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 #if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
24
25 _LIBCPP_BEGIN_NAMESPACE_STD
26
27 template <class>
28 void __pstl_reduce();
29
30 template <class _ExecutionPolicy,
31 class _ForwardIterator,
32 class _Tp,
33 class _BinaryOperation = plus<>,
34 class _RawPolicy = __remove_cvref_t<_ExecutionPolicy>,
35 enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
36 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI optional<_Tp>
37 __reduce(_ExecutionPolicy&& __policy,
38 _ForwardIterator&& __first,
39 _ForwardIterator&& __last,
40 _Tp&& __init,
41 _BinaryOperation&& __op = {}) noexcept {
42 return std::__pstl_frontend_dispatch(
43 _LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_reduce, _RawPolicy),
44 [&__policy](_ForwardIterator __g_first, _ForwardIterator __g_last, _Tp __g_init, _BinaryOperation __g_op) {
45 return std::__transform_reduce(
46 __policy, std::move(__g_first), std::move(__g_last), std::move(__g_init), std::move(__g_op), __identity{});
47 },
48 std::move(__first),
49 std::move(__last),
50 std::move(__init),
51 std::move(__op));
52 }
53
54 template <class _ExecutionPolicy,
55 class _ForwardIterator,
56 class _Tp,
57 class _BinaryOperation = plus<>,
58 class _RawPolicy = __remove_cvref_t<_ExecutionPolicy>,
59 enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
60 _LIBCPP_HIDE_FROM_ABI _Tp
61 reduce(_ExecutionPolicy&& __policy,
62 _ForwardIterator __first,
63 _ForwardIterator __last,
64 _Tp __init,
65 _BinaryOperation __op = {}) {
66 auto __res = std::__reduce(__policy, std::move(__first), std::move(__last), std::move(__init), std::move(__op));
67 if (!__res)
68 std::__throw_bad_alloc();
69 return *std::move(__res);
70 }
71
72 template <class _ExecutionPolicy,
73 class _ForwardIterator,
74 class _RawPolicy = __remove_cvref_t<_ExecutionPolicy>,
75 enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
76 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI optional<__iter_value_type<_ForwardIterator>>
__reduce(_ExecutionPolicy && __policy,_ForwardIterator && __first,_ForwardIterator && __last)77 __reduce(_ExecutionPolicy&& __policy, _ForwardIterator&& __first, _ForwardIterator&& __last) noexcept {
78 return std::__pstl_frontend_dispatch(
79 _LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_reduce, _RawPolicy),
80 [&__policy](_ForwardIterator __g_first, _ForwardIterator __g_last) {
81 return std::__reduce(
82 __policy, std::move(__g_first), std::move(__g_last), __iter_value_type<_ForwardIterator>());
83 },
84 std::move(__first),
85 std::move(__last));
86 }
87
88 template <class _ExecutionPolicy,
89 class _ForwardIterator,
90 class _RawPolicy = __remove_cvref_t<_ExecutionPolicy>,
91 enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
92 _LIBCPP_HIDE_FROM_ABI __iter_value_type<_ForwardIterator>
reduce(_ExecutionPolicy && __policy,_ForwardIterator __first,_ForwardIterator __last)93 reduce(_ExecutionPolicy&& __policy, _ForwardIterator __first, _ForwardIterator __last) {
94 auto __res = std::__reduce(__policy, std::move(__first), std::move(__last));
95 if (!__res)
96 std::__throw_bad_alloc();
97 return *std::move(__res);
98 }
99
100 _LIBCPP_END_NAMESPACE_STD
101
102 #endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
103
104 #endif // _LIBCPP___NUMERIC_PSTL_REDUCE_H
105