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

   1 // Multiset implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2004 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
  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_multiset.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 _MULTISET_H
  62 #define _MULTISET_H 1
  63
  64 #include <bits/concept_check.h>
  65
  66 namespace __gnu_norm
  67 {
  68
  69   // Forward declaration of operators < and ==, needed for friend declaration.
  70   template <class _Key, class _Compare = less<_Key>,
  71             class _Alloc = allocator<_Key> >
  72     class multiset;
  73
  74   template <class _Key, class _Compare, class _Alloc>
  75     inline bool
  76     operator==(const multiset<_Key,_Compare,_Alloc>& __x,
  77                const multiset<_Key,_Compare,_Alloc>& __y);
  78
  79   template <class _Key, class _Compare, class _Alloc>
  80     inline bool
  81     operator<(const multiset<_Key,_Compare,_Alloc>& __x,
  82               const multiset<_Key,_Compare,_Alloc>& __y);
  83
  84   /**
  85    *  @brief A standard container made up of elements, which can be retrieved
  86    *  in logarithmic time.
  87    *
  88    *  @ingroup Containers
  89    *  @ingroup Assoc_containers
  90    *
  91    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
  92    *  <a href="tables.html#66">reversible container</a>, and an
  93    *  <a href="tables.html#69">associative container</a> (using equivalent
  94    *  keys).  For a @c multiset<Key> the key_type and value_type are Key.
  95    *
  96    *  Multisets support bidirectional iterators.
  97    *
  98    *  @if maint
  99    *  The private tree data is declared exactly the same way for set and
 100    *  multiset; the distinction is made entirely in how the tree functions are
 101    *  called (*_unique versus *_equal, same as the standard).
 102    *  @endif
 103   */
 104   template <class _Key, class _Compare, class _Alloc>
 105     class multiset
 106     {
 107       // concept requirements
 108       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
 109       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
 110                                 _BinaryFunctionConcept)
 111
 112     public:
 113       // typedefs:
 114       typedef _Key     key_type;
 115       typedef _Key     value_type;
 116       typedef _Compare key_compare;
 117       typedef _Compare value_compare;
 118
 119     private:
 120       /// @if maint  This turns a red-black tree into a [multi]set.  @endif
 121       typedef _Rb_tree<key_type, value_type,
 122                        _Identity<value_type>, key_compare, _Alloc> _Rep_type;
 123       /// @if maint  The actual tree structure.  @endif
 124       _Rep_type _M_t;
 125
 126     public:
 127       typedef typename _Alloc::pointer pointer;
 128       typedef typename _Alloc::const_pointer const_pointer;
 129       typedef typename _Alloc::reference reference;
 130       typedef typename _Alloc::const_reference const_reference;
 131       typedef typename _Rep_type::const_iterator iterator;
 132       typedef typename _Rep_type::const_iterator const_iterator;
 133       typedef typename _Rep_type::const_reverse_iterator reverse_iterator;
 134       typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
 135       typedef typename _Rep_type::size_type size_type;
 136       typedef typename _Rep_type::difference_type difference_type;
 137       typedef typename _Rep_type::allocator_type allocator_type;
 138
 139     // allocation/deallocation
 140
 141     /**
 142      *  @brief  Default constructor creates no elements.
 143      */
 144       multiset()
 145       : _M_t(_Compare(), allocator_type()) { }
 146
 147       explicit
 148       multiset(const _Compare& __comp,
 149                const allocator_type& __a = allocator_type())
 150       : _M_t(__comp, __a) { }
 151
 152       /**
 153        *  @brief  Builds a %multiset from a range.
 154        *  @param  first  An input iterator.
 155        *  @param  last  An input iterator.
 156        *
 157        *  Create a %multiset consisting of copies of the elements from
 158        *  [first,last).  This is linear in N if the range is already sorted,
 159        *  and NlogN otherwise (where N is distance(first,last)).
