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 template <class Ret, typename... T>
9 struct coroutine_traits { using promise_type = typename Ret::promise_type; };
10 // expected-note@-1{{declared here}}
11 
12 template <class Promise = void>
13 struct coroutine_handle {
14   static coroutine_handle from_address(void *);
15   void *address() const noexcept;
16 };
17 template <>
18 struct coroutine_handle<void> {
19   template <class PromiseType>
20   coroutine_handle(coroutine_handle<PromiseType>);
21   void *address() const noexcept;
22 };
23 
24 struct suspend_always {
await_readystd::experimental::suspend_always25   bool await_ready() { return false; }      // expected-note 2 {{must be declared with 'noexcept'}}
await_suspendstd::experimental::suspend_always26   void await_suspend(coroutine_handle<>) {} // expected-note 2 {{must be declared with 'noexcept'}}
await_resumestd::experimental::suspend_always27   void await_resume() {}                    // expected-note 2 {{must be declared with 'noexcept'}}
28   ~suspend_always() noexcept(false);        // expected-note 2 {{must be declared with 'noexcept'}}
29 };
30 } // namespace experimental
31 } // namespace std
32 
33 using namespace std::experimental;
34 
35 struct A {
36   bool await_ready();
37   void await_resume();
38   template <typename F>
39   void await_suspend(F);
40 };
41 
42 struct coro_t {
43   struct promise_type {
44     coro_t get_return_object();
45     suspend_always initial_suspend();
46     suspend_always final_suspend(); // expected-note 2 {{must be declared with 'noexcept'}}
47     void return_void();
48     static void unhandled_exception();
49   };
50 };
51 
f(int n)52 coro_t f(int n) { // expected-error {{the expression 'co_await __promise.final_suspend()' is required to be non-throwing}}
53   A a{};
54   co_await a; // expected-warning {{support for std::experimental::coroutine_traits will be removed}}
55 }
56 
57 template <typename T>
f_dep(T n)58 coro_t f_dep(T n) { // expected-error {{the expression 'co_await __promise.final_suspend()' is required to be non-throwing}}
59   A a{};
60   co_await a;
61 }
62 
foo()63 void foo() {
64   f_dep<int>(5); // expected-note {{in instantiation of function template specialization 'f_dep<int>' requested here}}
65 }
66 
67 struct PositiveFinalSuspend {
68   bool await_ready() noexcept;
69   coroutine_handle<> await_suspend(coroutine_handle<>) noexcept;
70   void await_resume() noexcept;
71 };
72 
73 struct correct_coro {
74   struct promise_type {
75     correct_coro get_return_object();
76     suspend_always initial_suspend();
77     PositiveFinalSuspend final_suspend() noexcept;
78     void return_void();
79     static void unhandled_exception();
80   };
81 };
82 
f2(int n)83 correct_coro f2(int n) {
84   co_return;
85 }
86 
87 struct NegativeFinalSuspend {
88   bool await_ready() noexcept;
89   coroutine_handle<> await_suspend(coroutine_handle<>) noexcept;
90   void await_resume() noexcept;
91   ~NegativeFinalSuspend() noexcept(false); // expected-note {{must be declared with 'noexcept'}}
92 };
93 
94 struct incorrect_coro {
95   struct promise_type {
96     incorrect_coro get_return_object();
97     suspend_always initial_suspend();
98     NegativeFinalSuspend final_suspend() noexcept;
99     void return_void();
100     static void unhandled_exception();
101   };
102 };
103 
f3(int n)104 incorrect_coro f3(int n) { // expected-error {{the expression 'co_await __promise.final_suspend()' is required to be non-throwing}}
105   co_return;
106 }
107