xref: /llvm-project/libcxx/include/__coroutine/trivial_awaitables.h (revision 5aaefa510ef055e8f044ca89e352d4313f3aba49)
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 #ifndef __LIBCPP___COROUTINE_TRIVIAL_AWAITABLES_H
10 #define __LIBCPP___COROUTINE_TRIVIAL_AWAITABLES_H
11 
12 #include <__config>
13 #include <__coroutine/coroutine_handle.h>
14 
15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
16 #  pragma GCC system_header
17 #  pragma clang include_instead(<coroutine>)
18 #endif
19 
20 #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CXX20_COROUTINES)
21 
22 _LIBCPP_BEGIN_NAMESPACE_STD
23 
24 // [coroutine.trivial.awaitables]
25 struct suspend_never {
26     _LIBCPP_HIDE_FROM_ABI
27     constexpr bool await_ready() const noexcept { return true; }
28     _LIBCPP_HIDE_FROM_ABI
29     constexpr void await_suspend(coroutine_handle<>) const noexcept {}
30     _LIBCPP_HIDE_FROM_ABI
31     constexpr void await_resume() const noexcept {}
32 };
33 
34 struct suspend_always {
35     _LIBCPP_HIDE_FROM_ABI
36     constexpr bool await_ready() const noexcept { return false; }
37     _LIBCPP_HIDE_FROM_ABI
38     constexpr void await_suspend(coroutine_handle<>) const noexcept {}
39     _LIBCPP_HIDE_FROM_ABI
40     constexpr void await_resume() const noexcept {}
41 };
42 
43 _LIBCPP_END_NAMESPACE_STD
44 
45 #endif // __LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CXX20_COROUTINES)
46 
47 #endif // __LIBCPP___COROUTINE_TRIVIAL_AWAITABLES_H
48