1 // This file contains references to sections of the Coroutines TS, which can be 2 // found at http://wg21.link/coroutines. 3 4 // RUN: %clang_cc1 -std=c++14 -fcoroutines-ts -verify %s -fcxx-exceptions -fexceptions -Wunused-result 5 6 namespace std { 7 namespace experimental { 8 9 template<typename ...T> 10 struct coroutine_traits { 11 struct promise_type {}; 12 }; 13 14 template<> struct coroutine_traits<void>; // expected-note {{forward declaration of 'std::experimental::coroutine_traits<void>'}} 15 }} // namespace std::experimental 16 uses_forward_declaration()17void uses_forward_declaration() { 18 co_return; // expected-error {{this function cannot be a coroutine: missing definition of specialization 'coroutine_traits<void>'}} 19 } 20