! crate_version {
+    () => {
+        env!("CARGO_PKG_VERSION")
+    };
+}
+
+/// Allows you to pull the authors for the app from your Cargo.toml at
+/// compile time in the form:
+/// `"author1 lastname <author1@example.com>:author2 lastname <author2@example.com>"`
+///
+/// You can replace the colons with a custom separator by supplying a
+/// replacement string, so, for example,
+/// `crate_authors!(",\n")` would become
+/// `"author1 lastname <author1@example.com>,\nauthor2 lastname <author2@example.com>,\nauthor3 lastname <author3@example.com>"`
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[macro_use]
+/// # extern crate clap;
+/// # use clap::App;
+/// # fn main() {
+/// let m = App::new("app")
+///             .author(crate_authors!("\n"))
+///             .get_matches();
+/// # }
+/// ```
+#[cfg(not(feature = "no_cargo"))]
+#[macro_export]
+macro_rules! crate_authors {
+    ($sep:expr) => {{
+        use std::ops::Deref;
+        use std::sync::{ONCE_INIT, Once};
+
+        #[allow(missing_copy_implementations)]
+        #[allow(dead_code)]
+        struct CargoAuthors { __private_field: () };
+
+        impl Deref for CargoAuthors {
+            type Target = str;
+
+            #[allow(unsafe_code)]
+            fn deref(&self) -> &'static str {
+                static ONCE: Once = ONCE_INIT;
+                static mut VALUE: *const String = 0 as *const String;
+
+                unsafe {
+                    ONCE.call_once(|| {
+                        let s = env!("CARGO_PKG_AUTHORS").replace(':', $sep);
+                        VALUE = Box::into_raw(Box::new(s));
+                    });
+
+                    &(*VALUE)[..]
+                }
+            }
+        }
+
+        &*CargoAuthors { __private_field: () }
+    }};
+    () => {
+        env!("CARGO_PKG_AUTHORS")
+    };
+}
+
+/// Allows you to pull the description from your Cargo.toml at compile time.
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[macro_use]
+/// # extern crate clap;
+/// # use clap::App;
+/// # fn main() {
+/// let m = App::new("app")
+///             .about(crate_description!())
+///             .get_matches();
+/// # }
+/// ```
+#[cfg(not(feature = "no_cargo"))]
+#[macro_export]
+macro_rules! crate_description {
+    () => {
+        env!("CARGO_PKG_DESCRIPTION")
+    };
+}
+
+/// Allows you to pull the name from your Cargo.toml at compile time.
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[macro_use]
+/// # extern crate clap;
+/// # use clap::App;
+/// # fn main() {
+/// let m = App::new(crate_name!())
+///             .get_matches();
+/// # }
+/// ```
+#[cfg(not(feature = "no_cargo"))]
+#[macro_export]
+macro_rules! crate_name {
+    () => {
+        env!("CARGO_PKG_NAME")
+    };
+}
+
+/// Allows you to build the `App` instance from your Cargo.toml at compile time.
+///
+/// Equivalent to using the `crate_*!` macros with their respective fields.
+///
+/// Provided separator is for the [`crate_authors!`](macro.crate_authors.html) macro,
+/// refer to the documentation therefor.
+///
+/// **NOTE:** Changing the values in your `Cargo.toml` does not trigger a re-build automatically,
+/// and therefore won't change the generated output until you recompile.
+///
+/// **Pro Tip:** In some cases you can "trick" the compiler into triggering a rebuild when your
+/// `Cargo.toml` is changed by including this in your `src/main.rs` file
+/// `include_str!("../Cargo.toml");`
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[macro_use]
+/// # extern crate clap;
+/// # fn main() {
+/// let m = app_from_crate!().get_matches();
+/// # }
+/// ```
+#[cfg(not(feature = "no_cargo"))]
+#[macro_export]
+macro_rules! app_from_crate {
+    () => {
+        $crate::App::new(crate_name!())
+            .version(crate_version!())
+            .author(crate_authors!())
+            .about(crate_description!())
+    };
+    ($sep:expr) => {
+        $crate::App::new(crate_name!())
+            .version(crate_version!())
+            .author(crate_authors!($sep))
+            .about(crate_description!())
+    };
+}
+
+/// Build `App`, `Arg`s, `SubCommand`s and `Group`s with Usage-string like input
+/// but without the associated parsing runtime cost.
+///
+/// `clap_app!` also supports several shorthand syntaxes.
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[macro_use]
+/// # extern crate clap;
+/// # fn main() {
+/// let matches = clap_app!(myapp =>
+///     (version: "1.0")
+///     (author: "Kevin K. <kbknapp@gmail.com>")
+///     (about: "Does awesome things")
+///     (@arg CONFIG: -c --config +takes_value "Sets a custom config file")
+///     (@arg INPUT: +required "Sets the input file to use")
+///     (@arg debug: -d ... "Sets the level of debugging information")
+///     (@group difficulty =>
+///         (@arg hard: -h --hard "Sets hard mode")
+///         (@arg normal: -n --normal "Sets normal mode")
+///         (@arg easy: -e --easy "Sets easy mode")
+///     )
+///     (@subcommand test =>
+///         (about: "controls testing features")
+///         (version: "1.3")
+///         (author: "Someone E. <someone_else@other.com>")
+///         (@arg verbose: -v --verbose "Print test information verbosely")
+///     )
+/// )
+/// .get_matches();
+/// # }
+/// ```
+/// # Shorthand Syntax for Args
+///
+/// * A single hyphen followed by a character (such as `-c`) sets the [`Arg::short`]
+/// * A double hyphen followed by a character or word (such as `--config`) sets [`Arg::long`]
+///   * If one wishes to use a [`Arg::long`] with a hyphen inside (i.e. `--config-file`), you
+///     must use `--("config-file")` due to limitations of the Rust macro system.
+/// * Three dots (`...`) sets [`Arg::multiple(true)`]
+/// * Angled brackets after either a short or long will set [`Arg::value_name`] and
+/// `Arg::required(true)` such as `--config <FILE>` = `Arg::value_name("FILE")` and
+/// `Arg::required(true)`
+/// * Square brackets after either a short or long will set [`Arg::value_name`] and
+/// `Arg::required(false)` such as `--config [FILE]` = `Arg::value_name("FILE")` and
+/// `Arg::required(false)`
+/// * There are short hand syntaxes for Arg methods that accept booleans
+///   * A plus sign will set that method to `true` such as `+required` = `Arg::required(true)`
+///   * An exclamation will set that method to `false` such as `!required` = `Arg::required(false)`
+/// * A `#{min, max}` will set [`Arg::min_values(min)`] and [`Arg::max_values(max)`]
+/// * An asterisk (`*`) will set `Arg::required(true)`
+/// * Curly brackets around a `fn` will set [`Arg::validator`] as in `{fn}` = `Arg::validator(fn)`
+/// * An Arg method that accepts a string followed by square brackets will set that method such as
+/// `conflicts_with[FOO]` will set `Arg::conflicts_with("FOO")` (note the lack of quotes around
+/// `FOO` in the macro)
+/// * An Arg method that takes a string and can be set multiple times (such as
+/// [`Arg::conflicts_with`]) followed by square brackets and a list of values separated by spaces
+/// will set that method such as `conflicts_with[FOO BAR BAZ]` will set
+/// `Arg::conflicts_with("FOO")`, `Arg::conflicts_with("BAR")`, and `Arg::conflicts_with("BAZ")`
