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_REVERSE_H 10 #define _LIBCPP___ALGORITHM_REVERSE_H 11 12 #include <__algorithm/iter_swap.h> 13 #include <__algorithm/iterator_operations.h> 14 #include <__config> 15 #include <__iterator/iterator_traits.h> 16 #include <__utility/move.h> 17 18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19 # pragma GCC system_header 20 #endif 21 22 _LIBCPP_PUSH_MACROS 23 #include <__undef_macros> 24 25 _LIBCPP_BEGIN_NAMESPACE_STD 26 27 template <class _AlgPolicy, class _BidirectionalIterator> 28 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void 29 __reverse_impl(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag) { 30 while (__first != __last) { 31 if (__first == --__last) 32 break; 33 _IterOps<_AlgPolicy>::iter_swap(__first, __last); 34 ++__first; 35 } 36 } 37 38 template <class _AlgPolicy, class _RandomAccessIterator> 39 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void 40 __reverse_impl(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag) { 41 if (__first != __last) 42 for (; __first < --__last; ++__first) 43 _IterOps<_AlgPolicy>::iter_swap(__first, __last); 44 } 45 46 template <class _AlgPolicy, class _BidirectionalIterator, class _Sentinel> 47 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __reverse(_BidirectionalIterator __first, _Sentinel __last) { 48 using _IterCategory = typename _IterOps<_AlgPolicy>::template __iterator_category<_BidirectionalIterator>; 49 std::__reverse_impl<_AlgPolicy>(std::move(__first), std::move(__last), _IterCategory()); 50 } 51 52 template <class _BidirectionalIterator> 53 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void 54 reverse(_BidirectionalIterator __first, _BidirectionalIterator __last) { 55 std::__reverse<_ClassicAlgPolicy>(std::move(__first), std::move(__last)); 56 } 57 58 _LIBCPP_END_NAMESPACE_STD 59 60 _LIBCPP_POP_MACROS 61 62 #endif // _LIBCPP___ALGORITHM_REVERSE_H 63