 160        */
 161       template <class _InputIterator>
 162         multiset(_InputIterator __first, _InputIterator __last)
 163         : _M_t(_Compare(), allocator_type())
 164         { _M_t.insert_equal(__first, __last); }
 165
 166       /**
 167        *  @brief  Builds a %multiset from a range.
 168        *  @param  first  An input iterator.
 169        *  @param  last  An input iterator.
 170        *  @param  comp  A comparison functor.
 171        *  @param  a  An allocator object.
 172        *
 173        *  Create a %multiset consisting of copies of the elements from
 174        *  [first,last).  This is linear in N if the range is already sorted,
 175        *  and NlogN otherwise (where N is distance(first,last)).
 176        */
 177       template <class _InputIterator>
 178         multiset(_InputIterator __first, _InputIterator __last,
 179                  const _Compare& __comp,
 180                  const allocator_type& __a = allocator_type())
 181         : _M_t(__comp, __a)
 182         { _M_t.insert_equal(__first, __last); }
 183
 184       /**
 185        *  @brief  %Multiset copy constructor.
 186        *  @param  x  A %multiset of identical element and allocator types.
 187        *
 188        *  The newly-created %multiset uses a copy of the allocation object used
 189        *  by @a x.
 190        */
 191       multiset(const multiset<_Key,_Compare,_Alloc>& __x)
 192       : _M_t(__x._M_t) { }
 193
 194       /**
 195        *  @brief  %Multiset assignment operator.
 196        *  @param  x  A %multiset of identical element and allocator types.
 197        *
 198        *  All the elements of @a x are copied, but unlike the copy constructor,
 199        *  the allocator object is not copied.
 200        */
 201       multiset<_Key,_Compare,_Alloc>&
 202       operator=(const multiset<_Key,_Compare,_Alloc>& __x)
 203       {
 204         _M_t = __x._M_t;
 205         return *this;
 206       }
 207
 208       // accessors:
 209
 210       ///  Returns the comparison object.
 211       key_compare
 212       key_comp() const
 213       { return _M_t.key_comp(); }
 214       ///  Returns the comparison object.
 215       value_compare
 216       value_comp() const
 217       { return _M_t.key_comp(); }
 218       ///  Returns the memory allocation object.
 219       allocator_type
 220       get_allocator() const
 221       { return _M_t.get_allocator(); }
 222
 223       /**
 224        *  Returns a read/write iterator that points to the first element in the
 225        *  %multiset.  Iteration is done in ascending order according to the
 226        *  keys.
 227        */
 228       iterator
 229       begin() const
 230       { return _M_t.begin(); }
 231
 232       /**
 233        *  Returns a read/write iterator that points one past the last element in
 234        *  the %multiset.  Iteration is done in ascending order according to the
 235        *  keys.
 236        */
 237       iterator
 238       end() const
 239       { return _M_t.end(); }
 240
 241       /**
 242        *  Returns a read/write reverse iterator that points to the last element
 243        *  in the %multiset.  Iteration is done in descending order according to
 244        *  the keys.
 245        */
 246       reverse_iterator
 247       rbegin() const
 248       { return _M_t.rbegin(); }
 249
 250       /**
 251        *  Returns a read/write reverse iterator that points to the last element
 252        *  in the %multiset.  Iteration is done in descending order according to
 253        *  the keys.
 254        */
 255       reverse_iterator
 256       rend() const
 257       { return _M_t.rend(); }
 258
 259       ///  Returns true if the %set is empty.
 260       bool
 261       empty() const
 262       { return _M_t.empty(); }
 263
 264       ///  Returns the size of the %set.
 265       size_type
 266       size() const
 267       { return _M_t.size(); }
 268
 269       ///  Returns the maximum size of the %set.
 270       size_type
 271       max_size() const
 272       { return _M_t.max_size(); }
 273
 274       /**
 275        *  @brief  Swaps data with another %multiset.
 276        *  @param  x  A %multiset of the same element and allocator types.
