https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103295
--- Comment #12 from Jonathan Wakely <redi at gcc dot gnu.org> --- But even with those problems fixed, Clang fails for anything that doesn't fit in the SSO buffer, as shown by this: #include <memory> constexpr char test() { char* p = std::allocator<char>().allocate(2); p[0] = 'a'; char c = *p; std::allocator<char>().deallocate(p, 2); return c; } static_assert( test() == 'a' );