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 /* NOTE: This is an internal header file, included by other STL headers.
  57  *   You should not attempt to use it directly.
  58  */
  59
  60 #ifndef __SGI_STL_INTERNAL_ITERATOR_H
  61 #define __SGI_STL_INTERNAL_ITERATOR_H
  62
  63 namespace std
  64 {
  65   // 24.4.1 Reverse iterators
  66   template<typename _Iterator>
  67     class reverse_iterator
  68       : public iterator<typename iterator_traits<_Iterator>::iterator_category,
  69                         typename iterator_traits<_Iterator>::value_type,
  70                         typename iterator_traits<_Iterator>::difference_type,
  71                         typename iterator_traits<_Iterator>::pointer,
  72                         typename iterator_traits<_Iterator>::reference>
  73     {
  74     protected:
  75       _Iterator current;
  76
  77     public:
  78       typedef _Iterator                                        iterator_type;
  79       typedef typename iterator_traits<_Iterator>::difference_type
  80                                                                difference_type;
  81       typedef typename iterator_traits<_Iterator>::reference   reference;
  82       typedef typename iterator_traits<_Iterator>::pointer     pointer;
  83
  84     public:
  85       reverse_iterator() {}
  86
  87       explicit
  88       reverse_iterator(iterator_type __x) : current(__x) {}
  89
  90       reverse_iterator(const reverse_iterator& __x)
  91         : current(__x.current) { }
  92
  93       template<typename _Iter>
  94         reverse_iterator(const reverse_iterator<_Iter>& __x)
  95         : current(__x.base()) {}
  96
  97       iterator_type
  98       base() const { return current; }
  99
 100       reference
 101       operator*() const
 102       {
 103         _Iterator __tmp = current;
 104         return *--__tmp;
 105       }
 106
 107       pointer
 108       operator->() const { return &(operator*()); }
 109
 110       reverse_iterator&
 111       operator++()
 112       {
 113         --current;
 114         return *this;
 115       }
 116
 117       reverse_iterator
 118       operator++(int)
 119       {
 120         reverse_iterator __tmp = *this;
 121         --current;
 122         return __tmp;
 123       }
 124
 125       reverse_iterator&
 126       operator--()
 127       {
 128         ++current;
 129         return *this;
 130       }
 131
 132       reverse_iterator operator--(int)
 133       {
 134         reverse_iterator __tmp = *this;
 135         ++current;
 136         return __tmp;
 137       }
 138
 139       reverse_iterator
 140       operator+(difference_type __n) const
 141       { return reverse_iterator(current - __n); }
 142
 143       reverse_iterator&
 144       operator+=(difference_type __n)
 145       {
 146         current -= __n;
 147         return *this;
 148       }
 149
 150       reverse_iterator
 151       operator-(difference_type __n) const
 152       { return reverse_iterator(current + __n); }
 153
 154       reverse_iterator&
 155       operator-=(difference_type __n)
 156       {
 157         _M_current += __n;
 158         return *this;
 159       }
 160
 161       reference
 162       operator[](difference_type __n) const { return *(*this + __n); }
 163     };
 164
 165   template<typename _Iterator>
 166     inline bool
 167     operator==(const reverse_iterator<_Iterator>& __x,
 168                const reverse_iterator<_Iterator>& __y)
 169     { return __x.base() == __y.base(); }
 170
 171   template<typename _Iterator>
 172     inline bool
 173     operator<(const reverse_iterator<_Iterator>& __x,
 174               const reverse_iterator<_Iterator>& __y)
 175     { return __y.base() < __x.base(); }
 176
 177   template<typename _Iterator>
 178     inline bool
 179     operator!=(const reverse_iterator<_Iterator>& __x,
 180                const reverse_iterator<_Iterator>& __y)
 181     { return !(__x == __y); }
 182
 183   template<typename _Iterator>
 184     inline bool
 185     operator>(const reverse_iterator<_Iterator>& __x,
 186               const reverse_iterator<_Iterator>& __y)
 187     { return __y < __x; }
 188
 189   template<typename _Iterator>
 190     inline bool
 191     operator<=(const reverse_iterator<_Iterator>& __x,
 192                 const reverse_iterator<_Iterator>& __y)
 193     { return !(__y < __x); }
 194
 195   template<typename _Iterator>
 196     inline bool
