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2c1bc4eb PC |
1 | // Algorithm extensions -*- C++ -*- |
2 | ||
60a40f62 PC |
3 | // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, |
4 | // 2009, 2010, 2011 | |
360721e3 | 5 | // Free Software Foundation, Inc. |
2c1bc4eb PC |
6 | // |
7 | // This file is part of the GNU ISO C++ Library. This library is free | |
8 | // software; you can redistribute it and/or modify it under the | |
9 | // terms of the GNU General Public License as published by the | |
748086b7 | 10 | // Free Software Foundation; either version 3, or (at your option) |
2c1bc4eb PC |
11 | // any later version. |
12 | ||
13 | // This library is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
748086b7 JJ |
18 | // Under Section 7 of GPL version 3, you are granted additional |
19 | // permissions described in the GCC Runtime Library Exception, version | |
20 | // 3.1, as published by the Free Software Foundation. | |
2c1bc4eb | 21 | |
748086b7 JJ |
22 | // You should have received a copy of the GNU General Public License and |
23 | // a copy of the GCC Runtime Library Exception along with this program; | |
24 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
25 | // <http://www.gnu.org/licenses/>. | |
2c1bc4eb PC |
26 | |
27 | /* | |
28 | * | |
29 | * Copyright (c) 1994 | |
30 | * Hewlett-Packard Company | |
31 | * | |
32 | * Permission to use, copy, modify, distribute and sell this software | |
33 | * and its documentation for any purpose is hereby granted without fee, | |
34 | * provided that the above copyright notice appear in all copies and | |
35 | * that both that copyright notice and this permission notice appear | |
36 | * in supporting documentation. Hewlett-Packard Company makes no | |
37 | * representations about the suitability of this software for any | |
38 | * purpose. It is provided "as is" without express or implied warranty. | |
39 | * | |
40 | * | |
41 | * Copyright (c) 1996 | |
42 | * Silicon Graphics Computer Systems, Inc. | |
43 | * | |
44 | * Permission to use, copy, modify, distribute and sell this software | |
45 | * and its documentation for any purpose is hereby granted without fee, | |
46 | * provided that the above copyright notice appear in all copies and | |
47 | * that both that copyright notice and this permission notice appear | |
48 | * in supporting documentation. Silicon Graphics makes no | |
49 | * representations about the suitability of this software for any | |
50 | * purpose. It is provided "as is" without express or implied warranty. | |
51 | */ | |
52 | ||
ffe94f83 PE |
53 | /** @file ext/algorithm |
54 | * This file is a GNU extension to the Standard C++ Library (possibly | |
0aa06b18 | 55 | * containing extensions from the HP/SGI STL subset). |
ffe94f83 PE |
56 | */ |
57 | ||
2c1bc4eb | 58 | #ifndef _EXT_ALGORITHM |
3d7c150e | 59 | #define _EXT_ALGORITHM 1 |
2c1bc4eb | 60 | |
36955a95 | 61 | #pragma GCC system_header |
3d7c150e | 62 | |
54c1bf78 | 63 | #include <algorithm> |
2c1bc4eb | 64 | |
12ffa228 BK |
65 | namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) |
66 | { | |
67 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
3cbc7af0 | 68 | |
f53d0ff1 PC |
69 | using std::ptrdiff_t; |
70 | using std::min; | |
71 | using std::pair; | |
72 | using std::input_iterator_tag; | |
73 | using std::random_access_iterator_tag; | |
74 | using std::iterator_traits; | |
75 | ||
76 | //-------------------------------------------------- | |
77 | // copy_n (not part of the C++ standard) | |
78 | ||
08addde6 PE |
