1 // Iterators -*- C++ -*- 2 3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 4 // 2010, 2011, 2012 5 // Free Software Foundation, Inc. 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 10 // Free Software Foundation; either version 3, or (at your option) 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 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. 21 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/>. 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) 1996-1998 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 53 /** @file bits/stl_iterator.h 54 * This is an internal header file, included by other library headers. 55 * Do not attempt to use it directly. @headername{iterator} 56 * 57 * This file implements reverse_iterator, back_insert_iterator, 58 * front_insert_iterator, insert_iterator, __normal_iterator, and their 59 * supporting functions and overloaded operators. 60 */ 61 62 #ifndef _STL_ITERATOR_H 63 #define _STL_ITERATOR_H 1 64 65 #include <bits/cpp_type_traits.h> 66 #include <ext/type_traits.h> 67 #include <bits/move.h> 68 69 namespace std _GLIBCXX_VISIBILITY(default) 70 { 71 _GLIBCXX_BEGIN_NAMESPACE_VERSION 72 73 /** 74 * @addtogroup iterators 75 * @{ 76 */ 77 78 // 24.4.1 Reverse iterators 79 /** 80 * Bidirectional and random access iterators have corresponding reverse 81 * %iterator adaptors that iterate through the data structure in the 82 * opposite direction. They have the same signatures as the corresponding 83 * iterators. The fundamental relation between a reverse %iterator and its 84 * corresponding %iterator @c i is established by the identity: 85 * @code 86 * &*(reverse_iterator(i)) == &*(i - 1) 87 * @endcode 88 * 89 * <em>This mapping is dictated by the fact that while there is always a 90 * pointer past the end of an array, there might not be a valid pointer 91 * before the beginning of an array.</em> [24.4.1]/1,2 92 * 93 * Reverse iterators can be tricky and surprising at first. Their 94 * semantics make sense, however, and the trickiness is a side effect of 95 * the requirement that the iterators must be safe. 96 */ 97 template<typename _Iterator> 98 class reverse_iterator 99 : public iterator<typename iterator_traits<_Iterator>::iterator_category, 100 typename iterator_traits<_Iterator>::value_type, 101 typename iterator_traits<_Iterator>::difference_type, 102 typename iterator_traits<_Iterator>::pointer, 103 typename iterator_traits<_Iterator>::reference> 104 { 105 protected: 106 _Iterator current; 107 108 typedef iterator_traits<_Iterator> __traits_type; 109 110 public: 111 typedef _Iterator iterator_type; 112 typedef typename __traits_type::difference_type difference_type; 113 typedef typename __traits_type::pointer pointer; 114 typedef typename __traits_type::reference reference; 115 116 /** 117 * The default constructor value-initializes member @p current. 118 * If it is a pointer, that means it is zero-initialized. 119 */ 120 // _GLIBCXX_RESOLVE_LIB_DEFECTS 121 // 235 No specification of default ctor for reverse_iterator 122 reverse_iterator() : current() { } 123 124 /** 125 * This %iterator will move in the opposite direction that @p x does. 126 */ 127 explicit 128 reverse_iterator(iterator_type __x) : current(__x) { } 129 130 /** 131 * The copy constructor is normal. 132 */ 133 reverse_iterator(const reverse_iterator& __x) 134 : current(__x.current) { } 135 136 /** 137 * A %reverse_iterator across other types can be copied if the 138 * underlying %iterator can be converted to the type of @c current. 139 */ 140 template<typename _Iter> 141 reverse_iterator(const reverse_iterator<_Iter>& __x) 142 : current(__x.base()) { } 143 144 /** 145 * @return @c current, the %iterator used for underlying work. 146 */ 147 iterator_type 148 base() const 149 { return current; } 150 151 /** 152 * @return A reference to the value at @c --current 153 * 154 * This requires that @c --current is dereferenceable. 155 * 156 * @warning This implementation requires that for an iterator of the 157 * underlying iterator type, @c x, a reference obtained by 158 * @c *x remains valid after @c x has been modified or 159 * destroyed. This is a bug: http://gcc.gnu.org/PR51823 160 */ 161 reference 162 operator*() const 163 { 164 _Iterator __tmp = current; 165 return *--__tmp; 166 } 167 168 /** 169 * @return A pointer to the value at @c --current 170 * 171 * This requires that @c --current is dereferenceable. 172 */ 173 pointer 174 operator->() const 175 { return &(operator*()); } 176 177 /** 178 * @return @c *this 179 * 180 * Decrements the underlying iterator. 181 */ 182 reverse_iterator& 183 operator++() 184 { 185 --current; 186 return *this; 187 } 188 189 /** 190 * @return The original value of @c *this 191 * 192 * Decrements the underlying iterator. 193 */ 194 reverse_iterator 195 operator++(int) 196 { 197 reverse_iterator __tmp = *this; 198 --current; 199 return __tmp; 200 } 201 202 /** 203 * @return @c *this 204 * 205 * Increments the underlying iterator. 206 */ 207 reverse_iterator& 208 operator--() 209 { 210 ++current; 211 return *this; 212 } 213 214 /** 215 * @return A reverse_iterator with the previous value of @c *this 216 * 217 * Increments the underlying iterator. 218 */ 219 reverse_iterator 220 operator--(int) 221 { 222 reverse_iterator __tmp = *this; 223 ++current; 224 return __tmp; 225 } 226 227 /** 228 * @return A reverse_iterator that refers to @c current - @a __n 229 * 230 * The underlying iterator must be a Random Access Iterator. 231 */ 232 reverse_iterator 233 operator+(difference_type __n) const 234 { return reverse_iterator(current - __n); } 235 236 /** 237 * @return *this 238 * 239 * Moves the underlying iterator backwards @a __n steps. 240 * The underlying iterator must be a Random Access Iterator. 241 */ 242 reverse_iterator& 243 operator+=(difference_type __n) 244 { 245 current -= __n; 246 return *this; 247 } 248 249 /** 250 * @return A reverse_iterator that refers to @c current - @a __n 251 * 252 * The underlying iterator must be a Random Access Iterator. 253 */ 254 reverse_iterator 255 operator-(difference_type __n) const 256 { return reverse_iterator(current + __n); } 257 258 /** 259 * @return *this 260 * 261 * Moves the underlying iterator forwards @a __n steps. 262 * The underlying iterator must be a Random Access Iterator. 263 */ 264 reverse_iterator& 265 operator-=(difference_type __n) 266 { 267 current += __n; 268 return *this; 269 } 270 271 /** 272 * @return The value at @c current - @a __n - 1 273 * 274 * The underlying iterator must be a Random Access Iterator. 275 */ 276 reference 277 operator[](difference_type __n) const 278 { return *(*this + __n); } 279 }; 280 281 //@{ 282 /** 283 * @param __x A %reverse_iterator. 284 * @param __y A %reverse_iterator. 285 * @return A simple bool. 286 * 287 * Reverse iterators forward many operations to their underlying base() 288 * iterators. Others are implemented in terms of one another. 289 * 290 */ 291 template<typename _Iterator> 292 inline bool 293 operator==(const reverse_iterator<_Iterator>& __x, 294 const reverse_iterator<_Iterator>& __y) 295 { return __x.base() == __y.base(); } 296 297 template<typename _Iterator> 298 inline bool 299 operator<(const reverse_iterator<_Iterator>& __x, 300 const reverse_iterator<_Iterator>& __y) 301 { return __y.base() < __x.base(); } 302 303 template<typename _Iterator> 304 inline bool 305 operator!=(const reverse_iterator<_Iterator>& __x, 306 const reverse_iterator<_Iterator>& __y) 307 { return !(__x == __y); } 308 309 template<typename _Iterator> 310 inline bool 311 operator>(const reverse_iterator<_Iterator>& __x, 312 const reverse_iterator<_Iterator>& __y) 313 { return __y < __x; } 314 315 template<typename _Iterator> 316 inline bool 317 operator<=(const reverse_iterator<_Iterator>& __x, 318 const reverse_iterator<_Iterator>& __y) 319 { return !(__y < __x); } 320 321 template<typename _Iterator> 322 inline bool 323 operator>=(const reverse_iterator<_Iterator>& __x, 324 const reverse_iterator<_Iterator>& __y) 325 { return !(__x < __y); } 326 327 template<typename _Iterator> 328 inline typename reverse_iterator<_Iterator>::difference_type 329 operator-(const reverse_iterator<_Iterator>& __x, 330 const reverse_iterator<_Iterator>& __y) 331 { return __y.base() - __x.base(); } 332 333 template<typename _Iterator> 334 inline reverse_iterator<_Iterator> 335 operator+(typename reverse_iterator<_Iterator>::difference_type __n, 336 const reverse_iterator<_Iterator>& __x) 337 { return reverse_iterator<_Iterator>(__x.base() - __n); } 338 339 // _GLIBCXX_RESOLVE_LIB_DEFECTS 340 // DR 280. Comparison of reverse_iterator to const reverse_iterator. 341 template<typename _IteratorL, typename _IteratorR> 342 inline bool 343 operator==(const reverse_iterator<_IteratorL>& __x, 344 const reverse_iterator<_IteratorR>& __y) 345 { return __x.base() == __y.base(); } 346 347 template<typename _IteratorL, typename _IteratorR> 348 inline bool 349 operator<(const reverse_iterator<_IteratorL>& __x, 350 const reverse_iterator<_IteratorR>& __y) 351 { return __y.base() < __x.base(); } 352 353 template<typename _IteratorL, typename _IteratorR> 354 inline bool 355 operator!=(const reverse_iterator<_IteratorL>& __x, 356 const reverse_iterator<_IteratorR>& __y) 357 { return !(__x == __y); } 358 359 template<typename _IteratorL, typename _IteratorR> 360 inline bool 361 operator>(const reverse_iterator<_IteratorL>& __x, 362 const reverse_iterator<_IteratorR>& __y) 363 { return __y < __x; } 364 365 template<typename _IteratorL, typename _IteratorR> 366 inline bool 367 operator<=(const reverse_iterator<_IteratorL>& __x, 368 const reverse_iterator<_IteratorR>& __y) 369 { return !(__y < __x); } 370 371 template<typename _IteratorL, typename _IteratorR> 372 inline bool 373 operator>=(const reverse_iterator<_IteratorL>& __x, 374 const reverse_iterator<_IteratorR>& __y) 375 { return !(__x < __y); } 376 377 template<typename _IteratorL, typename _IteratorR> 378 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 379 // DR 685. 380 inline auto 381 operator-(const reverse_iterator<_IteratorL>& __x, 382 const reverse_iterator<_IteratorR>& __y) 383 -> decltype(__y.base() - __x.base()) 384 #else 385 inline typename reverse_iterator<_IteratorL>::difference_type 386 operator-(const reverse_iterator<_IteratorL>& __x, 387 const reverse_iterator<_IteratorR>& __y) 388 #endif 389 { return __y.base() - __x.base(); } 390 //@} 391 392 // 24.4.2.2.1 back_insert_iterator 393 /** 394 * @brief Turns assignment into insertion. 395 * 396 * These are output iterators, constructed from a container-of-T. 397 * Assigning a T to the iterator appends it to the container using 398 * push_back. 399 * 400 * Tip: Using the back_inserter function to create these iterators can 401 * save typing. 402 */ 403 template<typename _Container> 404 class back_insert_iterator 405 : public iterator<output_iterator_tag, void, void, void, void> 406 { 407 protected: 408 _Container* container; 409 410 public: 411 /// A nested typedef for the type of whatever container you used. 412 typedef _Container container_type; 413 414 /// The only way to create this %iterator is with a container. 415 explicit 416 back_insert_iterator(_Container& __x) : container(&__x) { } 417 418 /** 419 * @param __value An instance of whatever type 420 * container_type::const_reference is; presumably a 421 * reference-to-const T for container<T>. 422 * @return This %iterator, for chained operations. 423 * 424 * This kind of %iterator doesn't really have a @a position in the 425 * container (you can think of the position as being permanently at 426 * the end, if you like). Assigning a value to the %iterator will 427 * always append the value to the end of the container. 428 */ 429 #ifndef __GXX_EXPERIMENTAL_CXX0X__ 430 back_insert_iterator& 431 operator=(typename _Container::const_reference __value) 432 { 433 container->push_back(__value); 434 return *this; 435 } 436 #else 437 back_insert_iterator& 438 operator=(const typename _Container::value_type& __value) 439 { 440 container->push_back(__value); 441 return *this; 442 } 443 444 back_insert_iterator& 445 operator=(typename _Container::value_type&& __value) 446 { 447 container->push_back(std::move(__value)); 448 return *this; 449 } 450 #endif 451 452 /// Simply returns *this. 453 back_insert_iterator& 454 operator*() 455 { return *this; } 456 457 /// Simply returns *this. (This %iterator does not @a move.) 458 back_insert_iterator& 459 operator++() 460 { return *this; } 461 462 /// Simply returns *this. (This %iterator does not @a move.) 463 back_insert_iterator 464 operator++(int) 465 { return *this; } 466 }; 467 468 /** 469 * @param __x A container of arbitrary type. 470 * @return An instance of back_insert_iterator working on @p __x. 471 * 472 * This wrapper function helps in creating back_insert_iterator instances. 