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

   1 // Multiset implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001-2013 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /*
  26  *
  27  * Copyright (c) 1994
  28  * Hewlett-Packard Company
  29  *
  30  * Permission to use, copy, modify, distribute and sell this software
  31  * and its documentation for any purpose is hereby granted without fee,
  32  * provided that the above copyright notice appear in all copies and
  33  * that both that copyright notice and this permission notice appear
  34  * in supporting documentation.  Hewlett-Packard Company makes no
  35  * representations about the suitability of this software for any
  36  * purpose.  It is provided "as is" without express or implied warranty.
  37  *
  38  *
  39  * Copyright (c) 1996
  40  * Silicon Graphics Computer Systems, Inc.
  41  *
  42  * Permission to use, copy, modify, distribute and sell this software
  43  * and its documentation for any purpose is hereby granted without fee,
  44  * provided that the above copyright notice appear in all copies and
  45  * that both that copyright notice and this permission notice appear
  46  * in supporting documentation.  Silicon Graphics makes no
  47  * representations about the suitability of this software for any
  48  * purpose.  It is provided "as is" without express or implied warranty.
  49  */
  50
  51 /** @file bits/stl_multiset.h
  52  *  This is an internal header file, included by other library headers.
  53  *  Do not attempt to use it directly. @headername{set}
  54  */
  55
  56 #ifndef _STL_MULTISET_H
  57 #define _STL_MULTISET_H 1
  58
  59 #include <bits/concept_check.h>
  60 #if __cplusplus >= 201103L
  61 #include <initializer_list>
  62 #endif
  63
  64 namespace std _GLIBCXX_VISIBILITY(default)
  65 {
  66 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
  67
  68   /**
  69    *  @brief A standard container made up of elements, which can be retrieved
  70    *  in logarithmic time.
  71    *
  72    *  @ingroup associative_containers
  73    *
  74    *
  75    *  @tparam _Key  Type of key objects.
  76    *  @tparam _Compare  Comparison function object type, defaults to less<_Key>.
  77    *  @tparam _Alloc  Allocator type, defaults to allocator<_Key>.
  78    *
  79    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
  80    *  <a href="tables.html#66">reversible container</a>, and an
  81    *  <a href="tables.html#69">associative container</a> (using equivalent
  82    *  keys).  For a @c multiset<Key> the key_type and value_type are Key.
  83    *
  84    *  Multisets support bidirectional iterators.
  85    *
  86    *  The private tree data is declared exactly the same way for set and
  87    *  multiset; the distinction is made entirely in how the tree functions are
  88    *  called (*_unique versus *_equal, same as the standard).
  89   */
  90   template <typename _Key, typename _Compare = std::less<_Key>,
  91             typename _Alloc = std::allocator<_Key> >
  92     class multiset
  93     {
  94       // concept requirements
  95       typedef typename _Alloc::value_type                   _Alloc_value_type;
  96       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
  97       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
  98                                 _BinaryFunctionConcept)
  99       __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
 100
 101     public:
 102       // typedefs:
 103       typedef _Key     key_type;
 104       typedef _Key     value_type;
 105       typedef _Compare key_compare;
 106       typedef _Compare value_compare;
 107       typedef _Alloc   allocator_type;
 108
 109     private:
 110       /// This turns a red-black tree into a [multi]set.
 111       typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type;
 112
 113       typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
 114                        key_compare, _Key_alloc_type> _Rep_type;
 115       /// The actual tree structure.
 116       _Rep_type _M_t;
 117
 118     public:
 119       typedef typename _Key_alloc_type::pointer             pointer;
 120       typedef typename _Key_alloc_type::const_pointer       const_pointer;
 121       typedef typename _Key_alloc_type::reference           reference;
 122       typedef typename _Key_alloc_type::const_reference     const_reference;
 123       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 124       // DR 103. set::iterator is required to be modifiable,
 125       // but this allows modification of keys.
 126       typedef typename _Rep_type::const_iterator            iterator;
 127       typedef typename _Rep_type::const_iterator            const_iterator;
 128       typedef typename _Rep_type::const_reverse_iterator    reverse_iterator;
 129       typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
 130       typedef typename _Rep_type::size_type                 size_type;
 131       typedef typename _Rep_type::difference_type           difference_type;
 132
 133       // allocation/deallocation
 134       /**
 135        *  @brief  Default constructor creates no elements.
