https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112296
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- I think you mean std::is_constant_evaluated, but that doesn't check values, it checks if the function is being evaluated as constexpr. And if-constexpr can't be used here either, that works like templates, so only on static types, not runtime values.
