https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82148
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- The gimplifier is handed call to foo with argument of type Derived, the conversion has been omitted. As the call expects a type (in this case empty class) passed by value, but the argument is one that should be passed by invisible reference, this obviously crashes during expansion.