https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84849
--- Comment #10 from Jason Merrill <jason at gcc dot gnu.org> --- (In reply to ensadc from comment #7) > (In reply to Zhihao Yuan from comment #6) > > I think this is a different bug. GCC thinks the implicitly-deleted move > assignment operator `pair<int&>& pair<int&>::operator=(pair<int&>&&)` is a > candidate for the assignment, which causes ambiguity with > `operator=(value_type&&)` (where value_type = pair<int>). But as part of > resolution of CWG 1402, [class.copy.assign] specifies that "A defaulted move > assignment operator that is defined as deleted is ignored by overload > resolution". Incidentally, no: GCC mentions it, but considers it worse than any other candidate. The real ambiguity is with operator=(const pair<int&>&), the implicitly-deleted *copy* assignment. I don't think this is a bug; if you disagree, please open another PR for it.
