commit | 7ba826e50dff1878e6ecc6b9af44097c040c8968 | [log] [tgz] |
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author | Abseil Team <absl-team@google.com> | Mon May 10 12:57:06 2021 -0700 |
committer | vslashg <gfalcon@google.com> | Tue May 11 09:59:12 2021 -0400 |
tree | a465938ae07904733beafdaa830866dbe8cbc7ac | |
parent | 079cf662544a14bd1cfaae6d6512645541ba10fb [diff] |
Export of internal Abseil changes -- 5f3c139695d5c497ca030e95a607537a7be7caa7 by Benjamin Barenblat <bbaren@google.com>: Don’t examine irrelevant destination buckets in DiscreteDistributionTest Abseil generates discrete distributions using Walker’s aliasing algorithm. This creates uniformly distributed buckets, each with a probability of sending traffic to a different bucket. Abseil represents a bucket as a pair (probability of retaining traffic × alternate bucket if traffic is passed) and a distribution as a vector of such pairs. For example, {(0.3, 1), (1.0, 1)} represents a distribution with two buckets, the zeroth of which passes 70% of its traffic to bucket 1 and the first of which holds on to all its traffic. This representation is not unique: When a bucket retains traffic with probability 1, the alternate bucket is irrelevant. Continuing the example above, {(0.3, 1), (1.0, 0)} _also_ represents a two-bucket distribution where the zeroth bucket passes 70% of its traffic to the first and the first hangs on to all traffic. Exactly what representation Abseil generates for a given input is related to how much precision is used in intermediate floating-point operations, which is an architectural implementation detail. Remove sensitivity to that detail by not examining the alternate bucket when the retention probability is 1.0. PiperOrigin-RevId: 372993410 -- 062ac80699f748831c09a061538abffec2cdea5c by Martijn Vels <mvels@google.com>: Avoid alredy sampled cord remaining sampled if not picked or source is sampled PiperOrigin-RevId: 372985990 -- a9f3537e1110b7bb6450fd72a03f0c5dc6b8c89b by Evan Brown <ezb@google.com>: Add tests for function pointer comparators, comparators that have SFINAE-visible comparison operators that are unimplemented, and for implicit construction from unadapted comparators. PiperOrigin-RevId: 372927616 GitOrigin-RevId: 5f3c139695d5c497ca030e95a607537a7be7caa7 Change-Id: I996a8452e7bd88f9dd2e59633b01bbc09f42620d
The repository contains the Abseil C++ library code. Abseil is an open-source collection of C++ code (compliant to C++11) designed to augment the C++ standard library.
Abseil is an open-source collection of C++ library code designed to augment the C++ standard library. The Abseil library code is collected from Google's own C++ code base, has been extensively tested and used in production, and is the same code we depend on in our daily coding lives.
In some cases, Abseil provides pieces missing from the C++ standard; in others, Abseil provides alternatives to the standard for special needs we've found through usage in the Google code base. We denote those cases clearly within the library code we provide you.
Abseil is not meant to be a competitor to the standard library; we've just found that many of these utilities serve a purpose within our code base, and we now want to provide those resources to the C++ community as a whole.
If you want to just get started, make sure you at least run through the Abseil Quickstart. The Quickstart contains information about setting up your development environment, downloading the Abseil code, running tests, and getting a simple binary working.
Bazel and CMake are the official build systems for Abseil.
See the quickstart for more information on building Abseil using the Bazel build system.
If you require CMake support, please check the CMake build instructions and CMake Quickstart.
Abseil is officially supported on many platforms. See the Abseil platform support guide for details on supported operating systems, compilers, CPUs, etc.
Abseil contains the following C++ library components:
base
Abseil Fundamentals base
library contains initialization code and other code which all other Abseil code depends on. Code within base
may not depend on any other code (other than the C++ standard library).algorithm
algorithm
library contains additions to the C++ <algorithm>
library and container-based versions of such algorithms.cleanup
cleanup
library contains the control-flow-construct-like type absl::Cleanup
which is used for executing a callback on scope exit.container
container
library contains additional STL-style containers, including Abseil's unordered "Swiss table" containers.debugging
debugging
library contains code useful for enabling leak checks, and stacktrace and symbolization utilities.hash
hash
library contains the hashing framework and default hash functor implementations for hashable types in Abseil.memory
memory
library contains C++11-compatible versions of std::make_unique()
and related memory management facilities.meta
meta
library contains C++11-compatible versions of type checks available within C++14 and C++17 versions of the C++ <type_traits>
library.numeric
numeric
library contains C++11-compatible 128-bit integers.status
status
contains abstractions for error handling, specifically absl::Status
and absl::StatusOr<T>
.strings
strings
library contains a variety of strings routines and utilities, including a C++11-compatible version of the C++17 std::string_view
type.synchronization
synchronization
library contains concurrency primitives (Abseil's absl::Mutex
class, an alternative to std::mutex
) and a variety of synchronization abstractions.time
time
library contains abstractions for computing with absolute points in time, durations of time, and formatting and parsing time within time zones.types
types
library contains non-container utility types, like a C++11-compatible version of the C++17 std::optional
type.utility
utility
library contains utility and helper code.Abseil recommends users "live-at-head" (update to the latest commit from the master branch as often as possible). However, we realize this philosophy doesn't work for every project, so we also provide Long Term Support Releases to which we backport fixes for severe bugs. See our release management document for more details.
The Abseil C++ library is licensed under the terms of the Apache license. See LICENSE for more information.
For more information about Abseil: