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_SET_SYMMETRIC_DIFFERENCE_H
10#define _LIBCPP___ALGORITHM_SET_SYMMETRIC_DIFFERENCE_H
11
12#include <__algorithm/comp.h>
13#include <__algorithm/comp_ref_type.h>
14#include <__algorithm/copy.h>
15#include <__algorithm/iterator_operations.h>
16#include <__config>
17#include <__iterator/iterator_traits.h>
18#include <__utility/move.h>
19#include <__utility/pair.h>
20
21#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22#  pragma GCC system_header
23#endif
24
25_LIBCPP_BEGIN_NAMESPACE_STD
26
27template <class _InIter1, class _InIter2, class _OutIter>
28struct __set_symmetric_difference_result {
29  _InIter1 __in1_;
30  _InIter2 __in2_;
31  _OutIter __out_;
32
33  // need a constructor as C++03 aggregate init is hard
34  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
35  __set_symmetric_difference_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
36      : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
37};
38
39template <class _AlgPolicy, class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
40_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>
41__set_symmetric_difference(
42    _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
43  while (__first1 != __last1) {
44    if (__first2 == __last2) {
45      auto __ret1 = std::__copy<_AlgPolicy>(std::move(__first1), std::move(__last1), std::move(__result));
46      return __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>(
47          std::move(__ret1.first), std::move(__first2), std::move((__ret1.second)));
48    }
49    if (__comp(*__first1, *__first2)) {
50      *__result = *__first1;
51      ++__result;
52      ++__first1;
53    } else {
54      if (__comp(*__first2, *__first1)) {
55        *__result = *__first2;
56        ++__result;
57      } else {
58        ++__first1;
59      }
60      ++__first2;
61    }
62  }
63  auto __ret2 = std::__copy<_AlgPolicy>(std::move(__first2), std::move(__last2), std::move(__result));
64  return __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>(
65      std::move(__first1), std::move(__ret2.first), std::move((__ret2.second)));
66}
67
68template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
69_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_symmetric_difference(
70    _InputIterator1 __first1,
71    _InputIterator1 __last1,
72    _InputIterator2 __first2,
73    _InputIterator2 __last2,
74    _OutputIterator __result,
75    _Compare __comp) {
76  return std::__set_symmetric_difference<_ClassicAlgPolicy, __comp_ref_type<_Compare> >(
77             std::move(__first1),
78             std::move(__last1),
79             std::move(__first2),
80             std::move(__last2),
81             std::move(__result),
82             __comp)
83      .__out_;
84}
85
86template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
87_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_symmetric_difference(
88    _InputIterator1 __first1,
89    _InputIterator1 __last1,
90    _InputIterator2 __first2,
91    _InputIterator2 __last2,
92    _OutputIterator __result) {
93  return std::set_symmetric_difference(
94      std::move(__first1),
95      std::move(__last1),
96      std::move(__first2),
97      std::move(__last2),
98      std::move(__result),
99      __less<typename iterator_traits<_InputIterator1>::value_type,
100             typename iterator_traits<_InputIterator2>::value_type>());
101}
102
103_LIBCPP_END_NAMESPACE_STD
104
105#endif // _LIBCPP___ALGORITHM_SET_SYMMETRIC_DIFFERENCE_H
106