1// Bits and pieces used in algorithms -*- C++ -*- 2 3// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007 4// Free Software Foundation, Inc. 5// 6// This file is part of the GNU ISO C++ Library. This library is free 7// software; you can redistribute it and/or modify it under the 8// terms of the GNU General Public License as published by the 9// Free Software Foundation; either version 2, or (at your option) 10// any later version. 11 12// This library is distributed in the hope that it will be useful, 13// but WITHOUT ANY WARRANTY; without even the implied warranty of 14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15// GNU General Public License for more details. 16 17// You should have received a copy of the GNU General Public License along 18// with this library; see the file COPYING. If not, write to the Free 19// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 20// USA. 21 22// As a special exception, you may use this file as part of a free software 23// library without restriction. Specifically, if other files instantiate 24// templates or use macros or inline functions from this file, or you compile 25// this file and link it with other files to produce an executable, this 26// file does not by itself cause the resulting executable to be covered by 27// the GNU General Public License. This exception does not however 28// invalidate any other reasons why the executable file might be covered by 29// the GNU General Public License. 30 31/* 32 * 33 * Copyright (c) 1994 34 * Hewlett-Packard Company 35 * 36 * Permission to use, copy, modify, distribute and sell this software 37 * and its documentation for any purpose is hereby granted without fee, 38 * provided that the above copyright notice appear in all copies and 39 * that both that copyright notice and this permission notice appear 40 * in supporting documentation. Hewlett-Packard Company makes no 41 * representations about the suitability of this software for any 42 * purpose. It is provided "as is" without express or implied warranty. 43 * 44 * 45 * Copyright (c) 1996-1998 46 * Silicon Graphics Computer Systems, Inc. 47 * 48 * Permission to use, copy, modify, distribute and sell this software 49 * and its documentation for any purpose is hereby granted without fee, 50 * provided that the above copyright notice appear in all copies and 51 * that both that copyright notice and this permission notice appear 52 * in supporting documentation. Silicon Graphics makes no 53 * representations about the suitability of this software for any 54 * purpose. It is provided "as is" without express or implied warranty. 55 */ 56 57/** @file stl_algobase.h 58 * This is an internal header file, included by other library headers. 59 * You should not attempt to use it directly. 60 */ 61 62#ifndef _ALGOBASE_H 63#define _ALGOBASE_H 1 64 65#include <bits/c++config.h> 66#include <cstring> 67#include <climits> 68#include <cstdlib> 69#include <cstddef> 70#include <iosfwd> 71#include <bits/stl_pair.h> 72#include <bits/cpp_type_traits.h> 73#include <ext/type_traits.h> 74#include <bits/stl_iterator_base_types.h> 75#include <bits/stl_iterator_base_funcs.h> 76#include <bits/stl_iterator.h> 77#include <bits/concept_check.h> 78#include <debug/debug.h> 79 80_GLIBCXX_BEGIN_NAMESPACE(std) 81 82 /** 83 * @brief Swaps two values. 84 * @param a A thing of arbitrary type. 85 * @param b Another thing of arbitrary type. 86 * @return Nothing. 87 * 88 * This is the simple classic generic implementation. It will work on 89 * any type which has a copy constructor and an assignment operator. 90 */ 91 template<typename _Tp> 92 inline void 93 swap(_Tp& __a, _Tp& __b) 94 { 95 // concept requirements 96 __glibcxx_function_requires(_SGIAssignableConcept<_Tp>) 97 98 _Tp __tmp = __a; 99 __a = __b; 100 __b = __tmp; 101 } 102 103 // See http://gcc.gnu.org/ml/libstdc++/2004-08/msg00167.html: in a 104 // nutshell, we are partially implementing the resolution of DR 187, 105 // when it's safe, i.e., the value_types are equal. 106 template<bool _BoolType> 107 struct __iter_swap 108 { 109 template<typename _ForwardIterator1, typename _ForwardIterator2> 110 static void 111 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b) 112 { 113 typedef typename iterator_traits<_ForwardIterator1>::value_type 114 _ValueType1; 115 _ValueType1 __tmp = *__a; 116 *__a = *__b; 117 *__b = __tmp; 118 } 119 }; 120 121 template<> 122 struct __iter_swap<true> 123 { 124 template<typename _ForwardIterator1, typename _ForwardIterator2> 125 static void 126 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b) 127 { 128 swap(*__a, *__b); 129 } 130 }; 131 132 /** 133 * @brief Swaps the contents of two iterators. 134 * @param a An iterator. 135 * @param b Another iterator. 136 * @return Nothing. 137 * 138 * This function swaps the values pointed to by two iterators, not the 139 * iterators themselves. 140 */ 141 template<typename _ForwardIterator1, typename _ForwardIterator2> 142 inline void 143 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b) 144 { 145 typedef typename iterator_traits<_ForwardIterator1>::value_type 146 _ValueType1; 147 typedef typename iterator_traits<_ForwardIterator2>::value_type 148 _ValueType2; 149 150 // concept requirements 151 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< 152 _ForwardIterator1>) 153 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< 154 _ForwardIterator2>) 155 __glibcxx_function_requires(_ConvertibleConcept<_ValueType1, 156 _ValueType2>) 157 __glibcxx_function_requires(_ConvertibleConcept<_ValueType2, 158 _ValueType1>) 159 160 typedef typename iterator_traits<_ForwardIterator1>::reference 161 _ReferenceType1; 162 typedef typename iterator_traits<_ForwardIterator2>::reference 163 _ReferenceType2; 164 std::__iter_swap<__are_same<_ValueType1, _ValueType2>::__value && 165 __are_same<_ValueType1 &, _ReferenceType1>::__value && 166 __are_same<_ValueType2 &, _ReferenceType2>::__value>:: 167 iter_swap(__a, __b); 168 } 169 170 /** 171 * @brief This does what you think it does. 172 * @param a A thing of arbitrary type. 173 * @param b Another thing of arbitrary type. 174 * @return The lesser of the parameters. 175 * 176 * This is the simple classic generic implementation. It will work on 177 * temporary expressions, since they are only evaluated once, unlike a 178 * preprocessor macro. 179 */ 180 template<typename _Tp> 181 inline const _Tp& 182 min(const _Tp& __a, const _Tp& __b) 183 { 184 // concept requirements 185 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>) 186 //return __b < __a ? __b : __a; 187 if (__b < __a) 188 return __b; 189 return __a; 190 } 191 192 /** 193 * @brief This does what you think it does. 194 * @param a A thing of arbitrary type. 195 * @param b Another thing of arbitrary type. 196 * @return The greater of the parameters. 197 * 198 * This is the simple classic generic implementation. It will work on 199 * temporary expressions, since they are only evaluated once, unlike a 200 * preprocessor macro. 201 */ 202 template<typename _Tp> 203 inline const _Tp& 204 max(const _Tp& __a, const _Tp& __b) 205 { 206 // concept requirements 207 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>) 208 //return __a < __b ? __b : __a; 209 if (__a < __b) 210 return __b; 211 return __a; 212 } 213 214 /** 215 * @brief This does what you think it does. 216 * @param a A thing of arbitrary type. 217 * @param b Another thing of arbitrary type. 218 * @param comp A @link s20_3_3_comparisons comparison functor@endlink. 219 * @return The lesser of the parameters. 220 * 221 * This will work on temporary expressions, since they are only evaluated 222 * once, unlike a preprocessor macro. 223 */ 224 template<typename _Tp, typename _Compare> 225 inline const _Tp& 226 min(const _Tp& __a, const _Tp& __b, _Compare __comp) 227 { 228 //return __comp(__b, __a) ? __b : __a; 229 if (__comp(__b, __a)) 230 return __b; 231 return __a; 232 } 233 234 /** 235 * @brief This does what you think it does. 236 * @param a A thing of arbitrary type. 237 * @param b Another thing of arbitrary type. 238 * @param comp A @link s20_3_3_comparisons comparison functor@endlink. 239 * @return The greater of the parameters. 240 * 241 * This will work on temporary expressions, since they are only evaluated 242 * once, unlike a preprocessor macro. 243 */ 244 template<typename _Tp, typename _Compare> 245 inline const _Tp& 246 max(const _Tp& __a, const _Tp& __b, _Compare __comp) 247 { 248 //return __comp(__a, __b) ? __b : __a; 249 if (__comp(__a, __b)) 250 return __b; 251 return __a; 252 } 253 254 // All of these auxiliary structs serve two purposes. (1) Replace 255 // calls to copy with memmove whenever possible. (Memmove, not memcpy, 256 // because the input and output ranges are permitted to overlap.) 257 // (2) If we're using random access iterators, then write the loop as 258 // a for loop with an explicit count. 259 260 template<bool, typename> 261 struct __copy 262 { 263 template<typename _II, typename _OI> 264 static _OI 265 copy(_II __first, _II __last, _OI __result) 266 { 267 for (; __first != __last; ++__result, ++__first) 268 *__result = *__first; 269 return __result; 270 } 271 }; 272 273 template<bool _BoolType> 274 struct __copy<_BoolType, random_access_iterator_tag> 275 { 276 template<typename _II, typename _OI> 277 static _OI 278 copy(_II __first, _II __last, _OI __result) 279 { 280 typedef typename iterator_traits<_II>::difference_type _Distance; 281 for(_Distance __n = __last - __first; __n > 0; --__n) 282 { 283 *__result = *__first; 284 ++__first; 285 ++__result; 286 } 287 return __result; 288 } 289 }; 290 291 template<> 292 struct __copy<true, random_access_iterator_tag> 293 { 294 template<typename _Tp> 295 static _Tp* 296 copy(const _Tp* __first, const _Tp* __last, _Tp* __result) 297 { 298 std::memmove(__result, __first, sizeof(_Tp) * (__last - __first)); 299 return __result + (__last - __first); 300 } 301 }; 302 303 template<typename _II, typename _OI> 304 inline _OI 305 __copy_aux(_II __first, _II __last, _OI __result) 306 { 307 typedef typename iterator_traits<_II>::value_type _ValueTypeI; 308 typedef typename iterator_traits<_OI>::value_type _ValueTypeO; 309 typedef typename iterator_traits<_II>::iterator_category _Category; 310 const bool __simple = (__is_scalar<_ValueTypeI>::__value 311 && __is_pointer<_II>::__value 312 && __is_pointer<_OI>::__value 313 && __are_same<_ValueTypeI, _ValueTypeO>::__value); 314 315 return std::__copy<__simple, _Category>::copy(__first, __last, __result); 316 } 317 318 // Helpers for streambuf iterators (either istream or ostream). 319 template<typename _CharT> 320 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 321 ostreambuf_iterator<_CharT> >::__type 322 __copy_aux(_CharT*, _CharT*, ostreambuf_iterator<_CharT>); 323 324 template<typename _CharT> 325 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 326 ostreambuf_iterator<_CharT> >::__type 327 __copy_aux(const _CharT*, const _CharT*, ostreambuf_iterator<_CharT>); 328 329 template<typename _CharT> 330 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, _CharT*>::__type 331 __copy_aux(istreambuf_iterator<_CharT>, istreambuf_iterator<_CharT>, 332 _CharT*); 333 334 template<bool, bool> 335 struct __copy_normal 336 { 337 template<typename _II, typename _OI> 338 static _OI 339 __copy_n(_II __first, _II __last, _OI __result) 340 { return std::__copy_aux(__first, __last, __result); } 341 }; 342 343 template<> 344 struct __copy_normal<true, false> 345 { 346 template<typename _II, typename _OI> 347 static _OI 348 __copy_n(_II __first, _II __last, _OI __result) 349 { return std::__copy_aux(__first.base(), __last.base(), __result); } 350 }; 351 352 template<> 353 struct __copy_normal<false, true> 354 { 355 template<typename _II, typename _OI> 356 static _OI 357 __copy_n(_II __first, _II __last, _OI __result) 358 { return _OI(std::__copy_aux(__first, __last, __result.base())); } 359 }; 360 361 template<> 362 struct __copy_normal<true, true> 363 { 364 template<typename _II, typename _OI> 365 static _OI 366 __copy_n(_II __first, _II __last, _OI __result) 367 { return _OI(std::__copy_aux(__first.base(), __last.base(), 368 __result.base())); } 369 }; 370 371 /** 372 * @brief Copies the range [first,last) into result. 373 * @param first An input iterator. 374 * @param last An input iterator. 375 * @param result An output iterator. 376 * @return result + (last - first) 377 * 378 * This inline function will boil down to a call to @c memmove whenever 379 * possible. Failing that, if random access iterators are passed, then the 380 * loop count will be known (and therefore a candidate for compiler 381 * optimizations such as unrolling). Result may not be contained within 382 * [first,last); the copy_backward function should be used instead. 383 * 384 * Note that the end of the output range is permitted to be contained 385 * within [first,last). 386 */ 387 template<typename _InputIterator, typename _OutputIterator> 388 inline _OutputIterator 389 copy(_InputIterator __first, _InputIterator __last, 390 _OutputIterator __result) 391 { 392 // concept requirements 393 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) 394 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, 395 typename iterator_traits<_InputIterator>::value_type>) 396 __glibcxx_requires_valid_range(__first, __last); 397 398 const bool __in = __is_normal_iterator<_InputIterator>::__value; 399 const bool __out = __is_normal_iterator<_OutputIterator>::__value; 400 return std::__copy_normal<__in, __out>::__copy_n(__first, __last, 401 __result); 402 } 403 404 // Overload for streambuf iterators. 405 template<typename _CharT> 406 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 407 ostreambuf_iterator<_CharT> >::__type 408 copy(istreambuf_iterator<_CharT>, istreambuf_iterator<_CharT>, 409 ostreambuf_iterator<_CharT>); 410 411 template<bool, typename> 412 struct __copy_backward 413 { 414 template<typename _BI1, typename _BI2> 415 static _BI2 416 __copy_b(_BI1 __first, _BI1 __last, _BI2 __result) 417 { 418 while (__first != __last) 419 *--__result = *--__last; 420 return __result; 421 } 422 }; 423 424 template<bool _BoolType> 425 struct __copy_backward<_BoolType, random_access_iterator_tag> 426 { 427 template<typename _BI1, typename _BI2> 428 static _BI2 429 __copy_b(_BI1 __first, _BI1 __last, _BI2 __result) 430 { 431 typename iterator_traits<_BI1>::difference_type __n; 432 for (__n = __last - __first; __n > 0; --__n) 433 *--__result = *--__last; 434 return __result; 435 } 436 }; 437 438 template<> 439 struct __copy_backward<true, random_access_iterator_tag> 440 { 441 template<typename _Tp> 442 static _Tp* 443 __copy_b(const _Tp* __first, const _Tp* __last, _Tp* __result) 444 { 445 const ptrdiff_t _Num = __last - __first; 446 std::memmove(__result - _Num, __first, sizeof(_Tp) * _Num); 447 return __result - _Num; 448 } 449 }; 450 451 template<typename _BI1, typename _BI2> 452 inline _BI2 453 __copy_backward_aux(_BI1 __first, _BI1 __last, _BI2 __result) 454 { 455 typedef typename iterator_traits<_BI1>::value_type _ValueType1; 456 typedef typename iterator_traits<_BI2>::value_type _ValueType2; 457 typedef typename iterator_traits<_BI1>::iterator_category _Category; 458 const bool __simple = (__is_scalar<_ValueType1>::__value 459 && __is_pointer<_BI1>::__value 460 && __is_pointer<_BI2>::__value 461 && __are_same<_ValueType1, _ValueType2>::__value); 462 463 return std::__copy_backward<__simple, _Category>::__copy_b(__first, 464 __last, 465 __result); 466 } 467 468 template<bool, bool> 469 struct __copy_backward_normal 470 { 471 template<typename _BI1, typename _BI2> 472 static _BI2 473 __copy_b_n(_BI1 __first, _BI1 __last, _BI2 __result) 474 { return std::__copy_backward_aux(__first, __last, __result); } 475 }; 476 477 template<> 478 struct __copy_backward_normal<true, false> 479 { 480 template<typename _BI1, typename _BI2> 481 static _BI2 482 __copy_b_n(_BI1 __first, _BI1 __last, _BI2 __result) 483 { return std::__copy_backward_aux(__first.base(), __last.base(), 484 __result); } 485 }; 486 487 template<> 488 struct __copy_backward_normal<false, true> 489 { 490 template<typename _BI1, typename _BI2> 491 static _BI2 492 __copy_b_n(_BI1 __first, _BI1 __last, _BI2 __result) 493 { return _BI2(std::__copy_backward_aux(__first, __last, 494 __result.base())); } 495 }; 496 497 template<> 498 struct __copy_backward_normal<true, true> 499 { 500 template<typename _BI1, typename _BI2> 501 static _BI2 502 __copy_b_n(_BI1 __first, _BI1 __last, _BI2 __result) 503 { return _BI2(std::__copy_backward_aux(__first.base(), __last.base(), 504 __result.base())); } 505 }; 506 507 /** 508 * @brief Copies the range [first,last) into result. 509 * @param first A bidirectional iterator. 510 * @param last A bidirectional iterator. 511 * @param result A bidirectional iterator. 512 * @return result - (first - last) 513 * 514 * The function has the same effect as copy, but starts at the end of the 515 * range and works its way to the start, returning the start of the result. 516 * This inline function will boil down to a call to @c memmove whenever 517 * possible. Failing that, if random access iterators are passed, then the 518 * loop count will be known (and therefore a candidate for compiler 519 * optimizations such as unrolling). 520 * 521 * Result may not be in the range [first,last). Use copy instead. Note 522 * that the start of the output range may overlap [first,last). 523 */ 524 template <typename _BI1, typename _BI2> 525 inline _BI2 526 copy_backward(_BI1 __first, _BI1 __last, _BI2 __result) 527 { 528 // concept requirements 529 __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>) 530 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>) 531 __glibcxx_function_requires(_ConvertibleConcept< 532 typename iterator_traits<_BI1>::value_type, 533 typename iterator_traits<_BI2>::value_type>) 534 __glibcxx_requires_valid_range(__first, __last); 535 536 const bool __bi1 = __is_normal_iterator<_BI1>::__value; 537 const bool __bi2 = __is_normal_iterator<_BI2>::__value; 538 return std::__copy_backward_normal<__bi1, __bi2>::__copy_b_n(__first, 539 __last, 540 __result); 541 } 542 543 template<bool> 544 struct __fill 545 { 546 template<typename _ForwardIterator, typename _Tp> 547 static void 548 fill(_ForwardIterator __first, _ForwardIterator __last, 549 const _Tp& __value) 550 { 551 for (; __first != __last; ++__first) 552 *__first = __value; 553 } 554 }; 555 556 template<> 557 struct __fill<true> 558 { 559 template<typename _ForwardIterator, typename _Tp> 560 static void 561 fill(_ForwardIterator __first, _ForwardIterator __last, 562 const _Tp& __value) 563 { 564 const _Tp __tmp = __value; 565 for (; __first != __last; ++__first) 566 *__first = __tmp; 567 } 568 }; 569 570 /** 571 * @brief Fills the range [first,last) with copies of value. 572 * @param first A forward iterator. 573 * @param last A forward iterator. 574 * @param value A reference-to-const of arbitrary type. 575 * @return Nothing. 576 * 577 * This function fills a range with copies of the same value. For one-byte 578 * types filling contiguous areas of memory, this becomes an inline call to 579 * @c memset. 580 */ 581 template<typename _ForwardIterator, typename _Tp> 582 void 583 fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) 584 { 585 // concept requirements 586 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< 587 _ForwardIterator>) 588 __glibcxx_requires_valid_range(__first, __last); 589 590 const bool __scalar = __is_scalar<_Tp>::__value; 591 std::__fill<__scalar>::fill(__first, __last, __value); 592 } 593 594 // Specialization: for one-byte types we can use memset. 