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 <__config>
16 #include <__iterator/iterator_traits.h>
17 #include <__utility/move.h>
18 
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 #  pragma GCC system_header
21 #endif
22 
23 _LIBCPP_BEGIN_NAMESPACE_STD
24 
25 template <class _InIter1, class _InIter2, class _OutIter>
26 struct __set_symmetric_difference_result {
27   _InIter1 __in1_;
28   _InIter2 __in2_;
29   _OutIter __out_;
30 
31   // need a constructor as C++03 aggregate init is hard
32   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
33   __set_symmetric_difference_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
34       : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
35 };
36 
37 template <class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
38 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>
39 __set_symmetric_difference(
40     _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
41   while (__first1 != __last1) {
42     if (__first2 == __last2) {
43       auto __ret1 = std::__copy_impl(std::move(__first1), std::move(__last1), std::move(__result));
44       return __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>(
45           std::move(__ret1.first), std::move(__first2), std::move((__ret1.second)));
46     }
47     if (__comp(*__first1, *__first2)) {
48       *__result = *__first1;
49       ++__result;
50       ++__first1;
51     } else {
52       if (__comp(*__first2, *__first1)) {
53         *__result = *__first2;
54         ++__result;
55       } else {
56         ++__first1;
57       }
58       ++__first2;
59     }
60   }
61   auto __ret2 = std::__copy_impl(std::move(__first2), std::move(__last2), std::move(__result));
62   return __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>(
63       std::move(__first1), std::move(__ret2.first), std::move((__ret2.second)));
64 }
65 
66 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
67 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator set_symmetric_difference(
68     _InputIterator1 __first1,
69     _InputIterator1 __last1,
70     _InputIterator2 __first2,
71     _InputIterator2 __last2,
72     _OutputIterator __result,
73     _Compare __comp) {
74   typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
75   return std::__set_symmetric_difference<_Comp_ref>(
76              std::move(__first1),
77              std::move(__last1),
78              std::move(__first2),
79              std::move(__last2),
80              std::move(__result),
81              __comp)
82       .__out_;
83 }
84 
85 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
86 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator set_symmetric_difference(
87     _InputIterator1 __first1,
88     _InputIterator1 __last1,
89     _InputIterator2 __first2,
90     _InputIterator2 __last2,
91     _OutputIterator __result) {
92   return std::set_symmetric_difference(
93       std::move(__first1),
94       std::move(__last1),
95       std::move(__first2),
96       std::move(__last2),
97       std::move(__result),
98       __less<typename iterator_traits<_InputIterator1>::value_type,
99              typename iterator_traits<_InputIterator2>::value_type>());
100 }
101 
102 _LIBCPP_END_NAMESPACE_STD
103 
104 #endif // _LIBCPP___ALGORITHM_SET_SYMMETRIC_DIFFERENCE_H
105