 277        *
 278        *  This exchanges the elements between two multisets in constant time.
 279        *  (It is only swapping a pointer, an integer, and an instance of the @c
 280        *  Compare type (which itself is often stateless and empty), so it should
 281        *  be quite fast.)
 282        *  Note that the global std::swap() function is specialized such that
 283        *  std::swap(s1,s2) will feed to this function.
 284        */
 285       void
 286       swap(multiset<_Key,_Compare,_Alloc>& __x)
 287       { _M_t.swap(__x._M_t); }
 288
 289       // insert/erase
 290       /**
 291        *  @brief Inserts an element into the %multiset.
 292        *  @param  x  Element to be inserted.
 293        *  @return An iterator that points to the inserted element.
 294        *
 295        *  This function inserts an element into the %multiset.  Contrary
 296        *  to a std::set the %multiset does not rely on unique keys and thus
 297        *  multiple copies of the same element can be inserted.
 298        *
 299        *  Insertion requires logarithmic time.
 300        */
 301       iterator
 302       insert(const value_type& __x)
 303       { return _M_t.insert_equal(__x); }
 304
 305       /**
 306        *  @brief Inserts an element into the %multiset.
 307        *  @param  position  An iterator that serves as a hint as to where the
 308        *                    element should be inserted.
 309        *  @param  x  Element to be inserted.
 310        *  @return An iterator that points to the inserted element.
 311        *
 312        *  This function inserts an element into the %multiset.  Contrary
 313        *  to a std::set the %multiset does not rely on unique keys and thus
 314        *  multiple copies of the same element can be inserted.
 315        *
 316        *  Note that the first parameter is only a hint and can potentially
 317        *  improve the performance of the insertion process.  A bad hint would
 318        *  cause no gains in efficiency.
 319        *
 320        *  See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4
 321        *  for more on "hinting".
 322        *
 323        *  Insertion requires logarithmic time (if the hint is not taken).
 324        */
 325       iterator
 326       insert(iterator __position, const value_type& __x)
 327       {
 328         typedef typename _Rep_type::iterator _Rep_iterator;
 329         return _M_t.insert_equal((_Rep_iterator&)__position, __x);
 330       }
 331
 332       /**
 333        *  @brief A template function that attemps to insert a range of elements.
 334        *  @param  first  Iterator pointing to the start of the range to be
 335        *                 inserted.
 336        *  @param  last  Iterator pointing to the end of the range.
 337        *
 338        *  Complexity similar to that of the range constructor.
 339        */
 340       template <class _InputIterator>
 341         void
 342         insert(_InputIterator __first, _InputIterator __last)
 343         { _M_t.insert_equal(__first, __last); }
 344
 345       /**
 346        *  @brief Erases an element from a %multiset.
 347        *  @param  position  An iterator pointing to the element to be erased.
 348        *
 349        *  This function erases an element, pointed to by the given iterator,
 350        *  from a %multiset.  Note that this function only erases the element,
 351        *  and that if the element is itself a pointer, the pointed-to memory is
 352        *  not touched in any way.  Managing the pointer is the user's
 353        *  responsibilty.
 354        */
 355       void
 356       erase(iterator __position)
 357       {
 358         typedef typename _Rep_type::iterator _Rep_iterator;
 359         _M_t.erase((_Rep_iterator&)__position);
 360       }
 361
 362       /**
 363        *  @brief Erases elements according to the provided key.
 364        *  @param  x  Key of element to be erased.
 365        *  @return  The number of elements erased.
 366        *
 367        *  This function erases all elements located by the given key from a
 368        *  %multiset.
 369        *  Note that this function only erases the element, and that if
 370        *  the element is itself a pointer, the pointed-to memory is not touched
 371        *  in any way.  Managing the pointer is the user's responsibilty.
 372        */
 373       size_type
 374       erase(const key_type& __x)
 375       { return _M_t.erase(__x); }
 376
 377       /**
 378        *  @brief Erases a [first,last) range of elements from a %multiset.