79 | template<typename _InputIterator, typename _Size, typename _OutputIterator> |
80 | pair<_InputIterator, _OutputIterator> | |
81 | __copy_n(_InputIterator __first, _Size __count, | |
82 | _OutputIterator __result, | |
f53d0ff1 PC |
83 | input_iterator_tag) |
84 | { | |
4a787fa8 PC |
85 | for ( ; __count > 0; --__count) |
86 | { | |
87 | *__result = *__first; | |
88 | ++__first; | |
89 | ++__result; | |
90 | } | |
08addde6 | 91 | return pair<_InputIterator, _OutputIterator>(__first, __result); |
f53d0ff1 PC |
92 | } |
93 | ||
08addde6 PE |
94 | template<typename _RAIterator, typename _Size, typename _OutputIterator> |
95 | inline pair<_RAIterator, _OutputIterator> | |
96 | __copy_n(_RAIterator __first, _Size __count, | |
97 | _OutputIterator __result, | |
f53d0ff1 PC |
98 | random_access_iterator_tag) |
99 | { | |
08addde6 | 100 | _RAIterator __last = __first + __count; |
4a787fa8 PC |
101 | return pair<_RAIterator, _OutputIterator>(__last, std::copy(__first, |
102 | __last, | |
103 | __result)); | |
f53d0ff1 PC |
104 | } |
105 | ||
106 | /** | |
107 | * @brief Copies the range [first,first+count) into [result,result+count). | |
108 | * @param first An input iterator. | |
109 | * @param count The number of elements to copy. | |
110 | * @param result An output iterator. | |
111 | * @return A std::pair composed of first+count and result+count. | |
112 | * | |
113 | * This is an SGI extension. | |
114 | * This inline function will boil down to a call to @c memmove whenever | |
115 | * possible. Failing that, if random access iterators are passed, then the | |
116 | * loop count will be known (and therefore a candidate for compiler | |
117 | * optimizations such as unrolling). | |
118 | * @ingroup SGIextensions | |
119 | */ | |
08addde6 PE |
120 | template<typename _InputIterator, typename _Size, typename _OutputIterator> |
121 | inline pair<_InputIterator, _OutputIterator> | |
122 | copy_n(_InputIterator __first, _Size __count, _OutputIterator __result) | |
f53d0ff1 PC |
123 | { |
124 | // concept requirements | |
3d7c150e BK |
125 | __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) |
126 | __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, | |
08addde6 | 127 | typename iterator_traits<_InputIterator>::value_type>) |
f53d0ff1 | 128 | |
6ff7e964 PC |
129 | return __gnu_cxx::__copy_n(__first, __count, __result, |
130 | std::__iterator_category(__first)); | |
f53d0ff1 PC |
131 | } |
132 | ||
08addde6 | 133 | template<typename _InputIterator1, typename _InputIterator2> |
f53d0ff1 | 134 | int |
4a787fa8 PC |
135 | __lexicographical_compare_3way(_InputIterator1 __first1, |
136 | _InputIterator1 __last1, | |
137 | _InputIterator2 __first2, | |
138 | _InputIterator2 __last2) | |
f53d0ff1 | 139 | { |
4a787fa8 PC |
140 | while (__first1 != __last1 && __first2 != __last2) |
141 | { | |
142 | if (*__first1 < *__first2) | |
143 | return -1; | |
144 | if (*__first2 < *__first1) | |
145 | return 1; | |
146 | ++__first1; | |
147 | ++__first2; | |
148 | } | |
149 | if (__first2 == __last2) | |
f53d0ff1 | 150 | return !(__first1 == __last1); |
4a787fa8 | 151 | else |
f53d0ff1 | 152 | return -1; |
f53d0ff1 PC |
153 | } |
154 | ||
155 | inline int | |
156 | __lexicographical_compare_3way(const unsigned char* __first1, | |
157 | const unsigned char* __last1, | |
158 | const unsigned char* __first2, | |
159 | const unsigned char* __last2) | |
160 | { | |
161 | const ptrdiff_t __len1 = __last1 - __first1; | |
162 | const ptrdiff_t __len2 = __last2 - __first2; | |
360721e3 PC |
163 | const int __result = __builtin_memcmp(__first1, __first2, |