+/// (note the lack of quotes around the values in the macro)
+///
+/// # Shorthand Syntax for Groups
+///
+/// * There are short hand syntaxes for `ArgGroup` methods that accept booleans
+///   * A plus sign will set that method to `true` such as `+required` = `ArgGroup::required(true)`
+///   * An exclamation will set that method to `false` such as `!required` = `ArgGroup::required(false)`
+///
+/// [`Arg::short`]: ./struct.Arg.html#method.short
+/// [`Arg::long`]: ./struct.Arg.html#method.long
+/// [`Arg::multiple(true)`]: ./struct.Arg.html#method.multiple
+/// [`Arg::value_name`]: ./struct.Arg.html#method.value_name
+/// [`Arg::min_values(min)`]: ./struct.Arg.html#method.min_values
+/// [`Arg::max_values(max)`]: ./struct.Arg.html#method.max_values
+/// [`Arg::validator`]: ./struct.Arg.html#method.validator
+/// [`Arg::conflicts_with`]: ./struct.Arg.html#method.conflicts_with
+#[macro_export]
+macro_rules! clap_app {
+    (@app ($builder:expr)) => { $builder };
+    (@app ($builder:expr) (@arg ($name:expr): $($tail:tt)*) $($tt:tt)*) => {
+        clap_app!{ @app
+            ($builder.arg(
+                clap_app!{ @arg ($crate::Arg::with_name($name)) (-) $($tail)* }))
+            $($tt)*
+        }
+    };
+    (@app ($builder:expr) (@arg $name:ident: $($tail:tt)*) $($tt:tt)*) => {
+        clap_app!{ @app
+            ($builder.arg(
+                clap_app!{ @arg ($crate::Arg::with_name(stringify!($name))) (-) $($tail)* }))
+            $($tt)*
+        }
+    };
+    (@app ($builder:expr) (@setting $setting:ident) $($tt:tt)*) => {
+        clap_app!{ @app
+            ($builder.setting($crate::AppSettings::$setting))
+            $($tt)*
+        }
+    };
+// Treat the application builder as an argument to set its attributes
+    (@app ($builder:expr) (@attributes $($attr:tt)*) $($tt:tt)*) => {
+        clap_app!{ @app (clap_app!{ @arg ($builder) $($attr)* }) $($tt)* }
+    };
+    (@app ($builder:expr) (@group $name:ident => $($tail:tt)*) $($tt:tt)*) => {
+        clap_app!{ @app
+            (clap_app!{ @group ($builder, $crate::ArgGroup::with_name(stringify!($name))) $($tail)* })
+            $($tt)*
+        }
+    };
+    (@app ($builder:expr) (@group $name:ident !$ident:ident => $($tail:tt)*) $($tt:tt)*) => {
+        clap_app!{ @app
+            (clap_app!{ @group ($builder, $crate::ArgGroup::with_name(stringify!($name)).$ident(false)) $($tail)* })
+            $($tt)*
+        }
+    };
+    (@app ($builder:expr) (@group $name:ident +$ident:ident => $($tail:tt)*) $($tt:tt)*) => {
+        clap_app!{ @app
+            (clap_app!{ @group ($builder, $crate::ArgGroup::with_name(stringify!($name)).$ident(true)) $($tail)* })
+            $($tt)*
+        }
+    };
+// Handle subcommand creation
+    (@app ($builder:expr) (@subcommand $name:ident => $($tail:tt)*) $($tt:tt)*) => {
+        clap_app!{ @app
+            ($builder.subcommand(
+                clap_app!{ @app ($crate::SubCommand::with_name(stringify!($name))) $($tail)* }
+            ))
+            $($tt)*
+        }
+    };
+// Yaml like function calls - used for setting various meta directly against the app
+    (@app ($builder:expr) ($ident:ident: $($v:expr),*) $($tt:tt)*) => {
+// clap_app!{ @app ($builder.$ident($($v),*)) $($tt)* }
+        clap_app!{ @app
+            ($builder.$ident($($v),*))
+            $($tt)*
+        }
+    };
+
+// Add members to group and continue argument handling with the parent builder
+    (@group ($builder:expr, $group:expr)) => { $builder.group($group) };
+    // Treat the group builder as an argument to set its attributes
+    (@group ($builder:expr, $group:expr) (@attributes $($attr:tt)*) $($tt:tt)*) => {
+        clap_app!{ @group ($builder, clap_app!{ @arg ($group) (-) $($attr)* }) $($tt)* }
+    };
+    (@group ($builder:expr, $group:expr) (@arg $name:ident: $($tail:tt)*) $($tt:tt)*) => {
+        clap_app!{ @group
+            (clap_app!{ @app ($builder) (@arg $name: $($tail)*) },
+             $group.arg(stringify!($name)))
+            $($tt)*
+        }
+    };
+
+// No more tokens to munch
+    (@arg ($arg:expr) $modes:tt) => { $arg };
+// Shorthand tokens influenced by the usage_string
+    (@arg ($arg:expr) $modes:tt --($long:expr) $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.long($long)) $modes $($tail)* }
+    };
+    (@arg ($arg:expr) $modes:tt --$long:ident $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.long(stringify!($long))) $modes $($tail)* }
+    };
+    (@arg ($arg:expr) $modes:tt -$short:ident $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.short(stringify!($short))) $modes $($tail)* }
+    };
+    (@arg ($arg:expr) (-) <$var:ident> $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.value_name(stringify!($var))) (+) +takes_value +required $($tail)* }
+    };
+    (@arg ($arg:expr) (+) <$var:ident> $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.value_name(stringify!($var))) (+) $($tail)* }
+    };
+    (@arg ($arg:expr) (-) [$var:ident] $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.value_name(stringify!($var))) (+) +takes_value $($tail)* }
+    };
+    (@arg ($arg:expr) (+) [$var:ident] $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.value_name(stringify!($var))) (+) $($tail)* }
+    };
+    (@arg ($arg:expr) $modes:tt ... $($tail:tt)*) => {
+        clap_app!{ @arg ($arg) $modes +multiple $($tail)* }
+    };
+// Shorthand magic
+    (@arg ($arg:expr) $modes:tt #{$n:expr, $m:expr} $($tail:tt)*) => {
+        clap_app!{ @arg ($arg) $modes min_values($n) max_values($m) $($tail)* }
+    };
+    (@arg ($arg:expr) $modes:tt * $($tail:tt)*) => {
+        clap_app!{ @arg ($arg) $modes +required $($tail)* }
+    };
+// !foo -> .foo(false)
+    (@arg ($arg:expr) $modes:tt !$ident:ident $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.$ident(false)) $modes $($tail)* }
+    };
+// +foo -> .foo(true)
+    (@arg ($arg:expr) $modes:tt +$ident:ident $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.$ident(true)) $modes $($tail)* }
+    };
+// Validator
+    (@arg ($arg:expr) $modes:tt {$fn_:expr} $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.validator($fn_)) $modes $($tail)* }
+    };
+    (@as_expr $expr:expr) => { $expr };
+// Help
+    (@arg ($arg:expr) $modes:tt $desc:tt) => { $arg.help(clap_app!{ @as_expr $desc }) };
+// Handle functions that need to be called multiple times for each argument
+    (@arg ($arg:expr) $modes:tt $ident:ident[$($target:ident)*] $($tail:tt)*) => {
+        clap_app!{ @arg ($arg $( .$ident(stringify!($target)) )*) $modes $($tail)* }
+    };
+// Inherit builder's functions, e.g. `index(2)`, `requires_if("val", "arg")`
+    (@arg ($arg:expr) $modes:tt $ident:ident($($expr:expr),*) $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.$ident($($expr),*)) $modes $($tail)* }
+    };
+// Inherit builder's functions with trailing comma, e.g. `index(2,)`, `requires_if("val", "arg",)`
+    (@arg ($arg:expr) $modes:tt $ident:ident($($expr:expr,)*) $($tail:tt)*) => {
+        clap_app!{ @arg ($arg.$ident($($expr),*)) $modes $($tail)* }
+    };
+
+// Build a subcommand outside of an app.