473 * Typing the name of the %iterator requires knowing the precise full 474 * type of the container, which can be tedious and impedes generic 475 * programming. Using this function lets you take advantage of automatic 476 * template parameter deduction, making the compiler match the correct 477 * types for you. 478 */ 479 template<typename _Container> 480 inline back_insert_iterator<_Container> 481 back_inserter(_Container& __x) 482 { return back_insert_iterator<_Container>(__x); } 483 484 /** 485 * @brief Turns assignment into insertion. 486 * 487 * These are output iterators, constructed from a container-of-T. 488 * Assigning a T to the iterator prepends it to the container using 489 * push_front. 490 * 491 * Tip: Using the front_inserter function to create these iterators can 492 * save typing. 493 */ 494 template<typename _Container> 495 class front_insert_iterator 496 : public iterator<output_iterator_tag, void, void, void, void> 497 { 498 protected: 499 _Container* container; 500 501 public: 502 /// A nested typedef for the type of whatever container you used. 503 typedef _Container container_type; 504 505 /// The only way to create this %iterator is with a container. 506 explicit front_insert_iterator(_Container& __x) : container(&__x) { } 507 508 /** 509 * @param __value An instance of whatever type 510 * container_type::const_reference is; presumably a 511 * reference-to-const T for container<T>. 512 * @return This %iterator, for chained operations. 513 * 514 * This kind of %iterator doesn't really have a @a position in the 515 * container (you can think of the position as being permanently at 516 * the front, if you like). Assigning a value to the %iterator will 517 * always prepend the value to the front of the container. 518 */ 519 #ifndef __GXX_EXPERIMENTAL_CXX0X__ 520 front_insert_iterator& 521 operator=(typename _Container::const_reference __value) 522 { 523 container->push_front(__value); 524 return *this; 525 } 526 #else 527 front_insert_iterator& 528 operator=(const typename _Container::value_type& __value) 529 { 530 container->push_front(__value); 531 return *this; 532 } 533 534 front_insert_iterator& 535 operator=(typename _Container::value_type&& __value) 536 { 537 container->push_front(std::move(__value)); 538 return *this; 539 } 540 #endif 541 542 /// Simply returns *this. 543 front_insert_iterator& 544 operator*() 545 { return *this; } 546 547 /// Simply returns *this. (This %iterator does not @a move.) 548 front_insert_iterator& 549 operator++() 550 { return *this; } 551 552 /// Simply returns *this. (This %iterator does not @a move.) 553 front_insert_iterator 554 operator++(int) 555 { return *this; } 556 }; 557 558 /** 559 * @param __x A container of arbitrary type. 560 * @return An instance of front_insert_iterator working on @p x. 561 * 562 * This wrapper function helps in creating front_insert_iterator instances. 563 * Typing the name of the %iterator requires knowing the precise full 564 * type of the container, which can be tedious and impedes generic 565 * programming. Using this function lets you take advantage of automatic 566 * template parameter deduction, making the compiler match the correct 567 * types for you. 568 */ 569 template<typename _Container> 570 inline front_insert_iterator<_Container> 571 front_inserter(_Container& __x) 572 { return front_insert_iterator<_Container>(__x); } 573 574 /** 575 * @brief Turns assignment into insertion. 576 * 577 * These are output iterators, constructed from a container-of-T. 578 * Assigning a T to the iterator inserts it in the container at the 579 * %iterator's position, rather than overwriting the value at that 580 * position. 581 * 582 * (Sequences will actually insert a @e copy of the value before the 583 * %iterator's position.) 584 * 585 * Tip: Using the inserter function to create these iterators can 586 * save typing. 587 */ 588 template<typename _Container> 589 class insert_iterator 590 : public iterator<output_iterator_tag, void, void, void, void> 591 { 592 protected: 593 _Container* container; 594 typename _Container::iterator iter; 595 596 public: 597 /// A nested typedef for the type of whatever container you used. 598 typedef _Container container_type; 599 600 /** 601 * The only way to create this %iterator is with a container and an 602 * initial position (a normal %iterator into the container). 603 */ 604 insert_iterator(_Container& __x, typename _Container::iterator __i) 605 : container(&__x), iter(__i) {} 606 607 /** 608 * @param __value An instance of whatever type 609 * container_type::const_reference is; presumably a 610 * reference-to-const T for container<T>. 