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_DIFFERENCE_H
10#define _LIBCPP___ALGORITHM_SET_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 <__functional/identity.h>
18#include <__functional/invoke.h>
19#include <__iterator/iterator_traits.h>
20#include <__utility/move.h>
21#include <__utility/pair.h>
22#include <type_traits>
23
24#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
25#  pragma GCC system_header
26#endif
27
28_LIBCPP_BEGIN_NAMESPACE_STD
29
30template <class _AlgPolicy, class _Comp, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
31_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<__remove_cvref_t<_InIter1>, __remove_cvref_t<_OutIter> >
32__set_difference(
33    _InIter1&& __first1, _Sent1&& __last1, _InIter2&& __first2, _Sent2&& __last2, _OutIter&& __result, _Comp&& __comp) {
34  while (__first1 != __last1 && __first2 != __last2) {
35    if (__comp(*__first1, *__first2)) {
36      *__result = *__first1;
37      ++__first1;
38      ++__result;
39    } else if (__comp(*__first2, *__first1)) {
40      ++__first2;
41    } else {
42      ++__first1;
43      ++__first2;
44    }
45  }
46  return std::__copy<_AlgPolicy>(std::move(__first1), std::move(__last1), std::move(__result));
47}
48
49template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
50inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_difference(
51    _InputIterator1 __first1,
52    _InputIterator1 __last1,
53    _InputIterator2 __first2,
54    _InputIterator2 __last2,
55    _OutputIterator __result,
56    _Compare __comp) {
57  return std::__set_difference<_ClassicAlgPolicy, __comp_ref_type<_Compare> >(
58      __first1, __last1, __first2, __last2, __result, __comp)
59      .second;
60}
61
62template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
63inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_difference(
64    _InputIterator1 __first1,
65    _InputIterator1 __last1,
66    _InputIterator2 __first2,
67    _InputIterator2 __last2,
68    _OutputIterator __result) {
69  return std::__set_difference<_ClassicAlgPolicy>(
70      __first1,
71      __last1,
72      __first2,
73      __last2,
74      __result,
75      __less<typename iterator_traits<_InputIterator1>::value_type,
76             typename iterator_traits<_InputIterator2>::value_type>()).second;
77}
78
79_LIBCPP_END_NAMESPACE_STD
80
81#endif // _LIBCPP___ALGORITHM_SET_DIFFERENCE_H
82