164 | min(__len1, __len2)); | |
fa30fe72 | 165 | return __result != 0 ? __result |
f53d0ff1 PC |
166 | : (__len1 == __len2 ? 0 : (__len1 < __len2 ? -1 : 1)); |
167 | } | |
168 | ||
fa30fe72 | 169 | inline int |
f53d0ff1 PC |
170 | __lexicographical_compare_3way(const char* __first1, const char* __last1, |
171 | const char* __first2, const char* __last2) | |
172 | { | |
173 | #if CHAR_MAX == SCHAR_MAX | |
4a787fa8 PC |
174 | return __lexicographical_compare_3way((const signed char*) __first1, |
175 | (const signed char*) __last1, | |
176 | (const signed char*) __first2, | |
177 | (const signed char*) __last2); | |
f53d0ff1 PC |
178 | #else |
179 | return __lexicographical_compare_3way((const unsigned char*) __first1, | |
180 | (const unsigned char*) __last1, | |
181 | (const unsigned char*) __first2, | |
182 | (const unsigned char*) __last2); | |
183 | #endif | |
184 | } | |
185 | ||
186 | /** | |
187 | * @brief @c memcmp on steroids. | |
188 | * @param first1 An input iterator. | |
189 | * @param last1 An input iterator. | |
190 | * @param first2 An input iterator. | |
191 | * @param last2 An input iterator. | |
192 | * @return An int, as with @c memcmp. | |
193 | * | |
194 | * The return value will be less than zero if the first range is | |
2a60a9f6 BK |
195 | * <em>lexigraphically less than</em> the second, greater than zero |
196 | * if the second range is <em>lexigraphically less than</em> the | |
197 | * first, and zero otherwise. | |
f53d0ff1 PC |
198 | * This is an SGI extension. |
199 | * @ingroup SGIextensions | |
200 | */ | |
08addde6 | 201 | template<typename _InputIterator1, typename _InputIterator2> |
f53d0ff1 | 202 | int |
4a787fa8 PC |
203 | lexicographical_compare_3way(_InputIterator1 __first1, |
204 | _InputIterator1 __last1, | |
205 | _InputIterator2 __first2, | |
206 | _InputIterator2 __last2) | |
f53d0ff1 PC |
207 | { |
208 | // concept requirements | |
3d7c150e BK |
209 | __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) |
210 | __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) | |
211 | __glibcxx_function_requires(_LessThanComparableConcept< | |
08addde6 | 212 | typename iterator_traits<_InputIterator1>::value_type>) |
3d7c150e | 213 | __glibcxx_function_requires(_LessThanComparableConcept< |
08addde6 | 214 | typename iterator_traits<_InputIterator2>::value_type>) |
285b36d6 BK |
215 | __glibcxx_requires_valid_range(__first1, __last1); |
216 | __glibcxx_requires_valid_range(__first2, __last2); | |
f53d0ff1 | 217 | |
4a787fa8 PC |
218 | return __lexicographical_compare_3way(__first1, __last1, __first2, |
219 | __last2); | |
f53d0ff1 PC |
220 | } |
221 | ||
2c1bc4eb PC |
222 | // count and count_if: this version, whose return type is void, was present |
223 | // in the HP STL, and is retained as an extension for backward compatibility. | |
08addde6 | 224 | template<typename _InputIterator, typename _Tp, typename _Size> |
2c1bc4eb | 225 | void |
08addde6 | 226 | count(_InputIterator __first, _InputIterator __last, |
2c1bc4eb PC |
227 | const _Tp& __value, |
228 | _Size& __n) | |
229 | { | |
230 | // concept requirements | |
3d7c150e BK |
231 | __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) |
232 | __glibcxx_function_requires(_EqualityComparableConcept< | |
08addde6 | 233 | typename iterator_traits<_InputIterator>::value_type >) |
3d7c150e | 234 | __glibcxx_function_requires(_EqualityComparableConcept<_Tp>) |
285b36d6 BK |
235 | __glibcxx_requires_valid_range(__first, __last); |
236 | ||
2c1bc4eb PC |
237 | for ( ; __first != __last; ++__first) |
238 | if (*__first == __value) | |
