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      1 // Multimap implementation -*- C++ -*-
      2 
      3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
      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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
     18 // permissions described in the GCC Runtime Library Exception, version
     19 // 3.1, as published by the Free Software Foundation.
     20 
     21 // You should have received a copy of the GNU General Public License and
     22 // a copy of the GCC Runtime Library Exception along with this program;
     23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
     24 // <http://www.gnu.org/licenses/>.
     25 
     26 /*
     27  *
     28  * Copyright (c) 1994
     29  * Hewlett-Packard Company
     30  *
     31  * Permission to use, copy, modify, distribute and sell this software
     32  * and its documentation for any purpose is hereby granted without fee,
     33  * provided that the above copyright notice appear in all copies and
     34  * that both that copyright notice and this permission notice appear
     35  * in supporting documentation.  Hewlett-Packard Company makes no
     36  * representations about the suitability of this software for any
     37  * purpose.  It is provided "as is" without express or implied warranty.
     38  *
     39  *
     40  * Copyright (c) 1996,1997
     41  * Silicon Graphics Computer Systems, Inc.
     42  *
     43  * Permission to use, copy, modify, distribute and sell this software
     44  * and its documentation for any purpose is hereby granted without fee,
     45  * provided that the above copyright notice appear in all copies and
     46  * that both that copyright notice and this permission notice appear
     47  * in supporting documentation.  Silicon Graphics makes no
     48  * representations about the suitability of this software for any
     49  * purpose.  It is provided "as is" without express or implied warranty.
     50  */
     51 
     52 /** @file stl_multimap.h
     53  *  This is an internal header file, included by other library headers.
     54  *  You should not attempt to use it directly.
     55  */
     56 
     57 #ifndef _STL_MULTIMAP_H
     58 #define _STL_MULTIMAP_H 1
     59 
     60 #include <bits/concept_check.h>
     61 #include <initializer_list>
     62 
     63 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
     64 
     65   /**
     66    *  @brief A standard container made up of (key,value) pairs, which can be
     67    *  retrieved based on a key, in logarithmic time.
     68    *
     69    *  @ingroup associative_containers
     70    *
     71    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
     72    *  <a href="tables.html#66">reversible container</a>, and an
     73    *  <a href="tables.html#69">associative container</a> (using equivalent
     74    *  keys).  For a @c multimap<Key,T> the key_type is Key, the mapped_type
     75    *  is T, and the value_type is std::pair<const Key,T>.
     76    *
     77    *  Multimaps support bidirectional iterators.
     78    *
     79    *  The private tree data is declared exactly the same way for map and
     80    *  multimap; the distinction is made entirely in how the tree functions are
     81    *  called (*_unique versus *_equal, same as the standard).
     82   */
     83   template <typename _Key, typename _Tp,
     84 	    typename _Compare = std::less<_Key>,
     85 	    typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
     86     class multimap
     87     {
     88     public:
     89       typedef _Key                                          key_type;
     90       typedef _Tp                                           mapped_type;
     91       typedef std::pair<const _Key, _Tp>                    value_type;
     92       typedef _Compare                                      key_compare;
     93       typedef _Alloc                                        allocator_type;
     94 
     95     private:
     96       // concept requirements
     97       typedef typename _Alloc::value_type                   _Alloc_value_type;
     98       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
     99       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
    100 				_BinaryFunctionConcept)
    101       __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
    102 
    103     public:
    104       class value_compare
    105       : public std::binary_function<value_type, value_type, bool>
    106       {
    107 	friend class multimap<_Key, _Tp, _Compare, _Alloc>;
    108       protected:
    109 	_Compare comp;
    110 
    111 	value_compare(_Compare __c)
    112 	: comp(__c) { }
    113 
    114       public:
    115 	bool operator()(const value_type& __x, const value_type& __y) const
    116 	{ return comp(__x.first, __y.first); }
    117       };
    118 
    119     private:
    120       /// This turns a red-black tree into a [multi]map.
