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

   1 // Multiset implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 /*
  32  *
  33  * Copyright (c) 1994
  34  * Hewlett-Packard Company
  35  *
  36  * Permission to use, copy, modify, distribute and sell this software
  37  * and its documentation for any purpose is hereby granted without fee,
  38  * provided that the above copyright notice appear in all copies and
  39  * that both that copyright notice and this permission notice appear
  40  * in supporting documentation.  Hewlett-Packard Company makes no
  41  * representations about the suitability of this software for any
  42  * purpose.  It is provided "as is" without express or implied warranty.
  43  *
  44  *
  45  * Copyright (c) 1996
  46  * Silicon Graphics Computer Systems, Inc.
  47  *
  48  * Permission to use, copy, modify, distribute and sell this software
  49  * and its documentation for any purpose is hereby granted without fee,
  50  * provided that the above copyright notice appear in all copies and
  51  * that both that copyright notice and this permission notice appear
  52  * in supporting documentation.  Silicon Graphics makes no
  53  * representations about the suitability of this software for any
  54  * purpose.  It is provided "as is" without express or implied warranty.
  55  */
  56
  57 /** @file stl_multiset.h
  58  *  This is an internal header file, included by other library headers.
  59  *  You should not attempt to use it directly.
  60  */
  61
  62 #ifndef _STL_MULTISET_H
  63 #define _STL_MULTISET_H 1
  64
  65 #include <bits/concept_check.h>
  66
  67 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD)
  68
  69   /**
  70    *  @brief A standard container made up of elements, which can be retrieved
  71    *  in logarithmic time.
  72    *
  73    *  @ingroup Containers
  74    *  @ingroup Assoc_containers
  75    *
  76    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
  77    *  <a href="tables.html#66">reversible container</a>, and an
  78    *  <a href="tables.html#69">associative container</a> (using equivalent
  79    *  keys).  For a @c multiset<Key> the key_type and value_type are Key.
  80    *
  81    *  Multisets support bidirectional iterators.
  82    *
  83    *  @if maint
  84    *  The private tree data is declared exactly the same way for set and
  85    *  multiset; the distinction is made entirely in how the tree functions are
  86    *  called (*_unique versus *_equal, same as the standard).
  87    *  @endif
  88   */
  89   template <class _Key, class _Compare = std::less<_Key>,
  90             class _Alloc = std::allocator<_Key> >
  91     class multiset
  92     {
  93       // concept requirements
  94       typedef typename _Alloc::value_type                   _Alloc_value_type;
  95       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
  96       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
  97                                 _BinaryFunctionConcept)
  98       __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
  99
 100     public:
 101       // typedefs:
 102       typedef _Key     key_type;
 103       typedef _Key     value_type;
 104       typedef _Compare key_compare;
 105       typedef _Compare value_compare;
 106       typedef _Alloc   allocator_type;
 107
 108     private:
 109       /// @if maint  This turns a red-black tree into a [multi]set.  @endif
 110       typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type;
 111
 112       typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
 113                        key_compare, _Key_alloc_type> _Rep_type;
 114       /// @if maint  The actual tree structure.  @endif
 115       _Rep_type _M_t;
 116
 117     public:
 118       typedef typename _Key_alloc_type::pointer             pointer;
 119       typedef typename _Key_alloc_type::const_pointer       const_pointer;
 120       typedef typename _Key_alloc_type::reference           reference;
 121       typedef typename _Key_alloc_type::const_reference     const_reference;
 122       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 123       // DR 103. set::iterator is required to be modifiable,
 124       // but this allows modification of keys.
 125       typedef typename _Rep_type::const_iterator            iterator;
 126       typedef typename _Rep_type::const_iterator            const_iterator;
 127       typedef typename _Rep_type::const_reverse_iterator    reverse_iterator;
 128       typedef typename _Rep_type::const_reverse_iterator    const_reverse_iterator;
 129       typedef typename _Rep_type::size_type                 size_type;
 130       typedef typename _Rep_type::difference_type           difference_type;
 131
 132       // allocation/deallocation
 133
 134       /**
 135        *  @brief  Default constructor creates no elements.
