1 // PR c++/100102 2 // { dg-do compile { target c++11 } } 3 4 template<int()> struct ratio; 5 template<class T, class U> struct duration { 6 static constexpr int _S_gcd(); 7 template<class> using __is_harmonic = ratio<_S_gcd>; 8 using type = __is_harmonic<int>; 9 }; 10