libcxx/include/__algorithm/pstl_fill.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_FILL_H
  10 #define _LIBCPP___ALGORITHM_PSTL_FILL_H
  11
  12 #include <__algorithm/fill_n.h>
  13 #include <__algorithm/pstl_for_each.h>
  14 #include <__algorithm/pstl_frontend_dispatch.h>
  15 #include <__config>
  16 #include <__iterator/concepts.h>
  17 #include <__iterator/cpp17_iterator_concepts.h>
  18 #include <__iterator/iterator_traits.h>
  19 #include <__type_traits/enable_if.h>
  20 #include <__type_traits/is_execution_policy.h>
  21 #include <__type_traits/remove_cvref.h>
  22 #include <__utility/move.h>
  23 #include <optional>
  24
  25 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  26 #  pragma GCC system_header
  27 #endif
  28
  29 #if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
  30
  31 _LIBCPP_BEGIN_NAMESPACE_STD
  32
  33 template <class>
  34 void __pstl_fill(); // declaration needed for the frontend dispatch below
  35
  36 template <class _ExecutionPolicy,
  37           class _ForwardIterator,
  38           class _Tp,
  39           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  40           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  41 _LIBCPP_HIDE_FROM_ABI optional<__empty>
  42 __fill(_ExecutionPolicy&& __policy, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) noexcept {
  43   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator);
  44   return std::__pstl_frontend_dispatch(
  45       _LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_fill, _RawPolicy),
  46       [&](_ForwardIterator __g_first, _ForwardIterator __g_last, const _Tp& __g_value) {
  47         return std::__for_each(__policy, __g_first, __g_last, [&](__iter_reference<_ForwardIterator> __element) {
  48           __element = __g_value;
  49         });
  50       },
  51       std::move(__first),
  52       std::move(__last),
  53       __value);
  54 }
  55
  56 template <class _ExecutionPolicy,
  57           class _ForwardIterator,
  58           class _Tp,
  59           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  60           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  61 _LIBCPP_HIDE_FROM_ABI void
  62 fill(_ExecutionPolicy&& __policy, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
  63   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator);
  64   if (!std::__fill(__policy, std::move(__first), std::move(__last), __value))
  65     std::__throw_bad_alloc();
  66 }
  67
  68 template <class>
  69 void __pstl_fill_n(); // declaration needed for the frontend dispatch below
  70
  71 template <class _ExecutionPolicy,
  72           class _ForwardIterator,
  73           class _SizeT,
  74           class _Tp,
  75           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  76           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  77 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI optional<__empty>
  78 __fill_n(_ExecutionPolicy&& __policy, _ForwardIterator&& __first, _SizeT&& __n, const _Tp& __value) noexcept {
  79   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator);
  80   return std::__pstl_frontend_dispatch(
  81       _LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_fill_n, _RawPolicy),
  82       [&](_ForwardIterator __g_first, _SizeT __g_n, const _Tp& __g_value) {
  83         if constexpr (__has_random_access_iterator_category_or_concept<_ForwardIterator>::value)
  84           std::fill(__policy, __g_first, __g_first + __g_n, __g_value);
  85         else
  86           std::fill_n(__g_first, __g_n, __g_value);
  87         return optional<__empty>{__empty{}};
  88       },
  89       std::move(__first),
  90       std::move(__n),
  91       __value);
  92 }
  93
  94 template <class _ExecutionPolicy,
  95           class _ForwardIterator,
  96           class _SizeT,
  97           class _Tp,
  98           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  99           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
 100 _LIBCPP_HIDE_FROM_ABI void
 101 fill_n(_ExecutionPolicy&& __policy, _ForwardIterator __first, _SizeT __n, const _Tp& __value) {
 102   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator);
 103   if (!std::__fill_n(__policy, std::move(__first), std::move(__n), __value))
 104     std::__throw_bad_alloc();
 105 }
 106
 107 _LIBCPP_END_NAMESPACE_STD
 108
 109 #endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
 110
 111 #endif // _LIBCPP___ALGORITHM_PSTL_FILL_H