libcxx/include/__algorithm/ranges_partition.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_RANGES_PARTITION_H
  10 #define _LIBCPP___ALGORITHM_RANGES_PARTITION_H
  11
  12 #include <__algorithm/iterator_operations.h>
  13 #include <__algorithm/make_projected.h>
  14 #include <__algorithm/partition.h>
  15 #include <__algorithm/ranges_iterator_concept.h>
  16 #include <__config>
  17 #include <__functional/identity.h>
  18 #include <__functional/invoke.h>
  19 #include <__functional/ranges_operations.h>
  20 #include <__iterator/concepts.h>
  21 #include <__iterator/iterator_traits.h>
  22 #include <__iterator/permutable.h>
  23 #include <__iterator/projected.h>
  24 #include <__ranges/access.h>
  25 #include <__ranges/concepts.h>
  26 #include <__ranges/subrange.h>
  27 #include <__utility/forward.h>
  28 #include <__utility/move.h>
  29 #include <__utility/pair.h>
  30
  31 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  32 #  pragma GCC system_header
  33 #endif
  34
  35 #if _LIBCPP_STD_VER >= 20
  36
  37 _LIBCPP_BEGIN_NAMESPACE_STD
  38
  39 namespace ranges {
  40 namespace __partition {
  41
  42 struct __fn {
  43   template <class _Iter, class _Sent, class _Proj, class _Pred>
  44   _LIBCPP_HIDE_FROM_ABI static constexpr subrange<__remove_cvref_t<_Iter>>
  45   __partition_fn_impl(_Iter&& __first, _Sent&& __last, _Pred&& __pred, _Proj&& __proj) {
  46     auto&& __projected_pred = std::__make_projected(__pred, __proj);
  47     auto __result           = std::__partition<_RangeAlgPolicy>(
  48         std::move(__first), std::move(__last), __projected_pred, __iterator_concept<_Iter>());
  49
  50     return {std::move(__result.first), std::move(__result.second)};
  51   }
  52
  53   template <permutable _Iter,
  54             sentinel_for<_Iter> _Sent,
  55             class _Proj = identity,
  56             indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
  57   _LIBCPP_HIDE_FROM_ABI constexpr subrange<_Iter>
  58   operator()(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) const {
  59     return __partition_fn_impl(__first, __last, __pred, __proj);
  60   }
  61
  62   template <forward_range _Range,
  63             class _Proj = identity,
  64             indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
  65     requires permutable<iterator_t<_Range>>
  66   _LIBCPP_HIDE_FROM_ABI constexpr borrowed_subrange_t<_Range>
  67   operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
  68     return __partition_fn_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
  69   }
  70 };
  71
  72 } // namespace __partition
  73
  74 inline namespace __cpo {
  75 inline constexpr auto partition = __partition::__fn{};
  76 } // namespace __cpo
  77 } // namespace ranges
  78
  79 _LIBCPP_END_NAMESPACE_STD
  80
  81 #endif // _LIBCPP_STD_VER >= 20
  82
  83 #endif // _LIBCPP___ALGORITHM_RANGES_PARTITION_H