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

   1 // Multiset implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2004, 2005, 2006 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  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 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD)
  67
  68   // Forward declaration of operators < and ==, needed for friend declaration.
  69   template <class _Key, class _Compare = std::less<_Key>,
  70             class _Alloc = std::allocator<_Key> >
  71     class multiset;
  72
  73   template <class _Key, class _Compare, class _Alloc>
  74     inline bool
  75     operator==(const multiset<_Key, _Compare, _Alloc>& __x,
  76                const multiset<_Key, _Compare, _Alloc>& __y);
  77
  78   template <class _Key, class _Compare, class _Alloc>
  79     inline bool
  80     operator<(const multiset<_Key, _Compare, _Alloc>& __x,
  81               const multiset<_Key, _Compare, _Alloc>& __y);
  82
  83   /**
  84    *  @brief A standard container made up of elements, which can be retrieved
  85    *  in logarithmic time.
  86    *
  87    *  @ingroup Containers
  88    *  @ingroup Assoc_containers
  89    *
  90    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
  91    *  <a href="tables.html#66">reversible container</a>, and an
  92    *  <a href="tables.html#69">associative container</a> (using equivalent
  93    *  keys).  For a @c multiset<Key> the key_type and value_type are Key.
  94    *
  95    *  Multisets support bidirectional iterators.
  96    *
  97    *  @if maint
  98    *  The private tree data is declared exactly the same way for set and
  99    *  multiset; the distinction is made entirely in how the tree functions are
 100    *  called (*_unique versus *_equal, same as the standard).
 101    *  @endif
 102   */
 103   template <class _Key, class _Compare, class _Alloc>
 104     class multiset
 105     {
 106       // concept requirements
 107       typedef typename _Alloc::value_type                   _Alloc_value_type;
 108       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
 109       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
 110                                 _BinaryFunctionConcept)
 111       __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
 112
 113     public:
 114       // typedefs:
 115       typedef _Key     key_type;
 116       typedef _Key     value_type;
 117       typedef _Compare key_compare;
 118       typedef _Compare value_compare;
 119       typedef _Alloc   allocator_type;
 120
 121     private:
 122       /// @if maint  This turns a red-black tree into a [multi]set.  @endif
 123       typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type;
 124
 125       typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
 126                        key_compare, _Key_alloc_type> _Rep_type;
 127       /// @if maint  The actual tree structure.  @endif
 128       _Rep_type _M_t;
 129
 130     public:
 131       typedef typename _Key_alloc_type::pointer             pointer;
 132       typedef typename _Key_alloc_type::const_pointer       const_pointer;
 133       typedef typename _Key_alloc_type::reference           reference;
 134       typedef typename _Key_alloc_type::const_reference     const_reference;
 135       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 136       // DR 103. set::iterator is required to be modifiable,
 137       // but this allows modification of keys.
 138       typedef typename _Rep_type::const_iterator            iterator;
 139       typedef typename _Rep_type::const_iterator            const_iterator;
 140       typedef typename _Rep_type::const_reverse_iterator    reverse_iterator;
 141       typedef typename _Rep_type::const_reverse_iterator    const_reverse_iterator;
 142       typedef typename _Rep_type::size_type                 size_type;
 143       typedef typename _Rep_type::difference_type           difference_type;
 144
 145       // allocation/deallocation
 146
 147       /**
 148        *  @brief  Default constructor creates no elements.
 149        */
 150       multiset()
 151       : _M_t(_Compare(), allocator_type()) { }
 152
 153       explicit
 154       multiset(const _Compare& __comp,
 155                const allocator_type& __a = allocator_type())
 156       : _M_t(__comp, __a) { }
 157
 158       /**
 159        *  @brief  Builds a %multiset from a range.
 160        *  @param  first  An input iterator.
 161        *  @param  last  An input iterator.
 162        *
 163        *  Create a %multiset consisting of copies of the elements from
 164        *  [first,last).  This is linear in N if the range is already sorted,
 165        *  and NlogN otherwise (where N is distance(first,last)).
 166        */
 167       template <class _InputIterator>
 168         multiset(_InputIterator __first, _InputIterator __last)
 169         : _M_t(_Compare(), allocator_type())
 170         { _M_t._M_insert_equal(__first, __last); }
 171
 172       /**
 173        *  @brief  Builds a %multiset from a range.
 174        *  @param  first  An input iterator.
 175        *  @param  last  An input iterator.
 176        *  @param  comp  A comparison functor.
 177        *  @param  a  An allocator object.