239 | ++__n; | |
240 | } | |
241 | ||
08addde6 | 242 | template<typename _InputIterator, typename _Predicate, typename _Size> |
2c1bc4eb | 243 | void |
08addde6 | 244 | count_if(_InputIterator __first, _InputIterator __last, |
2c1bc4eb PC |
245 | _Predicate __pred, |
246 | _Size& __n) | |
247 | { | |
248 | // concept requirements | |
3d7c150e BK |
249 | __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) |
250 | __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, | |
08addde6 | 251 | typename iterator_traits<_InputIterator>::value_type>) |
285b36d6 BK |
252 | __glibcxx_requires_valid_range(__first, __last); |
253 | ||
2c1bc4eb PC |
254 | for ( ; __first != __last; ++__first) |
255 | if (__pred(*__first)) | |
256 | ++__n; | |
257 | } | |
258 | ||
259 | // random_sample and random_sample_n (extensions, not part of the standard). | |
260 | ||
fc7f0a80 PE |
261 | /** |
262 | * This is an SGI extension. | |
263 | * @ingroup SGIextensions | |
264 | * @doctodo | |
265 | */ | |
4a787fa8 PC |
266 | template<typename _ForwardIterator, typename _OutputIterator, |
267 | typename _Distance> | |
08addde6 PE |
268 | _OutputIterator |
269 | random_sample_n(_ForwardIterator __first, _ForwardIterator __last, | |
270 | _OutputIterator __out, const _Distance __n) | |
2c1bc4eb PC |
271 | { |
272 | // concept requirements | |
3d7c150e BK |
273 | __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) |
274 | __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, | |
08addde6 | 275 | typename iterator_traits<_ForwardIterator>::value_type>) |
285b36d6 | 276 | __glibcxx_requires_valid_range(__first, __last); |
2c1bc4eb PC |
277 | |
278 | _Distance __remaining = std::distance(__first, __last); | |
f53d0ff1 | 279 | _Distance __m = min(__n, __remaining); |
2c1bc4eb | 280 | |
4a787fa8 PC |
281 | while (__m > 0) |
282 | { | |
283 | if ((std::rand() % __remaining) < __m) | |
284 | { | |
2c1bc4eb PC |
285 | *__out = *__first; |
286 | ++__out; | |
287 | --__m; | |
4a787fa8 PC |
288 | } |
289 | --__remaining; | |
290 | ++__first; | |
2c1bc4eb | 291 | } |
2c1bc4eb PC |
292 | return __out; |
293 | } | |
294 | ||
fc7f0a80 PE |
295 | /** |
296 | * This is an SGI extension. | |
297 | * @ingroup SGIextensions | |
298 | * @doctodo | |
299 | */ | |
4a787fa8 PC |
300 | template<typename _ForwardIterator, typename _OutputIterator, |
301 | typename _Distance, typename _RandomNumberGenerator> | |
08addde6 PE |
302 | _OutputIterator |
303 | random_sample_n(_ForwardIterator __first, _ForwardIterator __last, | |
fa30fe72 | 304 | _OutputIterator __out, const _Distance __n, |
2c1bc4eb PC |
305 | _RandomNumberGenerator& __rand) |
306 | { | |
307 | // concept requirements | |
3d7c150e BK |
308 | __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) |
309 | __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, | |
08addde6 | 310 | typename iterator_traits<_ForwardIterator>::value_type>) |
3d7c150e | 311 | __glibcxx_function_requires(_UnaryFunctionConcept< |
2c1bc4eb | 312 | _RandomNumberGenerator, _Distance, _Distance>) |
285b36d6 | 313 | __glibcxx_requires_valid_range(__first, __last); |
2c1bc4eb PC |
314 | |
315 | _Distance __remaining = std::distance(__first, __last); | |
f53d0ff1 | 316 | _Distance __m = min(__n, __remaining); |
2c1bc4eb | 317 | |
4a787fa8 PC |
318 | while (__m > 0) |
319 | { | |
320 | if (__rand(__remaining) < __m) | |
321 | { | |
2c1bc4eb PC |
322 | *__out = *__first; |
323 | ++__out; | |
324 | --__m; | |
4a787fa8 PC |
325 | } |
326 | --__remaining; | |
327 | ++__first; | |
2c1bc4eb | 328 | } |
2c1bc4eb PC |
