libcxx/include/__algorithm/pstl_merge.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_MERGE_H
  10 #define _LIBCPP___ALGORITHM_PSTL_MERGE_H
  11
  12 #include <__algorithm/pstl_backend.h>
  13 #include <__config>
  14 #include <__functional/operations.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 _ForwardIterator1,
  31           class _ForwardIterator2,
  32           class _ForwardOutIterator,
  33           class _Comp                                         = std::less<>,
  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<_ForwardOutIterator>
  37 __merge(_ExecutionPolicy&&,
  38         _ForwardIterator1 __first1,
  39         _ForwardIterator1 __last1,
  40         _ForwardIterator2 __first2,
  41         _ForwardIterator2 __last2,
  42         _ForwardOutIterator __result,
  43         _Comp __comp = {}) noexcept {
  44   using _Backend = typename __select_backend<_RawPolicy>::type;
  45   return std::__pstl_merge<_RawPolicy>(
  46       _Backend{},
  47       std::move(__first1),
  48       std::move(__last1),
  49       std::move(__first2),
  50       std::move(__last2),
  51       std::move(__result),
  52       std::move(__comp));
  53 }
  54
  55 template <class _ExecutionPolicy,
  56           class _ForwardIterator1,
  57           class _ForwardIterator2,
  58           class _ForwardOutIterator,
  59           class _Comp                                         = std::less<>,
  60           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  61           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  62 _LIBCPP_HIDE_FROM_ABI _ForwardOutIterator
  63 merge(_ExecutionPolicy&& __policy,
  64       _ForwardIterator1 __first1,
  65       _ForwardIterator1 __last1,
  66       _ForwardIterator2 __first2,
  67       _ForwardIterator2 __last2,
  68       _ForwardOutIterator __result,
  69       _Comp __comp = {}) {
  70   auto __res = std::__merge(
  71       __policy,
  72       std::move(__first1),
  73       std::move(__last1),
  74       std::move(__first2),
  75       std::move(__last2),
  76       std::move(__result),
  77       std::move(__comp));
  78   if (!__res)
  79     std::__throw_bad_alloc();
  80   return *std::move(__res);
  81 }
  82
  83 _LIBCPP_END_NAMESPACE_STD
  84
  85 #endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
  86
  87 #endif // _LIBCPP___ALGORITHM_PSTL_MERGE_H