    121       typedef typename _Alloc::template rebind<value_type>::other
    122         _Pair_alloc_type;
    123 
    124       typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
    125 		       key_compare, _Pair_alloc_type> _Rep_type;
    126       /// The actual tree structure.
    127       _Rep_type _M_t;
    128 
    129     public:
    130       // many of these are specified differently in ISO, but the following are
    131       // "functionally equivalent"
    132       typedef typename _Pair_alloc_type::pointer         pointer;
    133       typedef typename _Pair_alloc_type::const_pointer   const_pointer;
    134       typedef typename _Pair_alloc_type::reference       reference;
    135       typedef typename _Pair_alloc_type::const_reference const_reference;
    136       typedef typename _Rep_type::iterator               iterator;
    137       typedef typename _Rep_type::const_iterator         const_iterator;
    138       typedef typename _Rep_type::size_type              size_type;
    139       typedef typename _Rep_type::difference_type        difference_type;
    140       typedef typename _Rep_type::reverse_iterator       reverse_iterator;
    141       typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
    142 
    143       // [23.3.2] construct/copy/destroy
    144       // (get_allocator() is also listed in this section)
    145       /**
    146        *  @brief  Default constructor creates no elements.
    147        */
    148       multimap()
    149       : _M_t() { }
    150 
    151       /**
    152        *  @brief  Creates a %multimap with no elements.
    153        *  @param  comp  A comparison object.
    154        *  @param  a  An allocator object.
    155        */
    156       explicit
    157       multimap(const _Compare& __comp,
    158 	       const allocator_type& __a = allocator_type())
    159       : _M_t(__comp, __a) { }
    160 
    161       /**
    162        *  @brief  %Multimap copy constructor.
    163        *  @param  x  A %multimap of identical element and allocator types.
    164        *
    165        *  The newly-created %multimap uses a copy of the allocation object
    166        *  used by @a x.
    167        */
    168       multimap(const multimap& __x)
    169       : _M_t(__x._M_t) { }
    170 
    171 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    172       /**
    173        *  @brief  %Multimap move constructor.
    174        *  @param   x  A %multimap of identical element and allocator types.
    175        *
    176        *  The newly-created %multimap contains the exact contents of @a x.
    177        *  The contents of @a x are a valid, but unspecified %multimap.
    178        */
    179       multimap(multimap&& __x)
    180       : _M_t(std::forward<_Rep_type>(__x._M_t)) { }
    181 
    182       /**
    183        *  @brief  Builds a %multimap from an initializer_list.
    184        *  @param  l  An initializer_list.
    185        *  @param  comp  A comparison functor.
    186        *  @param  a  An allocator object.
    187        *
    188        *  Create a %multimap consisting of copies of the elements from
    189        *  the initializer_list.  This is linear in N if the list is already
    190        *  sorted, and NlogN otherwise (where N is @a __l.size()).
    191        */
    192       multimap(initializer_list<value_type> __l,
    193 	       const _Compare& __comp = _Compare(),
    194 	       const allocator_type& __a = allocator_type())
    195       : _M_t(__comp, __a)
    196       { _M_t._M_insert_equal(__l.begin(), __l.end()); }
    197 #endif
    198 
    199       /**
    200        *  @brief  Builds a %multimap from a range.
    201        *  @param  first  An input iterator.
    202        *  @param  last  An input iterator.
    203        *
    204        *  Create a %multimap consisting of copies of the elements from
    205        *  [first,last).  This is linear in N if the range is already sorted,
    206        *  and NlogN otherwise (where N is distance(first,last)).
    207        */
    208       template<typename _InputIterator>
    209         multimap(_InputIterator __first, _InputIterator __last)
    210 	: _M_t()
    211         { _M_t._M_insert_equal(__first, __last); }
    212 
    213       /**
    214        *  @brief  Builds a %multimap from a range.
    215        *  @param  first  An input iterator.
    216        *  @param  last  An input iterator.
    217        *  @param  comp  A comparison functor.
    218        *  @param  a  An allocator object.
    219        *
    220        *  Create a %multimap consisting of copies of the elements from
    221        *  [first,last).  This is linear in N if the range is already sorted,
    222        *  and NlogN otherwise (where N is distance(first,last)).
