https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89130
--- Comment #6 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #5) > Looking at the standard, the requirements for the push_back call in comment > 0 are that X is Cpp17CopyInsertable into vector<X>, which is true. The check > whether to use relocation fails if it isn't also Cpp17MoveInsertable into > vector<X>, which is not a requirement. So we do need to fix it, which I've > now done. "T is Cpp17CopyInsertable into X means that, in addition to T being Cpp17MoveInsertable into X, [...]"
