Yi Kong | 8328301 | 2023-12-13 12:57:00 +0900 | [diff] [blame^] | 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_COROUTINE_TRAITS_H |
| 10 | #define _LIBCPP___COROUTINE_COROUTINE_TRAITS_H |
| 11 | |
| 12 | #include <__config> |
| 13 | #include <__type_traits/void_t.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.traits] |
| 24 | // [coroutine.traits.primary] |
| 25 | // The header <coroutine> defined the primary template coroutine_traits such that |
| 26 | // if ArgTypes is a parameter pack of types and if the qualified-id R::promise_type |
| 27 | // is valid and denotes a type ([temp.deduct]), then coroutine_traits<R, ArgTypes...> |
| 28 | // has the following publicly accessible memebr: |
| 29 | // |
| 30 | // using promise_type = typename R::promise_type; |
| 31 | // |
| 32 | // Otherwise, coroutine_traits<R, ArgTypes...> has no members. |
| 33 | template <class _Tp, class = void> |
| 34 | struct __coroutine_traits_sfinae {}; |
| 35 | |
| 36 | template <class _Tp> |
| 37 | struct __coroutine_traits_sfinae< |
| 38 | _Tp, __void_t<typename _Tp::promise_type> > |
| 39 | { |
| 40 | using promise_type = typename _Tp::promise_type; |
| 41 | }; |
| 42 | |
| 43 | template <class _Ret, class... _Args> |
| 44 | struct coroutine_traits |
| 45 | : public __coroutine_traits_sfinae<_Ret> |
| 46 | { |
| 47 | }; |
| 48 | |
| 49 | _LIBCPP_END_NAMESPACE_STD |
| 50 | |
| 51 | #endif // __LIBCPP_STD_VER >= 20 |
| 52 | |
| 53 | #endif // _LIBCPP___COROUTINE_COROUTINE_TRAITS_H |