libc++ is compiled by compilers other than clang. It's a completely invalid assumption that it will only ever be compiled by clang, because it's never only ove

libc++ is compiled by compilers other than clang. It's a completely invalid assumption that it will only ever be compiled by clang, because it's never only over been compiled by clang. I say this as someone with a full time paid job supporting libc++ compiled by another compiler for a commercial organization in a safety context.