https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79671
--- Comment #55 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Bernd Edlinger from comment #53) > The boost code was: "this->functor = f.functor;" And I still don't understand why may_alias doesn't help on the type of this->functor.