 136        */
 137       multiset()
 138       : _M_t() { }
 139
 140       /**
 141        *  @brief  Creates a %multiset with no elements.
 142        *  @param  __comp  Comparator to use.
 143        *  @param  __a  An allocator object.
 144        */
 145       explicit
 146       multiset(const _Compare& __comp,
 147                const allocator_type& __a = allocator_type())
 148       : _M_t(__comp, _Key_alloc_type(__a)) { }
 149
 150       /**
 151        *  @brief  Builds a %multiset from a range.
 152        *  @param  __first  An input iterator.
 153        *  @param  __last  An input iterator.
 154        *
 155        *  Create a %multiset consisting of copies of the elements from
 156        *  [first,last).  This is linear in N if the range is already sorted,
 157        *  and NlogN otherwise (where N is distance(__first,__last)).
 158        */
 159       template<typename _InputIterator>
 160         multiset(_InputIterator __first, _InputIterator __last)
 161         : _M_t()
 162         { _M_t._M_insert_equal(__first, __last); }
 163
 164       /**
 165        *  @brief  Builds a %multiset from a range.
 166        *  @param  __first  An input iterator.
 167        *  @param  __last  An input iterator.
 168        *  @param  __comp  A comparison functor.
 169        *  @param  __a  An allocator object.
 170        *
 171        *  Create a %multiset consisting of copies of the elements from
 172        *  [__first,__last).  This is linear in N if the range is already sorted,
 173        *  and NlogN otherwise (where N is distance(__first,__last)).
 174        */
 175       template<typename _InputIterator>
 176         multiset(_InputIterator __first, _InputIterator __last,
 177                  const _Compare& __comp,
 178                  const allocator_type& __a = allocator_type())
 179         : _M_t(__comp, _Key_alloc_type(__a))
 180         { _M_t._M_insert_equal(__first, __last); }
 181
 182       /**
 183        *  @brief  %Multiset copy constructor.
 184        *  @param  __x  A %multiset of identical element and allocator types.
 185        *
 186        *  The newly-created %multiset uses a copy of the allocation object used
 187        *  by @a __x.
 188        */
 189       multiset(const multiset& __x)
 190       : _M_t(__x._M_t) { }
 191
 192 #if __cplusplus >= 201103L
 193      /**
 194        *  @brief  %Multiset move constructor.
 195        *  @param  __x  A %multiset of identical element and allocator types.
 196        *
 197        *  The newly-created %multiset contains the exact contents of @a __x.
 198        *  The contents of @a __x are a valid, but unspecified %multiset.
 199        */
 200       multiset(multiset&& __x)
 201       noexcept(is_nothrow_copy_constructible<_Compare>::value)
 202       : _M_t(std::move(__x._M_t)) { }
 203
 204       /**
 205        *  @brief  Builds a %multiset from an initializer_list.
 206        *  @param  __l  An initializer_list.
 207        *  @param  __comp  A comparison functor.
 208        *  @param  __a  An allocator object.
 209        *
 210        *  Create a %multiset consisting of copies of the elements from
 211        *  the list.  This is linear in N if the list is already sorted,
 212        *  and NlogN otherwise (where N is @a __l.size()).
 213        */
 214       multiset(initializer_list<value_type> __l,
 215                const _Compare& __comp = _Compare(),
 216                const allocator_type& __a = allocator_type())
 217       : _M_t(__comp, _Key_alloc_type(__a))
 218       { _M_t._M_insert_equal(__l.begin(), __l.end()); }
 219 #endif
 220
 221       /**
 222        *  @brief  %Multiset assignment operator.
 223        *  @param  __x  A %multiset of identical element and allocator types.
 224        *
 225        *  All the elements of @a __x are copied, but unlike the copy
 226        *  constructor, the allocator object is not copied.
 227        */
 228       multiset&
 229       operator=(const multiset& __x)
 230       {
 231         _M_t = __x._M_t;
 232         return *this;
 233       }
 234
 235 #if __cplusplus >= 201103L
 236       /**
 237        *  @brief  %Multiset move assignment operator.
