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_UNION_H
10#define _LIBCPP___ALGORITHM_SET_UNION_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_PUSH_MACROS
26#include <__undef_macros>
27
28_LIBCPP_BEGIN_NAMESPACE_STD
29
30template <class _InIter1, class _InIter2, class _OutIter>
31struct __set_union_result {
32  _InIter1 __in1_;
33  _InIter2 __in2_;
34  _OutIter __out_;
35
36  // need a constructor as C++03 aggregate init is hard
37  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
38  __set_union_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
39      : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
40};
41
42template <class _AlgPolicy, class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
43_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __set_union_result<_InIter1, _InIter2, _OutIter> __set_union(
44    _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
45  for (; __first1 != __last1; ++__result) {
46    if (__first2 == __last2) {
47      auto __ret1 = std::__copy<_AlgPolicy>(std::move(__first1), std::move(__last1), std::move(__result));
48      return __set_union_result<_InIter1, _InIter2, _OutIter>(
49          std::move(__ret1.first), std::move(__first2), std::move((__ret1.second)));
50    }
51    if (__comp(*__first2, *__first1)) {
52      *__result = *__first2;
53      ++__first2;
54    } else {
55      if (!__comp(*__first1, *__first2)) {
56        ++__first2;
57      }
58      *__result = *__first1;
59      ++__first1;
60    }
61  }
62  auto __ret2 = std::__copy<_AlgPolicy>(std::move(__first2), std::move(__last2), std::move(__result));
63  return __set_union_result<_InIter1, _InIter2, _OutIter>(
64      std::move(__first1), std::move(__ret2.first), std::move((__ret2.second)));
65}
66
67template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
68_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_union(
69    _InputIterator1 __first1,
70    _InputIterator1 __last1,
71    _InputIterator2 __first2,
72    _InputIterator2 __last2,
73    _OutputIterator __result,
74    _Compare __comp) {
75  return std::__set_union<_ClassicAlgPolicy, __comp_ref_type<_Compare> >(
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
85template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
86_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_union(
87    _InputIterator1 __first1,
88    _InputIterator1 __last1,
89    _InputIterator2 __first2,
90    _InputIterator2 __last2,
91    _OutputIterator __result) {
92  return std::set_union(
93      std::move(__first1),
94      std::move(__last1),
95      std::move(__first2),
96      std::move(__last2),
97      std::move(__result),
98      __less<>());
99}
100
101_LIBCPP_END_NAMESPACE_STD
102
103_LIBCPP_POP_MACROS
104
105#endif // _LIBCPP___ALGORITHM_SET_UNION_H
106