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_COPY_BACKWARD_H
10 #define _LIBCPP___ALGORITHM_COPY_BACKWARD_H
11 
12 #include <__algorithm/copy.h>
13 #include <__algorithm/unwrap_iter.h>
14 #include <__config>
15 #include <__iterator/iterator_traits.h>
16 #include <__iterator/reverse_iterator.h>
17 #include <cstring>
18 #include <type_traits>
19 
20 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
21 #  pragma GCC system_header
22 #endif
23 
24 _LIBCPP_BEGIN_NAMESPACE_STD
25 
26 template <class _Iter1, class _Sent1, class _Iter2>
27 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
28 pair<_Iter1, _Iter2> __copy_backward_impl(_Iter1 __first, _Sent1 __last, _Iter2 __result) {
29   auto __ret = std::__copy(reverse_iterator<_Iter1>(__last),
30                            reverse_iterator<_Sent1>(__first),
31                            reverse_iterator<_Iter2>(__result));
32   return pair<_Iter1, _Iter2>(__ret.first.base(), __ret.second.base());
33 }
34 
35 template <class _Iter1, class _Sent1, class _Iter2>
36 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
37 pair<_Iter1, _Iter2> __copy_backward(_Iter1 __first, _Sent1 __last, _Iter2 __result) {
38   auto __ret = std::__copy_backward_impl(std::__unwrap_iter(__first),
39                                          std::__unwrap_iter(__last),
40                                          std::__unwrap_iter(__result));
41   return pair<_Iter1, _Iter2>(std::__rewrap_iter(__first, __ret.first), std::__rewrap_iter(__result, __ret.second));
42 }
43 
44 template <class _BidirectionalIterator1, class _BidirectionalIterator2>
45 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
46 _BidirectionalIterator2
47 copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last, _BidirectionalIterator2 __result) {
48   return std::__copy_backward(__first, __last, __result).second;
49 }
50 
51 _LIBCPP_END_NAMESPACE_STD
52 
53 #endif // _LIBCPP___ALGORITHM_COPY_BACKWARD_H
54