xref: /llvm-project/libcxx/include/__cxx03/__algorithm/reverse.h (revision ce7771902dc50d900de639d499a60486b83f70e0)
1e78f53d1SNikolas Klauser //===----------------------------------------------------------------------===//
2e78f53d1SNikolas Klauser //
3e78f53d1SNikolas Klauser // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4e78f53d1SNikolas Klauser // See https://llvm.org/LICENSE.txt for license information.
5e78f53d1SNikolas Klauser // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6e78f53d1SNikolas Klauser //
7e78f53d1SNikolas Klauser //===----------------------------------------------------------------------===//
8e78f53d1SNikolas Klauser 
9*ce777190SNikolas Klauser #ifndef _LIBCPP___CXX03___ALGORITHM_REVERSE_H
10*ce777190SNikolas Klauser #define _LIBCPP___CXX03___ALGORITHM_REVERSE_H
11e78f53d1SNikolas Klauser 
1273fbae83SNikolas Klauser #include <__cxx03/__algorithm/iter_swap.h>
1373fbae83SNikolas Klauser #include <__cxx03/__algorithm/iterator_operations.h>
1473fbae83SNikolas Klauser #include <__cxx03/__config>
1573fbae83SNikolas Klauser #include <__cxx03/__iterator/iterator_traits.h>
1673fbae83SNikolas Klauser #include <__cxx03/__utility/move.h>
17e78f53d1SNikolas Klauser 
18e78f53d1SNikolas Klauser #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19e78f53d1SNikolas Klauser #  pragma GCC system_header
20e78f53d1SNikolas Klauser #endif
21e78f53d1SNikolas Klauser 
22e78f53d1SNikolas Klauser _LIBCPP_PUSH_MACROS
2373fbae83SNikolas Klauser #include <__cxx03/__undef_macros>
24e78f53d1SNikolas Klauser 
25e78f53d1SNikolas Klauser _LIBCPP_BEGIN_NAMESPACE_STD
26e78f53d1SNikolas Klauser 
27e78f53d1SNikolas Klauser template <class _AlgPolicy, class _BidirectionalIterator>
28e78f53d1SNikolas Klauser inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
29e78f53d1SNikolas Klauser __reverse_impl(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag) {
30e78f53d1SNikolas Klauser   while (__first != __last) {
31e78f53d1SNikolas Klauser     if (__first == --__last)
32e78f53d1SNikolas Klauser       break;
33e78f53d1SNikolas Klauser     _IterOps<_AlgPolicy>::iter_swap(__first, __last);
34e78f53d1SNikolas Klauser     ++__first;
35e78f53d1SNikolas Klauser   }
36e78f53d1SNikolas Klauser }
37e78f53d1SNikolas Klauser 
38e78f53d1SNikolas Klauser template <class _AlgPolicy, class _RandomAccessIterator>
39e78f53d1SNikolas Klauser inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
40e78f53d1SNikolas Klauser __reverse_impl(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag) {
41e78f53d1SNikolas Klauser   if (__first != __last)
42e78f53d1SNikolas Klauser     for (; __first < --__last; ++__first)
43e78f53d1SNikolas Klauser       _IterOps<_AlgPolicy>::iter_swap(__first, __last);
44e78f53d1SNikolas Klauser }
45e78f53d1SNikolas Klauser 
46e78f53d1SNikolas Klauser template <class _AlgPolicy, class _BidirectionalIterator, class _Sentinel>
47e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __reverse(_BidirectionalIterator __first, _Sentinel __last) {
48e78f53d1SNikolas Klauser   using _IterCategory = typename _IterOps<_AlgPolicy>::template __iterator_category<_BidirectionalIterator>;
49e78f53d1SNikolas Klauser   std::__reverse_impl<_AlgPolicy>(std::move(__first), std::move(__last), _IterCategory());
50e78f53d1SNikolas Klauser }
51e78f53d1SNikolas Klauser 
52e78f53d1SNikolas Klauser template <class _BidirectionalIterator>
53e78f53d1SNikolas Klauser inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
54e78f53d1SNikolas Klauser reverse(_BidirectionalIterator __first, _BidirectionalIterator __last) {
55e78f53d1SNikolas Klauser   std::__reverse<_ClassicAlgPolicy>(std::move(__first), std::move(__last));
56e78f53d1SNikolas Klauser }
57e78f53d1SNikolas Klauser 
58e78f53d1SNikolas Klauser _LIBCPP_END_NAMESPACE_STD
59e78f53d1SNikolas Klauser 
60e78f53d1SNikolas Klauser _LIBCPP_POP_MACROS
61e78f53d1SNikolas Klauser 
62*ce777190SNikolas Klauser #endif // _LIBCPP___CXX03___ALGORITHM_REVERSE_H
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