 178        *
 179        *  Create a %multiset consisting of copies of the elements from
 180        *  [first,last).  This is linear in N if the range is already sorted,
 181        *  and NlogN otherwise (where N is distance(first,last)).
 182        */
 183       template <class _InputIterator>
 184         multiset(_InputIterator __first, _InputIterator __last,
 185                  const _Compare& __comp,
 186                  const allocator_type& __a = allocator_type())
 187         : _M_t(__comp, __a)
 188         { _M_t._M_insert_equal(__first, __last); }
 189
 190       /**
 191        *  @brief  %Multiset copy constructor.
 192        *  @param  x  A %multiset of identical element and allocator types.
 193        *
 194        *  The newly-created %multiset uses a copy of the allocation object used
 195        *  by @a x.
 196        */
 197       multiset(const multiset<_Key,_Compare,_Alloc>& __x)
 198       : _M_t(__x._M_t) { }
 199
 200       /**
 201        *  @brief  %Multiset assignment operator.
 202        *  @param  x  A %multiset of identical element and allocator types.
 203        *
 204        *  All the elements of @a x are copied, but unlike the copy constructor,
 205        *  the allocator object is not copied.
 206        */
 207       multiset<_Key,_Compare,_Alloc>&
 208       operator=(const multiset<_Key,_Compare,_Alloc>& __x)
 209       {
 210         _M_t = __x._M_t;
 211         return *this;
 212       }
 213
 214       // accessors:
 215
 216       ///  Returns the comparison object.
 217       key_compare
 218       key_comp() const
 219       { return _M_t.key_comp(); }
 220       ///  Returns the comparison object.
 221       value_compare
 222       value_comp() const
 223       { return _M_t.key_comp(); }
 224       ///  Returns the memory allocation object.
 225       allocator_type
 226       get_allocator() const
 227       { return _M_t.get_allocator(); }
 228
 229       /**
 230        *  Returns a read/write iterator that points to the first element in the
 231        *  %multiset.  Iteration is done in ascending order according to the
 232        *  keys.
 233        */
 234       iterator
 235       begin() const
 236       { return _M_t.begin(); }
 237
 238       /**
 239        *  Returns a read/write iterator that points one past the last element in
 240        *  the %multiset.  Iteration is done in ascending order according to the
 241        *  keys.
 242        */
 243       iterator
 244       end() const
 245       { return _M_t.end(); }
 246
 247       /**
 248        *  Returns a read/write reverse iterator that points to the last element
 249        *  in the %multiset.  Iteration is done in descending order according to
 250        *  the keys.
 251        */
 252       reverse_iterator
 253       rbegin() const
 254       { return _M_t.rbegin(); }
 255
 256       /**
 257        *  Returns a read/write reverse iterator that points to the last element
 258        *  in the %multiset.  Iteration is done in descending order according to
 259        *  the keys.
 260        */
 261       reverse_iterator
 262       rend() const
 263       { return _M_t.rend(); }
 264
 265       ///  Returns true if the %set is empty.
 266       bool
 267       empty() const
 268       { return _M_t.empty(); }
 269
 270       ///  Returns the size of the %set.
 271       size_type
 272       size() const
 273       { return _M_t.size(); }
 274
 275       ///  Returns the maximum size of the %set.
 276       size_type
 277       max_size() const
 278       { return _M_t.max_size(); }
 279
 280       /**
 281        *  @brief  Swaps data with another %multiset.
 282        *  @param  x  A %multiset of the same element and allocator types.
 283        *
 284        *  This exchanges the elements between two multisets in constant time.
 285        *  (It is only swapping a pointer, an integer, and an instance of the @c
 286        *  Compare type (which itself is often stateless and empty), so it should
 287        *  be quite fast.)
 288        *  Note that the global std::swap() function is specialized such that
 289        *  std::swap(s1,s2) will feed to this function.
 290        */
 291       void
 292       swap(multiset<_Key, _Compare, _Alloc>& __x)
 293       { _M_t.swap(__x._M_t); }
 294
 295       // insert/erase
 296       /**
 297        *  @brief Inserts an element into the %multiset.
 298        *  @param  x  Element to be inserted.
 299        *  @return An iterator that points to the inserted element.
 300        *
 301        *  This function inserts an element into the %multiset.  Contrary
 302        *  to a std::set the %multiset does not rely on unique keys and thus
 303        *  multiple copies of the same element can be inserted.
 304        *
 305        *  Insertion requires logarithmic time.
 306        */
 307       iterator
 308       insert(const value_type& __x)
 309       { return _M_t._M_insert_equal(__x); }
 310
 311       /**
 312        *  @brief Inserts an element into the %multiset.
