|
221
|
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_STABLE_PARTITION_H
|
|
|
10 #define _LIBCPP___ALGORITHM_STABLE_PARTITION_H
|
|
|
11
|
|
|
12 #include <__config>
|
|
|
13 #include <__algorithm/rotate.h>
|
|
|
14 #include <__iterator/iterator_traits.h>
|
|
|
15 #include <memory>
|
|
|
16
|
|
|
17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
|
18 #pragma GCC system_header
|
|
|
19 #endif
|
|
|
20
|
|
|
21 _LIBCPP_PUSH_MACROS
|
|
|
22 #include <__undef_macros>
|
|
|
23
|
|
|
24 _LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
25
|
|
|
26 template <class _Predicate, class _ForwardIterator, class _Distance, class _Pair>
|
|
|
27 _ForwardIterator
|
|
|
28 __stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
|
|
|
29 _Distance __len, _Pair __p, forward_iterator_tag __fit)
|
|
|
30 {
|
|
|
31 // *__first is known to be false
|
|
|
32 // __len >= 1
|
|
|
33 if (__len == 1)
|
|
|
34 return __first;
|
|
|
35 if (__len == 2)
|
|
|
36 {
|
|
|
37 _ForwardIterator __m = __first;
|
|
|
38 if (__pred(*++__m))
|
|
|
39 {
|
|
|
40 swap(*__first, *__m);
|
|
|
41 return __m;
|
|
|
42 }
|
|
|
43 return __first;
|
|
|
44 }
|
|
|
45 if (__len <= __p.second)
|
|
|
46 { // The buffer is big enough to use
|
|
|
47 typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
|
|
|
48 __destruct_n __d(0);
|
|
|
49 unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
|
|
|
50 // Move the falses into the temporary buffer, and the trues to the front of the line
|
|
|
51 // Update __first to always point to the end of the trues
|
|
|
52 value_type* __t = __p.first;
|
|
|
53 ::new ((void*)__t) value_type(_VSTD::move(*__first));
|
|
|
54 __d.template __incr<value_type>();
|
|
|
55 ++__t;
|
|
|
56 _ForwardIterator __i = __first;
|
|
|
57 while (++__i != __last)
|
|
|
58 {
|
|
|
59 if (__pred(*__i))
|
|
|
60 {
|
|
|
61 *__first = _VSTD::move(*__i);
|
|
|
62 ++__first;
|
|
|
63 }
|
|
|
64 else
|
|
|
65 {
|
|
|
66 ::new ((void*)__t) value_type(_VSTD::move(*__i));
|
|
|
67 __d.template __incr<value_type>();
|
|
|
68 ++__t;
|
|
|
69 }
|
|
|
70 }
|
|
|
71 // All trues now at start of range, all falses in buffer
|
|
|
72 // Move falses back into range, but don't mess up __first which points to first false
|
|
|
73 __i = __first;
|
|
|
74 for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, (void) ++__i)
|
|
|
75 *__i = _VSTD::move(*__t2);
|
|
|
76 // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
|
|
|
77 return __first;
|
|
|
78 }
|
|
|
79 // Else not enough buffer, do in place
|
|
|
80 // __len >= 3
|
|
|
81 _ForwardIterator __m = __first;
|
|
|
82 _Distance __len2 = __len / 2; // __len2 >= 2
|
|
|
83 _VSTD::advance(__m, __len2);
|
|
|
84 // recurse on [__first, __m), *__first know to be false
|
|
|
85 // F?????????????????
|
|
|
86 // f m l
|
|
|
87 typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
|
|
|
88 _ForwardIterator __first_false = _VSTD::__stable_partition<_PredRef>(__first, __m, __pred, __len2, __p, __fit);
|
|
|
89 // TTTFFFFF??????????
|
|
|
90 // f ff m l
|
|
|
91 // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
|
|
|
92 _ForwardIterator __m1 = __m;
|
|
|
93 _ForwardIterator __second_false = __last;
|
|
|
94 _Distance __len_half = __len - __len2;
|
|
|
95 while (__pred(*__m1))
|
|
|
96 {
|
|
|
97 if (++__m1 == __last)
|
|
|
98 goto __second_half_done;
|
|
|
99 --__len_half;
|
|
|
100 }
|
|
|
101 // TTTFFFFFTTTF??????