 379        *  @param  first  Iterator pointing to the start of the range to be
 380        *                 erased.
 381        *  @param  last  Iterator pointing to the end of the range to be erased.
 382        *
 383        *  This function erases a sequence of elements from a %multiset.
 384        *  Note that this function only erases the elements, and that if
 385        *  the elements themselves are pointers, the pointed-to memory is not
 386        *  touched in any way.  Managing the pointer is the user's responsibilty.
 387        */
 388       void
 389       erase(iterator __first, iterator __last)
 390       {
 391         typedef typename _Rep_type::iterator _Rep_iterator;
 392         _M_t.erase((_Rep_iterator&)__first, (_Rep_iterator&)__last);
 393       }
 394
 395       /**
 396        *  Erases all elements in a %multiset.  Note that this function only
 397        *  erases the elements, and that if the elements themselves are pointers,
 398        *  the pointed-to memory is not touched in any way.  Managing the pointer
 399        *  is the user's responsibilty.
 400        */
 401       void
 402       clear()
 403       { _M_t.clear(); }
 404
 405       // multiset operations:
 406
 407       /**
 408        *  @brief Finds the number of elements with given key.
 409        *  @param  x  Key of elements to be located.
 410        *  @return Number of elements with specified key.
 411        */
 412       size_type
 413       count(const key_type& __x) const
 414       { return _M_t.count(__x); }
 415
 416       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 417       // 214.  set::find() missing const overload
 418       //@{
 419       /**
 420        *  @brief Tries to locate an element in a %set.
 421        *  @param  x  Element to be located.
 422        *  @return  Iterator pointing to sought-after element, or end() if not
 423        *           found.
 424        *
 425        *  This function takes a key and tries to locate the element with which
 426        *  the key matches.  If successful the function returns an iterator
 427        *  pointing to the sought after element.  If unsuccessful it returns the
 428        *  past-the-end ( @c end() ) iterator.
 429        */
 430       iterator
 431       find(const key_type& __x)
 432       { return _M_t.find(__x); }
 433
 434       const_iterator
 435       find(const key_type& __x) const
 436       { return _M_t.find(__x); }
 437       //@}
 438
 439       //@{
 440       /**
 441        *  @brief Finds the beginning of a subsequence matching given key.
 442        *  @param  x  Key to be located.
 443        *  @return  Iterator pointing to first element equal to or greater
 444        *           than key, or end().
 445        *
 446        *  This function returns the first element of a subsequence of elements
 447        *  that matches the given key.  If unsuccessful it returns an iterator
 448        *  pointing to the first element that has a greater value than given key
 449        *  or end() if no such element exists.
 450        */
 451       iterator
 452       lower_bound(const key_type& __x)
 453       { return _M_t.lower_bound(__x); }
 454
 455       const_iterator
 456       lower_bound(const key_type& __x) const
 457       { return _M_t.lower_bound(__x); }
 458       //@}
 459
 460       //@{
 461       /**
 462        *  @brief Finds the end of a subsequence matching given key.
 463        *  @param  x  Key to be located.
 464        *  @return Iterator pointing to the first element
 465        *          greater than key, or end().
 466        */
 467       iterator
 468       upper_bound(const key_type& __x)
 469       { return _M_t.upper_bound(__x); }
 470
 471       const_iterator
 472       upper_bound(const key_type& __x) const
 473       { return _M_t.upper_bound(__x); }
 474       //@}
 475
 476       //@{
 477       /**
 478        *  @brief Finds a subsequence matching given key.
 479        *  @param  x  Key to be located.
 480        *  @return  Pair of iterators that possibly points to the subsequence
 481        *           matching given key.
 482        *
 483        *  This function is equivalent to
 484        *  @code
 485        *    std::make_pair(c.lower_bound(val),
 486        *                   c.upper_bound(val))
 487        *  @endcode
 488        *  (but is faster than making the calls separately).
 489        *
 490        *  This function probably only makes sense for multisets.
