1 //  { dg-additional-options "-fsyntax-only -fexceptions -w" }
2 
3 // Diagose missing coroutine handle class template.
4 
5 namespace std {
6   //  coroutine traits
7   template<typename _R, typename...> struct coroutine_traits {
8     using promise_type = typename _R::promise_type;
9   };
10 }
11 
12 int
bad_coroutine(void)13 bad_coroutine (void)
14 {
15   co_yield 5; // { dg-error {coroutines require a handle class template; cannot find 'std::coroutine_handle'} }
16   co_return;
17 }
18