libcxx/include/__algorithm/swap_ranges.h

   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