Windows build is not ready

[syoyo]

Some part of code is Windows-aware(ifdef'ed with OS_WINDOWS), but still incomplete(e.g. pthread.h in benchmark.h)

[pleroy]

FWIW I have a port for Windows based on the pthread library at http://locklessinc.com/downloads/ (BSD 3-clause). Not quite ready for a pull request, but getting there.

[dmah42]

#64 has landed which gives us a working mingw port. does that help?

[mattyclarkson]

@dominichamon, I tried having a go at getting VS2013 up and going but there are a few things missing with the C++11 support. I'll just brain dump here in case anyone can pick it up:

• gettimeofday needs to be polyfilled in walltime.cc
• (gm|local)time_r needs to be changed for (gm|local)time_s. arguments to swap over.
• constexpr support is sketchy so things don't compile
• noexcept wasn't supported
• CMakeList.txt needs if (MSVC) to avoid all the GCC/Clang flag checks (not an issue as they fail gracefully, just looks weird)
• By default cmake adds /Wall which turns on warnings that even the STL that is shipped with Visual Studio doesn't compile with. I'd suggest starting with /W0 and slowly cranking that up to /W4 putting the necessary /wdXXXX in the CMakeList.txt or the pragma warning() around the offending areas. It would be great to have a clean MSVC build at high warning levels as it might catch things that GCC/Clang might miss

It's almost there, just needs a bit of love. cmake -G "Visual Studio 12 2013" gets things going.

Once the Visual Studio build is going the appveyor support to continuously check for MSVC support can be added by implementing msbuild like cppformat does here. Will just have to add the necessary lines to appveyor.yml when if "%compiler_name%"=="msvc".

[KindDragon]

Relate to PR #175

[EricWF]

Closing since the Windows build seems to be working and Appveyor is testing it on every commit.

[syoyo]

Super cool! Thank you!