https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110348
--- Comment #17 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to corentinjabot from comment #16) > Clang always evaluate if i recall, the error is actually a warning that > defaults to error. I initially had a warning for it, but Jason preferred not to warn at all. Non-constexpr methods/functions is just one of many reasons why it could fail to constant evaluate. > > Last is clang++ ICEs on non-static data members size/data. > > You have a reproducer for that ? The static_assert1.C test above. https://godbolt.org/z/s3fffdsEq