http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52844
--- Comment #4 from Marc Glisse <glisse at gcc dot gnu.org> 2012-10-12 15:52:16 UTC --- template < class > struct V { }; template < int... > struct tuple ; template < int...Is > void f ( V < Is...>) { } auto g ( ) -> decltype ( f ( V < long > ( ) ) ) ;