https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107598
Jason Merrill <jason at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jason at gcc dot gnu.org --- Comment #1 from Jason Merrill <jason at gcc dot gnu.org> --- It's not constexpr because it wasn't declared to be constexpr (or defaulted) in the class body, and "If any declaration of a function or function template has a constexpr or consteval specifier, then all its declarations shall contain the same specifier." The wording (and the error) could use some clarification.