    223        */
    224       template<typename _InputIterator>
    225         multimap(_InputIterator __first, _InputIterator __last,
    226 		 const _Compare& __comp,
    227 		 const allocator_type& __a = allocator_type())
    228         : _M_t(__comp, __a)
    229         { _M_t._M_insert_equal(__first, __last); }
    230 
    231       // FIXME There is no dtor declared, but we should have something generated
    232       // by Doxygen.  I don't know what tags to add to this paragraph to make
    233       // that happen:
    234       /**
    235        *  The dtor only erases the elements, and note that if the elements
    236        *  themselves are pointers, the pointed-to memory is not touched in any
    237        *  way.  Managing the pointer is the user's responsibility.
    238        */
    239 
    240       /**
    241        *  @brief  %Multimap assignment operator.
    242        *  @param  x  A %multimap of identical element and allocator types.
    243        *
    244        *  All the elements of @a x are copied, but unlike the copy constructor,
    245        *  the allocator object is not copied.
    246        */
    247       multimap&
    248       operator=(const multimap& __x)
    249       {
    250 	_M_t = __x._M_t;
    251 	return *this;
    252       }
    253 
    254 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    255       /**
    256        *  @brief  %Multimap move assignment operator.
    257        *  @param  x  A %multimap of identical element and allocator types.
    258        *
    259        *  The contents of @a x are moved into this multimap (without copying).
    260        *  @a x is a valid, but unspecified multimap.
    261        */
    262       multimap&
    263       operator=(multimap&& __x)
    264       {
    265 	// NB: DR 675.
    266 	this->clear();
    267 	this->swap(__x);
    268 	return *this;
    269       }
    270 
    271       /**
    272        *  @brief  %Multimap list assignment operator.
    273        *  @param  l  An initializer_list.
    274        *
    275        *  This function fills a %multimap with copies of the elements
    276        *  in the initializer list @a l.
    277        *
    278        *  Note that the assignment completely changes the %multimap and
    279        *  that the resulting %multimap's size is the same as the number
    280        *  of elements assigned.  Old data may be lost.
    281        */
    282       multimap&
    283       operator=(initializer_list<value_type> __l)
    284       {
    285 	this->clear();
    286 	this->insert(__l.begin(), __l.end());
    287 	return *this;
    288       }
    289 #endif
    290 
    291       /// Get a copy of the memory allocation object.
    292       allocator_type
    293       get_allocator() const
    294       { return _M_t.get_allocator(); }
    295 
    296       // iterators
    297       /**
    298        *  Returns a read/write iterator that points to the first pair in the
    299        *  %multimap.  Iteration is done in ascending order according to the
    300        *  keys.
    301        */
    302       iterator
    303       begin()
    304       { return _M_t.begin(); }
    305 
    306       /**
    307        *  Returns a read-only (constant) iterator that points to the first pair
    308        *  in the %multimap.  Iteration is done in ascending order according to
    309        *  the keys.
    310        */
    311       const_iterator
    312       begin() const
    313       { return _M_t.begin(); }
    314 
    315       /**
    316        *  Returns a read/write iterator that points one past the last pair in
    317        *  the %multimap.  Iteration is done in ascending order according to the
    318        *  keys.
    319        */
    320       iterator
    321       end()
    322       { return _M_t.end(); }
    323 
    324       /**
    325        *  Returns a read-only (constant) iterator that points one past the last
    326        *  pair in the %multimap.  Iteration is done in ascending order according
    327        *  to the keys.
    328        */
    329       const_iterator
    330       end() const
    331       { return _M_t.end(); }
    332 
    333       /**
    334        *  Returns a read/write reverse iterator that points to the last pair in
    335        *  the %multimap.  Iteration is done in descending order according to the
    336        *  keys.
    337        */
    338       reverse_iterator
    339       rbegin()
    340       { return _M_t.rbegin(); }
    341 
    342       /**
    343        *  Returns a read-only (constant) reverse iterator that points to the
    344        *  last pair in the %multimap.  Iteration is done in descending order
    345        *  according to the keys.
