Hi everyone! I'm working on libc++ and we are currently discussing using language extensions from later standards (https://discourse.llvm.org/t/rfc-use-language-extensions-from-future-standards-in-libc/71898/4). By that I mean things like using `if constexpr` with `-std=c++11`. GCC has quite a lot of these kinds of conforming extensions, but doesn't document them AFAICT. While discussing using these extensions, the question came up what GCCs support policy for these is. Aaron was kind enough to answer these questions for us on the Clang side. Since I couldn't find anything in the documentation, I thought I'd ask here.
So, here are my questions: Do you expect that these extensions will ever be removed for some reason? If yes, what could those reasons be? Would you be interested in documenting them? Aaron noted that we should ask the Clang folks before using them, so they can evaluated whether the extension makes sense, since they might not be aware of them, and some might be broken. So I'd be interested whether you would also like us to ask whether you want to actually support these extensions. Thanks, Nikolas
