// { dg-do compile { target c++2a } }

template<typename T>
concept Concept =
  requires () {
    typename T::member_type1;
    typename T::member_type2;
  };

struct model {
  using member_type1 = int;
  using member_type2 = int;
};

template<Concept C>
struct S {};

S<model> s;