 197     operator>=(const reverse_iterator<_Iterator>& __x,
 198                const reverse_iterator<_Iterator>& __y)
 199     { return !(__x < __y); }
 200
 201   template<typename _Iterator>
 202     inline typename reverse_iterator<_Iterator>::difference_type
 203     operator-(const reverse_iterator<_Iterator>& __x,
 204               const reverse_iterator<_Iterator>& __y)
 205     { return __y.base() - __x.base(); }
 206
 207   template<typename _Iterator>
 208     inline reverse_iterator<_Iterator>
 209     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
 210               const reverse_iterator<_Iterator>& __x)
 211     { return reverse_iterator<_Iterator>(__x.base() - __n); }
 212
 213   // 24.4.2.2.1 back_insert_iterator
 214   template<typename _Container>
 215   class back_insert_iterator
 216     : public iterator<output_iterator_tag, void, void, void, void>
 217     {
 218     protected:
 219       _Container* container;
 220
 221     public:
 222       typedef _Container          container_type;
 223
 224       explicit
 225       back_insert_iterator(_Container& __x) : container(&__x) {}
 226
 227       back_insert_iterator&
 228       operator=(typename _Container::const_reference __value)
 229       {
 230         container->push_back(__value);
 231         return *this;
 232       }
 233
 234       back_insert_iterator&
 235       operator*() { return *this; }
 236
 237       back_insert_iterator&
 238       operator++() { return *this; }
 239
 240       back_insert_iterator
 241       operator++(int) { return *this; }
 242     };
 243
 244   template<typename _Container>
 245     inline back_insert_iterator<_Container>
 246     back_inserter(_Container& __x)
 247     { return back_insert_iterator<_Container>(__x); }
 248
 249   template<typename _Container>
 250     class front_insert_iterator
 251       : public iterator<output_iterator_tag, void, void, void, void>
 252     {
 253     protected:
 254       _Container* container;
 255
 256     public:
 257       typedef _Container          container_type;
 258
 259       explicit front_insert_iterator(_Container& __x) : container(&__x) {}
 260
 261       front_insert_iterator&
 262       operator=(typename _Container::const_reference __value)
 263       {
 264         container->push_front(__value);
 265         return *this;
 266       }
 267
 268       front_insert_iterator&
 269       operator*() { return *this; }
 270
 271       front_insert_iterator&
 272       operator++() { return *this; }
 273
 274       front_insert_iterator
 275       operator++(int) { return *this; }
 276     };
 277
 278   template<typename _Container>
 279   inline front_insert_iterator<_Container> front_inserter(_Container& __x)
 280   { return front_insert_iterator<_Container>(__x); }
 281
 282   template<typename _Container>
 283     class insert_iterator
 284       : public iterator<output_iterator_tag, void, void, void, void>
 285     {
 286     protected:
 287       _Container* container;
 288       typename _Container::iterator iter;
 289
 290     public:
 291       typedef _Container          container_type;
 292
 293       insert_iterator(_Container& __x, typename _Container::iterator __i)
 294         : container(&__x), iter(__i) {}
 295
 296       insert_iterator&
 297       operator=(const typename _Container::const_reference __value)
 298       {
 299         iter = container->insert(iter, __value);
 300         ++iter;
 301         return *this;
 302       }
 303
 304       insert_iterator&
 305       operator*() { return *this; }
 306
 307       insert_iterator&
 308       operator++() { return *this; }
 309
 310       insert_iterator&
 311       operator++(int) { return *this; }
 312     };
 313
 314   template<typename _Container, typename _Iterator>
 315     inline
 316     insert_iterator<_Container> inserter(_Container& __x, _Iterator __i)
 317     {
 318       typedef typename _Container::iterator __iter;
 319       return insert_iterator<_Container>(__x, __iter(__i));
 320     }
 321
 322   // This iterator adapter is 'normal' in the sense that it does not
 323   // change the semantics of any of the operators of its iterator
 324   // parameter.  Its primary purpose is to convert an iterator that is
 325   // not a class, e.g. a pointer, into an iterator that is a class.
 326   // The _Container parameter exists solely so that different containers
 327   // using this template can instantiate different types, even if the
 328   // _Iterator parameter is the same.