    346        */
    347       const_reverse_iterator
    348       rbegin() const
    349       { return _M_t.rbegin(); }
    350 
    351       /**
    352        *  Returns a read/write reverse iterator that points to one before the
    353        *  first pair in the %multimap.  Iteration is done in descending order
    354        *  according to the keys.
    355        */
    356       reverse_iterator
    357       rend()
    358       { return _M_t.rend(); }
    359 
    360       /**
    361        *  Returns a read-only (constant) reverse iterator that points to one
    362        *  before the first pair in the %multimap.  Iteration is done in
    363        *  descending order according to the keys.
    364        */
    365       const_reverse_iterator
    366       rend() const
    367       { return _M_t.rend(); }
    368 
    369 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    370       /**
    371        *  Returns a read-only (constant) iterator that points to the first pair
    372        *  in the %multimap.  Iteration is done in ascending order according to
    373        *  the keys.
    374        */
    375       const_iterator
    376       cbegin() const
    377       { return _M_t.begin(); }
    378 
    379       /**
    380        *  Returns a read-only (constant) iterator that points one past the last
    381        *  pair in the %multimap.  Iteration is done in ascending order according
    382        *  to the keys.
    383        */
    384       const_iterator
    385       cend() const
    386       { return _M_t.end(); }
    387 
    388       /**
    389        *  Returns a read-only (constant) reverse iterator that points to the
    390        *  last pair in the %multimap.  Iteration is done in descending order
    391        *  according to the keys.
    392        */
    393       const_reverse_iterator
    394       crbegin() const
    395       { return _M_t.rbegin(); }
    396 
    397       /**
    398        *  Returns a read-only (constant) reverse iterator that points to one
    399        *  before the first pair in the %multimap.  Iteration is done in
    400        *  descending order according to the keys.
    401        */
    402       const_reverse_iterator
    403       crend() const
    404       { return _M_t.rend(); }
    405 #endif
    406 
    407       // capacity
    408       /** Returns true if the %multimap is empty.  */
    409       bool
    410       empty() const
    411       { return _M_t.empty(); }
    412 
    413       /** Returns the size of the %multimap.  */
    414       size_type
    415       size() const
    416       { return _M_t.size(); }
    417 
    418       /** Returns the maximum size of the %multimap.  */
    419       size_type
    420       max_size() const
    421       { return _M_t.max_size(); }
    422 
    423       // modifiers
    424       /**
    425        *  @brief Inserts a std::pair into the %multimap.
    426        *  @param  x  Pair to be inserted (see std::make_pair for easy creation
    427        *             of pairs).
    428        *  @return An iterator that points to the inserted (key,value) pair.
    429        *
    430        *  This function inserts a (key, value) pair into the %multimap.
    431        *  Contrary to a std::map the %multimap does not rely on unique keys and
    432        *  thus multiple pairs with the same key can be inserted.
    433        *
    434        *  Insertion requires logarithmic time.
    435        */
    436       iterator
    437       insert(const value_type& __x)
    438       { return _M_t._M_insert_equal(__x); }
    439 
    440       /**
    441        *  @brief Inserts a std::pair into the %multimap.
    442        *  @param  position  An iterator that serves as a hint as to where the
    443        *                    pair should be inserted.
    444        *  @param  x  Pair to be inserted (see std::make_pair for easy creation
    445        *             of pairs).
    446        *  @return An iterator that points to the inserted (key,value) pair.
    447        *
    448        *  This function inserts a (key, value) pair into the %multimap.
    449        *  Contrary to a std::map the %multimap does not rely on unique keys and
    450        *  thus multiple pairs with the same key can be inserted.
    451        *  Note that the first parameter is only a hint and can potentially
    452        *  improve the performance of the insertion process.  A bad hint would
    453        *  cause no gains in efficiency.
    454        *
    455        *  For more on "hinting," see:
    456        *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
    457        *
    458        *  Insertion requires logarithmic time (if the hint is not taken).