611 * @return This %iterator, for chained operations. 612 * 613 * This kind of %iterator maintains its own position in the 614 * container. Assigning a value to the %iterator will insert the 615 * value into the container at the place before the %iterator. 616 * 617 * The position is maintained such that subsequent assignments will 618 * insert values immediately after one another. For example, 619 * @code 620 * // vector v contains A and Z 621 * 622 * insert_iterator i (v, ++v.begin()); 623 * i = 1; 624 * i = 2; 625 * i = 3; 626 * 627 * // vector v contains A, 1, 2, 3, and Z 628 * @endcode 629 */ 630 #ifndef __GXX_EXPERIMENTAL_CXX0X__ 631 insert_iterator& 632 operator=(typename _Container::const_reference __value) 633 { 634 iter = container->insert(iter, __value); 635 ++iter; 636 return *this; 637 } 638 #else 639 insert_iterator& 640 operator=(const typename _Container::value_type& __value) 641 { 642 iter = container->insert(iter, __value); 643 ++iter; 644 return *this; 645 } 646 647 insert_iterator& 648 operator=(typename _Container::value_type&& __value) 649 { 650 iter = container->insert(iter, std::move(__value)); 651 ++iter; 652 return *this; 653 } 654 #endif 655 656 /// Simply returns *this. 657 insert_iterator& 658 operator*() 659 { return *this; } 660 661 /// Simply returns *this. (This %iterator does not @a move.) 662 insert_iterator& 663 operator++() 664 { return *this; } 665 666 /// Simply returns *this. (This %iterator does not @a move.) 667 insert_iterator& 668 operator++(int) 669 { return *this; } 670 }; 671 672 /** 673 * @param __x A container of arbitrary type. 674 * @return An instance of insert_iterator working on @p __x. 675 * 676 * This wrapper function helps in creating insert_iterator instances. 677 * Typing the name of the %iterator requires knowing the precise full 678 * type of the container, which can be tedious and impedes generic 679 * programming. Using this function lets you take advantage of automatic 680 * template parameter deduction, making the compiler match the correct 681 * types for you. 682 */ 683 template<typename _Container, typename _Iterator> 684 inline insert_iterator<_Container> 685 inserter(_Container& __x, _Iterator __i) 686 { 687 return insert_iterator<_Container>(__x, 688 typename _Container::iterator(__i)); 689 } 690 691 // @} group iterators 692 693 _GLIBCXX_END_NAMESPACE_VERSION 694 } // namespace 695 696 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) 697 { 698 _GLIBCXX_BEGIN_NAMESPACE_VERSION 699 700 // This iterator adapter is @a normal in the sense that it does not 701 // change the semantics of any of the operators of its iterator 702 // parameter. Its primary purpose is to convert an iterator that is 703 // not a class, e.g. a pointer, into an iterator that is a class. 704 // The _Container parameter exists solely so that different containers 705 // using this template can instantiate different types, even if the 706 // _Iterator parameter is the same. 707 using std::iterator_traits; 708 using std::iterator; 709 template<typename _Iterator, typename _Container> 710 class __normal_iterator 711 { 712 protected: 713 _Iterator _M_current; 714 715 typedef iterator_traits<_Iterator> __traits_type; 716 717 public: 718 typedef _Iterator iterator_type; 719 typedef typename __traits_type::iterator_category iterator_category; 720 typedef typename __traits_type::value_type value_type; 721 typedef typename __traits_type::difference_type difference_type; 722 typedef typename __traits_type::reference reference; 723 typedef typename __traits_type::pointer pointer; 724 725 _GLIBCXX_CONSTEXPR __normal_iterator() : _M_current(_Iterator()) { } 726 727 explicit 728 __normal_iterator(const _Iterator& __i) : _M_current(__i) { } 729 730 // Allow iterator to const_iterator conversion 731 template<typename _Iter> 732 __normal_iterator(const __normal_iterator<_Iter, 733 typename __enable_if< 734 (std::__are_same<_Iter, typename _Container::pointer>::__value), 735 _Container>::__type>& __i) 736 : _M_current(__i.base()) { } 737 738 // Forward iterator requirements 739 reference 740 operator*() const 741 { return *_M_current; } 742 743 pointer 744 operator->() const 745 { return _M_current; } 746 747 __normal_iterator& 748 operator++() 749 { 750 ++_M_current; 751 return *this; 752 } 753 754 __normal_iterator 755 operator++(int) 756 { return __normal_iterator(_M_current++); } 757 758 // Bidirectional iterator requirements 759 __normal_iterator& 760 operator--() 761 { 762 --_M_current; 763 return *this; 764 } 765 766 __normal_iterator 767 operator--(int) 768 { return __normal_iterator(_M_current--); } 769 770 // Random access iterator requirements 771 reference 772 operator[](const difference_type& __n) const 773 { return _M_current[__n]; } 774 775 __normal_iterator& 776 operator+=(const difference_type& __n) 777 { _M_current += __n; return *this; } 778 779 __normal_iterator 780 operator+(const difference_type& __n) const 781 { return __normal_iterator(_M_current + __n); } 782 783 __normal_iterator& 784 operator-=(const difference_type& __n) 785 { _M_current -= __n; return *this; } 786 787 __normal_iterator 788 operator-(const difference_type& __n) const 789 { return __normal_iterator(_M_current - __n); } 790 791 const _Iterator& 792 base() const 793 { return _M_current; } 794 }; 795 796 // Note: In what follows, the left- and right-hand-side iterators are 797 // allowed to vary in types (conceptually in cv-qualification) so that 798 // comparison between cv-qualified and non-cv-qualified iterators be 799 // valid. However, the greedy and unfriendly operators in std::rel_ops 800 // will make overload resolution ambiguous (when in scope) if we don't 801 // provide overloads whose operands are of the same type. Can someone 802 // remind me what generic programming is about? -- Gaby 803 804 // Forward iterator requirements 805 template<typename _IteratorL, typename _IteratorR, typename _Container> 806 inline bool 807 operator==(const __normal_iterator<_IteratorL, _Container>& __lhs, 808 const __normal_iterator<_IteratorR, _Container>& __rhs) 809 { return __lhs.base() == __rhs.base(); } 810 811 template<typename _Iterator, typename _Container> 812 inline bool 813 operator==(const __normal_iterator<_Iterator, _Container>& __lhs, 814 const __normal_iterator<_Iterator, _Container>& __rhs) 815 { return __lhs.base() == __rhs.base(); } 816 817 template<typename _IteratorL, typename _IteratorR, typename _Container> 818 inline bool 819 operator!=(const __normal_iterator<_IteratorL, _Container>& __lhs, 820 const __normal_iterator<_IteratorR, _Container>& __rhs) 821 { return __lhs.base() != __rhs.base(); } 822 823 template<typename _Iterator, typename _Container> 824 inline bool 825 operator!=(const __normal_iterator<_Iterator, _Container>& __lhs, 826 const __normal_iterator<_Iterator, _Container>& __rhs) 827 { return __lhs.base() != __rhs.base(); } 828 829 // Random access iterator requirements 830 template<typename _IteratorL, typename _IteratorR, typename _Container> 831 inline bool 832 operator<(const __normal_iterator<_IteratorL, _Container>& __lhs, 833 const __normal_iterator<_IteratorR, _Container>& __rhs) 834 { return __lhs.base() < __rhs.base(); } 835 836 template<typename _Iterator, typename _Container> 837 inline bool 838 operator<(const __normal_iterator<_Iterator, _Container>& __lhs, 839 const __normal_iterator<_Iterator, _Container>& __rhs) 840 { return __lhs.base() < __rhs.base(); } 841 842 template<typename _IteratorL, typename _IteratorR, typename _Container> 843 inline bool 844 operator>(const __normal_iterator<_IteratorL, _Container>& __lhs, 845 const __normal_iterator<_IteratorR, _Container>& __rhs) 846 { return __lhs.base() > __rhs.base(); } 847 848 template<typename _Iterator, typename _Container> 849 inline bool 850 operator>(const __normal_iterator<_Iterator, _Container>& __lhs, 851 const __normal_iterator<_Iterator, _Container>& __rhs) 852 { return __lhs.base() > __rhs.base(); } 853 854 template<typename _IteratorL, typename _IteratorR, typename _Container> 855 inline bool 856 operator<=(const __normal_iterator<_IteratorL, _Container>& __lhs, 857 const __normal_iterator<_IteratorR, _Container>& __rhs) 858 { return __lhs.base() <= __rhs.base(); } 859 860 template<typename _Iterator, typename _Container> 861 inline bool 862 operator<=(const __normal_iterator<_Iterator, _Container>& __lhs, 863 const __normal_iterator<_Iterator, _Container>& __rhs) 864 { return __lhs.base() <= __rhs.base(); } 865 866 template<typename _IteratorL, typename _IteratorR, typename _Container> 867 inline bool 868 operator>=(const __normal_iterator<_IteratorL, _Container>& __lhs, 869 const __normal_iterator<_IteratorR, _Container>& __rhs) 870 { return __lhs.base() >= __rhs.base(); } 871 872 template<typename _Iterator, typename _Container> 873 inline bool 874 operator>=(const __normal_iterator<_Iterator, _Container>& __lhs, 875 const __normal_iterator<_Iterator, _Container>& __rhs) 876 { return __lhs.base() >= __rhs.base(); } 877 878 // _GLIBCXX_RESOLVE_LIB_DEFECTS 879 // According to the resolution of DR179 not only the various comparison 880 // operators but also operator- must accept mixed iterator/const_iterator 881 // parameters. 