 329   template<typename _Iterator, typename _Container>
 330     class __normal_iterator
 331       : public iterator<typename iterator_traits<_Iterator>::iterator_category,
 332                         typename iterator_traits<_Iterator>::value_type,
 333                         typename iterator_traits<_Iterator>::difference_type,
 334                         typename iterator_traits<_Iterator>::pointer,
 335                         typename iterator_traits<_Iterator>::reference>
 336     {
 337     protected:
 338       _Iterator _M_current;
 339
 340     public:
 341       typedef typename iterator_traits<_Iterator>::difference_type
 342                                                                difference_type;
 343       typedef typename iterator_traits<_Iterator>::reference   reference;
 344       typedef typename iterator_traits<_Iterator>::pointer     pointer;
 345
 346       __normal_iterator() : _M_current(_Iterator()) { }
 347
 348       explicit
 349       __normal_iterator(const _Iterator& __i) : _M_current(__i) { }
 350
 351       // Allow iterator to const_iterator conversion
 352       template<typename _Iter>
 353       inline __normal_iterator(const __normal_iterator<_Iter, _Container>& __i)
 354         : _M_current(__i.base()) { }
 355
 356       // Forward iterator requirements
 357       reference
 358       operator*() const { return *_M_current; }
 359
 360       pointer
 361       operator->() const { return _M_current; }
 362
 363       __normal_iterator&
 364       operator++() { ++_M_current; return *this; }
 365
 366       __normal_iterator
 367       operator++(int) { return __normal_iterator(_M_current++); }
 368
 369       // Bidirectional iterator requirements
 370       __normal_iterator&
 371       operator--() { --_M_current; return *this; }
 372
 373       __normal_iterator
 374       operator--(int) { return __normal_iterator(_M_current--); }
 375
 376       // Random access iterator requirements
 377       reference
 378       operator[](const difference_type& __n) const
 379       { return _M_current[__n]; }
 380
 381       __normal_iterator&
 382       operator+=(const difference_type& __n)
 383       { _M_current += __n; return *this; }
 384
 385       __normal_iterator
 386       operator+(const difference_type& __n) const
 387       { return __normal_iterator(_M_current + __n); }
 388
 389       __normal_iterator&
 390       operator-=(const difference_type& __n)
 391       { _M_current -= __n; return *this; }
 392
 393       __normal_iterator
 394       operator-(const difference_type& __n) const
 395       { return __normal_iterator(_M_current - __n); }
 396
 397       difference_type
 398       operator-(const __normal_iterator& __i) const
 399       { return _M_current - __i._M_current; }
 400
 401       const _Iterator&
 402       base() const { return _M_current; }
 403     };
 404
 405   // Forward iterator requirements
 406   template<typename _IteratorL, typename _IteratorR, typename _Container>
 407   inline bool
 408   operator==(const __normal_iterator<_IteratorL, _Container>& __lhs,
 409              const __normal_iterator<_IteratorR, _Container>& __rhs)
 410   { return __lhs.base() == __rhs.base(); }
 411
 412   template<typename _IteratorL, typename _IteratorR, typename _Container>
 413   inline bool
 414   operator!=(const __normal_iterator<_IteratorL, _Container>& __lhs,
 415              const __normal_iterator<_IteratorR, _Container>& __rhs)
 416   { return !(__lhs == __rhs); }
 417
 418   // Random access iterator requirements
 419   template<typename _IteratorL, typename _IteratorR, typename _Container>
 420   inline bool
 421   operator<(const __normal_iterator<_IteratorL, _Container>& __lhs,
 422             const __normal_iterator<_IteratorR, _Container>& __rhs)
 423   { return __lhs.base() < __rhs.base(); }
 424
 425   template<typename _IteratorL, typename _IteratorR, typename _Container>
 426   inline bool
 427   operator>(const __normal_iterator<_IteratorL, _Container>& __lhs,
 428             const __normal_iterator<_IteratorR, _Container>& __rhs)
 429   { return __rhs < __lhs; }
 430
 431   template<typename _IteratorL, typename _IteratorR, typename _Container>
 432   inline bool
 433   operator<=(const __normal_iterator<_IteratorL, _Container>& __lhs,
 434              const __normal_iterator<_IteratorR, _Container>& __rhs)
 435   { return !(__rhs < __lhs); }
 436
 437   template<typename _IteratorL, typename _IteratorR, typename _Container>
 438   inline bool
 439   operator>=(const __normal_iterator<_IteratorL, _Container>& __lhs,
 440              const __normal_iterator<_IteratorR, _Container>& __rhs)
 441   { return !(__lhs < __rhs); }
 442
 443   template<typename _Iterator, typename _Container>
 444   inline __normal_iterator<_Iterator, _Container>
 445   operator+(typename __normal_iterator<_Iterator, _Container>::difference_type __n,
 446             const __normal_iterator<_Iterator, _Container>& __i)
 447   { return __normal_iterator<_Iterator, _Container>(__i.base() + __n); }
 448 } // namespace std
 449
 450 #endif
 451
 452 // Local Variables:
 453 // mode:C++
 454 // End: