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