Warning: This file is not a C or C++ file. It does not have highlighting.

1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP___CXX03___ALGORITHM_FIND_END_OF_H
11#define _LIBCPP___CXX03___ALGORITHM_FIND_END_OF_H
12
13#include <__cxx03/__algorithm/comp.h>
14#include <__cxx03/__algorithm/iterator_operations.h>
15#include <__cxx03/__algorithm/search.h>
16#include <__cxx03/__config>
17#include <__cxx03/__functional/identity.h>
18#include <__cxx03/__iterator/advance.h>
19#include <__cxx03/__iterator/iterator_traits.h>
20#include <__cxx03/__iterator/next.h>
21#include <__cxx03/__iterator/reverse_iterator.h>
22#include <__cxx03/__type_traits/invoke.h>
23#include <__cxx03/__utility/pair.h>
24
25#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
26# pragma GCC system_header
27#endif
28
29_LIBCPP_BEGIN_NAMESPACE_STD
30
31template < class _AlgPolicy,
32 class _Iter1,
33 class _Sent1,
34 class _Iter2,
35 class _Sent2,
36 class _Pred,
37 class _Proj1,
38 class _Proj2>
39_LIBCPP_HIDE_FROM_ABI inline pair<_Iter1, _Iter1> __find_end_impl(
40 _Iter1 __first1,
41 _Sent1 __last1,
42 _Iter2 __first2,
43 _Sent2 __last2,
44 _Pred& __pred,
45 _Proj1& __proj1,
46 _Proj2& __proj2,
47 forward_iterator_tag,
48 forward_iterator_tag) {
49 // modeled after search algorithm
50 _Iter1 __match_first = _IterOps<_AlgPolicy>::next(__first1, __last1); // __last1 is the "default" answer
51 _Iter1 __match_last = __match_first;
52 if (__first2 == __last2)
53 return pair<_Iter1, _Iter1>(__match_last, __match_last);
54 while (true) {
55 while (true) {
56 if (__first1 == __last1) // if source exhausted return last correct answer (or __last1 if never found)
57 return pair<_Iter1, _Iter1>(__match_first, __match_last);
58 if (std::__invoke(__pred, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2)))
59 break;
60 ++__first1;
61 }
62 // *__first1 matches *__first2, now match elements after here
63 _Iter1 __m1 = __first1;
64 _Iter2 __m2 = __first2;
65 while (true) {
66 if (++__m2 == __last2) { // Pattern exhaused, record answer and search for another one
67 __match_first = __first1;
68 __match_last = ++__m1;
69 ++__first1;
70 break;
71 }
72 if (++__m1 == __last1) // Source exhausted, return last answer
73 return pair<_Iter1, _Iter1>(__match_first, __match_last);
74 // mismatch, restart with a new __first
75 if (!std::__invoke(__pred, std::__invoke(__proj1, *__m1), std::__invoke(__proj2, *__m2))) {
76 ++__first1;
77 break;
78 } // else there is a match, check next elements
79 }
80 }
81}
82
83template < class _IterOps,
84 class _Pred,
85 class _Iter1,
86 class _Sent1,
87 class _Iter2,
88 class _Sent2,
89 class _Proj1,
90 class _Proj2>
91_LIBCPP_HIDE_FROM_ABI _Iter1 __find_end(
92 _Iter1 __first1,
93 _Sent1 __sent1,
94 _Iter2 __first2,
95 _Sent2 __sent2,
96 _Pred& __pred,
97 _Proj1& __proj1,
98 _Proj2& __proj2,
99 bidirectional_iterator_tag,
100 bidirectional_iterator_tag) {
101 auto __last1 = _IterOps::next(__first1, __sent1);
102 auto __last2 = _IterOps::next(__first2, __sent2);
103 // modeled after search algorithm (in reverse)
104 if (__first2 == __last2)
105 return __last1; // Everything matches an empty sequence
106 _Iter1 __l1 = __last1;
107 _Iter2 __l2 = __last2;
108 --__l2;
109 while (true) {
110 // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks
111 while (true) {
112 if (__first1 == __l1) // return __last1 if no element matches *__first2
113 return __last1;
114 if (std::__invoke(__pred, std::__invoke(__proj1, *--__l1), std::__invoke(__proj2, *__l2)))
115 break;
116 }
117 // *__l1 matches *__l2, now match elements before here
118 _Iter1 __m1 = __l1;
119 _Iter2 __m2 = __l2;
120 while (true) {
121 if (__m2 == __first2) // If pattern exhausted, __m1 is the answer (works for 1 element pattern)
122 return __m1;
123 if (__m1 == __first1) // Otherwise if source exhaused, pattern not found
124 return __last1;
125
126 // if there is a mismatch, restart with a new __l1
127 if (!std::__invoke(__pred, std::__invoke(__proj1, *--__m1), std::__invoke(__proj2, *--__m2))) {
128 break;
129 } // else there is a match, check next elements
130 }
131 }
132}
133
134template < class _AlgPolicy,
135 class _Pred,
136 class _Iter1,
137 class _Sent1,
138 class _Iter2,
139 class _Sent2,
140 class _Proj1,
141 class _Proj2>
142_LIBCPP_HIDE_FROM_ABI _Iter1 __find_end(
143 _Iter1 __first1,
144 _Sent1 __sent1,
145 _Iter2 __first2,
146 _Sent2 __sent2,
147 _Pred& __pred,
148 _Proj1& __proj1,
149 _Proj2& __proj2,
150 random_access_iterator_tag,
151 random_access_iterator_tag) {
152 typedef typename iterator_traits<_Iter1>::difference_type _D1;
153 auto __last1 = _IterOps<_AlgPolicy>::next(__first1, __sent1);
154 auto __last2 = _IterOps<_AlgPolicy>::next(__first2, __sent2);
155 // Take advantage of knowing source and pattern lengths. Stop short when source is smaller than pattern
156 auto __len2 = __last2 - __first2;
157 if (__len2 == 0)
158 return __last1;
159 auto __len1 = __last1 - __first1;
160 if (__len1 < __len2)
161 return __last1;
162 const _Iter1 __s = __first1 + _D1(__len2 - 1); // End of pattern match can't go before here
163 _Iter1 __l1 = __last1;
164 _Iter2 __l2 = __last2;
165 --__l2;
166 while (true) {
167 while (true) {
168 if (__s == __l1)
169 return __last1;
170 if (std::__invoke(__pred, std::__invoke(__proj1, *--__l1), std::__invoke(__proj2, *__l2)))
171 break;
172 }
173 _Iter1 __m1 = __l1;
174 _Iter2 __m2 = __l2;
175 while (true) {
176 if (__m2 == __first2)
177 return __m1;
178 // no need to check range on __m1 because __s guarantees we have enough source
179 if (!std::__invoke(__pred, std::__invoke(__proj1, *--__m1), std::__invoke(*--__m2))) {
180 break;
181 }
182 }
183 }
184}
185
186template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
187_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator1 __find_end_classic(
188 _ForwardIterator1 __first1,
189 _ForwardIterator1 __last1,
190 _ForwardIterator2 __first2,
191 _ForwardIterator2 __last2,
192 _BinaryPredicate& __pred) {
193 auto __proj = __identity();
194 return std::__find_end_impl<_ClassicAlgPolicy>(
195 __first1,
196 __last1,
197 __first2,
198 __last2,
199 __pred,
200 __proj,
201 __proj,
202 typename iterator_traits<_ForwardIterator1>::iterator_category(),
203 typename iterator_traits<_ForwardIterator2>::iterator_category())
204 .first;
205}
206
207template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
208_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator1 find_end(
209 _ForwardIterator1 __first1,
210 _ForwardIterator1 __last1,
211 _ForwardIterator2 __first2,
212 _ForwardIterator2 __last2,
213 _BinaryPredicate __pred) {
214 return std::__find_end_classic(__first1, __last1, __first2, __last2, __pred);
215}
216
217template <class _ForwardIterator1, class _ForwardIterator2>
218_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator1
219find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2) {
220 return std::find_end(__first1, __last1, __first2, __last2, __equal_to());
221}
222
223_LIBCPP_END_NAMESPACE_STD
224
225#endif // _LIBCPP___CXX03___ALGORITHM_FIND_END_OF_H
226

Warning: This file is not a C or C++ file. It does not have highlighting.

source code of libcxx/include/__cxx03/__algorithm/find_end.h