text: // This file contains references to sections of the Coroutines TS, which can be
  // found at http://wg21.link/coroutines.
  
  // RUN: %clang_cc1 -std=c++14 -fcoroutines-ts -verify %s -fcxx-exceptions -fexceptions -Wunused-result
  
  namespace std {
  namespace experimental {
  
  template <class Ret, typename... T>
  struct coroutine_traits { using promise_type = typename Ret::promise_type; };
  
  template <class Promise = void>
  struct coroutine_handle {
    static coroutine_handle from_address(void *); // expected-note {{must be declared with 'noexcept'}}
  };
  template <>
  struct coroutine_handle<void> {
    template <class PromiseType>
    coroutine_handle(coroutine_handle<PromiseType>); // expected-note {{must be declared with 'noexcept'}}
  };
  
  struct suspend_never {
    bool await_ready() { return true; }       // expected-note {{must be declared with 'noexcept'}}
    void await_suspend(coroutine_handle<>) {} // expected-note {{must be declared with 'noexcept'}}
    void await_resume() {}                    // expected-note {{must be declared with 'noexcept'}}
    ~suspend_never() noexcept(false);         // expected-note {{must be declared with 'noexcept'}}
  };
  
  struct suspend_always {
    bool await_ready() { return false; }
    void await_suspend(coroutine_handle<>) {}
    void await_resume() {}
    suspend_never operator co_await(); // expected-note {{must be declared with 'noexcept'}}
    ~suspend_always() noexcept(false); // expected-note {{must be declared with 'noexcept'}}
  };
  
  } // namespace experimental
  } // namespace std
  
  using namespace std::experimental;
  
  struct A {
    bool await_ready();
    void await_resume();
    template <typename F>
    void await_suspend(F);
  };
  
  struct coro_t {
    struct promise_type {
      coro_t get_return_object();
      suspend_never initial_suspend();
      suspend_always final_suspend(); // expected-note {{must be declared with 'noexcept'}}
      void return_void();
      static void unhandled_exception();
    };
  };
  
  coro_t f(int n) { // expected-error {{the expression 'co_await __promise.final_suspend()' is required to be non-throwing}}
    A a{};
    co_await a;
  }
  