1 // { dg-do compile { target c++17_only } } 2 // { dg-options "-fconcepts" } 3 4 template<typename T> Tuple()5 concept bool Tuple() { // { dg-error "multiple statements" } 6 static_assert(T::value, ""); 7 return true; 8 } 9 10 void f(Tuple&); 11