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

[Nikolas Klauser via libcxx-commits]

philnik777 wrote:

> But it also looks like we have some sort of very odd bug: https://godbolt.org/z/5v1b5fr4T Why is this allowed in `constinit` but removing the `f` suffix to the operands makes the non-builtin form invalid?

Most likely libstdc++ already makes their overloads `constexpr` and uses the `__builtin_` internally. Using libc++ causes this to fail consistently. (I also feel vindicated that we shouldn't make just libc++'s overloads `constexpr` or try to do weird workarounds)

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