[libcxx-commits] [libcxx] [libc++][math] Add `constexpr` to `copysign`, `copysignf`, `copysignl` (PR #216285)

[Ambrose Leeb via libcxx-commits]

Sirraide wrote:

> The issue is that Clang doesn't make the C overloads `constexpr`, i.e. the `copysign`/`copysignf` etc. I'm quite certain that everything would work just fine if we change that.

By that you mean Clang should just treat the non-`__builtin` version as `constexpr` even if it wasn’t declared `constexpr`? Do we do that for any other library functions?

https://github.com/llvm/llvm-project/pull/216285