 313        *  @param  position  An iterator that serves as a hint as to where the
 314        *                    element should be inserted.
 315        *  @param  x  Element to be inserted.
 316        *  @return An iterator that points to the inserted element.
 317        *
 318        *  This function inserts an element into the %multiset.  Contrary
 319        *  to a std::set the %multiset does not rely on unique keys and thus
 320        *  multiple copies of the same element can be inserted.
 321        *
 322        *  Note that the first parameter is only a hint and can potentially
 323        *  improve the performance of the insertion process.  A bad hint would
 324        *  cause no gains in efficiency.
 325        *
 326        *  See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4
 327        *  for more on "hinting".
 328        *
 329        *  Insertion requires logarithmic time (if the hint is not taken).
 330        */
 331       iterator
 332       insert(iterator __position, const value_type& __x)
 333       { return _M_t._M_insert_equal(__position, __x); }
 334
 335       /**
 336        *  @brief A template function that attemps to insert a range of elements.
 337        *  @param  first  Iterator pointing to the start of the range to be
 338        *                 inserted.
 339        *  @param  last  Iterator pointing to the end of the range.
 340        *
 341        *  Complexity similar to that of the range constructor.
 342        */
 343       template <class _InputIterator>
 344         void
 345         insert(_InputIterator __first, _InputIterator __last)
 346         { _M_t._M_insert_equal(__first, __last); }
 347
 348       /**
 349        *  @brief Erases an element from a %multiset.
 350        *  @param  position  An iterator pointing to the element to be erased.
 351        *
 352        *  This function erases an element, pointed to by the given iterator,
 353        *  from a %multiset.  Note that this function only erases the element,
 354        *  and that if the element is itself a pointer, the pointed-to memory is
 355        *  not touched in any way.  Managing the pointer is the user's
 356        *  responsibilty.
 357        */
 358       void
 359       erase(iterator __position)
 360       { _M_t.erase(__position); }
 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       { _M_t.erase(__first, __last); }
 391
 392       /**
 393        *  Erases all elements in a %multiset.  Note that this function only
 394        *  erases the elements, and that if the elements themselves are pointers,
 395        *  the pointed-to memory is not touched in any way.  Managing the pointer
 396        *  is the user's responsibilty.
 397        */
 398       void
 399       clear()
 400       { _M_t.clear(); }
 401
 402       // multiset operations:
 403
 404       /**
 405        *  @brief Finds the number of elements with given key.
 406        *  @param  x  Key of elements to be located.
 407        *  @return Number of elements with specified key.
 408        */
 409       size_type
 410       count(const key_type& __x) const
 411       { return _M_t.count(__x); }
 412
 413       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 414       // 214.  set::find() missing const overload
 415       //@{
 416       /**
 417        *  @brief Tries to locate an element in a %set.
 418        *  @param  x  Element to be located.
 419        *  @return  Iterator pointing to sought-after element, or end() if not
 420        *           found.
 421        *
 422        *  This function takes a key and tries to locate the element with which
 423        *  the key matches.  If successful the function returns an iterator
 424        *  pointing to the sought after element.  If unsuccessful it returns the
 425        *  past-the-end ( @c end() ) iterator.
 426        */
 427       iterator
 428       find(const key_type& __x)
 429       { return _M_t.find(__x); }
 430
 431       const_iterator
 432       find(const key_type& __x) const
 433       { return _M_t.find(__x); }
 434       //@}
 435
 436       //@{
 437       /**
 438        *  @brief Finds the beginning of a subsequence matching given key.
 439        *  @param  x  Key to be located.
 440        *  @return  Iterator pointing to first element equal to or greater
 441        *           than key, or end().
 442        *
 443        *  This function returns the first element of a subsequence of elements
 444        *  that matches the given key.  If unsuccessful it returns an iterator
 445        *  pointing to the first element that has a greater value than given key
 446        *  or end() if no such element exists.
 447        */
 448       iterator
 449       lower_bound(const key_type& __x)
 450       { return _M_t.lower_bound(__x); }
 451
 452       const_iterator
 453       lower_bound(const key_type& __x) const
 454       { return _M_t.lower_bound(__x); }
 455       //@}
 456
 457       //@{
 458       /**
 459        *  @brief Finds the end of a subsequence matching given key.
 460        *  @param  x  Key to be located.
 461        *  @return Iterator pointing to the first element
 462        *          greater than key, or end().
