__cxx03/__algorithm/reverse.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___CXX03___ALGORITHM_REVERSE_H
0010 #define _LIBCPP___CXX03___ALGORITHM_REVERSE_H
0011
0012 #include <__cxx03/__algorithm/iter_swap.h>
0013 #include <__cxx03/__algorithm/iterator_operations.h>
0014 #include <__cxx03/__config>
0015 #include <__cxx03/__iterator/iterator_traits.h>
0016 #include <__cxx03/__utility/move.h>
0017
0018 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0019 #  pragma GCC system_header
0020 #endif
0021
0022 _LIBCPP_PUSH_MACROS
0023 #include <__cxx03/__undef_macros>
0024
0025 _LIBCPP_BEGIN_NAMESPACE_STD
0026
0027 template <class _AlgPolicy, class _BidirectionalIterator>
0028 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
0029 __reverse_impl(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag) {
0030   while (__first != __last) {
0031     if (__first == --__last)
0032       break;
0033     _IterOps<_AlgPolicy>::iter_swap(__first, __last);
0034     ++__first;
0035   }
0036 }
0037
0038 template <class _AlgPolicy, class _RandomAccessIterator>
0039 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
0040 __reverse_impl(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag) {
0041   if (__first != __last)
0042     for (; __first < --__last; ++__first)
0043       _IterOps<_AlgPolicy>::iter_swap(__first, __last);
0044 }
0045
0046 template <class _AlgPolicy, class _BidirectionalIterator, class _Sentinel>
0047 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __reverse(_BidirectionalIterator __first, _Sentinel __last) {
0048   using _IterCategory = typename _IterOps<_AlgPolicy>::template __iterator_category<_BidirectionalIterator>;
0049   std::__reverse_impl<_AlgPolicy>(std::move(__first), std::move(__last), _IterCategory());
0050 }
0051
0052 template <class _BidirectionalIterator>
0053 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
0054 reverse(_BidirectionalIterator __first, _BidirectionalIterator __last) {
0055   std::__reverse<_ClassicAlgPolicy>(std::move(__first), std::move(__last));
0056 }
0057
0058 _LIBCPP_END_NAMESPACE_STD
0059
0060 _LIBCPP_POP_MACROS
0061
0062 #endif // _LIBCPP___CXX03___ALGORITHM_REVERSE_H