|
|
|
102 // f ff m m1 l
|
|
|
103 __second_false = _VSTD::__stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __fit);
|
|
|
104 __second_half_done:
|
|
|
105 // TTTFFFFFTTTTTFFFFF
|
|
|
106 // f ff m sf l
|
|
|
107 return _VSTD::rotate(__first_false, __m, __second_false);
|
|
|
108 // TTTTTTTTFFFFFFFFFF
|
|
|
109 // |
|
|
|
110 }
|
|
|
111
|
|
|
112 template <class _Predicate, class _ForwardIterator>
|
|
|
113 _ForwardIterator
|
|
|
114 __stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
|
|
|
115 forward_iterator_tag)
|
|
|
116 {
|
|
|
117 const unsigned __alloc_limit = 3; // might want to make this a function of trivial assignment
|
|
|
118 // Either prove all true and return __first or point to first false
|
|
|
119 while (true)
|
|
|
120 {
|
|
|
121 if (__first == __last)
|
|
|
122 return __first;
|
|
|
123 if (!__pred(*__first))
|
|
|
124 break;
|
|
|
125 ++__first;
|
|
|
126 }
|
|
|
127 // We now have a reduced range [__first, __last)
|
|
|
128 // *__first is known to be false
|
|
|
129 typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
|
|
|
130 typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
|
|
|
131 difference_type __len = _VSTD::distance(__first, __last);
|
|
|
132 pair<value_type*, ptrdiff_t> __p(0, 0);
|
|
|
133 unique_ptr<value_type, __return_temporary_buffer> __h;
|
|
|
134 if (__len >= __alloc_limit)
|
|
|
135 {
|
|
|
136 __p = _VSTD::get_temporary_buffer<value_type>(__len);
|
|
|
137 __h.reset(__p.first);
|
|
|
138 }
|
|
|
139 return _VSTD::__stable_partition<typename add_lvalue_reference<_Predicate>::type>
|
|
|
140 (__first, __last, __pred, __len, __p, forward_iterator_tag());
|
|
|
141 }
|
|
|
142
|
|
|
143 template <class _Predicate, class _BidirectionalIterator, class _Distance, class _Pair>
|
|
|
144 _BidirectionalIterator
|
|
|
145 __stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
|
|
|
146 _Distance __len, _Pair __p, bidirectional_iterator_tag __bit)
|
|
|
147 {
|
|
|
148 // *__first is known to be false
|
|
|
149 // *__last is known to be true
|
|
|
150 // __len >= 2
|
|
|
151 if (__len == 2)
|
|
|
152 {
|
|
|
153 swap(*__first, *__last);
|
|
|
154 return __last;
|
|
|
155 }
|
|
|
156 if (__len == 3)
|
|
|
157 {
|
|
|
158 _BidirectionalIterator __m = __first;
|
|
|
159 if (__pred(*++__m))
|
|
|
160 {
|
|
|
161 swap(*__first, *__m);
|
|
|
162 swap(*__m, *__last);
|
|
|
163 return __last;
|
|
|
164 }
|
|
|
165 swap(*__m, *__last);
|
|
|
166 swap(*__first, *__m);
|
|
|
167 return __m;
|
|
|
168 }
|
|
|
169 if (__len <= __p.second)
|
|
|
170 { // The buffer is big enough to use
|
|
|
171 typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
|
|
|
172 __destruct_n __d(0);
|
|
|
173 unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
|
|
|
174 // Move the falses into the temporary buffer, and the trues to the front of the line
|
|
|
175 // Update __first to always point to the end of the trues
|
|
|
176 value_type* __t = __p.first;
|
|
|
177 ::new ((void*)__t) value_type(_VSTD::move(*__first));
|
|
|
178 __d.template __incr<value_type>();
|
|
|
179 ++__t;
|
|
|
180 _BidirectionalIterator __i = __first;
|
|
|
181 while (++__i != __last)
|
|
|
182 {
|
|
|
183 if (__pred(*__i))
|
|
|
184 {
|
|
|
185 *__first = _VSTD::move(*__i);
|
|
|
186 ++__first;
|
|
|
187 }
|
|
|
188 else
|
|
|
189 {
|
|
|
190 ::new ((void*)__t) value_type(_VSTD::move(*__i));
|
|
|
191 __d.template __incr<value_type>();
|
|
|
192 ++__t;
|
|
|
193 }
|
|
|
194 }
|
|
|
195 // move *__last, known to be true
|
|
|
196 *__first = _VSTD::move(*__i);
|
|
|
197 __i = ++__first;
|
|
|
198 // All trues now at start of range, all falses in buffer
|
|
|
199 // Move falses back into range, but don't mess up __first which points to first false
|
|
|
200 for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, (void) ++__i)
|
|
|
201 *__i = _VSTD::move(*__t2);
|
|
|
202 // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
|
|
|
203 return __first;
|
|
|
204 }
|
|
|
