xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/set_intersection.h (revision c8e7f78a3d28ff6e6223ed136ada8e1e2f34965e)
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_INTERSECTION_H
10 #define _LIBCPP___ALGORITHM_SET_INTERSECTION_H
11 
12 #include <__algorithm/comp.h>
13 #include <__algorithm/comp_ref_type.h>
14 #include <__algorithm/iterator_operations.h>
15 #include <__config>
16 #include <__iterator/iterator_traits.h>
17 #include <__iterator/next.h>
18 #include <__utility/move.h>
19 
20 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
21 #  pragma GCC system_header
22 #endif
23 
24 _LIBCPP_BEGIN_NAMESPACE_STD
25 
26 template <class _InIter1, class _InIter2, class _OutIter>
27 struct __set_intersection_result {
28   _InIter1 __in1_;
29   _InIter2 __in2_;
30   _OutIter __out_;
31 
32   // need a constructor as C++03 aggregate init is hard
33   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
34   __set_intersection_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
35       : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
36 };
37 
38 template <class _AlgPolicy, class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
39 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __set_intersection_result<_InIter1, _InIter2, _OutIter>
40 __set_intersection(
41     _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
42   while (__first1 != __last1 && __first2 != __last2) {
43     if (__comp(*__first1, *__first2))
44       ++__first1;
45     else {
46       if (!__comp(*__first2, *__first1)) {
47         *__result = *__first1;
48         ++__result;
49         ++__first1;
50       }
51       ++__first2;
52     }
53   }
54 
55   return __set_intersection_result<_InIter1, _InIter2, _OutIter>(
56       _IterOps<_AlgPolicy>::next(std::move(__first1), std::move(__last1)),
57       _IterOps<_AlgPolicy>::next(std::move(__first2), std::move(__last2)),
58       std::move(__result));
59 }
60 
61 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
62 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_intersection(
63     _InputIterator1 __first1,
64     _InputIterator1 __last1,
65     _InputIterator2 __first2,
66     _InputIterator2 __last2,
67     _OutputIterator __result,
68     _Compare __comp) {
69   return std::__set_intersection<_ClassicAlgPolicy, __comp_ref_type<_Compare> >(
70              std::move(__first1),
71              std::move(__last1),
72              std::move(__first2),
73              std::move(__last2),
74              std::move(__result),
75              __comp)
76       .__out_;
77 }
78 
79 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
80 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_intersection(
81     _InputIterator1 __first1,
82     _InputIterator1 __last1,
83     _InputIterator2 __first2,
84     _InputIterator2 __last2,
85     _OutputIterator __result) {
86   return std::__set_intersection<_ClassicAlgPolicy>(
87              std::move(__first1),
88              std::move(__last1),
89              std::move(__first2),
90              std::move(__last2),
91              std::move(__result),
92              __less<>())
93       .__out_;
94 }
95 
96 _LIBCPP_END_NAMESPACE_STD
97 
98 #endif // _LIBCPP___ALGORITHM_SET_INTERSECTION_H
99