libstdc++-v3/include/bits/stl_iterator.h

   1 // Iterators -*- C++ -*-
   2
   3 // Copyright (C) 2001 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 /*
  31  *
  32  * Copyright (c) 1994
  33  * Hewlett-Packard Company
  34  *
  35  * Permission to use, copy, modify, distribute and sell this software
  36  * and its documentation for any purpose is hereby granted without fee,
  37  * provided that the above copyright notice appear in all copies and
  38  * that both that copyright notice and this permission notice appear
  39  * in supporting documentation.  Hewlett-Packard Company makes no
  40  * representations about the suitability of this software for any
  41  * purpose.  It is provided "as is" without express or implied warranty.
  42  *
  43  *
  44  * Copyright (c) 1996-1998
  45  * Silicon Graphics Computer Systems, Inc.
  46  *
  47  * Permission to use, copy, modify, distribute and sell this software
  48  * and its documentation for any purpose is hereby granted without fee,
  49  * provided that the above copyright notice appear in all copies and
  50  * that both that copyright notice and this permission notice appear
  51  * in supporting documentation.  Silicon Graphics makes no
  52  * representations about the suitability of this software for any
  53  * purpose.  It is provided "as is" without express or implied warranty.
  54  */
  55
  56 /** @file stl_iterator.h
  57  *  This is an internal header file, included by other library headers.
  58  *  You should not attempt to use it directly.
  59  */
  60
  61 #ifndef __GLIBCPP_INTERNAL_ITERATOR_H
  62 #define __GLIBCPP_INTERNAL_ITERATOR_H
  63
  64 namespace std
  65 {
  66   // 24.4.1 Reverse iterators
  67   template<typename _Iterator>
  68     class reverse_iterator
  69       : public iterator<typename iterator_traits<_Iterator>::iterator_category,
  70                         typename iterator_traits<_Iterator>::value_type,
  71                         typename iterator_traits<_Iterator>::difference_type,
  72                         typename iterator_traits<_Iterator>::pointer,
  73                         typename iterator_traits<_Iterator>::reference>
  74     {
  75     protected:
  76       _Iterator current;
  77
  78     public:
  79       typedef _Iterator                                        iterator_type;
  80       typedef typename iterator_traits<_Iterator>::difference_type
  81                                                                difference_type;
  82       typedef typename iterator_traits<_Iterator>::reference   reference;
  83       typedef typename iterator_traits<_Iterator>::pointer     pointer;
  84
  85     public:
  86       reverse_iterator() {}
  87
  88       explicit
  89       reverse_iterator(iterator_type __x) : current(__x) {}
  90
  91       reverse_iterator(const reverse_iterator& __x)
  92         : current(__x.current) { }
  93
  94       template<typename _Iter>
  95         reverse_iterator(const reverse_iterator<_Iter>& __x)
  96         : current(__x.base()) {}
  97
  98       iterator_type
  99       base() const { return current; }
 100
 101       reference
 102       operator*() const
 103       {
 104         _Iterator __tmp = current;
 105         return *--__tmp;
 106       }
 107
 108       pointer
 109       operator->() const { return &(operator*()); }
 110
 111       reverse_iterator&
 112       operator++()
 113       {
 114         --current;
 115         return *this;
 116       }
 117
 118       reverse_iterator
 119       operator++(int)
 120       {
 121         reverse_iterator __tmp = *this;
 122         --current;
 123         return __tmp;
 124       }
 125
 126       reverse_iterator&
 127       operator--()
 128       {
 129         ++current;
 130         return *this;
 131       }
 132
 133       reverse_iterator operator--(int)
 134       {
 135         reverse_iterator __tmp = *this;
 136         ++current;
 137         return __tmp;
 138       }
 139
 140       reverse_iterator
 141       operator+(difference_type __n) const
 142       { return reverse_iterator(current - __n); }
 143
 144       reverse_iterator&
 145       operator+=(difference_type __n)
 146       {
 147         current -= __n;
 148         return *this;
 149       }
 150
 151       reverse_iterator
 152       operator-(difference_type __n) const
 153       { return reverse_iterator(current + __n); }
 154
 155       reverse_iterator&
 156       operator-=(difference_type __n)
 157       {
 158         _M_current += __n;
 159         return *this;
 160       }
 161
 162       reference
 163       operator[](difference_type __n) const { return *(*this + __n); }
 164     };
 165
 166   template<typename _Iterator>
 167     inline bool
 168     operator==(const reverse_iterator<_Iterator>& __x,
 169                const reverse_iterator<_Iterator>& __y)
 170     { return __x.base() == __y.base(); }
 171
 172   template<typename _Iterator>
 173     inline bool
 174     operator<(const reverse_iterator<_Iterator>& __x,
 175               const reverse_iterator<_Iterator>& __y)
 176     { return __y.base() < __x.base(); }
 177
 178   template<typename _Iterator>