 136        */
 137       multiset()
 138       : _M_t(_Compare(), allocator_type()) { }
 139
 140       explicit
 141       multiset(const _Compare& __comp,
 142                const allocator_type& __a = allocator_type())
 143       : _M_t(__comp, __a) { }
 144
 145       /**
 146        *  @brief  Builds a %multiset from a range.
 147        *  @param  first  An input iterator.
 148        *  @param  last  An input iterator.
 149        *
 150        *  Create a %multiset consisting of copies of the elements from
 151        *  [first,last).  This is linear in N if the range is already sorted,
 152        *  and NlogN otherwise (where N is distance(first,last)).
 153        */
 154       template <class _InputIterator>
 155         multiset(_InputIterator __first, _InputIterator __last)
 156         : _M_t(_Compare(), allocator_type())
 157         { _M_t._M_insert_equal(__first, __last); }
 158
 159       /**
 160        *  @brief  Builds a %multiset from a range.
 161        *  @param  first  An input iterator.
 162        *  @param  last  An input iterator.
 163        *  @param  comp  A comparison functor.
 164        *  @param  a  An allocator object.
 165        *
 166        *  Create a %multiset consisting of copies of the elements from
 167        *  [first,last).  This is linear in N if the range is already sorted,
 168        *  and NlogN otherwise (where N is distance(first,last)).
 169        */
 170       template <class _InputIterator>
 171         multiset(_InputIterator __first, _InputIterator __last,
 172                  const _Compare& __comp,
 173                  const allocator_type& __a = allocator_type())
 174         : _M_t(__comp, __a)
 175         { _M_t._M_insert_equal(__first, __last); }
 176
 177       /**
 178        *  @brief  %Multiset copy constructor.
 179        *  @param  x  A %multiset of identical element and allocator types.
 180        *
 181        *  The newly-created %multiset uses a copy of the allocation object used
 182        *  by @a x.
 183        */
 184       multiset(const multiset<_Key,_Compare,_Alloc>& __x)
 185       : _M_t(__x._M_t) { }
 186
 187       /**
 188        *  @brief  %Multiset assignment operator.
 189        *  @param  x  A %multiset of identical element and allocator types.
 190        *
 191        *  All the elements of @a x are copied, but unlike the copy constructor,
 192        *  the allocator object is not copied.
 193        */
 194       multiset<_Key,_Compare,_Alloc>&
 195       operator=(const multiset<_Key,_Compare,_Alloc>& __x)
 196       {
 197         _M_t = __x._M_t;
 198         return *this;
 199       }
 200
 201       // accessors:
 202
 203       ///  Returns the comparison object.
 204       key_compare
 205       key_comp() const
 206       { return _M_t.key_comp(); }
 207       ///  Returns the comparison object.
 208       value_compare
 209       value_comp() const
 210       { return _M_t.key_comp(); }
 211       ///  Returns the memory allocation object.
 212       allocator_type
 213       get_allocator() const
 214       { return _M_t.get_allocator(); }
 215
 216       /**
 217        *  Returns a read/write iterator that points to the first element in the
 218        *  %multiset.  Iteration is done in ascending order according to the
 219        *  keys.
 220        */
 221       iterator
 222       begin() const
 223       { return _M_t.begin(); }
 224
 225       /**
 226        *  Returns a read/write iterator that points one past the last element in
 227        *  the %multiset.  Iteration is done in ascending order according to the
 228        *  keys.
 229        */
 230       iterator
 231       end() const
 232       { return _M_t.end(); }
 233
 234       /**
 235        *  Returns a read/write reverse iterator that points to the last element
 236        *  in the %multiset.  Iteration is done in descending order according to
 237        *  the keys.
 238        */
 239       reverse_iterator
 240       rbegin() const
 241       { return _M_t.rbegin(); }
 242
 243       /**
 244        *  Returns a read/write reverse iterator that points to the last element
 245        *  in the %multiset.  Iteration is done in descending order according to
 246        *  the keys.
 247        */
 248       reverse_iterator
 249       rend() const
 250       { return _M_t.rend(); }
 251
 252       ///  Returns true if the %set is empty.
 253       bool
 254       empty() const
 255       { return _M_t.empty(); }
 256
 257       ///  Returns the size of the %set.
 258       size_type
 259       size() const
 260       { return _M_t.size(); }
 261
 262       ///  Returns the maximum size of the %set.
 263       size_type
 264       max_size() const
 265       { return _M_t.max_size(); }
 266
 267       /**
 268        *  @brief  Swaps data with another %multiset.
 269        *  @param  x  A %multiset of the same element and allocator types.
 270        *
 271        *  This exchanges the elements between two multisets in constant time.
 272        *  (It is only swapping a pointer, an integer, and an instance of the @c
 273        *  Compare type (which itself is often stateless and empty), so it should
 274        *  be quite fast.)
 275        *  Note that the global std::swap() function is specialized such that
 276        *  std::swap(s1,s2) will feed to this function.
 277        */
 278       void
 279       swap(multiset<_Key, _Compare, _Alloc>& __x)
 280       { _M_t.swap(__x._M_t); }
 281
 282       // insert/erase
 283       /**
 284        *  @brief Inserts an element into the %multiset.
 285        *  @param  x  Element to be inserted.
 286        *  @return An iterator that points to the inserted element.
 287        *
 288        *  This function inserts an element into the %multiset.  Contrary
 289        *  to a std::set the %multiset does not rely on unique keys and thus
 290        *  multiple copies of the same element can be inserted.
 291        *
 292        *  Insertion requires logarithmic time.
 293        */
 294       iterator
 295       insert(const value_type& __x)
 296       { return _M_t._M_insert_equal(__x); }
 297
 298       /**
 299        *  @brief Inserts an element into the %multiset.
 300        *  @param  position  An iterator that serves as a hint as to where the
 301        *                    element should be inserted.
 302        *  @param  x  Element to be inserted.
 303        *  @return An iterator that points to the inserted element.
 304        *
 305        *  This function inserts an element into the %multiset.  Contrary
 306        *  to a std::set the %multiset does not rely on unique keys and thus
 307        *  multiple copies of the same element can be inserted.
 308        *
 309        *  Note that the first parameter is only a hint and can potentially
 310        *  improve the performance of the insertion process.  A bad hint would
 311        *  cause no gains in efficiency.
 312        *
 313        *  See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4
 314        *  for more on "hinting".
 315        *
 316        *  Insertion requires logarithmic time (if the hint is not taken).
 317        */
 318       iterator
 319       insert(iterator __position, const value_type& __x)
 320       { return _M_t._M_insert_equal_(__position, __x); }
 321
 322       /**
 323        *  @brief A template function that attemps to insert a range of elements.
 324        *  @param  first  Iterator pointing to the start of the range to be
 325        *                 inserted.
 326        *  @param  last  Iterator pointing to the end of the range.
 327        *
 328        *  Complexity similar to that of the range constructor.
 329        */
 330       template <class _InputIterator>
 331         void
 332         insert(_InputIterator __first, _InputIterator __last)
 333         { _M_t._M_insert_equal(__first, __last); }
 334
 335       /**
 336        *  @brief Erases an element from a %multiset.
 337        *  @param  position  An iterator pointing to the element to be erased.
 338        *
 339        *  This function erases an element, pointed to by the given iterator,
 340        *  from a %multiset.  Note that this function only erases the element,
 341        *  and that if the element is itself a pointer, the pointed-to memory is
 342        *  not touched in any way.  Managing the pointer is the user's
 343        *  responsibilty.
 344        */
 345       void
 346       erase(iterator __position)
 347       { _M_t.erase(__position); }
 348
 349       /**
 350        *  @brief Erases elements according to the provided key.
 351        *  @param  x  Key of element to be erased.
 352        *  @return  The number of elements erased.
 353        *
 354        *  This function erases all elements located by the given key from a
 355        *  %multiset.
 356        *  Note that this function only erases the element, and that if
 357        *  the element is itself a pointer, the pointed-to memory is not touched
 358        *  in any way.  Managing the pointer is the user's responsibilty.
 359        */
 360       size_type
 361       erase(const key_type& __x)
 362       { return _M_t.erase(__x); }
 363
 364       /**
 365        *  @brief Erases a [first,last) range of elements from a %multiset.
 366        *  @param  first  Iterator pointing to the start of the range to be
 367        *                 erased.
 368        *  @param  last  Iterator pointing to the end of the range to be erased.
 369        *
 370        *  This function erases a sequence of elements from a %multiset.
 371        *  Note that this function only erases the elements, and that if
 372        *  the elements themselves are pointers, the pointed-to memory is not
 373        *  touched in any way.  Managing the pointer is the user's responsibilty.
 374        */
 375       void
 376       erase(iterator __first, iterator __last)
 377       { _M_t.erase(__first, __last); }
 378
 379       /**
 380        *  Erases all elements in a %multiset.  Note that this function only
 381        *  erases the elements, and that if the elements themselves are pointers,
 382        *  the pointed-to memory is not touched in any way.  Managing the pointer
 383        *  is the user's responsibilty.
 384        */
 385       void
 386       clear()
 387       { _M_t.clear(); }
 388
 389       // multiset operations:
 390
 391       /**
 392        *  @brief Finds the number of elements with given key.
 393        *  @param  x  Key of elements to be located.
 394        *  @return Number of elements with specified key.
 395        */
 396       size_type
 397       count(const key_type& __x) const
 398       { return _M_t.count(__x); }
 399
 400       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 401       // 214.  set::find() missing const overload
 402       //@{
 403       /**
 404        *  @brief Tries to locate an element in a %set.
 405        *  @param  x  Element to be located.
 406        *  @return  Iterator pointing to sought-after element, or end() if not
 407        *           found.
 408        *
 409        *  This function takes a key and tries to locate the element with which
 410        *  the key matches.  If successful the function returns an iterator
 411        *  pointing to the sought after element.  If unsuccessful it returns the
 412        *  past-the-end ( @c end() ) iterator.
 413        */
 414       iterator
 415       find(const key_type& __x)
 416       { return _M_t.find(__x); }
 417
 418       const_iterator
 419       find(const key_type& __x) const
 420       { return _M_t.find(__x); }
 421       //@}
 422
 423       //@{
 424       /**
 425        *  @brief Finds the beginning of a subsequence matching given key.
 426        *  @param  x  Key to be located.
 427        *  @return  Iterator pointing to first element equal to or greater
 428        *           than key, or end().
 429        *
 430        *  This function returns the first element of a subsequence of elements
 431        *  that matches the given key.  If unsuccessful it returns an iterator
 432        *  pointing to the first element that has a greater value than given key
 433        *  or end() if no such element exists.
 434        */
 435       iterator
 436       lower_bound(const key_type& __x)
 437       { return _M_t.lower_bound(__x); }
 438
 439       const_iterator
 440       lower_bound(const key_type& __x) const
 441       { return _M_t.lower_bound(__x); }
 442       //@}
 443
 444       //@{
 445       /**
 446        *  @brief Finds the end of a subsequence matching given key.
 447        *  @param  x  Key to be located.
 448        *  @return Iterator pointing to the first element
 449        *          greater than key, or end().
 450        */
 451       iterator
 452       upper_bound(const key_type& __x)
 453       { return _M_t.upper_bound(__x); }
 454
 455       const_iterator
 456       upper_bound(const key_type& __x) const
 457       { return _M_t.upper_bound(__x); }
 458       //@}
 459
 460       //@{
 461       /**
 462        *  @brief Finds a subsequence matching given key.
 463        *  @param  x  Key to be located.
 464        *  @return  Pair of iterators that possibly points to the subsequence
 465        *           matching given key.
 466        *
 467        *  This function is equivalent to
 468        *  @code
 469        *    std::make_pair(c.lower_bound(val),
 470        *                   c.upper_bound(val))
 471        *  @endcode
 472        *  (but is faster than making the calls separately).
