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 
27 template <class _InIter1, class _InIter2, class _OutIter>
28 struct __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 
39 template <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 
68 template <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 
86 template <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