 491        */
 492       pair<iterator,iterator>
 493       equal_range(const key_type& __x)
 494       { return _M_t.equal_range(__x); }
 495
 496       pair<const_iterator,const_iterator>
 497       equal_range(const key_type& __x) const
 498       { return _M_t.equal_range(__x); }
 499
 500       template <class _K1, class _C1, class _A1>
 501         friend bool
 502         operator== (const multiset<_K1,_C1,_A1>&,
 503                     const multiset<_K1,_C1,_A1>&);
 504
 505       template <class _K1, class _C1, class _A1>
 506         friend bool
 507         operator< (const multiset<_K1,_C1,_A1>&,
 508                    const multiset<_K1,_C1,_A1>&);
 509     };
 510
 511   /**
 512    *  @brief  Multiset equality comparison.
 513    *  @param  x  A %multiset.
 514    *  @param  y  A %multiset of the same type as @a x.
 515    *  @return  True iff the size and elements of the multisets are equal.
 516    *
 517    *  This is an equivalence relation.  It is linear in the size of the
 518    *  multisets.
 519    *  Multisets are considered equivalent if their sizes are equal, and if
 520    *  corresponding elements compare equal.
 521   */
 522   template <class _Key, class _Compare, class _Alloc>
 523     inline bool
 524     operator==(const multiset<_Key,_Compare,_Alloc>& __x,
 525                const multiset<_Key,_Compare,_Alloc>& __y)
 526     { return __x._M_t == __y._M_t; }
 527
 528   /**
 529    *  @brief  Multiset ordering relation.
 530    *  @param  x  A %multiset.
 531    *  @param  y  A %multiset of the same type as @a x.
 532    *  @return  True iff @a x is lexicographically less than @a y.
 533    *
 534    *  This is a total ordering relation.  It is linear in the size of the
 535    *  maps.  The elements must be comparable with @c <.
 536    *
 537    *  See std::lexicographical_compare() for how the determination is made.
 538   */
 539   template <class _Key, class _Compare, class _Alloc>
 540     inline bool
 541     operator<(const multiset<_Key,_Compare,_Alloc>& __x,
 542               const multiset<_Key,_Compare,_Alloc>& __y)
 543     { return __x._M_t < __y._M_t; }
 544
 545   ///  Returns !(x == y).
 546   template <class _Key, class _Compare, class _Alloc>
 547     inline bool
 548     operator!=(const multiset<_Key,_Compare,_Alloc>& __x,
 549                const multiset<_Key,_Compare,_Alloc>& __y)
 550     { return !(__x == __y); }
 551
 552   ///  Returns y < x.
 553   template <class _Key, class _Compare, class _Alloc>
 554     inline bool
 555     operator>(const multiset<_Key,_Compare,_Alloc>& __x,
 556               const multiset<_Key,_Compare,_Alloc>& __y)
 557     { return __y < __x; }
 558
 559   ///  Returns !(y < x)
 560   template <class _Key, class _Compare, class _Alloc>
 561     inline bool
 562     operator<=(const multiset<_Key,_Compare,_Alloc>& __x,
 563                const multiset<_Key,_Compare,_Alloc>& __y)
 564     { return !(__y < __x); }
 565
 566   ///  Returns !(x < y)
 567   template <class _Key, class _Compare, class _Alloc>
 568     inline bool
 569     operator>=(const multiset<_Key,_Compare,_Alloc>& __x,
 570                const multiset<_Key,_Compare,_Alloc>& __y)
 571     { return !(__x < __y); }
 572
 573   /// See std::multiset::swap().
 574   template <class _Key, class _Compare, class _Alloc>
 575     inline void
 576     swap(multiset<_Key,_Compare,_Alloc>& __x,
 577          multiset<_Key,_Compare,_Alloc>& __y)
 578     { __x.swap(__y); }
 579
 580 } // namespace __gnu_norm
 581
 582 #endif /* _MULTISET_H */