libcxx/include/__algorithm/ranges_partition_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_RANGES_PARTITION_COPY_H
  10 #define _LIBCPP___ALGORITHM_RANGES_PARTITION_COPY_H
  11
  12 #include <__algorithm/in_out_out_result.h>
  13 #include <__config>
  14 #include <__functional/identity.h>
  15 #include <__functional/invoke.h>
  16 #include <__iterator/concepts.h>
  17 #include <__iterator/iterator_traits.h>
  18 #include <__iterator/projected.h>
  19 #include <__ranges/access.h>
  20 #include <__ranges/concepts.h>
  21 #include <__ranges/dangling.h>
  22 #include <__type_traits/remove_cvref.h>
  23 #include <__utility/move.h>
  24
  25 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  26 #  pragma GCC system_header
  27 #endif
  28
  29 _LIBCPP_PUSH_MACROS
  30 #include <__undef_macros>
  31
  32 #if _LIBCPP_STD_VER >= 20
  33
  34 _LIBCPP_BEGIN_NAMESPACE_STD
  35
  36 namespace ranges {
  37
  38 template <class _InIter, class _OutIter1, class _OutIter2>
  39 using partition_copy_result = in_out_out_result<_InIter, _OutIter1, _OutIter2>;
  40
  41 struct __partition_copy {
  42   // TODO(ranges): delegate to the classic algorithm.
  43   template <class _InIter, class _Sent, class _OutIter1, class _OutIter2, class _Proj, class _Pred>
  44   _LIBCPP_HIDE_FROM_ABI constexpr static partition_copy_result<__remove_cvref_t<_InIter>,
  45                                                                __remove_cvref_t<_OutIter1>,
  46                                                                __remove_cvref_t<_OutIter2> >
  47   __partition_copy_fn_impl(
  48       _InIter&& __first,
  49       _Sent&& __last,
  50       _OutIter1&& __out_true,
  51       _OutIter2&& __out_false,
  52       _Pred& __pred,
  53       _Proj& __proj) {
  54     for (; __first != __last; ++__first) {
  55       if (std::invoke(__pred, std::invoke(__proj, *__first))) {
  56         *__out_true = *__first;
  57         ++__out_true;
  58
  59       } else {
  60         *__out_false = *__first;
  61         ++__out_false;
  62       }
  63     }
  64
  65     return {std::move(__first), std::move(__out_true), std::move(__out_false)};
  66   }
  67
  68   template <input_iterator _InIter,
  69             sentinel_for<_InIter> _Sent,
  70             weakly_incrementable _OutIter1,
  71             weakly_incrementable _OutIter2,
  72             class _Proj = identity,
  73             indirect_unary_predicate<projected<_InIter, _Proj>> _Pred>
  74     requires indirectly_copyable<_InIter, _OutIter1> && indirectly_copyable<_InIter, _OutIter2>
  75   _LIBCPP_HIDE_FROM_ABI constexpr partition_copy_result<_InIter, _OutIter1, _OutIter2> operator()(
  76       _InIter __first, _Sent __last, _OutIter1 __out_true, _OutIter2 __out_false, _Pred __pred, _Proj __proj = {})
  77       const {
  78     return __partition_copy_fn_impl(
  79         std::move(__first), std::move(__last), std::move(__out_true), std::move(__out_false), __pred, __proj);
  80   }
  81
  82   template <input_range _Range,
  83             weakly_incrementable _OutIter1,
  84             weakly_incrementable _OutIter2,
  85             class _Proj = identity,
  86             indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
  87     requires indirectly_copyable<iterator_t<_Range>, _OutIter1> && indirectly_copyable<iterator_t<_Range>, _OutIter2>
  88   _LIBCPP_HIDE_FROM_ABI constexpr partition_copy_result<borrowed_iterator_t<_Range>, _OutIter1, _OutIter2>
  89   operator()(_Range&& __range, _OutIter1 __out_true, _OutIter2 __out_false, _Pred __pred, _Proj __proj = {}) const {
  90     return __partition_copy_fn_impl(
  91         ranges::begin(__range), ranges::end(__range), std::move(__out_true), std::move(__out_false), __pred, __proj);
  92   }
  93 };
  94
  95 inline namespace __cpo {
  96 inline constexpr auto partition_copy = __partition_copy{};
  97 } // namespace __cpo
  98 } // namespace ranges
  99
 100 _LIBCPP_END_NAMESPACE_STD
 101
 102 #endif // _LIBCPP_STD_VER >= 20
 103
 104 _LIBCPP_POP_MACROS
 105
 106 #endif // _LIBCPP___ALGORITHM_RANGES_PARTITION_COPY_H