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++20 -verify %s -fcxx-exceptions -fexceptions -Wunused-result 5 6 namespace std { 7 8 template <class Ret, typename... T> 9 struct coroutine_traits { using promise_type = typename Ret::promise_type; }; 10 11 template <class Promise = void> 12 struct coroutine_handle { 13 static coroutine_handle from_address(void *); 14 void *address() const noexcept; 15 }; 16 template <> 17 struct coroutine_handle<void> { 18 template <class PromiseType> 19 coroutine_handle(coroutine_handle<PromiseType>); 20 void *address() const noexcept; 21 }; 22 23 struct suspend_always { await_readystd::suspend_always24 bool await_ready() { return false; } // expected-note 2 {{must be declared with 'noexcept'}} await_suspendstd::suspend_always25 void await_suspend(coroutine_handle<>) {} // expected-note 2 {{must be declared with 'noexcept'}} await_resumestd::suspend_always26 void await_resume() {} // expected-note 2 {{must be declared with 'noexcept'}} 27 ~suspend_always() noexcept(false); // expected-note 2 {{must be declared with 'noexcept'}} 28 }; 29 30 } // namespace std 31 32 using namespace std; 33 34 struct A { 35 bool await_ready(); 36 void await_resume(); 37 template <typename F> 38 void await_suspend(F); 39 }; 40 41 struct coro_t { 42 struct promise_type { 43 coro_t get_return_object(); 44 suspend_always initial_suspend(); 45 suspend_always final_suspend(); // expected-note 2 {{must be declared with 'noexcept'}} 46 void return_void(); 47 static void unhandled_exception(); 48 }; 49 }; 50 f(int n)51coro_t f(int n) { // expected-error {{the expression 'co_await __promise.final_suspend()' is required to be non-throwing}} 52 A a{}; 53 co_await a; 54 } 55 56 template <typename T> f_dep(T n)57coro_t f_dep(T n) { // expected-error {{the expression 'co_await __promise.final_suspend()' is required to be non-throwing}} 58 A a{}; 59 co_await a; 60 } 61 foo()62void foo() { 63 f_dep<int>(5); // expected-note {{in instantiation of function template specialization 'f_dep<int>' requested here}} 64 } 65 66 struct PositiveFinalSuspend { 67 bool await_ready() noexcept; 68 coroutine_handle<> await_suspend(coroutine_handle<>) noexcept; 69 void await_resume() noexcept; 70 }; 71 72 struct correct_coro { 73 struct promise_type { 74 correct_coro get_return_object(); 75 suspend_always initial_suspend(); 76 PositiveFinalSuspend final_suspend() noexcept; 77 void return_void(); 78 static void unhandled_exception(); 79 }; 80 }; 81 f2(int n)82correct_coro f2(int n) { 83 co_return; 84 } 85 86 struct NegativeFinalSuspend { 87 bool await_ready() noexcept; 88 coroutine_handle<> await_suspend(coroutine_handle<>) noexcept; 89 void await_resume() noexcept; 90 ~NegativeFinalSuspend() noexcept(false); // expected-note {{must be declared with 'noexcept'}} 91 }; 92 93 struct incorrect_coro { 94 struct promise_type { 95 incorrect_coro get_return_object(); 96 suspend_always initial_suspend(); 97 NegativeFinalSuspend final_suspend() noexcept; 98 void return_void(); 99 static void unhandled_exception(); 100 }; 101 }; 102 f3(int n)103incorrect_coro f3(int n) { // expected-error {{the expression 'co_await __promise.final_suspend()' is required to be non-throwing}} 104 co_return; 105 } 106