 463        */
 464       iterator
 465       upper_bound(const key_type& __x)
 466       { return _M_t.upper_bound(__x); }
 467
 468       const_iterator
 469       upper_bound(const key_type& __x) const
 470       { return _M_t.upper_bound(__x); }
 471       //@}
 472
 473       //@{
 474       /**
 475        *  @brief Finds a subsequence matching given key.
 476        *  @param  x  Key to be located.
 477        *  @return  Pair of iterators that possibly points to the subsequence
 478        *           matching given key.
 479        *
 480        *  This function is equivalent to
 481        *  @code
 482        *    std::make_pair(c.lower_bound(val),
 483        *                   c.upper_bound(val))
 484        *  @endcode
 485        *  (but is faster than making the calls separately).
 486        *
 487        *  This function probably only makes sense for multisets.
 488        */
 489       std::pair<iterator, iterator>
 490       equal_range(const key_type& __x)
 491       { return _M_t.equal_range(__x); }
 492
 493       std::pair<const_iterator, const_iterator>
 494       equal_range(const key_type& __x) const
 495       { return _M_t.equal_range(__x); }
 496
 497       template <class _K1, class _C1, class _A1>
 498         friend bool
 499         operator== (const multiset<_K1, _C1, _A1>&,
 500                     const multiset<_K1, _C1, _A1>&);
 501
 502       template <class _K1, class _C1, class _A1>
 503         friend bool
 504         operator< (const multiset<_K1, _C1, _A1>&,
 505                    const multiset<_K1, _C1, _A1>&);
 506     };
 507
 508   /**
 509    *  @brief  Multiset equality comparison.
 510    *  @param  x  A %multiset.
 511    *  @param  y  A %multiset of the same type as @a x.
 512    *  @return  True iff the size and elements of the multisets are equal.
 513    *
 514    *  This is an equivalence relation.  It is linear in the size of the
 515    *  multisets.
 516    *  Multisets are considered equivalent if their sizes are equal, and if
 517    *  corresponding elements compare equal.
 518   */
 519   template <class _Key, class _Compare, class _Alloc>
 520     inline bool
 521     operator==(const multiset<_Key, _Compare, _Alloc>& __x,
 522                const multiset<_Key, _Compare, _Alloc>& __y)
 523     { return __x._M_t == __y._M_t; }
 524
 525   /**
 526    *  @brief  Multiset ordering relation.
 527    *  @param  x  A %multiset.
 528    *  @param  y  A %multiset of the same type as @a x.
 529    *  @return  True iff @a x is lexicographically less than @a y.
 530    *
 531    *  This is a total ordering relation.  It is linear in the size of the
 532    *  maps.  The elements must be comparable with @c <.
 533    *
 534    *  See std::lexicographical_compare() for how the determination is made.
 535   */
 536   template <class _Key, class _Compare, class _Alloc>
 537     inline bool
 538     operator<(const multiset<_Key, _Compare, _Alloc>& __x,
 539               const multiset<_Key, _Compare, _Alloc>& __y)
 540     { return __x._M_t < __y._M_t; }
 541
 542   ///  Returns !(x == y).
 543   template <class _Key, class _Compare, class _Alloc>
 544     inline bool
 545     operator!=(const multiset<_Key, _Compare, _Alloc>& __x,
 546                const multiset<_Key, _Compare, _Alloc>& __y)
 547     { return !(__x == __y); }
 548
 549   ///  Returns y < x.
 550   template <class _Key, class _Compare, class _Alloc>
 551     inline bool
 552     operator>(const multiset<_Key,_Compare,_Alloc>& __x,
 553               const multiset<_Key,_Compare,_Alloc>& __y)
 554     { return __y < __x; }
 555
 556   ///  Returns !(y < x)
 557   template <class _Key, class _Compare, class _Alloc>
 558     inline bool
 559     operator<=(const multiset<_Key, _Compare, _Alloc>& __x,
 560                const multiset<_Key, _Compare, _Alloc>& __y)
 561     { return !(__y < __x); }
 562
 563   ///  Returns !(x < y)
 564   template <class _Key, class _Compare, class _Alloc>
 565     inline bool
 566     operator>=(const multiset<_Key, _Compare, _Alloc>& __x,
 567                const multiset<_Key, _Compare, _Alloc>& __y)
 568     { return !(__x < __y); }
 569
 570   /// See std::multiset::swap().
 571   template <class _Key, class _Compare, class _Alloc>
 572     inline void
 573     swap(multiset<_Key, _Compare, _Alloc>& __x,
 574          multiset<_Key, _Compare, _Alloc>& __y)
 575     { __x.swap(__y); }
 576
 577 _GLIBCXX_END_NESTED_NAMESPACE
 578
 579 #endif /* _MULTISET_H */