libcxx/include/__algorithm/pstl_transform.h

   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___ALGORITHM_PSTL_TRANSFORM_H
  10 #define _LIBCPP___ALGORITHM_PSTL_TRANSFORM_H
  11
  12 #include <__algorithm/pstl_backend.h>
  13 #include <__config>
  14 #include <__iterator/cpp17_iterator_concepts.h>
  15 #include <__type_traits/enable_if.h>
  16 #include <__type_traits/is_execution_policy.h>
  17 #include <__type_traits/remove_cvref.h>
  18 #include <__utility/move.h>
  19 #include <optional>
  20
  21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  22 #  pragma GCC system_header
  23 #endif
  24
  25 #if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
  26
  27 _LIBCPP_BEGIN_NAMESPACE_STD
  28
  29 template <class _ExecutionPolicy,
  30           class _ForwardIterator,
  31           class _ForwardOutIterator,
  32           class _UnaryOperation,
  33           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  34           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  35 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI optional<__remove_cvref_t<_ForwardOutIterator>>
  36 __transform(_ExecutionPolicy&&,
  37             _ForwardIterator&& __first,
  38             _ForwardIterator&& __last,
  39             _ForwardOutIterator&& __result,
  40             _UnaryOperation&& __op) noexcept {
  41   using _Backend = typename __select_backend<_RawPolicy>::type;
  42   return std::__pstl_transform<_RawPolicy>(
  43       _Backend{}, std::move(__first), std::move(__last), std::move(__result), std::move(__op));
  44 }
  45
  46 template <class _ExecutionPolicy,
  47           class _ForwardIterator,
  48           class _ForwardOutIterator,
  49           class _UnaryOperation,
  50           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  51           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  52 _LIBCPP_HIDE_FROM_ABI _ForwardOutIterator transform(
  53     _ExecutionPolicy&& __policy,
  54     _ForwardIterator __first,
  55     _ForwardIterator __last,
  56     _ForwardOutIterator __result,
  57     _UnaryOperation __op) {
  58   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator);
  59   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardOutIterator);
  60   _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(_ForwardOutIterator, decltype(__op(*__first)));
  61   auto __res = std::__transform(__policy, std::move(__first), std::move(__last), std::move(__result), std::move(__op));
  62   if (!__res)
  63     std::__throw_bad_alloc();
  64   return *std::move(__res);
  65 }
  66
  67 template <class _ExecutionPolicy,
  68           class _ForwardIterator1,
  69           class _ForwardIterator2,
  70           class _ForwardOutIterator,
  71           class _BinaryOperation,
  72           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  73           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  74 _LIBCPP_HIDE_FROM_ABI optional<__remove_cvref_t<_ForwardOutIterator>>
  75 __transform(_ExecutionPolicy&&,
  76             _ForwardIterator1&& __first1,
  77             _ForwardIterator1&& __last1,
  78             _ForwardIterator2&& __first2,
  79             _ForwardOutIterator&& __result,
  80             _BinaryOperation&& __op) noexcept {
  81   using _Backend = typename __select_backend<_RawPolicy>::type;
  82   return std::__pstl_transform<_RawPolicy>(
  83       _Backend{}, std::move(__first1), std::move(__last1), std::move(__first2), std::move(__result), std::move(__op));
  84 }
  85
  86 template <class _ExecutionPolicy,
  87           class _ForwardIterator1,
  88           class _ForwardIterator2,
  89           class _ForwardOutIterator,
  90           class _BinaryOperation,
  91           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  92           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  93 _LIBCPP_HIDE_FROM_ABI _ForwardOutIterator transform(
  94     _ExecutionPolicy&& __policy,
  95     _ForwardIterator1 __first1,
  96     _ForwardIterator1 __last1,
  97     _ForwardIterator2 __first2,
  98     _ForwardOutIterator __result,
  99     _BinaryOperation __op) {
 100   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator1);
 101   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator2);
 102   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardOutIterator);
 103   _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(_ForwardOutIterator, decltype(__op(*__first1, *__first2)));
 104   auto __res = std::__transform(
 105       __policy, std::move(__first1), std::move(__last1), std::move(__first2), std::move(__result), std::move(__op));
 106   if (!__res)
 107     std::__throw_bad_alloc();
 108   return *std::move(__res);
 109 }
 110
 111 _LIBCPP_END_NAMESPACE_STD
 112
 113 #endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
 114
 115 #endif // _LIBCPP___ALGORITHM_PSTL_TRANSFORM_H