    459        */
    460       iterator
    461       insert(iterator __position, const value_type& __x)
    462       { return _M_t._M_insert_equal_(__position, __x); }
    463 
    464       /**
    465        *  @brief A template function that attempts to insert a range
    466        *  of elements.
    467        *  @param  first  Iterator pointing to the start of the range to be
    468        *                 inserted.
    469        *  @param  last  Iterator pointing to the end of the range.
    470        *
    471        *  Complexity similar to that of the range constructor.
    472        */
    473       template<typename _InputIterator>
    474         void
    475         insert(_InputIterator __first, _InputIterator __last)
    476         { _M_t._M_insert_equal(__first, __last); }
    477 
    478 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    479       /**
    480        *  @brief Attempts to insert a list of std::pairs into the %multimap.
    481        *  @param  list  A std::initializer_list<value_type> of pairs to be
    482        *                inserted.
    483        *
    484        *  Complexity similar to that of the range constructor.
    485        */
    486       void
    487       insert(initializer_list<value_type> __l)
    488       { this->insert(__l.begin(), __l.end()); }
    489 #endif
    490 
    491       /**
    492        *  @brief Erases an element from a %multimap.
    493        *  @param  position  An iterator pointing to the element to be erased.
    494        *
    495        *  This function erases an element, pointed to by the given iterator,
    496        *  from a %multimap.  Note that this function only erases the element,
    497        *  and that if the element is itself a pointer, the pointed-to memory is
    498        *  not touched in any way.  Managing the pointer is the user's
    499        *  responsibility.
    500        */
    501       void
    502       erase(iterator __position)
    503       { _M_t.erase(__position); }
    504 
    505       /**
    506        *  @brief Erases elements according to the provided key.
    507        *  @param  x  Key of element to be erased.
    508        *  @return  The number of elements erased.
    509        *
    510        *  This function erases all elements located by the given key from a
    511        *  %multimap.
    512        *  Note that this function only erases the element, and that if
    513        *  the element is itself a pointer, the pointed-to memory is not touched
    514        *  in any way.  Managing the pointer is the user's responsibility.
    515        */
    516       size_type
    517       erase(const key_type& __x)
    518       { return _M_t.erase(__x); }
    519 
    520       /**
    521        *  @brief Erases a [first,last) range of elements from a %multimap.
    522        *  @param  first  Iterator pointing to the start of the range to be
    523        *                 erased.
    524        *  @param  last  Iterator pointing to the end of the range to be erased.
    525        *
    526        *  This function erases a sequence of elements from a %multimap.
    527        *  Note that this function only erases the elements, and that if
    528        *  the elements themselves are pointers, the pointed-to memory is not
    529        *  touched in any way.  Managing the pointer is the user's responsibility.
    530        */
    531       void
    532       erase(iterator __first, iterator __last)
    533       { _M_t.erase(__first, __last); }
    534 
    535       /**
    536        *  @brief  Swaps data with another %multimap.
    537        *  @param  x  A %multimap of the same element and allocator types.
    538        *
    539        *  This exchanges the elements between two multimaps in constant time.
    540        *  (It is only swapping a pointer, an integer, and an instance of
    541        *  the @c Compare type (which itself is often stateless and empty), so it
    542        *  should be quite fast.)
    543        *  Note that the global std::swap() function is specialized such that
    544        *  std::swap(m1,m2) will feed to this function.
    545        */
    546       void
    547 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    548       swap(multimap&& __x)
    549 #else
    550       swap(multimap& __x)
    551 #endif
    552       { _M_t.swap(__x._M_t); }
    553 
    554       /**
    555        *  Erases all elements in a %multimap.  Note that this function only
    556        *  erases the elements, and that if the elements themselves are pointers,
    557        *  the pointed-to memory is not touched in any way.  Managing the pointer
    558        *  is the user's responsibility.
    559        */
    560       void
    561       clear()
    562       { _M_t.clear(); }
    563 
    564       // observers
    565       /**
    566        *  Returns the key comparison object out of which the %multimap
    567        *  was constructed.
    568        */
    569       key_compare
    570       key_comp() const
    571       { return _M_t.key_comp(); }
    572 
    573       /**
    574        *  Returns a value comparison object, built from the key comparison
    575        *  object out of which the %multimap was constructed.
