libc++, Clang and LLVM on Windows
Quote from the project page:
if you want to compile C + + and uses the Microsoft C + + STL, please use the CL diver modes, namely: - dirver-mode = cl and disable RTTI;".
That answers your question. Best to interpret its accuracy for the way it reads, the unintentional hint of death by drowning is in fact appropriate. This page gives a very decent insight what more work needs to be done before it is close to usable.