libcxx/include/__coroutine/trivial_awaitables.h

   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 #endif
  18
  19 #if _LIBCPP_STD_VER >= 20
  20
  21 _LIBCPP_BEGIN_NAMESPACE_STD
  22
  23 // [coroutine.trivial.awaitables]
  24 struct suspend_never {
  25     _LIBCPP_HIDE_FROM_ABI
  26     constexpr bool await_ready() const noexcept { return true; }
  27     _LIBCPP_HIDE_FROM_ABI
  28     constexpr void await_suspend(coroutine_handle<>) const noexcept {}
  29     _LIBCPP_HIDE_FROM_ABI
  30     constexpr void await_resume() const noexcept {}
  31 };
  32
  33 struct suspend_always {
  34     _LIBCPP_HIDE_FROM_ABI
  35     constexpr bool await_ready() const noexcept { return false; }
  36     _LIBCPP_HIDE_FROM_ABI
  37     constexpr void await_suspend(coroutine_handle<>) const noexcept {}
  38     _LIBCPP_HIDE_FROM_ABI
  39     constexpr void await_resume() const noexcept {}
  40 };
  41
  42 _LIBCPP_END_NAMESPACE_STD
  43
  44 #endif // __LIBCPP_STD_VER >= 20
  45
  46 #endif // __LIBCPP___COROUTINE_TRIVIAL_AWAITABLES_H