libcxx/include/__algorithm/ranges_reverse_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_REVERSE_COPY_H
  10 #define _LIBCPP___ALGORITHM_RANGES_REVERSE_COPY_H
  11
  12 #include <__algorithm/in_out_result.h>
  13 #include <__algorithm/ranges_copy.h>
  14 #include <__config>
  15 #include <__iterator/concepts.h>
  16 #include <__iterator/next.h>
  17 #include <__iterator/reverse_iterator.h>
  18 #include <__ranges/access.h>
  19 #include <__ranges/concepts.h>
  20 #include <__ranges/dangling.h>
  21 #include <__ranges/subrange.h>
  22 #include <__utility/move.h>
  23
  24 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  25 #  pragma GCC system_header
  26 #endif
  27
  28 #if _LIBCPP_STD_VER >= 20
  29
  30 _LIBCPP_BEGIN_NAMESPACE_STD
  31
  32 namespace ranges {
  33
  34 template <class _InIter, class _OutIter>
  35 using reverse_copy_result = in_out_result<_InIter, _OutIter>;
  36
  37 namespace __reverse_copy {
  38 struct __fn {
  39   template <bidirectional_iterator _InIter, sentinel_for<_InIter> _Sent, weakly_incrementable _OutIter>
  40     requires indirectly_copyable<_InIter, _OutIter>
  41   _LIBCPP_HIDE_FROM_ABI constexpr reverse_copy_result<_InIter, _OutIter>
  42   operator()(_InIter __first, _Sent __last, _OutIter __result) const {
  43     return (*this)(subrange(std::move(__first), std::move(__last)), std::move(__result));
  44   }
  45
  46   template <bidirectional_range _Range, weakly_incrementable _OutIter>
  47     requires indirectly_copyable<iterator_t<_Range>, _OutIter>
  48   _LIBCPP_HIDE_FROM_ABI constexpr reverse_copy_result<borrowed_iterator_t<_Range>, _OutIter>
  49   operator()(_Range&& __range, _OutIter __result) const {
  50     auto __ret = ranges::copy(std::__reverse_range(__range), std::move(__result));
  51     return {ranges::next(ranges::begin(__range), ranges::end(__range)), std::move(__ret.out)};
  52   }
  53 };
  54 } // namespace __reverse_copy
  55
  56 inline namespace __cpo {
  57 inline constexpr auto reverse_copy = __reverse_copy::__fn{};
  58 } // namespace __cpo
  59 } // namespace ranges
  60
  61 _LIBCPP_END_NAMESPACE_STD
  62
  63 #endif // _LIBCPP_STD_VER >= 20
  64
  65 #endif // _LIBCPP___ALGORITHM_RANGES_REVERSE_COPY_H