882 template<typename _IteratorL, typename _IteratorR, typename _Container> 883 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 884 // DR 685. 885 inline auto 886 operator-(const __normal_iterator<_IteratorL, _Container>& __lhs, 887 const __normal_iterator<_IteratorR, _Container>& __rhs) 888 -> decltype(__lhs.base() - __rhs.base()) 889 #else 890 inline typename __normal_iterator<_IteratorL, _Container>::difference_type 891 operator-(const __normal_iterator<_IteratorL, _Container>& __lhs, 892 const __normal_iterator<_IteratorR, _Container>& __rhs) 893 #endif 894 { return __lhs.base() - __rhs.base(); } 895 896 template<typename _Iterator, typename _Container> 897 inline typename __normal_iterator<_Iterator, _Container>::difference_type 898 operator-(const __normal_iterator<_Iterator, _Container>& __lhs, 899 const __normal_iterator<_Iterator, _Container>& __rhs) 900 { return __lhs.base() - __rhs.base(); } 901 902 template<typename _Iterator, typename _Container> 903 inline __normal_iterator<_Iterator, _Container> 904 operator+(typename __normal_iterator<_Iterator, _Container>::difference_type 905 __n, const __normal_iterator<_Iterator, _Container>& __i) 906 { return __normal_iterator<_Iterator, _Container>(__i.base() + __n); } 907 908 _GLIBCXX_END_NAMESPACE_VERSION 909 } // namespace 910 911 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 912 913 namespace std _GLIBCXX_VISIBILITY(default) 914 { 915 _GLIBCXX_BEGIN_NAMESPACE_VERSION 916 917 /** 918 * @addtogroup iterators 919 * @{ 920 */ 921 922 // 24.4.3 Move iterators 923 /** 924 * Class template move_iterator is an iterator adapter with the same 925 * behavior as the underlying iterator except that its dereference 926 * operator implicitly converts the value returned by the underlying 927 * iterator's dereference operator to an rvalue reference. Some 928 * generic algorithms can be called with move iterators to replace 929 * copying with moving. 930 */ 931 template<typename _Iterator> 932 class move_iterator 933 { 934 protected: 935 _Iterator _M_current; 936 937 typedef iterator_traits<_Iterator> __traits_type; 938 939 public: 940 typedef _Iterator iterator_type; 941 typedef typename __traits_type::iterator_category iterator_category; 942 typedef typename __traits_type::value_type value_type; 943 typedef typename __traits_type::difference_type difference_type; 944 // NB: DR 680. 945 typedef _Iterator pointer; 946 typedef value_type&& reference; 947 948 move_iterator() 949 : _M_current() { } 950 951 explicit 952 move_iterator(iterator_type __i) 953 : _M_current(__i) { } 954 955 template<typename _Iter> 956 move_iterator(const move_iterator<_Iter>& __i) 957 : _M_current(__i.base()) { } 958 959 iterator_type 960 base() const 961 { return _M_current; } 962 963 reference 964 operator*() const 965 { return std::move(*_M_current); } 966 967 pointer 968 operator->() const 969 { return _M_current; } 970 971 move_iterator& 972 operator++() 973 { 974 ++_M_current; 975 return *this; 976 } 977 978 move_iterator 979 operator++(int) 980 { 981 move_iterator __tmp = *this; 982 ++_M_current; 983 return __tmp; 984 } 985 986 move_iterator& 987 operator--() 988 { 989 --_M_current; 990 return *this; 991 } 992 993 move_iterator 994 operator--(int) 995 { 996 move_iterator __tmp = *this; 997 --_M_current; 998 return __tmp; 999 } 1000 1001 move_iterator 1002 operator+(difference_type __n) const 1003 { return move_iterator(_M_current + __n); } 1004 1005 move_iterator& 1006 operator+=(difference_type __n) 1007 { 1008 _M_current += __n; 1009 return *this; 1010 } 1011 1012 move_iterator 1013 operator-(difference_type __n) const 1014 { return move_iterator(_M_current - __n); } 1015 1016 move_iterator& 1017 operator-=(difference_type __n) 1018 { 1019 _M_current -= __n; 1020 return *this; 1021 } 1022 1023 reference 1024 operator[](difference_type __n) const 1025 { return std::move(_M_current[__n]); } 1026 }; 1027 1028 // Note: See __normal_iterator operators note from Gaby to understand 1029 // why there are always 2 versions for most of the move_iterator 1030 // operators. 