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_BEGIN_NAMESPACE_STD
26
27template <class _InIter1, class _InIter2, class _OutIter>
28struct __set_union_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_union_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_union_result<_InIter1, _InIter2, _OutIter> __set_union(
41    _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
42  for (; __first1 != __last1; ++__result) {
43    if (__first2 == __last2) {
44      auto __ret1 = std::__copy<_AlgPolicy>(std::move(__first1), std::move(__last1), std::move(__result));
45      return __set_union_result<_InIter1, _InIter2, _OutIter>(
46          std::move(__ret1.first), std::move(__first2), std::move((__ret1.second)));
47    }
48    if (__comp(*__first2, *__first1)) {
49      *__result = *__first2;
50      ++__first2;
51    } else {
52      if (!__comp(*__first1, *__first2)) {
53        ++__first2;
54      }
55      *__result = *__first1;
56      ++__first1;
57    }
58  }
59  auto __ret2 = std::__copy<_AlgPolicy>(std::move(__first2), std::move(__last2), std::move(__result));
60  return __set_union_result<_InIter1, _InIter2, _OutIter>(
61      std::move(__first1), std::move(__ret2.first), std::move((__ret2.second)));
62}
63
64template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
65_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_union(
66    _InputIterator1 __first1,
67    _InputIterator1 __last1,
68    _InputIterator2 __first2,
69    _InputIterator2 __last2,
70    _OutputIterator __result,
71    _Compare __comp) {
72  return std::__set_union<_ClassicAlgPolicy, __comp_ref_type<_Compare> >(
73             std::move(__first1),
74             std::move(__last1),
75             std::move(__first2),
76             std::move(__last2),
77             std::move(__result),
78             __comp)
79      .__out_;
80}
81
82template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
83_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_union(
84    _InputIterator1 __first1,
85    _InputIterator1 __last1,
86    _InputIterator2 __first2,
87    _InputIterator2 __last2,
88    _OutputIterator __result) {
89  return std::set_union(
90      std::move(__first1),
91      std::move(__last1),
92      std::move(__first2),
93      std::move(__last2),
94      std::move(__result),
95      __less<typename iterator_traits<_InputIterator1>::value_type,
96             typename iterator_traits<_InputIterator2>::value_type>());
97}
98
99_LIBCPP_END_NAMESPACE_STD
100
101#endif // _LIBCPP___ALGORITHM_SET_UNION_H
102