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_UNIQUE_COPY_H
10#define _LIBCPP___ALGORITHM_UNIQUE_COPY_H
11
12#include <__algorithm/comp.h>
13#include <__algorithm/iterator_operations.h>
14#include <__config>
15#include <__iterator/iterator_traits.h>
16#include <__type_traits/conditional.h>
17#include <__type_traits/is_base_of.h>
18#include <__type_traits/is_same.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
31namespace __unique_copy_tags {
32
33struct __reread_from_input_tag {};
34struct __reread_from_output_tag {};
35struct __read_from_tmp_value_tag {};
36
37} // namespace __unique_copy_tags
38
39template <class _AlgPolicy, class _BinaryPredicate, class _InputIterator, class _Sent, class _OutputIterator>
40_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _OutputIterator>
41__unique_copy(_InputIterator __first,
42 _Sent __last,
43 _OutputIterator __result,
44 _BinaryPredicate&& __pred,
45 __unique_copy_tags::__read_from_tmp_value_tag) {
46 if (__first != __last) {
47 typename _IterOps<_AlgPolicy>::template __value_type<_InputIterator> __t(*__first);
48 *__result = __t;
49 ++__result;
50 while (++__first != __last) {
51 if (!__pred(__t, *__first)) {
52 __t = *__first;
53 *__result = __t;
54 ++__result;
55 }
56 }
57 }
58 return pair<_InputIterator, _OutputIterator>(std::move(__first), std::move(__result));
59}
60
61template <class _AlgPolicy, class _BinaryPredicate, class _ForwardIterator, class _Sent, class _OutputIterator>
62_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pair<_ForwardIterator, _OutputIterator>
63__unique_copy(_ForwardIterator __first,
64 _Sent __last,
65 _OutputIterator __result,
66 _BinaryPredicate&& __pred,
67 __unique_copy_tags::__reread_from_input_tag) {
68 if (__first != __last) {
69 _ForwardIterator __i = __first;
70 *__result = *__i;
71 ++__result;
72 while (++__first != __last) {
73 if (!__pred(*__i, *__first)) {
74 *__result = *__first;
75 ++__result;
76 __i = __first;
77 }
78 }
79 }
80 return pair<_ForwardIterator, _OutputIterator>(std::move(__first), std::move(__result));
81}
82
83template <class _AlgPolicy, class _BinaryPredicate, class _InputIterator, class _Sent, class _InputAndOutputIterator>
84_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _InputAndOutputIterator>
85__unique_copy(_InputIterator __first,
86 _Sent __last,
87 _InputAndOutputIterator __result,
88 _BinaryPredicate&& __pred,
89 __unique_copy_tags::__reread_from_output_tag) {
90 if (__first != __last) {
91 *__result = *__first;
92 while (++__first != __last)
93 if (!__pred(*__result, *__first))
94 *++__result = *__first;
95 ++__result;
96 }
97 return pair<_InputIterator, _InputAndOutputIterator>(std::move(__first), std::move(__result));
98}
99
100template <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
101inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
102unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred) {
103 using __algo_tag = __conditional_t<
104 is_base_of<forward_iterator_tag, typename iterator_traits<_InputIterator>::iterator_category>::value,
105 __unique_copy_tags::__reread_from_input_tag,
106 __conditional_t<
107 is_base_of<forward_iterator_tag, typename iterator_traits<_OutputIterator>::iterator_category>::value &&
108 is_same< typename iterator_traits<_InputIterator>::value_type,
109 typename iterator_traits<_OutputIterator>::value_type>::value,
110 __unique_copy_tags::__reread_from_output_tag,
111 __unique_copy_tags::__read_from_tmp_value_tag> >;
112 return std::__unique_copy<_ClassicAlgPolicy>(
113 std::move(__first), std::move(__last), std::move(__result), __pred, __algo_tag())
114 .second;
115}
116
117template <class _InputIterator, class _OutputIterator>
118inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
119unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
120 return std::unique_copy(std::move(__first), std::move(__last), std::move(__result), __equal_to());
121}
122
123_LIBCPP_END_NAMESPACE_STD
124
125_LIBCPP_POP_MACROS
126
127#endif // _LIBCPP___ALGORITHM_UNIQUE_COPY_H
128