http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49225
--- Comment #1 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2011-05-30 08:46:33 UTC --- I did some further investigation of this. The problem seems *not* to be located in __my_and_, but it seems that the compiler expands is_same<T, U>... for different T, U to the specialization is_same<T, T> in this scenario - which is obviously incorrect. This could be concluded after either removing the is_same<T, T> definition or by changing its value to false. When removing the definition, the occurring error message reveals, that the instantiation of is_same<A, A> instead of is_same<int, A> is tried, thus pointing to an incorrect expansion that does ignore the _Args1 expansion.