 238        *  @param  __x  A %multiset of identical element and allocator types.
 239        *
 240        *  The contents of @a __x are moved into this %multiset
 241        *  (without copying).  @a __x is a valid, but unspecified
 242        *  %multiset.
 243        */
 244       multiset&
 245       operator=(multiset&& __x)
 246       {
 247         // NB: DR 1204.
 248         // NB: DR 675.
 249         this->clear();
 250         this->swap(__x);
 251         return *this;
 252       }
 253
 254       /**
 255        *  @brief  %Multiset list assignment operator.
 256        *  @param  __l  An initializer_list.
 257        *
 258        *  This function fills a %multiset with copies of the elements in the
 259        *  initializer list @a __l.
 260        *
 261        *  Note that the assignment completely changes the %multiset and
 262        *  that the resulting %multiset's size is the same as the number
 263        *  of elements assigned.  Old data may be lost.
 264        */
 265       multiset&
 266       operator=(initializer_list<value_type> __l)
 267       {
 268         this->clear();
 269         this->insert(__l.begin(), __l.end());
 270         return *this;
 271       }
 272 #endif
 273
 274       // accessors:
 275
 276       ///  Returns the comparison object.
 277       key_compare
 278       key_comp() const
 279       { return _M_t.key_comp(); }
 280       ///  Returns the comparison object.
 281       value_compare
 282       value_comp() const
 283       { return _M_t.key_comp(); }
 284       ///  Returns the memory allocation object.
 285       allocator_type
 286       get_allocator() const _GLIBCXX_NOEXCEPT
 287       { return allocator_type(_M_t.get_allocator()); }
 288
 289       /**
 290        *  Returns a read-only (constant) iterator that points to the first
 291        *  element in the %multiset.  Iteration is done in ascending order
 292        *  according to the keys.
 293        */
 294       iterator
 295       begin() const _GLIBCXX_NOEXCEPT
 296       { return _M_t.begin(); }
 297
 298       /**
 299        *  Returns a read-only (constant) iterator that points one past the last
 300        *  element in the %multiset.  Iteration is done in ascending order
 301        *  according to the keys.
 302        */
 303       iterator
 304       end() const _GLIBCXX_NOEXCEPT
 305       { return _M_t.end(); }
 306
 307       /**
 308        *  Returns a read-only (constant) reverse iterator that points to the
 309        *  last element in the %multiset.  Iteration is done in descending order
 310        *  according to the keys.
 311        */
 312       reverse_iterator
 313       rbegin() const _GLIBCXX_NOEXCEPT
 314       { return _M_t.rbegin(); }
 315
 316       /**
 317        *  Returns a read-only (constant) reverse iterator that points to the
 318        *  last element in the %multiset.  Iteration is done in descending order
 319        *  according to the keys.
 320        */
 321       reverse_iterator
 322       rend() const _GLIBCXX_NOEXCEPT
 323       { return _M_t.rend(); }
 324
 325 #if __cplusplus >= 201103L
 326       /**
 327        *  Returns a read-only (constant) iterator that points to the first
 328        *  element in the %multiset.  Iteration is done in ascending order
 329        *  according to the keys.
 330        */
 331       iterator
 332       cbegin() const noexcept
 333       { return _M_t.begin(); }
 334
 335       /**
 336        *  Returns a read-only (constant) iterator that points one past the last
 337        *  element in the %multiset.  Iteration is done in ascending order
 338        *  according to the keys.
 339        */
 340       iterator
 341       cend() const noexcept
 342       { return _M_t.end(); }
 343
 344       /**
 345        *  Returns a read-only (constant) reverse iterator that points to the
 346        *  last element in the %multiset.  Iteration is done in descending order
 347        *  according to the keys.
 348        */
 349       reverse_iterator
 350       crbegin() const noexcept
 351       { return _M_t.rbegin(); }
 352
 353       /**
 354        *  Returns a read-only (constant) reverse iterator that points to the
 355        *  last element in the %multiset.  Iteration is done in descending order
 356        *  according to the keys.
 357        */
 358       reverse_iterator
 359       crend() const noexcept
 360       { return _M_t.rend(); }
 361 #endif
 362
 363       ///  Returns true if the %set is empty.