329 | return __out; |
330 | } | |
331 | ||
4a787fa8 PC |
332 | template<typename _InputIterator, typename _RandomAccessIterator, |
333 | typename _Distance> | |
08addde6 PE |
334 | _RandomAccessIterator |
335 | __random_sample(_InputIterator __first, _InputIterator __last, | |
336 | _RandomAccessIterator __out, | |
2c1bc4eb PC |
337 | const _Distance __n) |
338 | { | |
339 | _Distance __m = 0; | |
340 | _Distance __t = __n; | |
fa30fe72 | 341 | for ( ; __first != __last && __m < __n; ++__m, ++__first) |
2c1bc4eb PC |
342 | __out[__m] = *__first; |
343 | ||
4a787fa8 PC |
344 | while (__first != __last) |
345 | { | |
346 | ++__t; | |
347 | _Distance __M = std::rand() % (__t); | |
348 | if (__M < __n) | |
349 | __out[__M] = *__first; | |
350 | ++__first; | |
351 | } | |
2c1bc4eb PC |
352 | return __out + __m; |
353 | } | |
354 | ||
08addde6 | 355 | template<typename _InputIterator, typename _RandomAccessIterator, |
2c1bc4eb | 356 | typename _RandomNumberGenerator, typename _Distance> |
08addde6 PE |
357 | _RandomAccessIterator |
358 | __random_sample(_InputIterator __first, _InputIterator __last, | |
359 | _RandomAccessIterator __out, | |
2c1bc4eb PC |
360 | _RandomNumberGenerator& __rand, |
361 | const _Distance __n) | |
362 | { | |
363 | // concept requirements | |
3d7c150e | 364 | __glibcxx_function_requires(_UnaryFunctionConcept< |
2c1bc4eb PC |
365 | _RandomNumberGenerator, _Distance, _Distance>) |
366 | ||
367 | _Distance __m = 0; | |
368 | _Distance __t = __n; | |
369 | for ( ; __first != __last && __m < __n; ++__m, ++__first) | |
370 | __out[__m] = *__first; | |
371 | ||
4a787fa8 PC |
372 | while (__first != __last) |
373 | { | |
374 | ++__t; | |
375 | _Distance __M = __rand(__t); | |
376 | if (__M < __n) | |
377 | __out[__M] = *__first; | |
378 | ++__first; | |
379 | } | |
2c1bc4eb PC |
380 | return __out + __m; |
381 | } | |
382 | ||
fc7f0a80 PE |
383 | /** |
384 | * This is an SGI extension. | |
385 | * @ingroup SGIextensions | |
386 | * @doctodo | |
387 | */ | |
08addde6 PE |
388 | template<typename _InputIterator, typename _RandomAccessIterator> |
389 | inline _RandomAccessIterator | |
390 | random_sample(_InputIterator __first, _InputIterator __last, | |
4a787fa8 PC |
391 | _RandomAccessIterator __out_first, |
392 | _RandomAccessIterator __out_last) | |
2c1bc4eb PC |
393 | { |
394 | // concept requirements | |
3d7c150e BK |
395 | __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) |
396 | __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< | |
08addde6 | 397 | _RandomAccessIterator>) |
285b36d6 BK |
398 | __glibcxx_requires_valid_range(__first, __last); |
399 | __glibcxx_requires_valid_range(__out_first, __out_last); | |
2c1bc4eb PC |
400 | |
401 | return __random_sample(__first, __last, | |
402 | __out_first, __out_last - __out_first); | |
403 | } | |
404 | ||
fc7f0a80 PE |
405 | /** |
406 | * This is an SGI extension. | |
407 | * @ingroup SGIextensions | |
408 | * @doctodo | |
409 | */ | |
fa30fe72 | 410 | template<typename _InputIterator, typename _RandomAccessIterator, |
2c1bc4eb | 411 | typename _RandomNumberGenerator> |
08addde6 PE |
412 | inline _RandomAccessIterator |
413 | random_sample(_InputIterator __first, _InputIterator __last, | |
4a787fa8 PC |
414 | _RandomAccessIterator __out_first, |
415 | _RandomAccessIterator __out_last, | |
fa30fe72 | 416 | _RandomNumberGenerator& __rand) |
2c1bc4eb PC |
417 | { |
418 | // concept requirements | |
3d7c150e BK |
419 | __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) |
420 | __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< | |