+    (@subcommand $name:ident => $($tail:tt)*) => {
+        clap_app!{ @app ($crate::SubCommand::with_name(stringify!($name))) $($tail)* }
+    };
+// Start the magic
+    (($name:expr) => $($tail:tt)*) => {{
+        clap_app!{ @app ($crate::App::new($name)) $($tail)*}
+    }};
+
+    ($name:ident => $($tail:tt)*) => {{
+        clap_app!{ @app ($crate::App::new(stringify!($name))) $($tail)*}
+    }};
+}
+
+macro_rules! impl_settings {
+    ($n:ident, $($v:ident => $c:path),+) => {
+        pub fn set(&mut self, s: $n) {
+            match s {
+                $($n::$v => self.0.insert($c)),+
+            }
+        }
+
+        pub fn unset(&mut self, s: $n) {
+            match s {
+                $($n::$v => self.0.remove($c)),+
+            }
+        }
+
+        pub fn is_set(&self, s: $n) -> bool {
+            match s {
+                $($n::$v => self.0.contains($c)),+
+            }
+        }
+    };
+}
+
+// Convenience for writing to stderr thanks to https://github.com/BurntSushi
+macro_rules! wlnerr(
+    ($($arg:tt)*) => ({
+        use std::io::{Write, stderr};
+        writeln!(&mut stderr(), $($arg)*).ok();
+    })
+);
+
+#[cfg(feature = "debug")]
+#[cfg_attr(feature = "debug", macro_use)]
+#[cfg_attr(feature = "debug", allow(unused_macros))]
+mod debug_macros {
+    macro_rules! debugln {
+        ($fmt:expr) => (println!(concat!("DEBUG:clap:", $fmt)));
+        ($fmt:expr, $($arg:tt)*) => (println!(concat!("DEBUG:clap:",$fmt), $($arg)*));
+    }
+    macro_rules! sdebugln {
+        ($fmt:expr) => (println!($fmt));
+        ($fmt:expr, $($arg:tt)*) => (println!($fmt, $($arg)*));
+    }
+    macro_rules! debug {
+        ($fmt:expr) => (print!(concat!("DEBUG:clap:", $fmt)));
+        ($fmt:expr, $($arg:tt)*) => (print!(concat!("DEBUG:clap:",$fmt), $($arg)*));
+    }
+    macro_rules! sdebug {
+        ($fmt:expr) => (print!($fmt));
+        ($fmt:expr, $($arg:tt)*) => (print!($fmt, $($arg)*));
+    }
+}
+
+#[cfg(not(feature = "debug"))]
+#[cfg_attr(not(feature = "debug"), macro_use)]
+mod debug_macros {
+    macro_rules! debugln {
+        ($fmt:expr) => ();
+        ($fmt:expr, $($arg:tt)*) => ();
+    }
+    macro_rules! sdebugln {
+        ($fmt:expr) => ();
+        ($fmt:expr, $($arg:tt)*) => ();
+    }
+    macro_rules! debug {
+        ($fmt:expr) => ();
+        ($fmt:expr, $($arg:tt)*) => ();
+    }
+}
+
+// Helper/deduplication macro for printing the correct number of spaces in help messages
+// used in:
+//    src/args/arg_builder/*.rs
+//    src/app/mod.rs
+macro_rules! write_nspaces {
+    ($dst:expr, $num:expr) => ({
+        debugln!("write_spaces!: num={}", $num);
+        for _ in 0..$num {
+            $dst.write_all(b" ")?;
+        }
+    })
+}
+
+// convenience macro for remove an item from a vec
+//macro_rules! vec_remove_all {
+//    ($vec:expr, $to_rem:expr) => {
+//        debugln!("vec_remove_all! to_rem={:?}", $to_rem);
+//        for i in (0 .. $vec.len()).rev() {
+//            let should_remove = $to_rem.any(|name| name == &$vec[i]);
+//            if should_remove { $vec.swap_remove(i); }
+//        }
+//    };
+//}
+macro_rules! find_from {
+    ($_self:expr, $arg_name:expr, $from:ident, $matcher:expr) => {{
+        let mut ret = None;
+        for k in $matcher.arg_names() {
+            if let Some(f) = find_by_name!($_self, k, flags, iter) {
+                if let Some(ref v) = f.$from() {
+                    if v.contains($arg_name) {
+                        ret = Some(f.to_string());
+                    }
+                }
+            }
+            if let Some(o) = find_by_name!($_self, k, opts, iter) {
+                if let Some(ref v) = o.$from() {
+                    if v.contains(&$arg_name) {
+                        ret = Some(o.to_string());
+                    }
+                }
+            }
+            if let Some(pos) = find_by_name!($_self, k, positionals, values) {
+                if let Some(ref v) = pos.$from() {
+                    if v.contains($arg_name) {
+                        ret = Some(pos.b.name.to_owned());
+                    }
+                }
+            }
+        }
+        ret
+    }};
+}
+
+//macro_rules! find_name_from {
+//    ($_self:expr, $arg_name:expr, $from:ident, $matcher:expr) => {{
+//        let mut ret = None;
+//        for k in $matcher.arg_names() {
+//            if let Some(f) = find_by_name!($_self, k, flags, iter) {
+//                if let Some(ref v) = f.$from() {
+//                    if v.contains($arg_name) {
+//                        ret = Some(f.b.name);
+//                    }
+//                }
+//            }
+//            if let Some(o) = find_by_name!($_self, k, opts, iter) {
+//                if let Some(ref v) = o.$from() {
+//                    if v.contains(&$arg_name) {
+//                        ret = Some(o.b.name);
+//                    }
+//                }
+//            }
+//            if let Some(pos) = find_by_name!($_self, k, positionals, values) {
+//                if let Some(ref v) = pos.$from() {
+//                    if v.contains($arg_name) {
+//                        ret = Some(pos.b.name);
+//                    }
+//                }
+//            }
+//        }
+//        ret
+//    }};
+//}
+
+
+macro_rules! find_any_by_name {
+    ($p:expr, $name:expr) => {
+        {
+            fn as_trait_obj<'a, 'b, T: AnyArg<'a, 'b>>(x: &T) -> &AnyArg<'a, 'b> { x }
+            find_by_name!($p, $name, flags, iter).map(as_trait_obj).or(
+                find_by_name!($p, $name, opts, iter).map(as_trait_obj).or(
+                    find_by_name!($p, $name, positionals, values).map(as_trait_obj)
+                )
+            )
+        }
+    }
+}
+// Finds an arg by name
+macro_rules! find_by_name {
+    ($p:expr, $name:expr, $what:ident, $how:ident) => {
+        $p.$what.$how().find(|o| o.b.name == $name)
+    }
+}
+
+// Finds an option including if it's aliased
+macro_rules! find_opt_by_long {
+    (@os $_self:ident, $long:expr) => {{
+        _find_by_long!($_self, $long, opts)
+    }};
+    ($_self:ident, $long:expr) => {{
+        _find_by_long!($_self, $long, opts)
+    }};
+}
+
+macro_rules! find_flag_by_long {
+    (@os $_self:ident, $long:expr) => {{
+        _find_by_long!($_self, $long, flags)
+    }};
+    ($_self:ident, $long:expr) => {{
+        _find_by_long!($_self, $long, flags)
+    }};
+}
+
+macro_rules! _find_by_long {
+    ($_self:ident, $long:expr, $what:ident) => {{
+        $_self.$what
+            .iter()
+            .filter(|a| a.s.long.is_some())
+            .find(|a| {
+                a.s.long.unwrap() == $long ||
+                (a.s.aliases.is_some() &&
+                 a.s
+                    .aliases
+                    .as_ref()
+                    .unwrap()
+                    .iter()
+                    .any(|&(alias, _)| alias == $long))
+            })
+    }}
+}
+
+// Finds an option
+macro_rules! find_opt_by_short {
+    ($_self:ident, $short:expr) => {{
+        _find_by_short!($_self, $short, opts)
+    }}
+}
+
+macro_rules! find_flag_by_short {
+    ($_self:ident, $short:expr) => {{
+        _find_by_short!($_self, $short, flags)
+    }}
+}
+
+macro_rules! _find_by_short {
+    ($_self:ident, $short:expr, $what:ident) => {{
+        $_self.$what
+            .iter()
+            .filter(|a| a.s.short.is_some())
+            .find(|a| a.s.short.unwrap() == $short)
+    }}
+}
+
+macro_rules! find_subcmd {
+    ($_self:expr, $sc:expr) => {{
+        $_self.subcommands
+            .iter()
+            .find(|s| {
+                &*s.p.meta.name == $sc ||
+                (s.p.meta.aliases.is_some() &&
+                 s.p
+                    .meta
+                    .aliases
+                    .as_ref()
+                    .unwrap()
+                    .iter()
+                    .any(|&(n, _)| n == $sc))
+            })
+    }};
+}
+
+macro_rules! shorts {
+    ($_self:ident) => {{
+        _shorts_longs!($_self, short)
+    }};
+}
+
+
+macro_rules! longs {
+    ($_self:ident) => {{
+        _shorts_longs!($_self, long)
+    }};
+}
+
+macro_rules! _shorts_longs {
+    ($_self:ident, $what:ident) => {{
+        $_self.flags
+                .iter()
+                .filter(|f| f.s.$what.is_some())
+                .map(|f| f.s.$what.as_ref().unwrap())
+                .chain($_self.opts.iter()
+                                  .filter(|o| o.s.$what.is_some())
+                                  .map(|o| o.s.$what.as_ref().unwrap()))
+    }};
+}
+
+macro_rules! arg_names {
+    ($_self:ident) => {{
+        _names!(@args $_self)
+    }};
+}
+
+macro_rules! sc_names {
+    ($_self:ident) => {{
+        _names!(@sc $_self)
+    }};
+}
+
+macro_rules! _names {
+    (@args $_self:ident) => {{
+        $_self.flags
+                .iter()
+                .map(|f| &*f.b.name)
+                .chain($_self.opts.iter()
+                                  .map(|o| &*o.b.name)
+                                  .chain($_self.positionals.values()
+                                                           .map(|p| &*p.b.name)))
+    }};
+    (@sc $_self:ident) => {{
+        $_self.subcommands
+            .iter()
+            .map(|s| &*s.p.meta.name)
+            .chain($_self.subcommands
+                         .iter()
+                         .filter(|s| s.p.meta.aliases.is_some())
+                         .flat_map(|s| s.p.meta.aliases.as_ref().unwrap().iter().map(|&(n, _)| n)))
+
+    }}
+}
diff --git a/src/map.rs b/src/map.rs
new file mode 100644
index 0000000..063a860
--- /dev/null
+++ b/src/map.rs
@@ -0,0 +1,74 @@
+#[cfg(feature = "vec_map")]
+pub use vec_map::{Values, VecMap};
+
+#[cfg(not(feature = "vec_map"))]
+pub use self::vec_map::{Values, VecMap};
+
+#[cfg(not(feature = "vec_map"))]
+mod vec_map {
+    use std::collections::BTreeMap;
+    use std::collections::btree_map;
+    use std::fmt::{self, Debug, Formatter};
+
+    #[derive(Clone, Default, Debug)]
+    pub struct VecMap<V> {
+        inner: BTreeMap<usize, V>,
+    }
+
+    impl<V> VecMap<V> {
+        pub fn new() -> Self {
+            VecMap {
+                inner: Default::default(),
+            }
+        }
+
+        pub fn len(&self) -> usize { self.inner.len() }
+
+        pub fn is_empty(&self) -> bool { self.inner.is_empty() }
+
+        pub fn insert(&mut self, key: usize, value: V) -> Option<V> {
+            self.inner.insert(key, value)
+        }
+
+        pub fn values(&self) -> Values<V> { self.inner.values() }
+
+        pub fn iter(&self) -> Iter<V> {
+            Iter {
+                inner: self.inner.iter(),
+            }
+        }
+
+        pub fn contains_key(&self, key: usize) -> bool { self.inner.contains_key(&key) }
+
+        pub fn entry(&mut self, key: usize) -> Entry<V> { self.inner.entry(key) }
+
+        pub fn get(&self, key: usize) -> Option<&V> { self.inner.get(&key) }
+    }
+
+    pub type Values<'a, V> = btree_map::Values<'a, usize, V>;
+
+    pub type Entry<'a, V> = btree_map::Entry<'a, usize, V>;
+
+    #[derive(Clone)]
+    pub struct Iter<'a, V: 'a> {
+        inner: btree_map::Iter<'a, usize, V>,
+    }
+
+    impl<'a, V: 'a + Debug> Debug for Iter<'a, V> {
+        fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+            f.debug_list().entries(self.inner.clone()).finish()
+        }
+    }
+
+    impl<'a, V: 'a> Iterator for Iter<'a, V> {
+        type Item = (usize, &'a V);
+
+        fn next(&mut self) -> Option<Self::Item> { self.inner.next().map(|(k, v)| (*k, v)) }
+    }
+
+    impl<'a, V: 'a> DoubleEndedIterator for Iter<'a, V> {
+        fn next_back(&mut self) -> Option<Self::Item> {
+            self.inner.next_back().map(|(k, v)| (*k, v))
+        }
+    }
+}
diff --git a/src/osstringext.rs b/src/osstringext.rs
new file mode 100644
index 0000000..061c01d
--- /dev/null
+++ b/src/osstringext.rs
@@ -0,0 +1,119 @@
+#[cfg(any(target_os = "windows", target_arch = "wasm32"))]
+use INVALID_UTF8;
+use std::ffi::OsStr;
+#[cfg(not(any(target_os = "windows", target_arch = "wasm32")))]
+use std::os::unix::ffi::OsStrExt;
+
+#[cfg(any(target_os = "windows", target_arch = "wasm32"))]
+pub trait OsStrExt3 {
+    fn from_bytes(b: &[u8]) -> &Self;
+    fn as_bytes(&self) -> &[u8];
+}
+
+#[doc(hidden)]
+pub trait OsStrExt2 {
+    fn starts_with(&self, s: &[u8]) -> bool;
+    fn split_at_byte(&self, b: u8) -> (&OsStr, &OsStr);
+    fn split_at(&self, i: usize) -> (&OsStr, &OsStr);
+    fn trim_left_matches(&self, b: u8) -> &OsStr;
+    fn contains_byte(&self, b: u8) -> bool;
+    fn split(&self, b: u8) -> OsSplit;
+}
+
+#[cfg(any(target_os = "windows", target_arch = "wasm32"))]
+impl OsStrExt3 for OsStr {
+    fn from_bytes(b: &[u8]) -> &Self {
+        use std::mem;
+        unsafe { mem::transmute(b) }
+    }
+    fn as_bytes(&self) -> &[u8] {
+        self.to_str().map(|s| s.as_bytes()).expect(INVALID_UTF8)
+    }
+}
+
+impl OsStrExt2 for OsStr {
+    fn starts_with(&self, s: &[u8]) -> bool {
+        self.as_bytes().starts_with(s)
+    }
+
+    fn contains_byte(&self, byte: u8) -> bool {
+        for b in self.as_bytes() {
+            if b == &byte {
+                return true;
+            }
+        }
+        false
+    }
+
+    fn split_at_byte(&self, byte: u8) -> (&OsStr, &OsStr) {
+        for (i, b) in self.as_bytes().iter().enumerate() {
+            if b == &byte {
+                return (
+                    OsStr::from_bytes(&self.as_bytes()[..i]),
+                    OsStr::from_bytes(&self.as_bytes()[i + 1..]),
+                );
+            }
+        }
+        (
+            &*self,
+            OsStr::from_bytes(&self.as_bytes()[self.len()..self.len()]),
+        )
+    }
+
+    fn trim_left_matches(&self, byte: u8) -> &OsStr {
+        let mut found = false;
+        for (i, b) in self.as_bytes().iter().enumerate() {
+            if b != &byte {
+                return OsStr::from_bytes(&self.as_bytes()[i..]);
+            } else {
+                found = true;
+            }
+        }
+        if found {
+            return OsStr::from_bytes(&self.as_bytes()[self.len()..]);
+        }
+        &*self
+    }
+
+    fn split_at(&self, i: usize) -> (&OsStr, &OsStr) {
+        (
+            OsStr::from_bytes(&self.as_bytes()[..i]),
+            OsStr::from_bytes(&self.as_bytes()[i..]),
+        )
+    }
+
+    fn split(&self, b: u8) -> OsSplit {
+        OsSplit {
+            sep: b,
+            val: self.as_bytes(),
+            pos: 0,
+        }
+    }
+}
+
+#[doc(hidden)]
+#[derive(Clone, Debug)]
+pub struct OsSplit<'a> {
+    sep: u8,
+    val: &'a [u8],
+    pos: usize,
+}
+
+impl<'a> Iterator for OsSplit<'a> {
+    type Item = &'a OsStr;
+
+    fn next(&mut self) -> Option<&'a OsStr> {
+        debugln!("OsSplit::next: self={:?}", self);
+        if self.pos == self.val.len() {
+            return None;
+        }
+        let start = self.pos;
+        for b in &self.val[start..] {
+            self.pos += 1;
+            if *b == self.sep {
+                return Some(OsStr::from_bytes(&self.val[start..self.pos - 1]));
+            }
+        }
+        Some(OsStr::from_bytes(&self.val[start..]))
+    }
+}
diff --git a/src/strext.rs b/src/strext.rs
new file mode 100644
index 0000000..6f81367
--- /dev/null
+++ b/src/strext.rs
@@ -0,0 +1,16 @@
+pub trait _StrExt {
+    fn _is_char_boundary(&self, index: usize) -> bool;
+}
+
+impl _StrExt for str {
+    #[inline]
+    fn _is_char_boundary(&self, index: usize) -> bool {
+        if index == self.len() {
+            return true;
+        }
+        match self.as_bytes().get(index) {
+            None => false,
+            Some(&b) => b < 128 || b >= 192,
+        }
+    }
+}
diff --git a/src/suggestions.rs b/src/suggestions.rs
new file mode 100644
index 0000000..06071d2
--- /dev/null
+++ b/src/suggestions.rs
@@ -0,0 +1,147 @@
+use app::App;
+// Third Party
+#[cfg(feature = "suggestions")]
+use strsim;
+
+// Internal
+use fmt::Format;
+
+/// Produces a string from a given list of possible values which is similar to
+/// the passed in value `v` with a certain confidence.
+/// Thus in a list of possible values like ["foo", "bar"], the value "fop" will yield
+/// `Some("foo")`, whereas "blark" would yield `None`.
+#[cfg(feature = "suggestions")]
+#[cfg_attr(feature = "lints", allow(needless_lifetimes))]
+pub fn did_you_mean<'a, T: ?Sized, I>(v: &str, possible_values: I) -> Option<&'a str>
+where
+    T: AsRef<str> + 'a,
+    I: IntoIterator<Item = &'a T>,
+{
+    let mut candidate: Option<(f64, &str)> = None;
+    for pv in possible_values {
+        let confidence = strsim::jaro_winkler(v, pv.as_ref());
+        if confidence > 0.8 && (candidate.is_none() || (candidate.as_ref().unwrap().0 < confidence))
+        {
+            candidate = Some((confidence, pv.as_ref()));
+        }
+    }
+    match candidate {
+        None => None,
+        Some((_, candidate)) => Some(candidate),
+    }
+}
+
+#[cfg(not(feature = "suggestions"))]
+pub fn did_you_mean<'a, T: ?Sized, I>(_: &str, _: I) -> Option<&'a str>
+where
+    T: AsRef<str> + 'a,
+    I: IntoIterator<Item = &'a T>,
+{
+    None
+}
+
+/// Returns a suffix that can be empty, or is the standard 'did you mean' phrase
+#[cfg_attr(feature = "lints", allow(needless_lifetimes))]
+pub fn did_you_mean_flag_suffix<'z, T, I>(
+    arg: &str,
+    args_rest: &'z [&str],
+    longs: I,
+    subcommands: &'z [App],
+) -> (String, Option<&'z str>)
+where
+    T: AsRef<str> + 'z,
+    I: IntoIterator<Item = &'z T>,
+{
+    if let Some(candidate) = did_you_mean(arg, longs) {
+        let suffix = format!(
+            "\n\tDid you mean {}{}?",
+            Format::Good("--"),
+            Format::Good(candidate)
+            );
+        return (suffix, Some(candidate));
+    }
+
+    subcommands
+        .into_iter()
+        .filter_map(|subcommand| {
+            let opts = subcommand
+                .p
+                .flags
+                .iter()
+                .filter_map(|f| f.s.long)
+                .chain(subcommand.p.opts.iter().filter_map(|o| o.s.long));
+
+            let candidate = match did_you_mean(arg, opts) {
+                Some(candidate) => candidate,
+                None => return None
+            };
+            let score = match args_rest.iter().position(|x| *x == subcommand.get_name()) {
+                Some(score) => score,
+                None => return None
+            };
+
+            let suffix = format!(
+                "\n\tDid you mean to put '{}{}' after the subcommand '{}'?",
+                Format::Good("--"),
+                Format::Good(candidate),
+                Format::Good(subcommand.get_name())
+            );
+
+            Some((score, (suffix, Some(candidate))))
+        })
+        .min_by_key(|&(score, _)| score)
+        .map(|(_, suggestion)| suggestion)
+        .unwrap_or_else(|| (String::new(), None))
+}
+
+/// Returns a suffix that can be empty, or is the standard 'did you mean' phrase
+pub fn did_you_mean_value_suffix<'z, T, I>(arg: &str, values: I) -> (String, Option<&'z str>)
+where
+    T: AsRef<str> + 'z,
+    I: IntoIterator<Item = &'z T>,
+{
+    match did_you_mean(arg, values) {
+        Some(candidate) => {
+            let suffix = format!("\n\tDid you mean '{}'?", Format::Good(candidate));
+            (suffix, Some(candidate))
+        }
+        None => (String::new(), None),
+    }
+}
+
+#[cfg(all(test, features = "suggestions"))]
+mod test {
+    use super::*;
+
+    #[test]
+    fn possible_values_match() {
+        let p_vals = ["test", "possible", "values"];
+        assert_eq!(did_you_mean("tst", p_vals.iter()), Some("test"));
+    }
+
+    #[test]
+    fn possible_values_nomatch() {
+        let p_vals = ["test", "possible", "values"];
+        assert!(did_you_mean("hahaahahah", p_vals.iter()).is_none());
+    }
+
+    #[test]
+    fn suffix_long() {
+        let p_vals = ["test", "possible", "values"];
+        let suffix = "\n\tDid you mean \'--test\'?";
+        assert_eq!(
+            did_you_mean_flag_suffix("tst", p_vals.iter(), []),
+            (suffix, Some("test"))
+        );
+    }
+
+    #[test]
+    fn suffix_enum() {
+        let p_vals = ["test", "possible", "values"];
+        let suffix = "\n\tDid you mean \'test\'?";
+        assert_eq!(
+            did_you_mean_value_suffix("tst", p_vals.iter()),
+            (suffix, Some("test"))
+        );
+    }
+}
diff --git a/src/usage_parser.rs b/src/usage_parser.rs
new file mode 100644
index 0000000..f6d5ac6
--- /dev/null
+++ b/src/usage_parser.rs
@@ -0,0 +1,1347 @@
+// Internal
+use INTERNAL_ERROR_MSG;
+use args::Arg;
+use args::settings::ArgSettings;
+use map::VecMap;
+
+#[derive(PartialEq, Debug)]
+enum UsageToken {
+    Name,
+    ValName,
+    Short,
+    Long,
+    Help,
+    Multiple,
+    Unknown,
+}
+
+#[doc(hidden)]
+#[derive(Debug)]
+pub struct UsageParser<'a> {
+    usage: &'a str,
+    pos: usize,
+    start: usize,
+    prev: UsageToken,
+    explicit_name_set: bool,
+}
+
+impl<'a> UsageParser<'a> {
+    fn new(usage: &'a str) -> Self {
+        debugln!("UsageParser::new: usage={:?}", usage);
+        UsageParser {
+            usage: usage,
+            pos: 0,
+            start: 0,
+            prev: UsageToken::Unknown,
+            explicit_name_set: false,
+        }
+    }
+
+    pub fn from_usage(usage: &'a str) -> Self {
+        debugln!("UsageParser::from_usage;");
+        UsageParser::new(usage)
+    }
+
+    pub fn parse(mut self) -> Arg<'a, 'a> {
+        debugln!("UsageParser::parse;");
+        let mut arg = Arg::default();
+        loop {
+            debugln!("UsageParser::parse:iter: pos={};", self.pos);
+            self.stop_at(token);
+            if let Some(&c) = self.usage.as_bytes().get(self.pos) {
+                match c {
+                    b'-' => self.short_or_long(&mut arg),
+                    b'.' => self.multiple(&mut arg),
+                    b'\'' => self.help(&mut arg),
+                    _ => self.name(&mut arg),
+                }
+            } else {
+                break;
+            }
+        }
+        debug_assert!(
+            !arg.b.name.is_empty(),
+            format!(
+                "No name found for Arg when parsing usage string: {}",
+                self.usage
+            )
+        );
+        arg.v.num_vals = match arg.v.val_names {
+            Some(ref v) if v.len() >= 2 => Some(v.len() as u64),
+            _ => None,
+        };
+        debugln!("UsageParser::parse: vals...{:?}", arg.v.val_names);
+        arg
+    }
+
+    fn name(&mut self, arg: &mut Arg<'a, 'a>) {
+        debugln!("UsageParser::name;");
+        if *self.usage
+            .as_bytes()
+            .get(self.pos)
+            .expect(INTERNAL_ERROR_MSG) == b'<' && !self.explicit_name_set
+        {
+            arg.setb(ArgSettings::Required);
+        }
+        self.pos += 1;
+        self.stop_at(name_end);
+        let name = &self.usage[self.start..self.pos];
+        if self.prev == UsageToken::Unknown {
+            debugln!("UsageParser::name: setting name...{}", name);
+            arg.b.name = name;
+            if arg.s.long.is_none() && arg.s.short.is_none() {
+                debugln!("UsageParser::name: explicit name set...");
+                self.explicit_name_set = true;
+                self.prev = UsageToken::Name;
+            }
+        } else {
+            debugln!("UsageParser::name: setting val name...{}", name);
+            if let Some(ref mut v) = arg.v.val_names {
+                let len = v.len();
+                v.insert(len, name);
+            } else {
+                let mut v = VecMap::new();
+                v.insert(0, name);
+                arg.v.val_names = Some(v);
+                arg.setb(ArgSettings::TakesValue);
+            }
+            self.prev = UsageToken::ValName;
+        }
+    }
+
+    fn stop_at<F>(&mut self, f: F)
+    where
+        F: Fn(u8) -> bool,
+    {
+        debugln!("UsageParser::stop_at;");
+        self.start = self.pos;
+        self.pos += self.usage[self.start..]
