http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50025
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-08-08 22:46:31 UTC --- It's not just class members, it applies to list-initialization of any reference type: int i; int& ir{ i }; The FDIS requires a temporary to be created, and a non-const reference cannot bind to a temporary.