Just a note to everybody about using clang in Windows. I upgraded the latest clang-linux.jam file in Boost Build on the 'develop' branch so that clang in Windows using gcc should now work for the purposes of testing Boost libraries. If you get the latest clang and build it on Windows using CMake with any of the mingw generators or Ninja, you will have a clang executable which will default to a target using gcc headers and libraries. If you add a line in user-config.jam such as: using clang : : yourpath/clang++.exe ; then you should be able to execute: b2 toolset=clang in order to run tests from withion a test directory for any Boost library using clang as your compiler. The output looks very good without any of the problems I have seen before when running clang in Windows. Just make sure you switch to the Boost Build 'develop' branch and pull the latest source. I have been successful so far when running tests of preprocessor, mpl, type_traits, and tti with clang in Windows. I will test some more libraries but so far it looks to me that the clang developers have finally created a version under Windows which can be used to successfully test Boost libraries. This adds one more reliable testing environment under Windows. Now I can use the latest clang, various flavors of gcc under mingw, and various flavors of VC++.