595 inline void 596 fill(unsigned char* __first, unsigned char* __last, const unsigned char& __c) 597 { 598 __glibcxx_requires_valid_range(__first, __last); 599 const unsigned char __tmp = __c; 600 std::memset(__first, __tmp, __last - __first); 601 } 602 603 inline void 604 fill(signed char* __first, signed char* __last, const signed char& __c) 605 { 606 __glibcxx_requires_valid_range(__first, __last); 607 const signed char __tmp = __c; 608 std::memset(__first, static_cast<unsigned char>(__tmp), __last - __first); 609 } 610 611 inline void 612 fill(char* __first, char* __last, const char& __c) 613 { 614 __glibcxx_requires_valid_range(__first, __last); 615 const char __tmp = __c; 616 std::memset(__first, static_cast<unsigned char>(__tmp), __last - __first); 617 } 618 619 template<bool> 620 struct __fill_n 621 { 622 template<typename _OutputIterator, typename _Size, typename _Tp> 623 static _OutputIterator 624 fill_n(_OutputIterator __first, _Size __n, const _Tp& __value) 625 { 626 for (; __n > 0; --__n, ++__first) 627 *__first = __value; 628 return __first; 629 } 630 }; 631 632 template<> 633 struct __fill_n<true> 634 { 635 template<typename _OutputIterator, typename _Size, typename _Tp> 636 static _OutputIterator 637 fill_n(_OutputIterator __first, _Size __n, const _Tp& __value) 638 { 639 const _Tp __tmp = __value; 640 for (; __n > 0; --__n, ++__first) 641 *__first = __tmp; 642 return __first; 643 } 644 }; 645 646 /** 647 * @brief Fills the range [first,first+n) with copies of value. 648 * @param first An output iterator. 649 * @param n The count of copies to perform. 650 * @param value A reference-to-const of arbitrary type. 651 * @return The iterator at first+n. 652 * 653 * This function fills a range with copies of the same value. For one-byte 654 * types filling contiguous areas of memory, this becomes an inline call to 655 * @c memset. 656 */ 657 template<typename _OutputIterator, typename _Size, typename _Tp> 658 _OutputIterator 659 fill_n(_OutputIterator __first, _Size __n, const _Tp& __value) 660 { 661 // concept requirements 662 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, _Tp>) 663 664 const bool __scalar = __is_scalar<_Tp>::__value; 665 return std::__fill_n<__scalar>::fill_n(__first, __n, __value); 666 } 667 668 template<typename _Size> 669 inline unsigned char* 670 fill_n(unsigned char* __first, _Size __n, const unsigned char& __c) 671 { 672 std::fill(__first, __first + __n, __c); 673 return __first + __n; 674 } 675 676 template<typename _Size> 677 inline signed char* 678 fill_n(signed char* __first, _Size __n, const signed char& __c) 679 { 680 std::fill(__first, __first + __n, __c); 681 return __first + __n; 682 } 683 684 template<typename _Size> 685 inline char* 686 fill_n(char* __first, _Size __n, const char& __c) 687 { 688 std::fill(__first, __first + __n, __c); 689 return __first + __n; 690 } 691 692 /** 693 * @brief Finds the places in ranges which don't match. 694 * @param first1 An input iterator. 695 * @param last1 An input iterator. 696 * @param first2 An input iterator. 697 * @return A pair of iterators pointing to the first mismatch. 698 * 699 * This compares the elements of two ranges using @c == and returns a pair 700 * of iterators. The first iterator points into the first range, the 701 * second iterator points into the second range, and the elements pointed 702 * to by the iterators are not equal. 703 */ 704 template<typename _InputIterator1, typename _InputIterator2> 705 pair<_InputIterator1, _InputIterator2> 706 mismatch(_InputIterator1 __first1, _InputIterator1 __last1, 707 _InputIterator2 __first2) 708 { 709 // concept requirements 710 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) 711 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) 712 __glibcxx_function_requires(_EqualOpConcept< 713 typename iterator_traits<_InputIterator1>::value_type, 714 typename iterator_traits<_InputIterator2>::value_type>) 715 __glibcxx_requires_valid_range(__first1, __last1); 716 717 while (__first1 != __last1 && *__first1 == *__first2) 718 { 719 ++__first1; 720 ++__first2; 721 } 722 return pair<_InputIterator1, _InputIterator2>(__first1, __first2); 723 } 724 725 /** 726 * @brief Finds the places in ranges which don't match. 727 * @param first1 An input iterator. 728 * @param last1 An input iterator. 729 * @param first2 An input iterator. 730 * @param binary_pred A binary predicate @link s20_3_1_base functor@endlink. 731 * @return A pair of iterators pointing to the first mismatch. 732 * 733 * This compares the elements of two ranges using the binary_pred 734 * parameter, and returns a pair 735 * of iterators. The first iterator points into the first range, the 736 * second iterator points into the second range, and the elements pointed 737 * to by the iterators are not equal. 738 */ 739 template<typename _InputIterator1, typename _InputIterator2, 740 typename _BinaryPredicate> 741 pair<_InputIterator1, _InputIterator2> 742 mismatch(_InputIterator1 __first1, _InputIterator1 __last1, 743 _InputIterator2 __first2, _BinaryPredicate __binary_pred) 744 { 745 // concept requirements 746 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) 747 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) 748 __glibcxx_requires_valid_range(__first1, __last1); 749 750 while (__first1 != __last1 && __binary_pred(*__first1, *__first2)) 751 { 752 ++__first1; 753 ++__first2; 754 } 755 return pair<_InputIterator1, _InputIterator2>(__first1, __first2); 756 } 757 758 /** 759 * @brief Tests a range for element-wise equality. 760 * @param first1 An input iterator. 761 * @param last1 An input iterator. 762 * @param first2 An input iterator. 763 * @return A boolean true or false. 764 * 765 * This compares the elements of two ranges using @c == and returns true or 766 * false depending on whether all of the corresponding elements of the 767 * ranges are equal. 768 */ 769 template<typename _InputIterator1, typename _InputIterator2> 770 inline bool 771 equal(_InputIterator1 __first1, _InputIterator1 __last1, 772 _InputIterator2 __first2) 773 { 774 // concept requirements 775 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) 776 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) 777 __glibcxx_function_requires(_EqualOpConcept< 778 typename iterator_traits<_InputIterator1>::value_type, 779 typename iterator_traits<_InputIterator2>::value_type>) 780 __glibcxx_requires_valid_range(__first1, __last1); 781 782 for (; __first1 != __last1; ++__first1, ++__first2) 783 if (!(*__first1 == *__first2)) 784 return false; 785 return true; 786 } 787 788 /** 789 * @brief Tests a range for element-wise equality. 790 * @param first1 An input iterator. 791 * @param last1 An input iterator. 792 * @param first2 An input iterator. 793 * @param binary_pred A binary predicate @link s20_3_1_base functor@endlink. 794 * @return A boolean true or false. 795 * 796 * This compares the elements of two ranges using the binary_pred 797 * parameter, and returns true or 798 * false depending on whether all of the corresponding elements of the 799 * ranges are equal. 800 */ 801 template<typename _InputIterator1, typename _InputIterator2, 802 typename _BinaryPredicate> 803 inline bool 804 equal(_InputIterator1 __first1, _InputIterator1 __last1, 805 _InputIterator2 __first2, 806 _BinaryPredicate __binary_pred) 807 { 808 // concept requirements 809 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) 810 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) 811 __glibcxx_requires_valid_range(__first1, __last1); 812 813 for (; __first1 != __last1; ++__first1, ++__first2) 814 if (!__binary_pred(*__first1, *__first2)) 815 return false; 816 return true; 817 } 818 819 /** 820 * @brief Performs "dictionary" comparison on ranges. 821 * @param first1 An input iterator. 822 * @param last1 An input iterator. 823 * @param first2 An input iterator. 824 * @param last2 An input iterator. 825 * @return A boolean true or false. 826 * 827 * "Returns true if the sequence of elements defined by the range 828 * [first1,last1) is lexicographically less than the sequence of elements 829 * defined by the range [first2,last2). Returns false otherwise." 830 * (Quoted from [25.3.8]/1.) If the iterators are all character pointers, 831 * then this is an inline call to @c memcmp. 832 */ 833 template<typename _InputIterator1, typename _InputIterator2> 834 bool 835 lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1, 836 _InputIterator2 __first2, _InputIterator2 __last2) 837 { 838 // concept requirements 839 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) 840 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) 841 __glibcxx_function_requires(_LessThanOpConcept< 842 typename iterator_traits<_InputIterator1>::value_type, 843 typename iterator_traits<_InputIterator2>::value_type>) 844 __glibcxx_function_requires(_LessThanOpConcept< 845 typename iterator_traits<_InputIterator2>::value_type, 846 typename iterator_traits<_InputIterator1>::value_type>) 847 __glibcxx_requires_valid_range(__first1, __last1); 848 __glibcxx_requires_valid_range(__first2, __last2); 849 850 for (; __first1 != __last1 && __first2 != __last2; 851 ++__first1, ++__first2) 852 { 853 if (*__first1 < *__first2) 854 return true; 855 if (*__first2 < *__first1) 856 return false; 857 } 858 return __first1 == __last1 && __first2 != __last2; 859 } 860 861 /** 862 * @brief Performs "dictionary" comparison on ranges. 863 * @param first1 An input iterator. 864 * @param last1 An input iterator. 865 * @param first2 An input iterator. 866 * @param last2 An input iterator. 867 * @param comp A @link s20_3_3_comparisons comparison functor@endlink. 868 * @return A boolean true or false. 869 * 870 * The same as the four-parameter @c lexigraphical_compare, but uses the 871 * comp parameter instead of @c <. 872 */ 873 template<typename _InputIterator1, typename _InputIterator2, 874 typename _Compare> 875 bool 876 lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1, 877 _InputIterator2 __first2, _InputIterator2 __last2, 878 _Compare __comp) 879 { 880 // concept requirements 881 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) 882 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) 883 __glibcxx_requires_valid_range(__first1, __last1); 884 __glibcxx_requires_valid_range(__first2, __last2); 885 886 for (; __first1 != __last1 && __first2 != __last2; 887 ++__first1, ++__first2) 888 { 889 if (__comp(*__first1, *__first2)) 890 return true; 891 if (__comp(*__first2, *__first1)) 892 return false; 893 } 894 return __first1 == __last1 && __first2 != __last2; 895 } 896 897 inline bool 898 lexicographical_compare(const unsigned char* __first1, 899 const unsigned char* __last1, 900 const unsigned char* __first2, 901 const unsigned char* __last2) 902 { 903 __glibcxx_requires_valid_range(__first1, __last1); 904 __glibcxx_requires_valid_range(__first2, __last2); 905 906 const size_t __len1 = __last1 - __first1; 907 const size_t __len2 = __last2 - __first2; 908 const int __result = std::memcmp(__first1, __first2, 909 std::min(__len1, __len2)); 910 return __result != 0 ? __result < 0 : __len1 < __len2; 911 } 912 913 inline bool 914 lexicographical_compare(const char* __first1, const char* __last1, 915 const char* __first2, const char* __last2) 916 { 917 __glibcxx_requires_valid_range(__first1, __last1); 918 __glibcxx_requires_valid_range(__first2, __last2); 919 920#if CHAR_MAX == SCHAR_MAX 921 return std::lexicographical_compare((const signed char*) __first1, 922 (const signed char*) __last1, 923 (const signed char*) __first2, 924 (const signed char*) __last2); 925#else /* CHAR_MAX == SCHAR_MAX */ 926 return std::lexicographical_compare((const unsigned char*) __first1, 927 (const unsigned char*) __last1, 928 (const unsigned char*) __first2, 929 (const unsigned char*) __last2); 930#endif /* CHAR_MAX == SCHAR_MAX */ 931 } 932 933_GLIBCXX_END_NAMESPACE 934 935#endif 936