libcxx/include/__algorithm/pstl_rotate_copy.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_ROTATE_COPY_H
  10 #define _LIBCPP___ALGORITHM_PSTL_ROTATE_COPY_H
  11
  12 #include <__algorithm/pstl_backend.h>
  13 #include <__algorithm/pstl_copy.h>
  14 #include <__algorithm/pstl_frontend_dispatch.h>
  15 #include <__type_traits/is_execution_policy.h>
  16
  17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  18 #  pragma GCC system_header
  19 #endif
  20
  21 #if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
  22
  23 _LIBCPP_BEGIN_NAMESPACE_STD
  24
  25 template <class>
  26 void __pstl_rotate_copy();
  27
  28 template <class _ExecutionPolicy,
  29           class _ForwardIterator,
  30           class _ForwardOutIterator,
  31           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  32           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  33 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI optional<_ForwardOutIterator>
  34 __rotate_copy(_ExecutionPolicy&& __policy,
  35               _ForwardIterator&& __first,
  36               _ForwardIterator&& __middle,
  37               _ForwardIterator&& __last,
  38               _ForwardOutIterator&& __result) noexcept {
  39   return std::__pstl_frontend_dispatch(
  40       _LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_rotate_copy, _RawPolicy),
  41       [&__policy](_ForwardIterator __g_first,
  42                   _ForwardIterator __g_middle,
  43                   _ForwardIterator __g_last,
  44                   _ForwardOutIterator __g_result) -> optional<_ForwardOutIterator> {
  45         auto __result_mid =
  46             std::__copy(__policy, _ForwardIterator(__g_middle), std::move(__g_last), std::move(__g_result));
  47         if (!__result_mid)
  48           return nullopt;
  49         return std::__copy(__policy, std::move(__g_first), std::move(__g_middle), *std::move(__result_mid));
  50       },
  51       std::move(__first),
  52       std::move(__middle),
  53       std::move(__last),
  54       std::move(__result));
  55 }
  56
  57 template <class _ExecutionPolicy,
  58           class _ForwardIterator,
  59           class _ForwardOutIterator,
  60           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  61           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  62 _LIBCPP_HIDE_FROM_ABI _ForwardOutIterator rotate_copy(
  63     _ExecutionPolicy&& __policy,
  64     _ForwardIterator __first,
  65     _ForwardIterator __middle,
  66     _ForwardIterator __last,
  67     _ForwardOutIterator __result) {
  68   auto __res =
  69       std::__rotate_copy(__policy, std::move(__first), std::move(__middle), std::move(__last), std::move(__result));
  70   if (!__res)
  71     std::__throw_bad_alloc();
  72   return *__res;
  73 }
  74
  75 _LIBCPP_END_NAMESPACE_STD
  76
  77 #endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
  78
  79 #endif // _LIBCPP___ALGORITHM_PSTL_ROTATE_COPY_H