    576        */
    577       value_compare
    578       value_comp() const
    579       { return value_compare(_M_t.key_comp()); }
    580 
    581       // multimap operations
    582       /**
    583        *  @brief Tries to locate an element in a %multimap.
    584        *  @param  x  Key of (key, value) pair to be located.
    585        *  @return  Iterator pointing to sought-after element,
    586        *           or end() if not found.
    587        *
    588        *  This function takes a key and tries to locate the element with which
    589        *  the key matches.  If successful the function returns an iterator
    590        *  pointing to the sought after %pair.  If unsuccessful it returns the
    591        *  past-the-end ( @c end() ) iterator.
    592        */
    593       iterator
    594       find(const key_type& __x)
    595       { return _M_t.find(__x); }
    596 
    597       /**
    598        *  @brief Tries to locate an element in a %multimap.
    599        *  @param  x  Key of (key, value) pair to be located.
    600        *  @return  Read-only (constant) iterator pointing to sought-after
    601        *           element, or end() if not found.
    602        *
    603        *  This function takes a key and tries to locate the element with which
    604        *  the key matches.  If successful the function returns a constant
    605        *  iterator pointing to the sought after %pair.  If unsuccessful it
    606        *  returns the past-the-end ( @c end() ) iterator.
    607        */
    608       const_iterator
    609       find(const key_type& __x) const
    610       { return _M_t.find(__x); }
    611 
    612       /**
    613        *  @brief Finds the number of elements with given key.
    614        *  @param  x  Key of (key, value) pairs to be located.
    615        *  @return Number of elements with specified key.
    616        */
    617       size_type
    618       count(const key_type& __x) const
    619       { return _M_t.count(__x); }
    620 
    621       /**
    622        *  @brief Finds the beginning of a subsequence matching given key.
    623        *  @param  x  Key of (key, value) pair to be located.
    624        *  @return  Iterator pointing to first element equal to or greater
    625        *           than key, or end().
    626        *
    627        *  This function returns the first element of a subsequence of elements
    628        *  that matches the given key.  If unsuccessful it returns an iterator
    629        *  pointing to the first element that has a greater value than given key
    630        *  or end() if no such element exists.
    631        */
    632       iterator
    633       lower_bound(const key_type& __x)
    634       { return _M_t.lower_bound(__x); }
    635 
    636       /**
    637        *  @brief Finds the beginning of a subsequence matching given key.
    638        *  @param  x  Key of (key, value) pair to be located.
    639        *  @return  Read-only (constant) iterator pointing to first element
    640        *           equal to or greater than key, or end().
    641        *
    642        *  This function returns the first element of a subsequence of elements
    643        *  that matches the given key.  If unsuccessful the iterator will point
    644        *  to the next greatest element or, if no such greater element exists, to
    645        *  end().
    646        */
    647       const_iterator
    648       lower_bound(const key_type& __x) const
    649       { return _M_t.lower_bound(__x); }
    650 
    651       /**
    652        *  @brief Finds the end of a subsequence matching given key.
    653        *  @param  x  Key of (key, value) pair to be located.
    654        *  @return Iterator pointing to the first element
    655        *          greater than key, or end().
    656        */
    657       iterator
    658       upper_bound(const key_type& __x)
    659       { return _M_t.upper_bound(__x); }
    660 
    661       /**
    662        *  @brief Finds the end of a subsequence matching given key.
    663        *  @param  x  Key of (key, value) pair to be located.
    664        *  @return  Read-only (constant) iterator pointing to first iterator
    665        *           greater than key, or end().
    666        */
    667       const_iterator
    668       upper_bound(const key_type& __x) const
    669       { return _M_t.upper_bound(__x); }
    670 
    671       /**
    672        *  @brief Finds a subsequence matching given key.
    673        *  @param  x  Key of (key, value) pairs to be located.
    674        *  @return  Pair of iterators that possibly points to the subsequence
    675        *           matching given key.
