https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114118
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- I don't think we want to enable all the <cmath> functions etc. because those aren't expected to be present before C++23. But the types like _Float32 are already present, and that seems fine. I just think we should be able to detect them in the library traits. At the very least we should make __numeric_traits work for them, as that already works for __int128 and __float128 when those are defined, even when they're not considered to be an integer or floating-point type respectively.