08addde6 | 421 | _RandomAccessIterator>) |
285b36d6 BK |
422 | __glibcxx_requires_valid_range(__first, __last); |
423 | __glibcxx_requires_valid_range(__out_first, __out_last); | |
2c1bc4eb PC |
424 | |
425 | return __random_sample(__first, __last, | |
426 | __out_first, __rand, | |
427 | __out_last - __out_first); | |
428 | } | |
fa30fe72 | 429 | |
60a40f62 PC |
430 | #ifdef __GXX_EXPERIMENTAL_CXX0X__ |
431 | using std::is_heap; | |
432 | #else | |
fc7f0a80 PE |
433 | /** |
434 | * This is an SGI extension. | |
435 | * @ingroup SGIextensions | |
436 | * @doctodo | |
437 | */ | |
08addde6 | 438 | template<typename _RandomAccessIterator> |
2c1bc4eb | 439 | inline bool |
08addde6 | 440 | is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) |
2c1bc4eb PC |
441 | { |
442 | // concept requirements | |
4a787fa8 PC |
443 | __glibcxx_function_requires(_RandomAccessIteratorConcept< |
444 | _RandomAccessIterator>) | |
3d7c150e | 445 | __glibcxx_function_requires(_LessThanComparableConcept< |
08addde6 | 446 | typename iterator_traits<_RandomAccessIterator>::value_type>) |
285b36d6 | 447 | __glibcxx_requires_valid_range(__first, __last); |
2c1bc4eb | 448 | |
285b36d6 | 449 | return std::__is_heap(__first, __last - __first); |
2c1bc4eb PC |
450 | } |
451 | ||
fc7f0a80 PE |
452 | /** |
453 | * This is an SGI extension. | |
454 | * @ingroup SGIextensions | |
455 | * @doctodo | |
456 | */ | |
08addde6 | 457 | template<typename _RandomAccessIterator, typename _StrictWeakOrdering> |
2c1bc4eb | 458 | inline bool |
08addde6 | 459 | is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, |
2c1bc4eb PC |
460 | _StrictWeakOrdering __comp) |
461 | { | |
462 | // concept requirements | |
4a787fa8 PC |
463 | __glibcxx_function_requires(_RandomAccessIteratorConcept< |
464 | _RandomAccessIterator>) | |
3d7c150e | 465 | __glibcxx_function_requires(_BinaryPredicateConcept<_StrictWeakOrdering, |
fa30fe72 | 466 | typename iterator_traits<_RandomAccessIterator>::value_type, |
08addde6 | 467 | typename iterator_traits<_RandomAccessIterator>::value_type>) |
285b36d6 | 468 | __glibcxx_requires_valid_range(__first, __last); |
2c1bc4eb | 469 | |
285b36d6 | 470 | return std::__is_heap(__first, __comp, __last - __first); |
2c1bc4eb | 471 | } |
60a40f62 | 472 | #endif |
2c1bc4eb | 473 | |
7c16382a JY |
474 | #ifdef __GXX_EXPERIMENTAL_CXX0X__ |
475 | using std::is_sorted; | |
476 | #else | |
2c1bc4eb PC |
477 | // is_sorted, a predicated testing whether a range is sorted in |
478 | // nondescending order. This is an extension, not part of the C++ | |
479 | // standard. | |
480 | ||
fc7f0a80 PE |
481 | /** |
482 | * This is an SGI extension. | |
483 | * @ingroup SGIextensions | |
484 | * @doctodo | |
485 | */ | |
08addde6 | 486 | template<typename _ForwardIterator> |
2c1bc4eb | 487 | bool |
08addde6 | 488 | is_sorted(_ForwardIterator __first, _ForwardIterator __last) |
2c1bc4eb PC |
489 | { |
490 | // concept requirements | |
3d7c150e BK |
491 | __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) |
492 | __glibcxx_function_requires(_LessThanComparableConcept< | |
08addde6 | 493 | typename iterator_traits<_ForwardIterator>::value_type>) |
285b36d6 | 494 | __glibcxx_requires_valid_range(__first, __last); |
2c1bc4eb PC |
495 | |
496 | if (__first == __last) | |
497 | return true; | |
498 | ||
08addde6 | 499 | _ForwardIterator __next = __first; |
4a787fa8 | 500 | for (++__next; __next != __last; __first = __next, ++__next) |
2c1bc4eb PC |
501 | if (*__next < *__first) |
502 | return false; | |
2c1bc4eb PC |
503 | return true; |
504 | } | |
