libcxx/include/__algorithm/pstl_generate.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_GENERATE_H
  10 #define _LIBCPP___ALGORITHM_PSTL_GENERATE_H
  11
  12 #include <__algorithm/pstl_backend.h>
  13 #include <__algorithm/pstl_for_each.h>
  14 #include <__algorithm/pstl_frontend_dispatch.h>
  15 #include <__config>
  16 #include <__iterator/cpp17_iterator_concepts.h>
  17 #include <__iterator/iterator_traits.h>
  18 #include <__type_traits/enable_if.h>
  19 #include <__type_traits/is_execution_policy.h>
  20 #include <__type_traits/remove_cvref.h>
  21 #include <__utility/move.h>
  22 #include <optional>
  23
  24 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  25 #  pragma GCC system_header
  26 #endif
  27
  28 #if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
  29
  30 _LIBCPP_BEGIN_NAMESPACE_STD
  31
  32 template <class>
  33 void __pstl_generate();
  34
  35 template <class _ExecutionPolicy,
  36           class _ForwardIterator,
  37           class _Generator,
  38           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  39           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  40 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI optional<__empty>
  41 __generate(_ExecutionPolicy&& __policy, _ForwardIterator&& __first, _ForwardIterator&& __last, _Generator&& __gen) {
  42   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator);
  43   return std::__pstl_frontend_dispatch(
  44       _LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_generate, _RawPolicy),
  45       [&__policy](_ForwardIterator __g_first, _ForwardIterator __g_last, _Generator __g_gen) {
  46         return std::__for_each(
  47             __policy, std::move(__g_first), std::move(__g_last), [&](__iter_reference<_ForwardIterator> __element) {
  48               __element = __g_gen();
  49             });
  50       },
  51       std::move(__first),
  52       std::move(__last),
  53       std::move(__gen));
  54 }
  55
  56 template <class _ExecutionPolicy,
  57           class _ForwardIterator,
  58           class _Generator,
  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 generate(_ExecutionPolicy&& __policy, _ForwardIterator __first, _ForwardIterator __last, _Generator __gen) {
  63   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator);
  64   if (!std::__generate(__policy, std::move(__first), std::move(__last), std::move(__gen)))
  65     std::__throw_bad_alloc();
  66 }
  67
  68 template <class>
  69 void __pstl_generate_n();
  70
  71 template <class _ExecutionPolicy,
  72           class _ForwardIterator,
  73           class _Size,
  74           class _Generator,
  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 __generate_n(_ExecutionPolicy&& __policy, _ForwardIterator&& __first, _Size&& __n, _Generator&& __gen) {
  79   return std::__pstl_frontend_dispatch(
  80       _LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_generate_n, _RawPolicy),
  81       [&__policy](_ForwardIterator __g_first, _Size __g_n, _Generator __g_gen) {
  82         return std::__for_each_n(
  83             __policy, std::move(__g_first), std::move(__g_n), [&](__iter_reference<_ForwardIterator> __element) {
  84               __element = __g_gen();
  85             });
  86       },
  87       std::move(__first),
  88       __n,
  89       std::move(__gen));
  90 }
  91
  92 template <class _ExecutionPolicy,
  93           class _ForwardIterator,
  94           class _Size,
  95           class _Generator,
  96           class _RawPolicy                                    = __remove_cvref_t<_ExecutionPolicy>,
  97           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
  98 _LIBCPP_HIDE_FROM_ABI void
  99 generate_n(_ExecutionPolicy&& __policy, _ForwardIterator __first, _Size __n, _Generator __gen) {
 100   _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator);
 101   if (!std::__generate_n(__policy, std::move(__first), std::move(__n), std::move(__gen)))
 102     std::__throw_bad_alloc();
 103 }
 104
 105 _LIBCPP_END_NAMESPACE_STD
 106
 107 #endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
 108
 109 #endif // _LIBCPP___ALGORITHM_PSTL_GENERATE_H