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 <__config>
16#include <__functional/identity.h>
17#include <__iterator/iterator_traits.h>
18#include <__type_traits/remove_cvref.h>
19#include <__utility/move.h>
20#include <__utility/pair.h>
21
22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23#  pragma GCC system_header
24#endif
25
26_LIBCPP_PUSH_MACROS
27#include <__undef_macros>
28
29_LIBCPP_BEGIN_NAMESPACE_STD
30
31template <class _Comp, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
32_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<__remove_cvref_t<_InIter1>, __remove_cvref_t<_OutIter> >
33__set_difference(
34    _InIter1&& __first1, _Sent1&& __last1, _InIter2&& __first2, _Sent2&& __last2, _OutIter&& __result, _Comp&& __comp) {
35  while (__first1 != __last1 && __first2 != __last2) {
36    if (__comp(*__first1, *__first2)) {
37      *__result = *__first1;
38      ++__first1;
39      ++__result;
40    } else if (__comp(*__first2, *__first1)) {
41      ++__first2;
42    } else {
43      ++__first1;
44      ++__first2;
45    }
46  }
47  return std::__copy(std::move(__first1), std::move(__last1), std::move(__result));
48}
49
50template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
51inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_difference(
52    _InputIterator1 __first1,
53    _InputIterator1 __last1,
54    _InputIterator2 __first2,
55    _InputIterator2 __last2,
56    _OutputIterator __result,
57    _Compare __comp) {
58  return std::__set_difference<__comp_ref_type<_Compare> >(__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(__first1, __last1, __first2, __last2, __result, __less<>()).second;
70}
71
72_LIBCPP_END_NAMESPACE_STD
73
74_LIBCPP_POP_MACROS
75
76#endif // _LIBCPP___ALGORITHM_SET_DIFFERENCE_H