+            .bytes()
+            .take_while(|&b| f(b))
+            .count();
+    }
+
+    fn short_or_long(&mut self, arg: &mut Arg<'a, 'a>) {
+        debugln!("UsageParser::short_or_long;");
+        self.pos += 1;
+        if *self.usage
+            .as_bytes()
+            .get(self.pos)
+            .expect(INTERNAL_ERROR_MSG) == b'-'
+        {
+            self.pos += 1;
+            self.long(arg);
+            return;
+        }
+        self.short(arg)
+    }
+
+    fn long(&mut self, arg: &mut Arg<'a, 'a>) {
+        debugln!("UsageParser::long;");
+        self.stop_at(long_end);
+        let name = &self.usage[self.start..self.pos];
+        if !self.explicit_name_set {
+            debugln!("UsageParser::long: setting name...{}", name);
+            arg.b.name = name;
+        }
+        debugln!("UsageParser::long: setting long...{}", name);
+        arg.s.long = Some(name);
+        self.prev = UsageToken::Long;
+    }
+
+    fn short(&mut self, arg: &mut Arg<'a, 'a>) {
+        debugln!("UsageParser::short;");
+        let start = &self.usage[self.pos..];
+        let short = start.chars().nth(0).expect(INTERNAL_ERROR_MSG);
+        debugln!("UsageParser::short: setting short...{}", short);
+        arg.s.short = Some(short);
+        if arg.b.name.is_empty() {
+            // --long takes precedence but doesn't set self.explicit_name_set
+            let name = &start[..short.len_utf8()];
+            debugln!("UsageParser::short: setting name...{}", name);
+            arg.b.name = name;
+        }
+        self.prev = UsageToken::Short;
+    }
+
+    // "something..."
+    fn multiple(&mut self, arg: &mut Arg) {
+        debugln!("UsageParser::multiple;");
+        let mut dot_counter = 1;
+        let start = self.pos;
+        let mut bytes = self.usage[start..].bytes();
+        while bytes.next() == Some(b'.') {
+            dot_counter += 1;
+            self.pos += 1;
+            if dot_counter == 3 {
+                debugln!("UsageParser::multiple: setting multiple");
+                arg.setb(ArgSettings::Multiple);
+                if arg.is_set(ArgSettings::TakesValue) {
+                    arg.setb(ArgSettings::UseValueDelimiter);
+                    arg.unsetb(ArgSettings::ValueDelimiterNotSet);
+                    if arg.v.val_delim.is_none() {
+                        arg.v.val_delim = Some(',');
+                    }
+                }
+                self.prev = UsageToken::Multiple;
+                self.pos += 1;
+                break;
+            }
+        }
+    }
+
+    fn help(&mut self, arg: &mut Arg<'a, 'a>) {
+        debugln!("UsageParser::help;");
+        self.stop_at(help_start);
+        self.start = self.pos + 1;
+        self.pos = self.usage.len() - 1;
+        debugln!(
+            "UsageParser::help: setting help...{}",
+            &self.usage[self.start..self.pos]
+        );
+        arg.b.help = Some(&self.usage[self.start..self.pos]);
+        self.pos += 1; // Move to next byte to keep from thinking ending ' is a start
+        self.prev = UsageToken::Help;
+    }
+}
+
+#[inline]
+fn name_end(b: u8) -> bool { b != b']' && b != b'>' }
+
+#[inline]
+fn token(b: u8) -> bool { b != b'\'' && b != b'.' && b != b'<' && b != b'[' && b != b'-' }
+
+#[inline]
+fn long_end(b: u8) -> bool {
+    b != b'\'' && b != b'.' && b != b'<' && b != b'[' && b != b'=' && b != b' '
+}
+
+#[inline]
+fn help_start(b: u8) -> bool { b != b'\'' }
+
+#[cfg(test)]
+mod test {
+    use args::Arg;
+    use args::ArgSettings;
+
+    #[test]
+    fn create_flag_usage() {
+        let a = Arg::from_usage("[flag] -f 'some help info'");
+        assert_eq!(a.b.name, "flag");
+        assert_eq!(a.s.short.unwrap(), 'f');
+        assert!(a.s.long.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(!a.is_set(ArgSettings::Multiple));
+        assert!(a.v.val_names.is_none());
+        assert!(a.v.num_vals.is_none());
+
+        let b = Arg::from_usage("[flag] --flag 'some help info'");
+        assert_eq!(b.b.name, "flag");
+        assert_eq!(b.s.long.unwrap(), "flag");
+        assert!(b.s.short.is_none());
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(!b.is_set(ArgSettings::Multiple));
+        assert!(a.v.val_names.is_none());
+        assert!(a.v.num_vals.is_none());
+
+        let b = Arg::from_usage("--flag 'some help info'");
+        assert_eq!(b.b.name, "flag");
+        assert_eq!(b.s.long.unwrap(), "flag");
+        assert!(b.s.short.is_none());
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(!b.is_set(ArgSettings::Multiple));
+        assert!(b.v.val_names.is_none());
+        assert!(b.v.num_vals.is_none());
+
+        let c = Arg::from_usage("[flag] -f --flag 'some help info'");
+        assert_eq!(c.b.name, "flag");
+        assert_eq!(c.s.short.unwrap(), 'f');
+        assert_eq!(c.s.long.unwrap(), "flag");
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(!c.is_set(ArgSettings::Multiple));
+        assert!(c.v.val_names.is_none());
+        assert!(c.v.num_vals.is_none());
+
+        let d = Arg::from_usage("[flag] -f... 'some help info'");
+        assert_eq!(d.b.name, "flag");
+        assert_eq!(d.s.short.unwrap(), 'f');
+        assert!(d.s.long.is_none());
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(d.is_set(ArgSettings::Multiple));
+        assert!(d.v.val_names.is_none());
+        assert!(d.v.num_vals.is_none());
+
+        let e = Arg::from_usage("[flag] -f --flag... 'some help info'");
+        assert_eq!(e.b.name, "flag");
+        assert_eq!(e.s.long.unwrap(), "flag");
+        assert_eq!(e.s.short.unwrap(), 'f');
+        assert_eq!(e.b.help.unwrap(), "some help info");
+        assert!(e.is_set(ArgSettings::Multiple));
+        assert!(e.v.val_names.is_none());
+        assert!(e.v.num_vals.is_none());
+
+        let e = Arg::from_usage("-f --flag... 'some help info'");
+        assert_eq!(e.b.name, "flag");
+        assert_eq!(e.s.long.unwrap(), "flag");
+        assert_eq!(e.s.short.unwrap(), 'f');
+        assert_eq!(e.b.help.unwrap(), "some help info");
+        assert!(e.is_set(ArgSettings::Multiple));
+        assert!(e.v.val_names.is_none());
+        assert!(e.v.num_vals.is_none());
+
+        let e = Arg::from_usage("--flags");
+        assert_eq!(e.b.name, "flags");
+        assert_eq!(e.s.long.unwrap(), "flags");
+        assert!(e.v.val_names.is_none());
+        assert!(e.v.num_vals.is_none());
+
+        let e = Arg::from_usage("--flags...");
+        assert_eq!(e.b.name, "flags");
+        assert_eq!(e.s.long.unwrap(), "flags");
+        assert!(e.is_set(ArgSettings::Multiple));
+        assert!(e.v.val_names.is_none());
+        assert!(e.v.num_vals.is_none());
+
+        let e = Arg::from_usage("[flags] -f");
+        assert_eq!(e.b.name, "flags");
+        assert_eq!(e.s.short.unwrap(), 'f');
+        assert!(e.v.val_names.is_none());
+        assert!(e.v.num_vals.is_none());
+
+        let e = Arg::from_usage("[flags] -f...");
+        assert_eq!(e.b.name, "flags");
+        assert_eq!(e.s.short.unwrap(), 'f');
+        assert!(e.is_set(ArgSettings::Multiple));
+        assert!(e.v.val_names.is_none());
+        assert!(e.v.num_vals.is_none());
+
+        let a = Arg::from_usage("-f 'some help info'");
+        assert_eq!(a.b.name, "f");
+        assert_eq!(a.s.short.unwrap(), 'f');
+        assert!(a.s.long.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(!a.is_set(ArgSettings::Multiple));
+        assert!(a.v.val_names.is_none());
+        assert!(a.v.num_vals.is_none());
+
+        let e = Arg::from_usage("-f");
+        assert_eq!(e.b.name, "f");
+        assert_eq!(e.s.short.unwrap(), 'f');
+        assert!(e.v.val_names.is_none());
+        assert!(e.v.num_vals.is_none());
+
+        let e = Arg::from_usage("-f...");
+        assert_eq!(e.b.name, "f");
+        assert_eq!(e.s.short.unwrap(), 'f');
+        assert!(e.is_set(ArgSettings::Multiple));
+        assert!(e.v.val_names.is_none());
+        assert!(e.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage0() {
+        // Short only
+        let a = Arg::from_usage("[option] -o [opt] 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.short.unwrap(), 'o');
+        assert!(a.s.long.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(!a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage1() {
+        let b = Arg::from_usage("-o [opt] 'some help info'");
+        assert_eq!(b.b.name, "o");
+        assert_eq!(b.s.short.unwrap(), 'o');
+        assert!(b.s.long.is_none());
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(!b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::TakesValue));
+        assert!(!b.is_set(ArgSettings::Required));
+        assert_eq!(
+            b.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage2() {
+        let c = Arg::from_usage("<option> -o <opt> 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.short.unwrap(), 'o');
+        assert!(c.s.long.is_none());
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(!c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage3() {
+        let d = Arg::from_usage("-o <opt> 'some help info'");
+        assert_eq!(d.b.name, "o");
+        assert_eq!(d.s.short.unwrap(), 'o');
+        assert!(d.s.long.is_none());
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(!d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage4() {
+        let a = Arg::from_usage("[option] -o [opt]... 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.short.unwrap(), 'o');
+        assert!(a.s.long.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage5() {
+        let a = Arg::from_usage("[option]... -o [opt] 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.short.unwrap(), 'o');
+        assert!(a.s.long.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage6() {
+        let b = Arg::from_usage("-o [opt]... 'some help info'");
