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_SWAP_RANGES_H
10 #define _LIBCPP___ALGORITHM_SWAP_RANGES_H
11 
12 #include <__algorithm/iterator_operations.h>
13 #include <__config>
14 #include <__utility/move.h>
15 #include <__utility/pair.h>
16 
17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18 #  pragma GCC system_header
19 #endif
20 
21 _LIBCPP_PUSH_MACROS
22 #include <__undef_macros>
23 
24 _LIBCPP_BEGIN_NAMESPACE_STD
25 
26 // 2+2 iterators: the shorter size will be used.
27 template <class _AlgPolicy, class _ForwardIterator1, class _Sentinel1, class _ForwardIterator2, class _Sentinel2>
28 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_ForwardIterator1, _ForwardIterator2>
29 __swap_ranges(_ForwardIterator1 __first1, _Sentinel1 __last1, _ForwardIterator2 __first2, _Sentinel2 __last2) {
30   while (__first1 != __last1 && __first2 != __last2) {
31     _IterOps<_AlgPolicy>::iter_swap(__first1, __first2);
32     ++__first1;
33     ++__first2;
34   }
35 
36   return pair<_ForwardIterator1, _ForwardIterator2>(std::move(__first1), std::move(__first2));
37 }
38 
39 // 2+1 iterators: size2 >= size1.
40 template <class _AlgPolicy, class _ForwardIterator1, class _Sentinel1, class _ForwardIterator2>
41 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_ForwardIterator1, _ForwardIterator2>
42 __swap_ranges(_ForwardIterator1 __first1, _Sentinel1 __last1, _ForwardIterator2 __first2) {
43   while (__first1 != __last1) {
44     _IterOps<_AlgPolicy>::iter_swap(__first1, __first2);
45     ++__first1;
46     ++__first2;
47   }
48 
49   return pair<_ForwardIterator1, _ForwardIterator2>(std::move(__first1), std::move(__first2));
50 }
51 
52 template <class _ForwardIterator1, class _ForwardIterator2>
53 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator2
54 swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2) {
55   return std::__swap_ranges<_ClassicAlgPolicy>(std::move(__first1), std::move(__last1), std::move(__first2)).second;
56 }
57 
58 _LIBCPP_END_NAMESPACE_STD
59 
60 _LIBCPP_POP_MACROS
61 
62 #endif // _LIBCPP___ALGORITHM_SWAP_RANGES_H
63