 179     inline bool
 180     operator!=(const reverse_iterator<_Iterator>& __x,
 181                const reverse_iterator<_Iterator>& __y)
 182     { return !(__x == __y); }
 183
 184   template<typename _Iterator>
 185     inline bool
 186     operator>(const reverse_iterator<_Iterator>& __x,
 187               const reverse_iterator<_Iterator>& __y)
 188     { return __y < __x; }
 189
 190   template<typename _Iterator>
 191     inline bool
 192     operator<=(const reverse_iterator<_Iterator>& __x,
 193                 const reverse_iterator<_Iterator>& __y)
 194     { return !(__y < __x); }
 195
 196   template<typename _Iterator>
 197     inline bool
 198     operator>=(const reverse_iterator<_Iterator>& __x,
 199                const reverse_iterator<_Iterator>& __y)
 200     { return !(__x < __y); }
 201
 202   template<typename _Iterator>
 203     inline typename reverse_iterator<_Iterator>::difference_type
 204     operator-(const reverse_iterator<_Iterator>& __x,
 205               const reverse_iterator<_Iterator>& __y)
 206     { return __y.base() - __x.base(); }
 207
 208   template<typename _Iterator>
 209     inline reverse_iterator<_Iterator>
 210     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
 211               const reverse_iterator<_Iterator>& __x)
 212     { return reverse_iterator<_Iterator>(__x.base() - __n); }
 213
 214   // 24.4.2.2.1 back_insert_iterator
 215   template<typename _Container>
 216   class back_insert_iterator
 217     : public iterator<output_iterator_tag, void, void, void, void>
 218     {
 219     protected:
 220       _Container* container;
 221
 222     public:
 223       typedef _Container          container_type;
 224
 225       explicit
 226       back_insert_iterator(_Container& __x) : container(&__x) {}
 227
 228       back_insert_iterator&
 229       operator=(typename _Container::const_reference __value)
 230       {
 231         container->push_back(__value);
 232         return *this;
 233       }
 234
 235       back_insert_iterator&
 236       operator*() { return *this; }
 237
 238       back_insert_iterator&
 239       operator++() { return *this; }
 240
 241       back_insert_iterator
 242       operator++(int) { return *this; }
 243     };
 244
 245   template<typename _Container>
 246     inline back_insert_iterator<_Container>
 247     back_inserter(_Container& __x)
 248     { return back_insert_iterator<_Container>(__x); }
 249
 250   template<typename _Container>
 251     class front_insert_iterator
 252       : public iterator<output_iterator_tag, void, void, void, void>
 253     {
 254     protected:
 255       _Container* container;
 256
 257     public:
 258       typedef _Container          container_type;
 259
 260       explicit front_insert_iterator(_Container& __x) : container(&__x) {}
 261
 262       front_insert_iterator&
 263       operator=(typename _Container::const_reference __value)
 264       {
 265         container->push_front(__value);
 266         return *this;
 267       }
 268
 269       front_insert_iterator&
 270       operator*() { return *this; }
 271
 272       front_insert_iterator&
 273       operator++() { return *this; }
 274
 275       front_insert_iterator
 276       operator++(int) { return *this; }
 277     };
 278
 279   template<typename _Container>
 280   inline front_insert_iterator<_Container> front_inserter(_Container& __x)
 281   { return front_insert_iterator<_Container>(__x); }
 282
 283   template<typename _Container>
 284     class insert_iterator
 285       : public iterator<output_iterator_tag, void, void, void, void>
 286     {
 287     protected:
 288       _Container* container;
 289       typename _Container::iterator iter;
 290
 291     public:
 292       typedef _Container          container_type;
 293
 294       insert_iterator(_Container& __x, typename _Container::iterator __i)
 295         : container(&__x), iter(__i) {}
 296
 297       insert_iterator&
 298       operator=(const typename _Container::const_reference __value)
 299       {
 300         iter = container->insert(iter, __value);
 301         ++iter;
 302         return *this;
 303       }
 304
 305       insert_iterator&
 306       operator*() { return *this; }
 307
 308       insert_iterator&
 309       operator++() { return *this; }
 310
 311       insert_iterator&
 312       operator++(int) { return *this; }
 313     };
 314
 315   template<typename _Container, typename _Iterator>
 316     inline
 317     insert_iterator<_Container> inserter(_Container& __x, _Iterator __i)
 318     {
 319       typedef typename _Container::iterator __iter;
 320       return insert_iterator<_Container>(__x, __iter(__i));
 321     }
 322
 323   // This iterator adapter is 'normal' in the sense that it does not
 324   // change the semantics of any of the operators of its iterator
 325   // parameter.  Its primary purpose is to convert an iterator that is
 326   // not a class, e.g. a pointer, into an iterator that is a class.
 327   // The _Container parameter exists solely so that different containers
 328   // using this template can instantiate different types, even if the
 329   // _Iterator parameter is the same.