205 // Else not enough buffer, do in place
|
|
|
206 // __len >= 4
|
|
|
207 _BidirectionalIterator __m = __first;
|
|
|
208 _Distance __len2 = __len / 2; // __len2 >= 2
|
|
|
209 _VSTD::advance(__m, __len2);
|
|
|
210 // recurse on [__first, __m-1], except reduce __m-1 until *(__m-1) is true, *__first know to be false
|
|
|
211 // F????????????????T
|
|
|
212 // f m l
|
|
|
213 _BidirectionalIterator __m1 = __m;
|
|
|
214 _BidirectionalIterator __first_false = __first;
|
|
|
215 _Distance __len_half = __len2;
|
|
|
216 while (!__pred(*--__m1))
|
|
|
217 {
|
|
|
218 if (__m1 == __first)
|
|
|
219 goto __first_half_done;
|
|
|
220 --__len_half;
|
|
|
221 }
|
|
|
222 // F???TFFF?????????T
|
|
|
223 // f m1 m l
|
|
|
224 typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
|
|
|
225 __first_false = _VSTD::__stable_partition<_PredRef>(__first, __m1, __pred, __len_half, __p, __bit);
|
|
|
226 __first_half_done:
|
|
|
227 // TTTFFFFF?????????T
|
|
|
228 // f ff m l
|
|
|
229 // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
|
|
|
230 __m1 = __m;
|
|
|
231 _BidirectionalIterator __second_false = __last;
|
|
|
232 ++__second_false;
|
|
|
233 __len_half = __len - __len2;
|
|
|
234 while (__pred(*__m1))
|
|
|
235 {
|
|
|
236 if (++__m1 == __last)
|
|
|
237 goto __second_half_done;
|
|
|
238 --__len_half;
|
|
|
239 }
|
|
|
240 // TTTFFFFFTTTF?????T
|
|
|
241 // f ff m m1 l
|
|
|
242 __second_false = _VSTD::__stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __bit);
|
|
|
243 __second_half_done:
|
|
|
244 // TTTFFFFFTTTTTFFFFF
|
|
|
245 // f ff m sf l
|
|
|
246 return _VSTD::rotate(__first_false, __m, __second_false);
|
|
|
247 // TTTTTTTTFFFFFFFFFF
|
|
|
248 // |
|
|
|
249 }
|
|
|
250
|
|
|
251 template <class _Predicate, class _BidirectionalIterator>
|
|
|
252 _BidirectionalIterator
|
|
|
253 __stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
|
|
|
254 bidirectional_iterator_tag)
|
|
|
255 {
|
|
|
256 typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
|
|
|
257 typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
|
|
|
258 const difference_type __alloc_limit = 4; // might want to make this a function of trivial assignment
|
|
|
259 // Either prove all true and return __first or point to first false
|
|
|
260 while (true)
|
|
|
261 {
|
|
|
262 if (__first == __last)
|
|
|
263 return __first;
|
|
|
264 if (!__pred(*__first))
|
|
|
265 break;
|
|
|
266 ++__first;
|
|
|
267 }
|
|
|
268 // __first points to first false, everything prior to __first is already set.
|
|
|
269 // Either prove [__first, __last) is all false and return __first, or point __last to last true
|
|
|
270 do
|
|
|
271 {
|
|
|
272 if (__first == --__last)
|
|
|
273 return __first;
|
|
|
274 } while (!__pred(*__last));
|
|
|
275 // We now have a reduced range [__first, __last]
|
|
|
276 // *__first is known to be false
|
|
|
277 // *__last is known to be true
|
|
|
278 // __len >= 2
|
|
|
279 difference_type __len = _VSTD::distance(__first, __last) + 1;
|
|
|
280 pair<value_type*, ptrdiff_t> __p(0, 0);
|
|
|
281 unique_ptr<value_type, __return_temporary_buffer> __h;
|
|
|
282 if (__len >= __alloc_limit)
|
|
|
283 {
|
|
|
284 __p = _VSTD::get_temporary_buffer<value_type>(__len);
|
|
|
285 __h.reset(__p.first);
|
|
|
286 }
|
|
|
287 return _VSTD::__stable_partition<typename add_lvalue_reference<_Predicate>::type>
|
|
|
288 (__first, __last, __pred, __len, __p, bidirectional_iterator_tag());
|
|
|
289 }
|
|
|
290
|
|
|
291 template <class _ForwardIterator, class _Predicate>
|
|
|
292 inline _LIBCPP_INLINE_VISIBILITY
|
|
|
293 _ForwardIterator
|
|
|
294 stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
|
|
|
295 {
|
|
|
296 return _VSTD::__stable_partition<typename add_lvalue_reference<_Predicate>::type>
|
|
|
297 (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
|
|
|
298 }
|
|
|
299
|
|
|
300 _LIBCPP_END_NAMESPACE_STD
|
|
|
301
|
|
|
302 _LIBCPP_POP_MACROS
|
|
|
303
|
|
|
304 #endif // _LIBCPP___ALGORITHM_STABLE_PARTITION_H
|