 473        *
 474        *  This function probably only makes sense for multisets.
 475        */
 476       std::pair<iterator, iterator>
 477       equal_range(const key_type& __x)
 478       { return _M_t.equal_range(__x); }
 479
 480       std::pair<const_iterator, const_iterator>
 481       equal_range(const key_type& __x) const
 482       { return _M_t.equal_range(__x); }
 483
 484       template <class _K1, class _C1, class _A1>
 485         friend bool
 486         operator== (const multiset<_K1, _C1, _A1>&,
 487                     const multiset<_K1, _C1, _A1>&);
 488
 489       template <class _K1, class _C1, class _A1>
 490         friend bool
 491         operator< (const multiset<_K1, _C1, _A1>&,
 492                    const multiset<_K1, _C1, _A1>&);
 493     };
 494
 495   /**
 496    *  @brief  Multiset equality comparison.
 497    *  @param  x  A %multiset.
 498    *  @param  y  A %multiset of the same type as @a x.
 499    *  @return  True iff the size and elements of the multisets are equal.
 500    *
 501    *  This is an equivalence relation.  It is linear in the size of the
 502    *  multisets.
 503    *  Multisets are considered equivalent if their sizes are equal, and if
 504    *  corresponding elements compare equal.
 505   */
 506   template <class _Key, class _Compare, class _Alloc>
 507     inline bool
 508     operator==(const multiset<_Key, _Compare, _Alloc>& __x,
 509                const multiset<_Key, _Compare, _Alloc>& __y)
 510     { return __x._M_t == __y._M_t; }
 511
 512   /**
 513    *  @brief  Multiset ordering relation.
 514    *  @param  x  A %multiset.
 515    *  @param  y  A %multiset of the same type as @a x.
 516    *  @return  True iff @a x is lexicographically less than @a y.
 517    *
 518    *  This is a total ordering relation.  It is linear in the size of the
 519    *  maps.  The elements must be comparable with @c <.
 520    *
 521    *  See std::lexicographical_compare() for how the determination is made.
 522   */
 523   template <class _Key, class _Compare, class _Alloc>
 524     inline bool
 525     operator<(const multiset<_Key, _Compare, _Alloc>& __x,
 526               const multiset<_Key, _Compare, _Alloc>& __y)
 527     { return __x._M_t < __y._M_t; }
 528
 529   ///  Returns !(x == y).
 530   template <class _Key, class _Compare, class _Alloc>
 531     inline bool
 532     operator!=(const multiset<_Key, _Compare, _Alloc>& __x,
 533                const multiset<_Key, _Compare, _Alloc>& __y)
 534     { return !(__x == __y); }
 535
 536   ///  Returns y < x.
 537   template <class _Key, class _Compare, class _Alloc>
 538     inline bool
 539     operator>(const multiset<_Key,_Compare,_Alloc>& __x,
 540               const multiset<_Key,_Compare,_Alloc>& __y)
 541     { return __y < __x; }
 542
 543   ///  Returns !(y < x)
 544   template <class _Key, class _Compare, class _Alloc>
 545     inline bool
 546     operator<=(const multiset<_Key, _Compare, _Alloc>& __x,
 547                const multiset<_Key, _Compare, _Alloc>& __y)
 548     { return !(__y < __x); }
 549
 550   ///  Returns !(x < y)
 551   template <class _Key, class _Compare, class _Alloc>
 552     inline bool
 553     operator>=(const multiset<_Key, _Compare, _Alloc>& __x,
 554                const multiset<_Key, _Compare, _Alloc>& __y)
 555     { return !(__x < __y); }
 556
 557   /// See std::multiset::swap().
 558   template <class _Key, class _Compare, class _Alloc>
 559     inline void
 560     swap(multiset<_Key, _Compare, _Alloc>& __x,
 561          multiset<_Key, _Compare, _Alloc>& __y)
 562     { __x.swap(__y); }
 563
 564 _GLIBCXX_END_NESTED_NAMESPACE
 565
 566 #endif /* _STL_MULTISET_H */