1031 template<typename _IteratorL, typename _IteratorR> 1032 inline bool 1033 operator==(const move_iterator<_IteratorL>& __x, 1034 const move_iterator<_IteratorR>& __y) 1035 { return __x.base() == __y.base(); } 1036 1037 template<typename _Iterator> 1038 inline bool 1039 operator==(const move_iterator<_Iterator>& __x, 1040 const move_iterator<_Iterator>& __y) 1041 { return __x.base() == __y.base(); } 1042 1043 template<typename _IteratorL, typename _IteratorR> 1044 inline bool 1045 operator!=(const move_iterator<_IteratorL>& __x, 1046 const move_iterator<_IteratorR>& __y) 1047 { return !(__x == __y); } 1048 1049 template<typename _Iterator> 1050 inline bool 1051 operator!=(const move_iterator<_Iterator>& __x, 1052 const move_iterator<_Iterator>& __y) 1053 { return !(__x == __y); } 1054 1055 template<typename _IteratorL, typename _IteratorR> 1056 inline bool 1057 operator<(const move_iterator<_IteratorL>& __x, 1058 const move_iterator<_IteratorR>& __y) 1059 { return __x.base() < __y.base(); } 1060 1061 template<typename _Iterator> 1062 inline bool 1063 operator<(const move_iterator<_Iterator>& __x, 1064 const move_iterator<_Iterator>& __y) 1065 { return __x.base() < __y.base(); } 1066 1067 template<typename _IteratorL, typename _IteratorR> 1068 inline bool 1069 operator<=(const move_iterator<_IteratorL>& __x, 1070 const move_iterator<_IteratorR>& __y) 1071 { return !(__y < __x); } 1072 1073 template<typename _Iterator> 1074 inline bool 1075 operator<=(const move_iterator<_Iterator>& __x, 1076 const move_iterator<_Iterator>& __y) 1077 { return !(__y < __x); } 1078 1079 template<typename _IteratorL, typename _IteratorR> 1080 inline bool 1081 operator>(const move_iterator<_IteratorL>& __x, 1082 const move_iterator<_IteratorR>& __y) 1083 { return __y < __x; } 1084 1085 template<typename _Iterator> 1086 inline bool 1087 operator>(const move_iterator<_Iterator>& __x, 1088 const move_iterator<_Iterator>& __y) 1089 { return __y < __x; } 1090 1091 template<typename _IteratorL, typename _IteratorR> 1092 inline bool 1093 operator>=(const move_iterator<_IteratorL>& __x, 1094 const move_iterator<_IteratorR>& __y) 1095 { return !(__x < __y); } 1096 1097 template<typename _Iterator> 1098 inline bool 1099 operator>=(const move_iterator<_Iterator>& __x, 1100 const move_iterator<_Iterator>& __y) 1101 { return !(__x < __y); } 1102 1103 // DR 685. 1104 template<typename _IteratorL, typename _IteratorR> 1105 inline auto 1106 operator-(const move_iterator<_IteratorL>& __x, 1107 const move_iterator<_IteratorR>& __y) 1108 -> decltype(__x.base() - __y.base()) 1109 { return __x.base() - __y.base(); } 1110 1111 template<typename _Iterator> 1112 inline auto 1113 operator-(const move_iterator<_Iterator>& __x, 1114 const move_iterator<_Iterator>& __y) 1115 -> decltype(__x.base() - __y.base()) 1116 { return __x.base() - __y.base(); } 1117 1118 template<typename _Iterator> 1119 inline move_iterator<_Iterator> 1120 operator+(typename move_iterator<_Iterator>::difference_type __n, 1121 const move_iterator<_Iterator>& __x) 1122 { return __x + __n; } 1123 1124 template<typename _Iterator> 1125 inline move_iterator<_Iterator> 1126 make_move_iterator(_Iterator __i) 1127 { return move_iterator<_Iterator>(__i); } 1128 1129 template<typename _Iterator, typename _ReturnType 1130 = typename conditional<__move_if_noexcept_cond 1131 <typename iterator_traits<_Iterator>::value_type>::value, 1132 _Iterator, move_iterator<_Iterator>>::type> 1133 inline _ReturnType 1134 __make_move_if_noexcept_iterator(_Iterator __i) 1135 { return _ReturnType(__i); } 1136 1137 // @} group iterators 1138 1139 _GLIBCXX_END_NAMESPACE_VERSION 1140 } // namespace 1141 1142 #define _GLIBCXX_MAKE_MOVE_ITERATOR(_Iter) std::make_move_iterator(_Iter) 1143 #define _GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(_Iter) \ 1144 std::__make_move_if_noexcept_iterator(_Iter) 1145 #else 1146 #define _GLIBCXX_MAKE_MOVE_ITERATOR(_Iter) (_Iter) 1147 #define _GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(_Iter) (_Iter) 1148 #endif // __GXX_EXPERIMENTAL_CXX0X__ 1149 1150 #endif 1151