 364       bool
 365       empty() const _GLIBCXX_NOEXCEPT
 366       { return _M_t.empty(); }
 367
 368       ///  Returns the size of the %set.
 369       size_type
 370       size() const _GLIBCXX_NOEXCEPT
 371       { return _M_t.size(); }
 372
 373       ///  Returns the maximum size of the %set.
 374       size_type
 375       max_size() const _GLIBCXX_NOEXCEPT
 376       { return _M_t.max_size(); }
 377
 378       /**
 379        *  @brief  Swaps data with another %multiset.
 380        *  @param  __x  A %multiset of the same element and allocator types.
 381        *
 382        *  This exchanges the elements between two multisets in constant time.
 383        *  (It is only swapping a pointer, an integer, and an instance of the @c
 384        *  Compare type (which itself is often stateless and empty), so it should
 385        *  be quite fast.)
 386        *  Note that the global std::swap() function is specialized such that
 387        *  std::swap(s1,s2) will feed to this function.
 388        */
 389       void
 390       swap(multiset& __x)
 391       { _M_t.swap(__x._M_t); }
 392
 393       // insert/erase
 394 #if __cplusplus >= 201103L
 395       /**
 396        *  @brief Builds and inserts an element into the %multiset.
 397        *  @param  __args  Arguments used to generate the element instance to be
 398        *                 inserted.
 399        *  @return An iterator that points to the inserted element.
 400        *
 401        *  This function inserts an element into the %multiset.  Contrary
 402        *  to a std::set the %multiset does not rely on unique keys and thus
 403        *  multiple copies of the same element can be inserted.
 404        *
 405        *  Insertion requires logarithmic time.
 406        */
 407       template<typename... _Args>
 408         iterator
 409         emplace(_Args&&... __args)
 410         { return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); }
 411
 412       /**
 413        *  @brief Builds and inserts an element into the %multiset.
 414        *  @param  __pos  An iterator that serves as a hint as to where the
 415        *                element should be inserted.
 416        *  @param  __args  Arguments used to generate the element instance to be
 417        *                 inserted.
 418        *  @return An iterator that points to the inserted element.
 419        *
 420        *  This function inserts an element into the %multiset.  Contrary
 421        *  to a std::set the %multiset does not rely on unique keys and thus
 422        *  multiple copies of the same element can be inserted.
 423        *
 424        *  Note that the first parameter is only a hint and can potentially
 425        *  improve the performance of the insertion process.  A bad hint would
 426        *  cause no gains in efficiency.
 427        *
 428        *  See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
 429        *  for more on @a hinting.
 430        *
 431        *  Insertion requires logarithmic time (if the hint is not taken).
 432        */
 433       template<typename... _Args>
 434         iterator
 435         emplace_hint(const_iterator __pos, _Args&&... __args)
 436         {
 437           return _M_t._M_emplace_hint_equal(__pos,
 438                                             std::forward<_Args>(__args)...);
 439         }
 440 #endif
 441
 442       /**
 443        *  @brief Inserts an element into the %multiset.
 444        *  @param  __x  Element to be inserted.
 445        *  @return An iterator that points to the inserted element.
 446        *
 447        *  This function inserts an element into the %multiset.  Contrary
 448        *  to a std::set the %multiset does not rely on unique keys and thus
 449        *  multiple copies of the same element can be inserted.
 450        *
 451        *  Insertion requires logarithmic time.
 452        */
 453       iterator
 454       insert(const value_type& __x)
 455       { return _M_t._M_insert_equal(__x); }
 456
 457 #if __cplusplus >= 201103L
 458       iterator
 459       insert(value_type&& __x)
 460       { return _M_t._M_insert_equal(std::move(__x)); }
 461 #endif
 462
 463       /**
 464        *  @brief Inserts an element into the %multiset.
 465        *  @param  __position  An iterator that serves as a hint as to where the
 466        *                    element should be inserted.
 467        *  @param  __x  Element to be inserted.
 468        *  @return An iterator that points to the inserted element.
 469        *
 470        *  This function inserts an element into the %multiset.  Contrary
 471        *  to a std::set the %multiset does not rely on unique keys and thus
 472        *  multiple copies of the same element can be inserted.
