1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_EXECUTION
11#define _LIBCPP_EXECUTION
12
13/*
14namespace std::execution {
15 struct sequenced_policy;
16 struct parallel_policy;
17 struct parallel_unsequenced_policy;
18 struct unsequenced_policy; // since C++20
19
20 inline constexpr sequenced_policy seq = implementation-defined;
21 inline constexpr parallel_policy par = implementation-defined;
22 inline constexpr parallel_unsequenced_policy par_unseq = implementation-defined;
23 inline constexpr unsequenced_policy unseq = implementation-defined; // since C++20
24}
25
26namespace std {
27 template <class T>
28 struct is_execution_policy;
29
30 template <class T>
31 inline constexpr bool is_execution_policy_v;
32}
33*/
34
35#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
36# include <__cxx03/__config>
37#else
38# include <__config>
39# include <__type_traits/is_execution_policy.h>
40# include <__type_traits/is_same.h>
41# include <__type_traits/remove_cvref.h>
42# include <version>
43
44# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
45# pragma GCC system_header
46# endif
47
48# if _LIBCPP_HAS_EXPERIMENTAL_PSTL && _LIBCPP_STD_VER >= 17
49
50_LIBCPP_BEGIN_NAMESPACE_STD
51
52namespace execution {
53struct sequenced_policy {
54 _LIBCPP_HIDE_FROM_ABI constexpr explicit sequenced_policy(__disable_user_instantiations_tag) {}
55 sequenced_policy(const sequenced_policy&) = delete;
56 sequenced_policy& operator=(const sequenced_policy&) = delete;
57};
58
59inline constexpr sequenced_policy seq{__disable_user_instantiations_tag{}};
60
61struct parallel_policy {
62 _LIBCPP_HIDE_FROM_ABI constexpr explicit parallel_policy(__disable_user_instantiations_tag) {}
63 parallel_policy(const parallel_policy&) = delete;
64 parallel_policy& operator=(const parallel_policy&) = delete;
65};
66
67inline constexpr parallel_policy par{__disable_user_instantiations_tag{}};
68
69struct parallel_unsequenced_policy {
70 _LIBCPP_HIDE_FROM_ABI constexpr explicit parallel_unsequenced_policy(__disable_user_instantiations_tag) {}
71 parallel_unsequenced_policy(const parallel_unsequenced_policy&) = delete;
72 parallel_unsequenced_policy& operator=(const parallel_unsequenced_policy&) = delete;
73};
74
75inline constexpr parallel_unsequenced_policy par_unseq{__disable_user_instantiations_tag{}};
76
77struct __unsequenced_policy {
78 _LIBCPP_HIDE_FROM_ABI constexpr explicit __unsequenced_policy(__disable_user_instantiations_tag) {}
79 __unsequenced_policy(const __unsequenced_policy&) = delete;
80 __unsequenced_policy& operator=(const __unsequenced_policy&) = delete;
81};
82
83constexpr __unsequenced_policy __unseq{__disable_user_instantiations_tag{}};
84
85# if _LIBCPP_STD_VER >= 20
86
87struct unsequenced_policy {
88 _LIBCPP_HIDE_FROM_ABI constexpr explicit unsequenced_policy(__disable_user_instantiations_tag) {}
89 unsequenced_policy(const unsequenced_policy&) = delete;
90 unsequenced_policy& operator=(const unsequenced_policy&) = delete;
91};
92
93inline constexpr unsequenced_policy unseq{__disable_user_instantiations_tag{}};
94
95# endif // _LIBCPP_STD_VER >= 20
96
97} // namespace execution
98
99_LIBCPP_DIAGNOSTIC_PUSH
100# if __has_warning("-Winvalid-specialization")
101_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Winvalid-specialization")
102# endif
103template <>
104inline constexpr bool is_execution_policy_v<execution::sequenced_policy> = true;
105
106template <>
107inline constexpr bool is_execution_policy_v<execution::parallel_policy> = true;
108
109template <>
110inline constexpr bool is_execution_policy_v<execution::parallel_unsequenced_policy> = true;
111
112template <>
113inline constexpr bool is_execution_policy_v<execution::__unsequenced_policy> = true;
114_LIBCPP_DIAGNOSTIC_POP
115
116template <>
117inline constexpr bool __is_parallel_execution_policy_impl<execution::parallel_policy> = true;
118
119template <>
120inline constexpr bool __is_parallel_execution_policy_impl<execution::parallel_unsequenced_policy> = true;
121
122template <>
123inline constexpr bool __is_unsequenced_execution_policy_impl<execution::__unsequenced_policy> = true;
124
125template <>
126inline constexpr bool __is_unsequenced_execution_policy_impl<execution::parallel_unsequenced_policy> = true;
127
128# if _LIBCPP_STD_VER >= 20
129_LIBCPP_DIAGNOSTIC_PUSH
130# if __has_warning("-Winvalid-specialization")
131_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Winvalid-specialization")
132# endif
133template <>
134inline constexpr bool is_execution_policy_v<execution::unsequenced_policy> = true;
135_LIBCPP_DIAGNOSTIC_POP
136
137template <>
138inline constexpr bool __is_unsequenced_execution_policy_impl<execution::unsequenced_policy> = true;
139
140# endif
141
142template <class _Tp>
143struct _LIBCPP_NO_SPECIALIZATIONS is_execution_policy : bool_constant<is_execution_policy_v<_Tp>> {};
144
145template <class _ExecutionPolicy>
146_LIBCPP_HIDE_FROM_ABI auto __remove_parallel_policy(const _ExecutionPolicy&) {
147 if constexpr (is_same_v<_ExecutionPolicy, execution::parallel_policy>) {
148 return execution::sequenced_policy(execution::__disable_user_instantiations_tag{});
149 } else if constexpr (is_same_v<_ExecutionPolicy, execution::parallel_unsequenced_policy>) {
150 return execution::__unsequenced_policy{execution::__disable_user_instantiations_tag{}};
151 }
152}
153
154_LIBCPP_END_NAMESPACE_STD
155
156# endif // _LIBCPP_HAS_EXPERIMENTAL_PSTL && _LIBCPP_STD_VER >= 17
157
158# if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
159# include <cstddef>
160# endif
161#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
162
163#endif // _LIBCPP_EXECUTION