See http://blogs.msdn.com/b/vcblog/archive/2015/12/04/introducing-clang-with-microsoft-codegen-in-vs-2015-update-1.aspx

I've been testing clang/c2 both via the Visual Studio IDE and from the command line. While it is just a preview release, it already works well enough that having a Boost.Build toolset would be quite useful.

It would be great if someone could contribute such a toolset!

--Beman