505 | ||
fc7f0a80 PE |
506 | /** |
507 | * This is an SGI extension. | |
508 | * @ingroup SGIextensions | |
509 | * @doctodo | |
510 | */ | |
08addde6 | 511 | template<typename _ForwardIterator, typename _StrictWeakOrdering> |
2c1bc4eb | 512 | bool |
4a787fa8 PC |
513 | is_sorted(_ForwardIterator __first, _ForwardIterator __last, |
514 | _StrictWeakOrdering __comp) | |
2c1bc4eb PC |
515 | { |
516 | // concept requirements | |
3d7c150e BK |
517 | __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) |
518 | __glibcxx_function_requires(_BinaryPredicateConcept<_StrictWeakOrdering, | |
fa30fe72 | 519 | typename iterator_traits<_ForwardIterator>::value_type, |
08addde6 | 520 | typename iterator_traits<_ForwardIterator>::value_type>) |
285b36d6 | 521 | __glibcxx_requires_valid_range(__first, __last); |
2c1bc4eb PC |
522 | |
523 | if (__first == __last) | |
524 | return true; | |
525 | ||
08addde6 | 526 | _ForwardIterator __next = __first; |
4a787fa8 | 527 | for (++__next; __next != __last; __first = __next, ++__next) |
2c1bc4eb PC |
528 | if (__comp(*__next, *__first)) |
529 | return false; | |
2c1bc4eb PC |
530 | return true; |
531 | } | |
7c16382a | 532 | #endif // __GXX_EXPERIMENTAL_CXX0X__ |
3cbc7af0 | 533 | |
d5c59224 PC |
534 | /** |
535 | * @brief Find the median of three values. | |
536 | * @param a A value. | |
537 | * @param b A value. | |
538 | * @param c A value. | |
539 | * @return One of @p a, @p b or @p c. | |
540 | * | |
541 | * If @c {l,m,n} is some convolution of @p {a,b,c} such that @c l<=m<=n | |
542 | * then the value returned will be @c m. | |
543 | * This is an SGI extension. | |
544 | * @ingroup SGIextensions | |
545 | */ | |
546 | template<typename _Tp> | |
547 | const _Tp& | |
548 | __median(const _Tp& __a, const _Tp& __b, const _Tp& __c) | |
549 | { | |
550 | // concept requirements | |
551 | __glibcxx_function_requires(_LessThanComparableConcept<_Tp>) | |
552 | if (__a < __b) | |
553 | if (__b < __c) | |
554 | return __b; | |
555 | else if (__a < __c) | |
556 | return __c; | |
557 | else | |
558 | return __a; | |
559 | else if (__a < __c) | |
560 | return __a; | |
561 | else if (__b < __c) | |
562 | return __c; | |
563 | else | |
564 | return __b; | |
565 | } | |
566 | ||
567 | /** | |
568 | * @brief Find the median of three values using a predicate for comparison. | |
569 | * @param a A value. | |
570 | * @param b A value. | |
571 | * @param c A value. | |
572 | * @param comp A binary predicate. | |
573 | * @return One of @p a, @p b or @p c. | |
574 | * | |
575 | * If @c {l,m,n} is some convolution of @p {a,b,c} such that @p comp(l,m) | |
576 | * and @p comp(m,n) are both true then the value returned will be @c m. | |
577 | * This is an SGI extension. | |
578 | * @ingroup SGIextensions | |
579 | */ | |
580 | template<typename _Tp, typename _Compare> | |
581 | const _Tp& | |
582 | __median(const _Tp& __a, const _Tp& __b, const _Tp& __c, _Compare __comp) | |
583 | { | |
584 | // concept requirements | |
585 | __glibcxx_function_requires(_BinaryFunctionConcept<_Compare, bool, | |
586 | _Tp, _Tp>) | |
587 | if (__comp(__a, __b)) | |
588 | if (__comp(__b, __c)) | |
589 | return __b; | |
590 | else if (__comp(__a, __c)) | |
591 | return __c; | |
592 | else | |
593 | return __a; | |
594 | else if (__comp(__a, __c)) | |
595 | return __a; | |
596 | else if (__comp(__b, __c)) | |
597 | return __c; | |
598 | else | |
599 | return __b; | |
600 | } | |
601 | ||
12ffa228 BK |
602 | _GLIBCXX_END_NAMESPACE_VERSION |
603 | } // namespace | |
2c1bc4eb PC |
604 | |
605 | #endif /* _EXT_ALGORITHM */ |