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
66