https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94811
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Marc Glisse from comment #1) > Each extra noexcept is one more chance to get things wrong And slows down compilation due to instantiating the trait class templates (which G++ was doing even when not being checked by a noexcept-expression, but I think that might have been fixed recently).