 330   template<typename _Iterator, typename _Container>
 331     class __normal_iterator
 332       : public iterator<typename iterator_traits<_Iterator>::iterator_category,
 333                         typename iterator_traits<_Iterator>::value_type,
 334                         typename iterator_traits<_Iterator>::difference_type,
 335                         typename iterator_traits<_Iterator>::pointer,
 336                         typename iterator_traits<_Iterator>::reference>
 337     {
 338     protected:
 339       _Iterator _M_current;
 340
 341     public:
 342       typedef typename iterator_traits<_Iterator>::difference_type
 343                                                                difference_type;
 344       typedef typename iterator_traits<_Iterator>::reference   reference;
 345       typedef typename iterator_traits<_Iterator>::pointer     pointer;
 346
 347       __normal_iterator() : _M_current(_Iterator()) { }
 348
 349       explicit
 350       __normal_iterator(const _Iterator& __i) : _M_current(__i) { }
 351
 352       // Allow iterator to const_iterator conversion
 353       template<typename _Iter>
 354       inline __normal_iterator(const __normal_iterator<_Iter, _Container>& __i)
 355         : _M_current(__i.base()) { }
 356
 357       // Forward iterator requirements
 358       reference
 359       operator*() const { return *_M_current; }
 360
 361       pointer
 362       operator->() const { return _M_current; }
 363
 364       __normal_iterator&
 365       operator++() { ++_M_current; return *this; }
 366
 367       __normal_iterator
 368       operator++(int) { return __normal_iterator(_M_current++); }
 369
 370       // Bidirectional iterator requirements
 371       __normal_iterator&
 372       operator--() { --_M_current; return *this; }
 373
 374       __normal_iterator
 375       operator--(int) { return __normal_iterator(_M_current--); }
 376
 377       // Random access iterator requirements
 378       reference
 379       operator[](const difference_type& __n) const
 380       { return _M_current[__n]; }
 381
 382       __normal_iterator&
 383       operator+=(const difference_type& __n)
 384       { _M_current += __n; return *this; }
 385
 386       __normal_iterator
 387       operator+(const difference_type& __n) const
 388       { return __normal_iterator(_M_current + __n); }
 389
 390       __normal_iterator&
 391       operator-=(const difference_type& __n)
 392       { _M_current -= __n; return *this; }
 393
 394       __normal_iterator
 395       operator-(const difference_type& __n) const
 396       { return __normal_iterator(_M_current - __n); }
 397
 398       difference_type
 399       operator-(const __normal_iterator& __i) const
 400       { return _M_current - __i._M_current; }
 401
 402       const _Iterator&
 403       base() const { return _M_current; }
 404     };
 405
 406   // Forward iterator requirements
 407   template<typename _IteratorL, typename _IteratorR, typename _Container>
 408   inline bool
 409   operator==(const __normal_iterator<_IteratorL, _Container>& __lhs,
 410              const __normal_iterator<_IteratorR, _Container>& __rhs)
 411   { return __lhs.base() == __rhs.base(); }
 412
 413   template<typename _IteratorL, typename _IteratorR, typename _Container>
 414   inline bool
 415   operator!=(const __normal_iterator<_IteratorL, _Container>& __lhs,
 416              const __normal_iterator<_IteratorR, _Container>& __rhs)
 417   { return !(__lhs == __rhs); }
 418
 419   // Random access iterator requirements
 420   template<typename _IteratorL, typename _IteratorR, typename _Container>
 421   inline bool
 422   operator<(const __normal_iterator<_IteratorL, _Container>& __lhs,
 423             const __normal_iterator<_IteratorR, _Container>& __rhs)
 424   { return __lhs.base() < __rhs.base(); }
 425
 426   template<typename _IteratorL, typename _IteratorR, typename _Container>
 427   inline bool
 428   operator>(const __normal_iterator<_IteratorL, _Container>& __lhs,
 429             const __normal_iterator<_IteratorR, _Container>& __rhs)
 430   { return __rhs < __lhs; }
 431
 432   template<typename _IteratorL, typename _IteratorR, typename _Container>
 433   inline bool
 434   operator<=(const __normal_iterator<_IteratorL, _Container>& __lhs,
 435              const __normal_iterator<_IteratorR, _Container>& __rhs)
 436   { return !(__rhs < __lhs); }
 437
 438   template<typename _IteratorL, typename _IteratorR, typename _Container>
 439   inline bool
 440   operator>=(const __normal_iterator<_IteratorL, _Container>& __lhs,
 441              const __normal_iterator<_IteratorR, _Container>& __rhs)
 442   { return !(__lhs < __rhs); }
 443
 444   template<typename _Iterator, typename _Container>
 445   inline __normal_iterator<_Iterator, _Container>
 446   operator+(typename __normal_iterator<_Iterator, _Container>::difference_type __n,
 447             const __normal_iterator<_Iterator, _Container>& __i)
 448   { return __normal_iterator<_Iterator, _Container>(__i.base() + __n); }
 449 } // namespace std
 450
 451 #endif
 452
 453 // Local Variables:
 454 // mode:C++
 455 // End: