Make PYBIND11_CPP_STANDARD work under MSVC
Under MSVC we were ignoring PYBIND11_CPP_STANDARD and simply not
passing any standard (which makes MSVC default to its C++14 mode).
MSVC 2015u3 added the `/std:c++14` and `/std:c++latest` flags; the
latter, under MSVC 2017, enables some C++17 features (such as
`std::optional` and `std::variant`), so it is something we need to
start supporting under MSVC.
This makes the PYBIND11_CPP_STANDARD cmake variable work under MSVC,
defaulting it to /std:c++14 (matching the default -std=c++14 for
non-MSVC).
It also adds a new appveyor test running under MSVC 2017 with
/std:c++latest, which runs (and passes) the
`std::optional`/`std::variant` tests.
Also updated the documentation to clarify the c++ flags and add show
MSVC flag examples.
diff --git a/.appveyor.yml b/.appveyor.yml
index 683494b..026e761 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -11,11 +11,20 @@
environment:
matrix:
- CONDA: 36
+ CPP: 14
- CONDA: 27
+ CPP: 14
+ - CONDA: 36
+ CPP: latest
matrix:
exclude:
- image: Visual Studio 2015
platform: x86
+ - image: Visual Studio 2015
+ CPP: latest
+ - image: Visual Studio 2017
+ CPP: latest
+ platform: x86
install:
- ps: |
if ($env:PLATFORM -eq "x64") { $env:CMAKE_ARCH = "x64" }
@@ -37,7 +46,7 @@
7z x 3.3.3.zip -y > $null
$env:CMAKE_INCLUDE_PATH = "eigen-eigen-67e894c6cd8f"
build_script:
-- cmake -G "%CMAKE_GENERATOR%" -A "%CMAKE_ARCH%" -DPYBIND11_WERROR=ON -DCMAKE_SUPPRESS_REGENERATION=1
+- cmake -G "%CMAKE_GENERATOR%" -A "%CMAKE_ARCH%" -DPYBIND11_CPP_STANDARD=/std:c++%CPP% -DPYBIND11_WERROR=ON -DCMAKE_SUPPRESS_REGENERATION=1
- set MSBuildLogger="C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll"
- cmake --build . --config Release --target pytest -- /v:m /logger:%MSBuildLogger%
- cmake --build . --config Release --target test_cmake_build -- /v:m /logger:%MSBuildLogger%