 473        *
 474        *  Note that the first parameter is only a hint and can potentially
 475        *  improve the performance of the insertion process.  A bad hint would
 476        *  cause no gains in efficiency.
 477        *
 478        *  See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
 479        *  for more on @a hinting.
 480        *
 481        *  Insertion requires logarithmic time (if the hint is not taken).
 482        */
 483       iterator
 484       insert(const_iterator __position, const value_type& __x)
 485       { return _M_t._M_insert_equal_(__position, __x); }
 486
 487 #if __cplusplus >= 201103L
 488       iterator
 489       insert(const_iterator __position, value_type&& __x)
 490       { return _M_t._M_insert_equal_(__position, std::move(__x)); }
 491 #endif
 492
 493       /**
 494        *  @brief A template function that tries to insert a range of elements.
 495        *  @param  __first  Iterator pointing to the start of the range to be
 496        *                   inserted.
 497        *  @param  __last  Iterator pointing to the end of the range.
 498        *
 499        *  Complexity similar to that of the range constructor.
 500        */
 501       template<typename _InputIterator>
 502         void
 503         insert(_InputIterator __first, _InputIterator __last)
 504         { _M_t._M_insert_equal(__first, __last); }
 505
 506 #if __cplusplus >= 201103L
 507       /**
 508        *  @brief Attempts to insert a list of elements into the %multiset.
 509        *  @param  __l  A std::initializer_list<value_type> of elements
 510        *               to be inserted.
 511        *
 512        *  Complexity similar to that of the range constructor.
 513        */
 514       void
 515       insert(initializer_list<value_type> __l)
 516       { this->insert(__l.begin(), __l.end()); }
 517 #endif
 518
 519 #if __cplusplus >= 201103L
 520       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 521       // DR 130. Associative erase should return an iterator.
 522       /**
 523        *  @brief Erases an element from a %multiset.
 524        *  @param  __position  An iterator pointing to the element to be erased.
 525        *  @return An iterator pointing to the element immediately following
 526        *          @a position prior to the element being erased. If no such
 527        *          element exists, end() is returned.
 528        *
 529        *  This function erases an element, pointed to by the given iterator,
 530        *  from a %multiset.  Note that this function only erases the element,
 531        *  and that if the element is itself a pointer, the pointed-to memory is
 532        *  not touched in any way.  Managing the pointer is the user's
 533        *  responsibility.
 534        */
 535       iterator
 536       erase(const_iterator __position)
 537       { return _M_t.erase(__position); }
 538 #else
 539       /**
 540        *  @brief Erases an element from a %multiset.
 541        *  @param  __position  An iterator pointing to the element to be erased.
 542        *
 543        *  This function erases an element, pointed to by the given iterator,
 544        *  from a %multiset.  Note that this function only erases the element,
 545        *  and that if the element is itself a pointer, the pointed-to memory is
 546        *  not touched in any way.  Managing the pointer is the user's
 547        *  responsibility.
 548        */
 549       void
 550       erase(iterator __position)
 551       { _M_t.erase(__position); }
 552 #endif
 553
 554       /**
 555        *  @brief Erases elements according to the provided key.
 556        *  @param  __x  Key of element to be erased.
 557        *  @return  The number of elements erased.
 558        *
 559        *  This function erases all elements located by the given key from a
 560        *  %multiset.
 561        *  Note that this function only erases the element, and that if
 562        *  the element is itself a pointer, the pointed-to memory is not touched
 563        *  in any way.  Managing the pointer is the user's responsibility.
 564        */
 565       size_type
 566       erase(const key_type& __x)
 567       { return _M_t.erase(__x); }
 568
 569 #if __cplusplus >= 201103L
 570       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 571       // DR 130. Associative erase should return an iterator.
 572       /**
 573        *  @brief Erases a [first,last) range of elements from a %multiset.
 574        *  @param  __first  Iterator pointing to the start of the range to be
 575        *                   erased.
 576        *  @param __last Iterator pointing to the end of the range to
 577        *                be erased.
 578        *  @return The iterator @a last.
 579        *
 580        *  This function erases a sequence of elements from a %multiset.
