https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89793
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jason at gcc dot gnu.org --- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- Jason, I'm not sure if this is a regression in gcc-8 or a bug in gcc-7 that was fixed. It looks like both conversion sequences (String -> string -> const string& and String -> NotString -> const allocator&) have Conversion rank, although the lack of a derived-to-base conversion in the first one would naively seem to make it better.