llvm-project/libcxx/include/__algorithm/reverse.h

57 lines
1.7 KiB
C++

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___ALGORITHM_REVERSE_H
#define _LIBCPP___ALGORITHM_REVERSE_H
#include <__algorithm/iter_swap.h>
#include <__config>
#include <__iterator/iterator_traits.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _BidirectionalIterator>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
void
__reverse(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag)
{
while (__first != __last)
{
if (__first == --__last)
break;
_VSTD::iter_swap(__first, __last);
++__first;
}
}
template <class _RandomAccessIterator>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
void
__reverse(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag)
{
if (__first != __last)
for (; __first < --__last; ++__first)
_VSTD::iter_swap(__first, __last);
}
template <class _BidirectionalIterator>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
void
reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
{
_VSTD::__reverse(__first, __last, typename iterator_traits<_BidirectionalIterator>::iterator_category());
}
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___ALGORITHM_REVERSE_H