    676        *
    677        *  This function is equivalent to
    678        *  @code
    679        *    std::make_pair(c.lower_bound(val),
    680        *                   c.upper_bound(val))
    681        *  @endcode
    682        *  (but is faster than making the calls separately).
    683        */
    684       std::pair<iterator, iterator>
    685       equal_range(const key_type& __x)
    686       { return _M_t.equal_range(__x); }
    687 
    688       /**
    689        *  @brief Finds a subsequence matching given key.
    690        *  @param  x  Key of (key, value) pairs to be located.
    691        *  @return  Pair of read-only (constant) iterators that possibly points
    692        *           to the subsequence matching given key.
    693        *
    694        *  This function is equivalent to
    695        *  @code
    696        *    std::make_pair(c.lower_bound(val),
    697        *                   c.upper_bound(val))
    698        *  @endcode
    699        *  (but is faster than making the calls separately).
    700        */
    701       std::pair<const_iterator, const_iterator>
    702       equal_range(const key_type& __x) const
    703       { return _M_t.equal_range(__x); }
    704 
    705       template<typename _K1, typename _T1, typename _C1, typename _A1>
    706         friend bool
    707         operator==(const multimap<_K1, _T1, _C1, _A1>&,
    708 		   const multimap<_K1, _T1, _C1, _A1>&);
    709 
    710       template<typename _K1, typename _T1, typename _C1, typename _A1>
    711         friend bool
    712         operator<(const multimap<_K1, _T1, _C1, _A1>&,
    713 		  const multimap<_K1, _T1, _C1, _A1>&);
    714   };
    715 
    716   /**
    717    *  @brief  Multimap equality comparison.
    718    *  @param  x  A %multimap.
    719    *  @param  y  A %multimap of the same type as @a x.
    720    *  @return  True iff the size and elements of the maps are equal.
    721    *
    722    *  This is an equivalence relation.  It is linear in the size of the
    723    *  multimaps.  Multimaps are considered equivalent if their sizes are equal,
    724    *  and if corresponding elements compare equal.
    725   */
    726   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    727     inline bool
    728     operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
    729                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    730     { return __x._M_t == __y._M_t; }
    731 
    732   /**
    733    *  @brief  Multimap ordering relation.
    734    *  @param  x  A %multimap.
    735    *  @param  y  A %multimap of the same type as @a x.
    736    *  @return  True iff @a x is lexicographically less than @a y.
    737    *
    738    *  This is a total ordering relation.  It is linear in the size of the
    739    *  multimaps.  The elements must be comparable with @c <.
    740    *
    741    *  See std::lexicographical_compare() for how the determination is made.
    742   */
    743   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    744     inline bool
    745     operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
    746               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    747     { return __x._M_t < __y._M_t; }
    748 
    749   /// Based on operator==
    750   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    751     inline bool
    752     operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
    753                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    754     { return !(__x == __y); }
    755 
    756   /// Based on operator<
    757   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    758     inline bool
    759     operator>(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
    760               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    761     { return __y < __x; }
    762 
    763   /// Based on operator<
    764   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    765     inline bool
    766     operator<=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
    767                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    768     { return !(__y < __x); }
    769 
    770   /// Based on operator<
    771   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    772     inline bool
    773     operator>=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
    774                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    775     { return !(__x < __y); }
    776 
    777   /// See std::multimap::swap().
    778   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    779     inline void
    780     swap(multimap<_Key, _Tp, _Compare, _Alloc>& __x,
    781          multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    782     { __x.swap(__y); }
    783 
    784 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    785   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    786     inline void
    787     swap(multimap<_Key, _Tp, _Compare, _Alloc>&& __x,
    788          multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    789     { __x.swap(__y); }
    790 
    791   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    792     inline void
    793     swap(multimap<_Key, _Tp, _Compare, _Alloc>& __x,
    794          multimap<_Key, _Tp, _Compare, _Alloc>&& __y)
    795     { __x.swap(__y); }
    796 #endif
    797 
    798 _GLIBCXX_END_NESTED_NAMESPACE
    799 
    800 #endif /* _STL_MULTIMAP_H */
    801