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#include <__config> 36#include <__type_traits/is_execution_policy.h> 37#include <__type_traits/is_same.h> 38#include <__type_traits/remove_cvref.h> 39#include <version> 40 41#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 42# pragma GCC system_header 43#endif 44 45#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17 46 47_LIBCPP_BEGIN_NAMESPACE_STD 48 49namespace execution { 50struct sequenced_policy { 51 _LIBCPP_HIDE_FROM_ABI constexpr explicit sequenced_policy(__disable_user_instantiations_tag) {} 52 sequenced_policy(const sequenced_policy&) = delete; 53 sequenced_policy& operator=(const sequenced_policy&) = delete; 54}; 55 56inline constexpr sequenced_policy seq{__disable_user_instantiations_tag{}}; 57 58struct parallel_policy { 59 _LIBCPP_HIDE_FROM_ABI constexpr explicit parallel_policy(__disable_user_instantiations_tag) {} 60 parallel_policy(const parallel_policy&) = delete; 61 parallel_policy& operator=(const parallel_policy&) = delete; 62}; 63 64inline constexpr parallel_policy par{__disable_user_instantiations_tag{}}; 65 66struct parallel_unsequenced_policy { 67 _LIBCPP_HIDE_FROM_ABI constexpr explicit parallel_unsequenced_policy(__disable_user_instantiations_tag) {} 68 parallel_unsequenced_policy(const parallel_unsequenced_policy&) = delete; 69 parallel_unsequenced_policy& operator=(const parallel_unsequenced_policy&) = delete; 70}; 71 72inline constexpr parallel_unsequenced_policy par_unseq{__disable_user_instantiations_tag{}}; 73 74struct __unsequenced_policy { 75 _LIBCPP_HIDE_FROM_ABI constexpr explicit __unsequenced_policy(__disable_user_instantiations_tag) {} 76 __unsequenced_policy(const __unsequenced_policy&) = delete; 77 __unsequenced_policy& operator=(const __unsequenced_policy&) = delete; 78}; 79 80constexpr __unsequenced_policy __unseq{__disable_user_instantiations_tag{}}; 81 82# if _LIBCPP_STD_VER >= 20 83 84struct unsequenced_policy { 85 _LIBCPP_HIDE_FROM_ABI constexpr explicit unsequenced_policy(__disable_user_instantiations_tag) {} 86 unsequenced_policy(const unsequenced_policy&) = delete; 87 unsequenced_policy& operator=(const unsequenced_policy&) = delete; 88}; 89 90inline constexpr unsequenced_policy unseq{__disable_user_instantiations_tag{}}; 91 92# endif // _LIBCPP_STD_VER >= 20 93 94} // namespace execution 95 96template <> 97inline constexpr bool is_execution_policy_v<execution::sequenced_policy> = true; 98 99template <> 100inline constexpr bool is_execution_policy_v<execution::parallel_policy> = true; 101 102template <> 103inline constexpr bool is_execution_policy_v<execution::parallel_unsequenced_policy> = true; 104 105template <> 106inline constexpr bool is_execution_policy_v<execution::__unsequenced_policy> = true; 107 108template <> 109inline constexpr bool __is_parallel_execution_policy_impl<execution::parallel_policy> = true; 110 111template <> 112inline constexpr bool __is_parallel_execution_policy_impl<execution::parallel_unsequenced_policy> = true; 113 114template <> 115inline constexpr bool __is_unsequenced_execution_policy_impl<execution::__unsequenced_policy> = true; 116 117template <> 118inline constexpr bool __is_unsequenced_execution_policy_impl<execution::parallel_unsequenced_policy> = true; 119 120# if _LIBCPP_STD_VER >= 20 121template <> 122inline constexpr bool is_execution_policy_v<execution::unsequenced_policy> = true; 123 124template <> 125inline constexpr bool __is_unsequenced_execution_policy_impl<execution::unsequenced_policy> = true; 126 127# endif 128 129template <class _Tp> 130struct is_execution_policy : bool_constant<is_execution_policy_v<_Tp>> {}; 131 132template <class _ExecutionPolicy> 133_LIBCPP_HIDE_FROM_ABI auto __remove_parallel_policy(const _ExecutionPolicy&) { 134 if constexpr (is_same_v<_ExecutionPolicy, execution::parallel_policy>) { 135 return execution::sequenced_policy(execution::__disable_user_instantiations_tag{}); 136 } else if constexpr (is_same_v<_ExecutionPolicy, execution::parallel_unsequenced_policy>) { 137 return execution::__unsequenced_policy{execution::__disable_user_instantiations_tag{}}; 138 } 139} 140 141_LIBCPP_END_NAMESPACE_STD 142 143#endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17 144 145#endif // _LIBCPP_EXECUTION 146