As barchar (my coworker on the STL team) mentioned, not only does Clang use MSVC’s STL on Windows, but also the support is from both Clang and Microsoft. We tes

As barchar (my coworker on the STL team) mentioned, not only does Clang use MSVC’s STL on Windows, but also the support is from both Clang and Microsoft. We test MSVC’s STL with Clang as a first-class citizen, and have shipped features active for Clang before they were active for C1XX (MSVC’s compiler front-end), notably Class Template Argument Deduction. Clang is a great compiler! We think it’s extra great with our STL. We added Clang/LLVM to the VS installer to make using it easier.