+        assert_eq!(b.b.name, "o");
+        assert_eq!(b.s.short.unwrap(), 'o');
+        assert!(b.s.long.is_none());
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::TakesValue));
+        assert!(!b.is_set(ArgSettings::Required));
+        assert_eq!(
+            b.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage7() {
+        let c = Arg::from_usage("<option> -o <opt>... 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.short.unwrap(), 'o');
+        assert!(c.s.long.is_none());
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage8() {
+        let c = Arg::from_usage("<option>... -o <opt> 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.short.unwrap(), 'o');
+        assert!(c.s.long.is_none());
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage9() {
+        let d = Arg::from_usage("-o <opt>... 'some help info'");
+        assert_eq!(d.b.name, "o");
+        assert_eq!(d.s.short.unwrap(), 'o');
+        assert!(d.s.long.is_none());
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long1() {
+        let a = Arg::from_usage("[option] --opt [opt] 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.long.unwrap(), "opt");
+        assert!(a.s.short.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(!a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long2() {
+        let b = Arg::from_usage("--opt [option] 'some help info'");
+        assert_eq!(b.b.name, "opt");
+        assert_eq!(b.s.long.unwrap(), "opt");
+        assert!(b.s.short.is_none());
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(!b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::TakesValue));
+        assert!(!b.is_set(ArgSettings::Required));
+        assert_eq!(
+            b.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long3() {
+        let c = Arg::from_usage("<option> --opt <opt> 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.long.unwrap(), "opt");
+        assert!(c.s.short.is_none());
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(!c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long4() {
+        let d = Arg::from_usage("--opt <option> 'some help info'");
+        assert_eq!(d.b.name, "opt");
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert!(d.s.short.is_none());
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(!d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long5() {
+        let a = Arg::from_usage("[option] --opt [opt]... 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.long.unwrap(), "opt");
+        assert!(a.s.short.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long6() {
+        let a = Arg::from_usage("[option]... --opt [opt] 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.long.unwrap(), "opt");
+        assert!(a.s.short.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long7() {
+        let b = Arg::from_usage("--opt [option]... 'some help info'");
+        assert_eq!(b.b.name, "opt");
+        assert_eq!(b.s.long.unwrap(), "opt");
+        assert!(b.s.short.is_none());
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::TakesValue));
+        assert!(!b.is_set(ArgSettings::Required));
+        assert_eq!(
+            b.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long8() {
+        let c = Arg::from_usage("<option> --opt <opt>... 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.long.unwrap(), "opt");
+        assert!(c.s.short.is_none());
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long9() {
+        let c = Arg::from_usage("<option>... --opt <opt> 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.long.unwrap(), "opt");
+        assert!(c.s.short.is_none());
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long10() {
+        let d = Arg::from_usage("--opt <option>... 'some help info'");
+        assert_eq!(d.b.name, "opt");
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert!(d.s.short.is_none());
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long_equals1() {
+        let a = Arg::from_usage("[option] --opt=[opt] 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.long.unwrap(), "opt");
+        assert!(a.s.short.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(!a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long_equals2() {
+        let b = Arg::from_usage("--opt=[option] 'some help info'");
+        assert_eq!(b.b.name, "opt");
+        assert_eq!(b.s.long.unwrap(), "opt");
+        assert!(b.s.short.is_none());
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(!b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::TakesValue));
+        assert!(!b.is_set(ArgSettings::Required));
+        assert_eq!(
+            b.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long_equals3() {
+        let c = Arg::from_usage("<option> --opt=<opt> 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.long.unwrap(), "opt");
+        assert!(c.s.short.is_none());
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(!c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long_equals4() {
+        let d = Arg::from_usage("--opt=<option> 'some help info'");
+        assert_eq!(d.b.name, "opt");
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert!(d.s.short.is_none());
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(!d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long_equals5() {
+        let a = Arg::from_usage("[option] --opt=[opt]... 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.long.unwrap(), "opt");
+        assert!(a.s.short.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long_equals6() {
+        let a = Arg::from_usage("[option]... --opt=[opt] 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.long.unwrap(), "opt");
+        assert!(a.s.short.is_none());
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long_equals7() {
+        let b = Arg::from_usage("--opt=[option]... 'some help info'");
+        assert_eq!(b.b.name, "opt");
+        assert_eq!(b.s.long.unwrap(), "opt");
+        assert!(b.s.short.is_none());
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::TakesValue));
+        assert!(!b.is_set(ArgSettings::Required));
+        assert_eq!(
+            b.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long_equals8() {
+        let c = Arg::from_usage("<option> --opt=<opt>... 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.long.unwrap(), "opt");
+        assert!(c.s.short.is_none());
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long_equals9() {
+        let c = Arg::from_usage("<option>... --opt=<opt> 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.long.unwrap(), "opt");
+        assert!(c.s.short.is_none());
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_long_equals10() {
+        let d = Arg::from_usage("--opt=<option>... 'some help info'");
+        assert_eq!(d.b.name, "opt");
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert!(d.s.short.is_none());
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both1() {
+        let a = Arg::from_usage("[option] -o --opt [option] 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.long.unwrap(), "opt");
+        assert_eq!(a.s.short.unwrap(), 'o');
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(!a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both2() {
+        let b = Arg::from_usage("-o --opt [option] 'some help info'");
+        assert_eq!(b.b.name, "opt");
+        assert_eq!(b.s.long.unwrap(), "opt");
+        assert_eq!(b.s.short.unwrap(), 'o');
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(!b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::TakesValue));
+        assert!(!b.is_set(ArgSettings::Required));
+        assert_eq!(
+            b.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both3() {
+        let c = Arg::from_usage("<option> -o --opt <opt> 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.long.unwrap(), "opt");
+        assert_eq!(c.s.short.unwrap(), 'o');
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(!c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both4() {
+        let d = Arg::from_usage("-o --opt <option> 'some help info'");
+        assert_eq!(d.b.name, "opt");
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert_eq!(d.s.short.unwrap(), 'o');
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(!d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both5() {
+        let a = Arg::from_usage("[option]... -o --opt [option] 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.long.unwrap(), "opt");
+        assert_eq!(a.s.short.unwrap(), 'o');
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both6() {
+        let b = Arg::from_usage("-o --opt [option]... 'some help info'");
+        assert_eq!(b.b.name, "opt");
+        assert_eq!(b.s.long.unwrap(), "opt");
+        assert_eq!(b.s.short.unwrap(), 'o');
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::TakesValue));
+        assert!(!b.is_set(ArgSettings::Required));
+        assert_eq!(
+            b.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both7() {
+        let c = Arg::from_usage("<option>... -o --opt <opt> 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.long.unwrap(), "opt");
+        assert_eq!(c.s.short.unwrap(), 'o');
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both8() {
+        let d = Arg::from_usage("-o --opt <option>... 'some help info'");
+        assert_eq!(d.b.name, "opt");
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert_eq!(d.s.short.unwrap(), 'o');
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both_equals1() {
+        let a = Arg::from_usage("[option] -o --opt=[option] 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.long.unwrap(), "opt");
+        assert_eq!(a.s.short.unwrap(), 'o');
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(!a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both_equals2() {
