https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67898
--- Comment #4 from Patrick Palka <ppalka at gcc dot gnu.org> --- Related rejects-valid C++11 testcase: template<class T, T V, class = decltype(V)> struct A; template<class U> using B = A<U, 0>; using type = A<bool, 0>; using type = B<bool>; // incorrectly resolves to A<bool, 0, int> // instead of A<bool, 0, bool>