 581        *  Note that this function only erases the elements, and that if
 582        *  the elements themselves are pointers, the pointed-to memory is not
 583        *  touched in any way.  Managing the pointer is the user's
 584        *  responsibility.
 585        */
 586       iterator
 587       erase(const_iterator __first, const_iterator __last)
 588       { return _M_t.erase(__first, __last); }
 589 #else
 590       /**
 591        *  @brief Erases a [first,last) range of elements from a %multiset.
 592        *  @param  first  Iterator pointing to the start of the range to be
 593        *                 erased.
 594        *  @param  last  Iterator pointing to the end of the range to be erased.
 595        *
 596        *  This function erases a sequence of elements from a %multiset.
 597        *  Note that this function only erases the elements, and that if
 598        *  the elements themselves are pointers, the pointed-to memory is not
 599        *  touched in any way.  Managing the pointer is the user's
 600        *  responsibility.
 601        */
 602       void
 603       erase(iterator __first, iterator __last)
 604       { _M_t.erase(__first, __last); }
 605 #endif
 606
 607       /**
 608        *  Erases all elements in a %multiset.  Note that this function only
 609        *  erases the elements, and that if the elements themselves are pointers,
 610        *  the pointed-to memory is not touched in any way.  Managing the pointer
 611        *  is the user's responsibility.
 612        */
 613       void
 614       clear() _GLIBCXX_NOEXCEPT
 615       { _M_t.clear(); }
 616
 617       // multiset operations:
 618
 619       /**
 620        *  @brief Finds the number of elements with given key.
 621        *  @param  __x  Key of elements to be located.
 622        *  @return Number of elements with specified key.
 623        */
 624       size_type
 625       count(const key_type& __x) const
 626       { return _M_t.count(__x); }
 627
 628       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 629       // 214.  set::find() missing const overload
 630       //@{
 631       /**
 632        *  @brief Tries to locate an element in a %set.
 633        *  @param  __x  Element to be located.
 634        *  @return  Iterator pointing to sought-after element, or end() if not
 635        *           found.
 636        *
 637        *  This function takes a key and tries to locate the element with which
 638        *  the key matches.  If successful the function returns an iterator
 639        *  pointing to the sought after element.  If unsuccessful it returns the
 640        *  past-the-end ( @c end() ) iterator.
 641        */
 642       iterator
 643       find(const key_type& __x)
 644       { return _M_t.find(__x); }
 645
 646       const_iterator
 647       find(const key_type& __x) const
 648       { return _M_t.find(__x); }
 649       //@}
 650
 651       //@{
 652       /**
 653        *  @brief Finds the beginning of a subsequence matching given key.
 654        *  @param  __x  Key to be located.
 655        *  @return  Iterator pointing to first element equal to or greater
 656        *           than key, or end().
 657        *
 658        *  This function returns the first element of a subsequence of elements
 659        *  that matches the given key.  If unsuccessful it returns an iterator
 660        *  pointing to the first element that has a greater value than given key
 661        *  or end() if no such element exists.
 662        */
 663       iterator
 664       lower_bound(const key_type& __x)
 665       { return _M_t.lower_bound(__x); }
 666
 667       const_iterator
 668       lower_bound(const key_type& __x) const
 669       { return _M_t.lower_bound(__x); }
 670       //@}
 671
 672       //@{
 673       /**
 674        *  @brief Finds the end of a subsequence matching given key.
 675        *  @param  __x  Key to be located.
 676        *  @return Iterator pointing to the first element
 677        *          greater than key, or end().
 678        */
 679       iterator
 680       upper_bound(const key_type& __x)
 681       { return _M_t.upper_bound(__x); }
 682
 683       const_iterator
 684       upper_bound(const key_type& __x) const
 685       { return _M_t.upper_bound(__x); }
 686       //@}
 687
 688       //@{
 689       /**
 690        *  @brief Finds a subsequence matching given key.
 691        *  @param  __x  Key to be located.
 692        *  @return  Pair of iterators that possibly points to the subsequence
 693        *           matching given key.
 694        *
 695        *  This function is equivalent to
 696        *  @code
 697        *    std::make_pair(c.lower_bound(val),
 698        *                   c.upper_bound(val))
 699        *  @endcode
 700        *  (but is faster than making the calls separately).
