clang support

[rolandschulz]

libstdc++ is used by many also for clang. It would be great if this will eventually also support clang. Do you already know the reasons (i.e. the list of missing compiler features and compiler bugs) why this doesn't work in clang? I think it would be nice to compile the list of clang issue numbers here to track when clang will support this. Do you want help with that?

[mattkretz]

At this point it's as simple as "I want to release something that's a full implementation, correct, and optimized" to show off the TS. Verifying more than one compiler makes that effort take longer than it already takes. So that's why I'm currently focusing on GCC 9/10 only.
That said, if you (or anyone else) wants to take up maintaining support for Clang or even pursue inclusion into libc++ you have my support.