+        let b = Arg::from_usage("-o --opt=[option] 'some help info'");
+        assert_eq!(b.b.name, "opt");
+        assert_eq!(b.s.long.unwrap(), "opt");
+        assert_eq!(b.s.short.unwrap(), 'o');
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(!b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::TakesValue));
+        assert!(!b.is_set(ArgSettings::Required));
+        assert_eq!(
+            b.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both_equals3() {
+        let c = Arg::from_usage("<option> -o --opt=<opt> 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.long.unwrap(), "opt");
+        assert_eq!(c.s.short.unwrap(), 'o');
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(!c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both_equals4() {
+        let d = Arg::from_usage("-o --opt=<option> 'some help info'");
+        assert_eq!(d.b.name, "opt");
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert_eq!(d.s.short.unwrap(), 'o');
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(!d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both_equals5() {
+        let a = Arg::from_usage("[option]... -o --opt=[option] 'some help info'");
+        assert_eq!(a.b.name, "option");
+        assert_eq!(a.s.long.unwrap(), "opt");
+        assert_eq!(a.s.short.unwrap(), 'o');
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(a.is_set(ArgSettings::Multiple));
+        assert!(a.is_set(ArgSettings::TakesValue));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both_equals6() {
+        let b = Arg::from_usage("-o --opt=[option]... 'some help info'");
+        assert_eq!(b.b.name, "opt");
+        assert_eq!(b.s.long.unwrap(), "opt");
+        assert_eq!(b.s.short.unwrap(), 'o');
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::TakesValue));
+        assert!(!b.is_set(ArgSettings::Required));
+        assert_eq!(
+            b.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both_equals7() {
+        let c = Arg::from_usage("<option>... -o --opt=<opt> 'some help info'");
+        assert_eq!(c.b.name, "option");
+        assert_eq!(c.s.long.unwrap(), "opt");
+        assert_eq!(c.s.short.unwrap(), 'o');
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(c.is_set(ArgSettings::TakesValue));
+        assert!(c.is_set(ArgSettings::Required));
+        assert_eq!(
+            c.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"opt"]
+        );
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_usage_both_equals8() {
+        let d = Arg::from_usage("-o --opt=<option>... 'some help info'");
+        assert_eq!(d.b.name, "opt");
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert_eq!(d.s.short.unwrap(), 'o');
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"option"]
+        );
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_option_with_vals1() {
+        let d = Arg::from_usage("-o <file> <mode> 'some help info'");
+        assert_eq!(d.b.name, "o");
+        assert!(d.s.long.is_none());
+        assert_eq!(d.s.short.unwrap(), 'o');
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(!d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"file", &"mode"]
+        );
+        assert_eq!(d.v.num_vals.unwrap(), 2);
+    }
+
+    #[test]
+    fn create_option_with_vals2() {
+        let d = Arg::from_usage("-o <file> <mode>... 'some help info'");
+        assert_eq!(d.b.name, "o");
+        assert!(d.s.long.is_none());
+        assert_eq!(d.s.short.unwrap(), 'o');
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"file", &"mode"]
+        );
+        assert_eq!(d.v.num_vals.unwrap(), 2);
+    }
+
+    #[test]
+    fn create_option_with_vals3() {
+        let d = Arg::from_usage("--opt <file> <mode>... 'some help info'");
+        assert_eq!(d.b.name, "opt");
+        assert!(d.s.short.is_none());
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"file", &"mode"]
+        );
+        assert_eq!(d.v.num_vals.unwrap(), 2);
+    }
+
+    #[test]
+    fn create_option_with_vals4() {
+        let d = Arg::from_usage("[myopt] --opt <file> <mode> 'some help info'");
+        assert_eq!(d.b.name, "myopt");
+        assert!(d.s.short.is_none());
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(!d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(!d.is_set(ArgSettings::Required));
+        assert_eq!(
+            d.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"file", &"mode"]
+        );
+        assert_eq!(d.v.num_vals.unwrap(), 2);
+    }
+
+    #[test]
+    fn create_option_with_vals5() {
+        let d = Arg::from_usage("--opt <file> <mode> 'some help info'");
+        assert_eq!(d.b.name, "opt");
+        assert!(d.s.short.is_none());
+        assert_eq!(d.s.long.unwrap(), "opt");
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(!d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::TakesValue));
+        assert!(d.is_set(ArgSettings::Required));
+        assert_eq!(d.v.num_vals.unwrap(), 2);
+    }
+
+    #[test]
+    fn create_positional_usage() {
+        let a = Arg::from_usage("[pos] 'some help info'");
+        assert_eq!(a.b.name, "pos");
+        assert_eq!(a.b.help.unwrap(), "some help info");
+        assert!(!a.is_set(ArgSettings::Multiple));
+        assert!(!a.is_set(ArgSettings::Required));
+        assert!(a.v.val_names.is_none());
+        assert!(a.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn create_positional_usage0() {
+        let b = Arg::from_usage("<pos> 'some help info'");
+        assert_eq!(b.b.name, "pos");
+        assert_eq!(b.b.help.unwrap(), "some help info");
+        assert!(!b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::Required));
+        assert!(b.v.val_names.is_none());
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn pos_mult_help() {
+        let c = Arg::from_usage("[pos]... 'some help info'");
+        assert_eq!(c.b.name, "pos");
+        assert_eq!(c.b.help.unwrap(), "some help info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(!c.is_set(ArgSettings::Required));
+        assert!(c.v.val_names.is_none());
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn pos_help_lit_single_quote() {
+        let c = Arg::from_usage("[pos]... 'some help\' info'");
+        assert_eq!(c.b.name, "pos");
+        assert_eq!(c.b.help.unwrap(), "some help' info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(!c.is_set(ArgSettings::Required));
+        assert!(c.v.val_names.is_none());
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn pos_help_double_lit_single_quote() {
+        let c = Arg::from_usage("[pos]... 'some \'help\' info'");
+        assert_eq!(c.b.name, "pos");
+        assert_eq!(c.b.help.unwrap(), "some 'help' info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(!c.is_set(ArgSettings::Required));
+        assert!(c.v.val_names.is_none());
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn pos_help_newline() {
+        let c = Arg::from_usage(
+            "[pos]... 'some help{n}\
+             info'",
+        );
+        assert_eq!(c.b.name, "pos");
+        assert_eq!(c.b.help.unwrap(), "some help{n}info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(!c.is_set(ArgSettings::Required));
+        assert!(c.v.val_names.is_none());
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn pos_help_newline_lit_sq() {
+        let c = Arg::from_usage(
+            "[pos]... 'some help\' stuff{n}\
+             info'",
+        );
+        assert_eq!(c.b.name, "pos");
+        assert_eq!(c.b.help.unwrap(), "some help' stuff{n}info");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(!c.is_set(ArgSettings::Required));
+        assert!(c.v.val_names.is_none());
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn pos_req_mult_help() {
+        let d = Arg::from_usage("<pos>... 'some help info'");
+        assert_eq!(d.b.name, "pos");
+        assert_eq!(d.b.help.unwrap(), "some help info");
+        assert!(d.is_set(ArgSettings::Multiple));
+        assert!(d.is_set(ArgSettings::Required));
+        assert!(d.v.val_names.is_none());
+        assert!(d.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn pos_req() {
+        let b = Arg::from_usage("<pos>");
+        assert_eq!(b.b.name, "pos");
+        assert!(!b.is_set(ArgSettings::Multiple));
+        assert!(b.is_set(ArgSettings::Required));
+        assert!(b.v.val_names.is_none());
+        assert!(b.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn pos_mult() {
+        let c = Arg::from_usage("[pos]...");
+        assert_eq!(c.b.name, "pos");
+        assert!(c.is_set(ArgSettings::Multiple));
+        assert!(!c.is_set(ArgSettings::Required));
+        assert!(c.v.val_names.is_none());
+        assert!(c.v.num_vals.is_none());
+    }
+
+    #[test]
+    fn nonascii() {
+        let a = Arg::from_usage("<ASCII> 'üñíčöĐ€'");
+        assert_eq!(a.b.name, "ASCII");
+        assert_eq!(a.b.help, Some("üñíčöĐ€"));
+        let a = Arg::from_usage("<üñíčöĐ€> 'ASCII'");
+        assert_eq!(a.b.name, "üñíčöĐ€");
+        assert_eq!(a.b.help, Some("ASCII"));
+        let a = Arg::from_usage("<üñíčöĐ€> 'üñíčöĐ€'");
+        assert_eq!(a.b.name, "üñíčöĐ€");
+        assert_eq!(a.b.help, Some("üñíčöĐ€"));
+        let a = Arg::from_usage("-ø 'ø'");
+        assert_eq!(a.b.name, "ø");
+        assert_eq!(a.s.short, Some('ø'));
+        assert_eq!(a.b.help, Some("ø"));
+        let a = Arg::from_usage("--üñíčöĐ€ 'Nōṫ ASCII'");
+        assert_eq!(a.b.name, "üñíčöĐ€");
+        assert_eq!(a.s.long, Some("üñíčöĐ€"));
+        assert_eq!(a.b.help, Some("Nōṫ ASCII"));
+        let a = Arg::from_usage("[ñämê] --ôpt=[üñíčöĐ€] 'hælp'");
+        assert_eq!(a.b.name, "ñämê");
+        assert_eq!(a.s.long, Some("ôpt"));
+        assert_eq!(
+            a.v.val_names.unwrap().values().collect::<Vec<_>>(),
+            [&"üñíčöĐ€"]
+        );
+        assert_eq!(a.b.help, Some("hælp"));
+    }
+}