 701        *
 702        *  This function probably only makes sense for multisets.
 703        */
 704       std::pair<iterator, iterator>
 705       equal_range(const key_type& __x)
 706       { return _M_t.equal_range(__x); }
 707
 708       std::pair<const_iterator, const_iterator>
 709       equal_range(const key_type& __x) const
 710       { return _M_t.equal_range(__x); }
 711       //@}
 712
 713       template<typename _K1, typename _C1, typename _A1>
 714         friend bool
 715         operator==(const multiset<_K1, _C1, _A1>&,
 716                    const multiset<_K1, _C1, _A1>&);
 717
 718       template<typename _K1, typename _C1, typename _A1>
 719         friend bool
 720         operator< (const multiset<_K1, _C1, _A1>&,
 721                    const multiset<_K1, _C1, _A1>&);
 722     };
 723
 724   /**
 725    *  @brief  Multiset equality comparison.
 726    *  @param  __x  A %multiset.
 727    *  @param  __y  A %multiset of the same type as @a __x.
 728    *  @return  True iff the size and elements of the multisets are equal.
 729    *
 730    *  This is an equivalence relation.  It is linear in the size of the
 731    *  multisets.
 732    *  Multisets are considered equivalent if their sizes are equal, and if
 733    *  corresponding elements compare equal.
 734   */
 735   template<typename _Key, typename _Compare, typename _Alloc>
 736     inline bool
 737     operator==(const multiset<_Key, _Compare, _Alloc>& __x,
 738                const multiset<_Key, _Compare, _Alloc>& __y)
 739     { return __x._M_t == __y._M_t; }
 740
 741   /**
 742    *  @brief  Multiset ordering relation.
 743    *  @param  __x  A %multiset.
 744    *  @param  __y  A %multiset of the same type as @a __x.
 745    *  @return  True iff @a __x is lexicographically less than @a __y.
 746    *
 747    *  This is a total ordering relation.  It is linear in the size of the
 748    *  maps.  The elements must be comparable with @c <.
 749    *
 750    *  See std::lexicographical_compare() for how the determination is made.
 751   */
 752   template<typename _Key, typename _Compare, typename _Alloc>
 753     inline bool
 754     operator<(const multiset<_Key, _Compare, _Alloc>& __x,
 755               const multiset<_Key, _Compare, _Alloc>& __y)
 756     { return __x._M_t < __y._M_t; }
 757
 758   ///  Returns !(x == y).
 759   template<typename _Key, typename _Compare, typename _Alloc>
 760     inline bool
 761     operator!=(const multiset<_Key, _Compare, _Alloc>& __x,
 762                const multiset<_Key, _Compare, _Alloc>& __y)
 763     { return !(__x == __y); }
 764
 765   ///  Returns y < x.
 766   template<typename _Key, typename _Compare, typename _Alloc>
 767     inline bool
 768     operator>(const multiset<_Key,_Compare,_Alloc>& __x,
 769               const multiset<_Key,_Compare,_Alloc>& __y)
 770     { return __y < __x; }
 771
 772   ///  Returns !(y < x)
 773   template<typename _Key, typename _Compare, typename _Alloc>
 774     inline bool
 775     operator<=(const multiset<_Key, _Compare, _Alloc>& __x,
 776                const multiset<_Key, _Compare, _Alloc>& __y)
 777     { return !(__y < __x); }
 778
 779   ///  Returns !(x < y)
 780   template<typename _Key, typename _Compare, typename _Alloc>
 781     inline bool
 782     operator>=(const multiset<_Key, _Compare, _Alloc>& __x,
 783                const multiset<_Key, _Compare, _Alloc>& __y)
 784     { return !(__x < __y); }
 785
 786   /// See std::multiset::swap().
 787   template<typename _Key, typename _Compare, typename _Alloc>
 788     inline void
 789     swap(multiset<_Key, _Compare, _Alloc>& __x,
 790          multiset<_Key, _Compare, _Alloc>& __y)
 791     { __x.swap(__y); }
 792
 793 _GLIBCXX_END_NAMESPACE_CONTAINER
 794 } // namespace std
 795
 796 #endif /* _STL_MULTISET_H */