1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // UNSUPPORTED: c++03, c++11, c++14, c++17
10 
11 #include <coroutine>
12 #include <type_traits>
13 
14 #include "test_macros.h"
15 
16 template <class T, class = typename T::promise_type>
has_promise_type(int)17 constexpr bool has_promise_type(int) { return true; }
18 template <class>
has_promise_type(long)19 constexpr bool has_promise_type(long) { return false; }
20 template <class T>
has_promise_type()21 constexpr bool has_promise_type() { return has_promise_type<T>(0); }
22 
23 struct A {
24   using promise_type = A*;
25 };
26 
27 struct B {};
28 struct C {};
29 struct D {
30 private:
31   using promise_type = void;
32 };
33 struct E {};
34 
35 template <>
36 struct std::coroutine_traits<A, int> {
37   using promise_type = int*;
38 };
39 template <class ...Args>
40 struct std::coroutine_traits<B, Args...> {
41   using promise_type = B*;
42 };
43 template <>
44 struct std::coroutine_traits<C> {
45   using promise_type = void;
46 };
47 
48 template <class Expect, class T, class ...Args>
check_type()49 void check_type() {
50   using Traits = std::coroutine_traits<T, Args...>;
51   static_assert(has_promise_type<Traits>(), "");
52   static_assert(std::is_same<typename Traits::promise_type, Expect>::value, "");
53 }
54 
55 template <class T, class ...Args>
check_no_type()56 void check_no_type() {
57   using Traits = std::coroutine_traits<T, Args...>;
58   static_assert(!has_promise_type<Traits>(), "");
59 }
60 
main(int,char **)61 int main(int, char**)
62 {
63   {
64     check_type<A*, A>();
65     check_type<int*, A, int>();
66     check_type<B*, B>();
67     check_type<void, C>();
68   }
69   {
70     check_no_type<D>();
71     check_no_type<E>();
72     check_no_type<C, int>();
73   }
74 
75   return 0;
76 }
77