https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113359
--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> --- I see the 'pair' type is marked TYPE_CXX_ODR_P, I'd say you should see a ODR type violation diagnostic, and if you don't, this means we force different alias sets for both? Not sure - Honza added this stuff. It only affects TYPE_CANONICAL though, regular type merging shouldn't merge them but it's likely that you get to see another type because of COMDATs and symbol merging chosing a different prevailing function which has that other type? Btw, can you dump the mangled name of the type? It should be type_with_linkage_p () I think, of course 'pair' itself is a template so only a specific instantiation should be subject to ODR. (of course there might be ODR functions that use different instantiated pair in the signature ..)
