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___NUMERIC_PSTL_REDUCE_H
10#define _LIBCPP___NUMERIC_PSTL_REDUCE_H
11
12#include <__algorithm/pstl_frontend_dispatch.h>
13#include <__config>
14#include <__functional/identity.h>
15#include <__iterator/iterator_traits.h>
16#include <__numeric/pstl_transform_reduce.h>
17#include <__type_traits/is_execution_policy.h>
18
19#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20#  pragma GCC system_header
21#endif
22
23_LIBCPP_PUSH_MACROS
24#include <__undef_macros>
25
26#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
27
28_LIBCPP_BEGIN_NAMESPACE_STD
29
30template <class>
31void __pstl_reduce();
32
33template <class _ExecutionPolicy,
34          class _ForwardIterator,
35          class _Tp,
36          class _BinaryOperation                              = plus<>,
37          class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
38          enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
39[[nodiscard]] _LIBCPP_HIDE_FROM_ABI optional<_Tp>
40__reduce(_ExecutionPolicy&& __policy,
41         _ForwardIterator&& __first,
42         _ForwardIterator&& __last,
43         _Tp&& __init,
44         _BinaryOperation&& __op = {}) noexcept {
45  return std::__pstl_frontend_dispatch(
46      _LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_reduce, _RawPolicy),
47      [&__policy](_ForwardIterator __g_first, _ForwardIterator __g_last, _Tp __g_init, _BinaryOperation __g_op) {
48        return std::__transform_reduce(
49            __policy, std::move(__g_first), std::move(__g_last), std::move(__g_init), std::move(__g_op), __identity{});
50      },
51      std::move(__first),
52      std::move(__last),
53      std::move(__init),
54      std::move(__op));
55}
56
57template <class _ExecutionPolicy,
58          class _ForwardIterator,
59          class _Tp,
60          class _BinaryOperation                              = plus<>,
61          class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
62          enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
63_LIBCPP_HIDE_FROM_ABI _Tp
64reduce(_ExecutionPolicy&& __policy,
65       _ForwardIterator __first,
66       _ForwardIterator __last,
67       _Tp __init,
68       _BinaryOperation __op = {}) {
69  auto __res = std::__reduce(__policy, std::move(__first), std::move(__last), std::move(__init), std::move(__op));
70  if (!__res)
71    std::__throw_bad_alloc();
72  return *std::move(__res);
73}
74
75template <class _ExecutionPolicy,
76          class _ForwardIterator,
77          class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
78          enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
79[[nodiscard]] _LIBCPP_HIDE_FROM_ABI optional<__iter_value_type<_ForwardIterator>>
80__reduce(_ExecutionPolicy&& __policy, _ForwardIterator&& __first, _ForwardIterator&& __last) noexcept {
81  return std::__pstl_frontend_dispatch(
82      _LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_reduce, _RawPolicy),
83      [&__policy](_ForwardIterator __g_first, _ForwardIterator __g_last) {
84        return std::__reduce(
85            __policy, std::move(__g_first), std::move(__g_last), __iter_value_type<_ForwardIterator>());
86      },
87      std::move(__first),
88      std::move(__last));
89}
90
91template <class _ExecutionPolicy,
92          class _ForwardIterator,
93          class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
94          enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
95_LIBCPP_HIDE_FROM_ABI __iter_value_type<_ForwardIterator>
96reduce(_ExecutionPolicy&& __policy, _ForwardIterator __first, _ForwardIterator __last) {
97  auto __res = std::__reduce(__policy, std::move(__first), std::move(__last));
98  if (!__res)
99    std::__throw_bad_alloc();
100  return *std::move(__res);
101}
102
103_LIBCPP_END_NAMESPACE_STD
104
105#endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
106
107_LIBCPP_POP_MACROS
108
109#endif // _LIBCPP___NUMERIC_PSTL_REDUCE_H
110