libstdc++
stl_multimap.h
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00001 // Multimap implementation -*- C++ -*-
00002 
00003 // Copyright (C) 2001-2019 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 3, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /*
00026  *
00027  * Copyright (c) 1994
00028  * Hewlett-Packard Company
00029  *
00030  * Permission to use, copy, modify, distribute and sell this software
00031  * and its documentation for any purpose is hereby granted without fee,
00032  * provided that the above copyright notice appear in all copies and
00033  * that both that copyright notice and this permission notice appear
00034  * in supporting documentation.  Hewlett-Packard Company makes no
00035  * representations about the suitability of this software for any
00036  * purpose.  It is provided "as is" without express or implied warranty.
00037  *
00038  *
00039  * Copyright (c) 1996,1997
00040  * Silicon Graphics Computer Systems, Inc.
00041  *
00042  * Permission to use, copy, modify, distribute and sell this software
00043  * and its documentation for any purpose is hereby granted without fee,
00044  * provided that the above copyright notice appear in all copies and
00045  * that both that copyright notice and this permission notice appear
00046  * in supporting documentation.  Silicon Graphics makes no
00047  * representations about the suitability of this software for any
00048  * purpose.  It is provided "as is" without express or implied warranty.
00049  */
00050 
00051 /** @file bits/stl_multimap.h
00052  *  This is an internal header file, included by other library headers.
00053  *  Do not attempt to use it directly. @headername{map}
00054  */
00055 
00056 #ifndef _STL_MULTIMAP_H
00057 #define _STL_MULTIMAP_H 1
00058 
00059 #include <bits/concept_check.h>
00060 #if __cplusplus >= 201103L
00061 #include <initializer_list>
00062 #endif
00063 
00064 namespace std _GLIBCXX_VISIBILITY(default)
00065 {
00066 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00067 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
00068 
00069   template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
00070     class map;
00071 
00072   /**
00073    *  @brief A standard container made up of (key,value) pairs, which can be
00074    *  retrieved based on a key, in logarithmic time.
00075    *
00076    *  @ingroup associative_containers
00077    *
00078    *  @tparam _Key  Type of key objects.
00079    *  @tparam  _Tp  Type of mapped objects.
00080    *  @tparam _Compare  Comparison function object type, defaults to less<_Key>.
00081    *  @tparam _Alloc  Allocator type, defaults to
00082    *                  allocator<pair<const _Key, _Tp>.
00083    *
00084    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
00085    *  <a href="tables.html#66">reversible container</a>, and an
00086    *  <a href="tables.html#69">associative container</a> (using equivalent
00087    *  keys).  For a @c multimap<Key,T> the key_type is Key, the mapped_type
00088    *  is T, and the value_type is std::pair<const Key,T>.
00089    *
00090    *  Multimaps support bidirectional iterators.
00091    *
00092    *  The private tree data is declared exactly the same way for map and
00093    *  multimap; the distinction is made entirely in how the tree functions are
00094    *  called (*_unique versus *_equal, same as the standard).
00095   */
00096   template <typename _Key, typename _Tp,
00097             typename _Compare = std::less<_Key>,
00098             typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
00099     class multimap
00100     {
00101     public:
00102       typedef _Key                                      key_type;
00103       typedef _Tp                                       mapped_type;
00104       typedef std::pair<const _Key, _Tp>                value_type;
00105       typedef _Compare                                  key_compare;
00106       typedef _Alloc                                    allocator_type;
00107 
00108     private:
00109 #ifdef _GLIBCXX_CONCEPT_CHECKS
00110       // concept requirements
00111       typedef typename _Alloc::value_type               _Alloc_value_type;
00112 # if __cplusplus < 201103L
00113       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
00114 # endif
00115       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
00116                                 _BinaryFunctionConcept)
00117       __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
00118 #endif
00119 
00120 #if __cplusplus >= 201103L && defined(__STRICT_ANSI__)
00121       static_assert(is_same<typename _Alloc::value_type, value_type>::value,
00122           "std::multimap must have the same value_type as its allocator");
00123 #endif
00124 
00125     public:
00126       class value_compare
00127       : public std::binary_function<value_type, value_type, bool>
00128       {
00129         friend class multimap<_Key, _Tp, _Compare, _Alloc>;
00130       protected:
00131         _Compare comp;
00132 
00133         value_compare(_Compare __c)
00134         : comp(__c) { }
00135 
00136       public:
00137         bool operator()(const value_type& __x, const value_type& __y) const
00138         { return comp(__x.first, __y.first); }
00139       };
00140 
00141     private:
00142       /// This turns a red-black tree into a [multi]map.
00143       typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
00144         rebind<value_type>::other _Pair_alloc_type;
00145 
00146       typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
00147                        key_compare, _Pair_alloc_type> _Rep_type;
00148       /// The actual tree structure.
00149       _Rep_type _M_t;
00150 
00151       typedef __gnu_cxx::__alloc_traits<_Pair_alloc_type> _Alloc_traits;
00152 
00153     public:
00154       // many of these are specified differently in ISO, but the following are
00155       // "functionally equivalent"
00156       typedef typename _Alloc_traits::pointer            pointer;
00157       typedef typename _Alloc_traits::const_pointer      const_pointer;
00158       typedef typename _Alloc_traits::reference          reference;
00159       typedef typename _Alloc_traits::const_reference    const_reference;
00160       typedef typename _Rep_type::iterator               iterator;
00161       typedef typename _Rep_type::const_iterator         const_iterator;
00162       typedef typename _Rep_type::size_type              size_type;
00163       typedef typename _Rep_type::difference_type        difference_type;
00164       typedef typename _Rep_type::reverse_iterator       reverse_iterator;
00165       typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
00166 
00167 #if __cplusplus > 201402L
00168       using node_type = typename _Rep_type::node_type;
00169 #endif
00170 
00171       // [23.3.2] construct/copy/destroy
00172       // (get_allocator() is also listed in this section)
00173 
00174       /**
00175        *  @brief  Default constructor creates no elements.
00176        */
00177 #if __cplusplus < 201103L
00178       multimap() : _M_t() { }
00179 #else
00180       multimap() = default;
00181 #endif
00182 
00183       /**
00184        *  @brief  Creates a %multimap with no elements.
00185        *  @param  __comp  A comparison object.
00186        *  @param  __a  An allocator object.
00187        */
00188       explicit
00189       multimap(const _Compare& __comp,
00190                const allocator_type& __a = allocator_type())
00191       : _M_t(__comp, _Pair_alloc_type(__a)) { }
00192 
00193       /**
00194        *  @brief  %Multimap copy constructor.
00195        *
00196        *  Whether the allocator is copied depends on the allocator traits.
00197        */
00198 #if __cplusplus < 201103L
00199       multimap(const multimap& __x)
00200       : _M_t(__x._M_t) { }
00201 #else
00202       multimap(const multimap&) = default;
00203 
00204       /**
00205        *  @brief  %Multimap move constructor.
00206        *
00207        *  The newly-created %multimap contains the exact contents of the
00208        *  moved instance. The moved instance is a valid, but unspecified
00209        *  %multimap.
00210        */
00211       multimap(multimap&&) = default;
00212 
00213       /**
00214        *  @brief  Builds a %multimap from an initializer_list.
00215        *  @param  __l  An initializer_list.
00216        *  @param  __comp  A comparison functor.
00217        *  @param  __a  An allocator object.
00218        *
00219        *  Create a %multimap consisting of copies of the elements from
00220        *  the initializer_list.  This is linear in N if the list is already
00221        *  sorted, and NlogN otherwise (where N is @a __l.size()).
00222        */
00223       multimap(initializer_list<value_type> __l,
00224                const _Compare& __comp = _Compare(),
00225                const allocator_type& __a = allocator_type())
00226       : _M_t(__comp, _Pair_alloc_type(__a))
00227       { _M_t._M_insert_range_equal(__l.begin(), __l.end()); }
00228 
00229       /// Allocator-extended default constructor.
00230       explicit
00231       multimap(const allocator_type& __a)
00232       : _M_t(_Pair_alloc_type(__a)) { }
00233 
00234       /// Allocator-extended copy constructor.
00235       multimap(const multimap& __m, const allocator_type& __a)
00236       : _M_t(__m._M_t, _Pair_alloc_type(__a)) { }
00237 
00238       /// Allocator-extended move constructor.
00239       multimap(multimap&& __m, const allocator_type& __a)
00240       noexcept(is_nothrow_copy_constructible<_Compare>::value
00241                && _Alloc_traits::_S_always_equal())
00242       : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { }
00243 
00244       /// Allocator-extended initialier-list constructor.
00245       multimap(initializer_list<value_type> __l, const allocator_type& __a)
00246       : _M_t(_Pair_alloc_type(__a))
00247       { _M_t._M_insert_range_equal(__l.begin(), __l.end()); }
00248 
00249       /// Allocator-extended range constructor.
00250       template<typename _InputIterator>
00251         multimap(_InputIterator __first, _InputIterator __last,
00252                  const allocator_type& __a)
00253         : _M_t(_Pair_alloc_type(__a))
00254         { _M_t._M_insert_range_equal(__first, __last); }
00255 #endif
00256 
00257       /**
00258        *  @brief  Builds a %multimap from a range.
00259        *  @param  __first  An input iterator.
00260        *  @param  __last  An input iterator.
00261        *
00262        *  Create a %multimap consisting of copies of the elements from
00263        *  [__first,__last).  This is linear in N if the range is already sorted,
00264        *  and NlogN otherwise (where N is distance(__first,__last)).
00265        */
00266       template<typename _InputIterator>
00267         multimap(_InputIterator __first, _InputIterator __last)
00268         : _M_t()
00269         { _M_t._M_insert_range_equal(__first, __last); }
00270 
00271       /**
00272        *  @brief  Builds a %multimap from a range.
00273        *  @param  __first  An input iterator.
00274        *  @param  __last  An input iterator.
00275        *  @param  __comp  A comparison functor.
00276        *  @param  __a  An allocator object.
00277        *
00278        *  Create a %multimap consisting of copies of the elements from
00279        *  [__first,__last).  This is linear in N if the range is already sorted,
00280        *  and NlogN otherwise (where N is distance(__first,__last)).
00281        */
00282       template<typename _InputIterator>
00283         multimap(_InputIterator __first, _InputIterator __last,
00284                  const _Compare& __comp,
00285                  const allocator_type& __a = allocator_type())
00286         : _M_t(__comp, _Pair_alloc_type(__a))
00287         { _M_t._M_insert_range_equal(__first, __last); }
00288 
00289 #if __cplusplus >= 201103L
00290       /**
00291        *  The dtor only erases the elements, and note that if the elements
00292        *  themselves are pointers, the pointed-to memory is not touched in any
00293        *  way. Managing the pointer is the user's responsibility.
00294        */
00295       ~multimap() = default;
00296 #endif
00297 
00298       /**
00299        *  @brief  %Multimap assignment operator.
00300        *
00301        *  Whether the allocator is copied depends on the allocator traits.
00302        */
00303 #if __cplusplus < 201103L
00304       multimap&
00305       operator=(const multimap& __x)
00306       {
00307         _M_t = __x._M_t;
00308         return *this;
00309       }
00310 #else
00311       multimap&
00312       operator=(const multimap&) = default;
00313 
00314       /// Move assignment operator.
00315       multimap&
00316       operator=(multimap&&) = default;
00317 
00318       /**
00319        *  @brief  %Multimap list assignment operator.
00320        *  @param  __l  An initializer_list.
00321        *
00322        *  This function fills a %multimap with copies of the elements
00323        *  in the initializer list @a __l.
00324        *
00325        *  Note that the assignment completely changes the %multimap and
00326        *  that the resulting %multimap's size is the same as the number
00327        *  of elements assigned.
00328        */
00329       multimap&
00330       operator=(initializer_list<value_type> __l)
00331       {
00332         _M_t._M_assign_equal(__l.begin(), __l.end());
00333         return *this;
00334       }
00335 #endif
00336 
00337       /// Get a copy of the memory allocation object.
00338       allocator_type
00339       get_allocator() const _GLIBCXX_NOEXCEPT
00340       { return allocator_type(_M_t.get_allocator()); }
00341 
00342       // iterators
00343       /**
00344        *  Returns a read/write iterator that points to the first pair in the
00345        *  %multimap.  Iteration is done in ascending order according to the
00346        *  keys.
00347        */
00348       iterator
00349       begin() _GLIBCXX_NOEXCEPT
00350       { return _M_t.begin(); }
00351 
00352       /**
00353        *  Returns a read-only (constant) iterator that points to the first pair
00354        *  in the %multimap.  Iteration is done in ascending order according to
00355        *  the keys.
00356        */
00357       const_iterator
00358       begin() const _GLIBCXX_NOEXCEPT
00359       { return _M_t.begin(); }
00360 
00361       /**
00362        *  Returns a read/write iterator that points one past the last pair in
00363        *  the %multimap.  Iteration is done in ascending order according to the
00364        *  keys.
00365        */
00366       iterator
00367       end() _GLIBCXX_NOEXCEPT
00368       { return _M_t.end(); }
00369 
00370       /**
00371        *  Returns a read-only (constant) iterator that points one past the last
00372        *  pair in the %multimap.  Iteration is done in ascending order according
00373        *  to the keys.
00374        */
00375       const_iterator
00376       end() const _GLIBCXX_NOEXCEPT
00377       { return _M_t.end(); }
00378 
00379       /**
00380        *  Returns a read/write reverse iterator that points to the last pair in
00381        *  the %multimap.  Iteration is done in descending order according to the
00382        *  keys.
00383        */
00384       reverse_iterator
00385       rbegin() _GLIBCXX_NOEXCEPT
00386       { return _M_t.rbegin(); }
00387 
00388       /**
00389        *  Returns a read-only (constant) reverse iterator that points to the
00390        *  last pair in the %multimap.  Iteration is done in descending order
00391        *  according to the keys.
00392        */
00393       const_reverse_iterator
00394       rbegin() const _GLIBCXX_NOEXCEPT
00395       { return _M_t.rbegin(); }
00396 
00397       /**
00398        *  Returns a read/write reverse iterator that points to one before the
00399        *  first pair in the %multimap.  Iteration is done in descending order
00400        *  according to the keys.
00401        */
00402       reverse_iterator
00403       rend() _GLIBCXX_NOEXCEPT
00404       { return _M_t.rend(); }
00405 
00406       /**
00407        *  Returns a read-only (constant) reverse iterator that points to one
00408        *  before the first pair in the %multimap.  Iteration is done in
00409        *  descending order according to the keys.
00410        */
00411       const_reverse_iterator
00412       rend() const _GLIBCXX_NOEXCEPT
00413       { return _M_t.rend(); }
00414 
00415 #if __cplusplus >= 201103L
00416       /**
00417        *  Returns a read-only (constant) iterator that points to the first pair
00418        *  in the %multimap.  Iteration is done in ascending order according to
00419        *  the keys.
00420        */
00421       const_iterator
00422       cbegin() const noexcept
00423       { return _M_t.begin(); }
00424 
00425       /**
00426        *  Returns a read-only (constant) iterator that points one past the last
00427        *  pair in the %multimap.  Iteration is done in ascending order according
00428        *  to the keys.
00429        */
00430       const_iterator
00431       cend() const noexcept
00432       { return _M_t.end(); }
00433 
00434       /**
00435        *  Returns a read-only (constant) reverse iterator that points to the
00436        *  last pair in the %multimap.  Iteration is done in descending order
00437        *  according to the keys.
00438        */
00439       const_reverse_iterator
00440       crbegin() const noexcept
00441       { return _M_t.rbegin(); }
00442 
00443       /**
00444        *  Returns a read-only (constant) reverse iterator that points to one
00445        *  before the first pair in the %multimap.  Iteration is done in
00446        *  descending order according to the keys.
00447        */
00448       const_reverse_iterator
00449       crend() const noexcept
00450       { return _M_t.rend(); }
00451 #endif
00452 
00453       // capacity
00454       /** Returns true if the %multimap is empty.  */
00455       _GLIBCXX_NODISCARD bool
00456       empty() const _GLIBCXX_NOEXCEPT
00457       { return _M_t.empty(); }
00458 
00459       /** Returns the size of the %multimap.  */
00460       size_type
00461       size() const _GLIBCXX_NOEXCEPT
00462       { return _M_t.size(); }
00463 
00464       /** Returns the maximum size of the %multimap.  */
00465       size_type
00466       max_size() const _GLIBCXX_NOEXCEPT
00467       { return _M_t.max_size(); }
00468 
00469       // modifiers
00470 #if __cplusplus >= 201103L
00471       /**
00472        *  @brief Build and insert a std::pair into the %multimap.
00473        *
00474        *  @param __args  Arguments used to generate a new pair instance (see
00475        *                std::piecewise_contruct for passing arguments to each
00476        *                part of the pair constructor).
00477        *
00478        *  @return An iterator that points to the inserted (key,value) pair.
00479        *
00480        *  This function builds and inserts a (key, value) %pair into the
00481        *  %multimap.
00482        *  Contrary to a std::map the %multimap does not rely on unique keys and
00483        *  thus multiple pairs with the same key can be inserted.
00484        *
00485        *  Insertion requires logarithmic time.
00486        */
00487       template<typename... _Args>
00488         iterator
00489         emplace(_Args&&... __args)
00490         { return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); }
00491 
00492       /**
00493        *  @brief Builds and inserts a std::pair into the %multimap.
00494        *
00495        *  @param  __pos  An iterator that serves as a hint as to where the pair
00496        *                should be inserted.
00497        *  @param  __args  Arguments used to generate a new pair instance (see
00498        *                 std::piecewise_contruct for passing arguments to each
00499        *                 part of the pair constructor).
00500        *  @return An iterator that points to the inserted (key,value) pair.
00501        *
00502        *  This function inserts a (key, value) pair into the %multimap.
00503        *  Contrary to a std::map the %multimap does not rely on unique keys and
00504        *  thus multiple pairs with the same key can be inserted.
00505        *  Note that the first parameter is only a hint and can potentially
00506        *  improve the performance of the insertion process.  A bad hint would
00507        *  cause no gains in efficiency.
00508        *
00509        *  For more on @a hinting, see:
00510        *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
00511        *
00512        *  Insertion requires logarithmic time (if the hint is not taken).
00513        */
00514       template<typename... _Args>
00515         iterator
00516         emplace_hint(const_iterator __pos, _Args&&... __args)
00517         {
00518           return _M_t._M_emplace_hint_equal(__pos,
00519                                             std::forward<_Args>(__args)...);
00520         }
00521 #endif
00522 
00523       /**
00524        *  @brief Inserts a std::pair into the %multimap.
00525        *  @param  __x  Pair to be inserted (see std::make_pair for easy creation
00526        *             of pairs).
00527        *  @return An iterator that points to the inserted (key,value) pair.
00528        *
00529        *  This function inserts a (key, value) pair into the %multimap.
00530        *  Contrary to a std::map the %multimap does not rely on unique keys and
00531        *  thus multiple pairs with the same key can be inserted.
00532        *
00533        *  Insertion requires logarithmic time.
00534        *  @{
00535        */
00536       iterator
00537       insert(const value_type& __x)
00538       { return _M_t._M_insert_equal(__x); }
00539 
00540 #if __cplusplus >= 201103L
00541       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00542       // 2354. Unnecessary copying when inserting into maps with braced-init
00543       iterator
00544       insert(value_type&& __x)
00545       { return _M_t._M_insert_equal(std::move(__x)); }
00546 
00547       template<typename _Pair>
00548         __enable_if_t<is_constructible<value_type, _Pair>::value, iterator>
00549         insert(_Pair&& __x)
00550         { return _M_t._M_emplace_equal(std::forward<_Pair>(__x)); }
00551 #endif
00552       // @}
00553 
00554       /**
00555        *  @brief Inserts a std::pair into the %multimap.
00556        *  @param  __position  An iterator that serves as a hint as to where the
00557        *                      pair should be inserted.
00558        *  @param  __x  Pair to be inserted (see std::make_pair for easy creation
00559        *               of pairs).
00560        *  @return An iterator that points to the inserted (key,value) pair.
00561        *
00562        *  This function inserts a (key, value) pair into the %multimap.
00563        *  Contrary to a std::map the %multimap does not rely on unique keys and
00564        *  thus multiple pairs with the same key can be inserted.
00565        *  Note that the first parameter is only a hint and can potentially
00566        *  improve the performance of the insertion process.  A bad hint would
00567        *  cause no gains in efficiency.
00568        *
00569        *  For more on @a hinting, see:
00570        *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
00571        *
00572        *  Insertion requires logarithmic time (if the hint is not taken).
00573        * @{
00574        */
00575       iterator
00576 #if __cplusplus >= 201103L
00577       insert(const_iterator __position, const value_type& __x)
00578 #else
00579       insert(iterator __position, const value_type& __x)
00580 #endif
00581       { return _M_t._M_insert_equal_(__position, __x); }
00582 
00583 #if __cplusplus >= 201103L
00584       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00585       // 2354. Unnecessary copying when inserting into maps with braced-init
00586       iterator
00587       insert(const_iterator __position, value_type&& __x)
00588       { return _M_t._M_insert_equal_(__position, std::move(__x)); }
00589 
00590       template<typename _Pair>
00591         __enable_if_t<is_constructible<value_type, _Pair&&>::value, iterator>
00592         insert(const_iterator __position, _Pair&& __x)
00593         {
00594           return _M_t._M_emplace_hint_equal(__position,
00595                                             std::forward<_Pair>(__x));
00596         }
00597 #endif
00598       // @}
00599 
00600       /**
00601        *  @brief A template function that attempts to insert a range
00602        *  of elements.
00603        *  @param  __first  Iterator pointing to the start of the range to be
00604        *                   inserted.
00605        *  @param  __last  Iterator pointing to the end of the range.
00606        *
00607        *  Complexity similar to that of the range constructor.
00608        */
00609       template<typename _InputIterator>
00610         void
00611         insert(_InputIterator __first, _InputIterator __last)
00612         { _M_t._M_insert_range_equal(__first, __last); }
00613 
00614 #if __cplusplus >= 201103L
00615       /**
00616        *  @brief Attempts to insert a list of std::pairs into the %multimap.
00617        *  @param  __l  A std::initializer_list<value_type> of pairs to be
00618        *               inserted.
00619        *
00620        *  Complexity similar to that of the range constructor.
00621        */
00622       void
00623       insert(initializer_list<value_type> __l)
00624       { this->insert(__l.begin(), __l.end()); }
00625 #endif
00626 
00627 #if __cplusplus > 201402L
00628       /// Extract a node.
00629       node_type
00630       extract(const_iterator __pos)
00631       {
00632         __glibcxx_assert(__pos != end());
00633         return _M_t.extract(__pos);
00634       }
00635 
00636       /// Extract a node.
00637       node_type
00638       extract(const key_type& __x)
00639       { return _M_t.extract(__x); }
00640 
00641       /// Re-insert an extracted node.
00642       iterator
00643       insert(node_type&& __nh)
00644       { return _M_t._M_reinsert_node_equal(std::move(__nh)); }
00645 
00646       /// Re-insert an extracted node.
00647       iterator
00648       insert(const_iterator __hint, node_type&& __nh)
00649       { return _M_t._M_reinsert_node_hint_equal(__hint, std::move(__nh)); }
00650 
00651       template<typename, typename>
00652         friend class std::_Rb_tree_merge_helper;
00653 
00654       template<typename _C2>
00655         void
00656         merge(multimap<_Key, _Tp, _C2, _Alloc>& __source)
00657         {
00658           using _Merge_helper = _Rb_tree_merge_helper<multimap, _C2>;
00659           _M_t._M_merge_equal(_Merge_helper::_S_get_tree(__source));
00660         }
00661 
00662       template<typename _C2>
00663         void
00664         merge(multimap<_Key, _Tp, _C2, _Alloc>&& __source)
00665         { merge(__source); }
00666 
00667       template<typename _C2>
00668         void
00669         merge(map<_Key, _Tp, _C2, _Alloc>& __source)
00670         {
00671           using _Merge_helper = _Rb_tree_merge_helper<multimap, _C2>;
00672           _M_t._M_merge_equal(_Merge_helper::_S_get_tree(__source));
00673         }
00674 
00675       template<typename _C2>
00676         void
00677         merge(map<_Key, _Tp, _C2, _Alloc>&& __source)
00678         { merge(__source); }
00679 #endif // C++17
00680 
00681 #if __cplusplus >= 201103L
00682       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00683       // DR 130. Associative erase should return an iterator.
00684       /**
00685        *  @brief Erases an element from a %multimap.
00686        *  @param  __position  An iterator pointing to the element to be erased.
00687        *  @return An iterator pointing to the element immediately following
00688        *          @a position prior to the element being erased. If no such
00689        *          element exists, end() is returned.
00690        *
00691        *  This function erases an element, pointed to by the given iterator,
00692        *  from a %multimap.  Note that this function only erases the element,
00693        *  and that if the element is itself a pointer, the pointed-to memory is
00694        *  not touched in any way.  Managing the pointer is the user's
00695        *  responsibility.
00696        *
00697        * @{
00698        */
00699       iterator
00700       erase(const_iterator __position)
00701       { return _M_t.erase(__position); }
00702 
00703       // LWG 2059.
00704       _GLIBCXX_ABI_TAG_CXX11
00705       iterator
00706       erase(iterator __position)
00707       { return _M_t.erase(__position); }
00708       // @}
00709 #else
00710       /**
00711        *  @brief Erases an element from a %multimap.
00712        *  @param  __position  An iterator pointing to the element to be erased.
00713        *
00714        *  This function erases an element, pointed to by the given iterator,
00715        *  from a %multimap.  Note that this function only erases the element,
00716        *  and that if the element is itself a pointer, the pointed-to memory is
00717        *  not touched in any way.  Managing the pointer is the user's
00718        *  responsibility.
00719        */
00720       void
00721       erase(iterator __position)
00722       { _M_t.erase(__position); }
00723 #endif
00724 
00725       /**
00726        *  @brief Erases elements according to the provided key.
00727        *  @param  __x  Key of element to be erased.
00728        *  @return  The number of elements erased.
00729        *
00730        *  This function erases all elements located by the given key from a
00731        *  %multimap.
00732        *  Note that this function only erases the element, and that if
00733        *  the element is itself a pointer, the pointed-to memory is not touched
00734        *  in any way.  Managing the pointer is the user's responsibility.
00735        */
00736       size_type
00737       erase(const key_type& __x)
00738       { return _M_t.erase(__x); }
00739 
00740 #if __cplusplus >= 201103L
00741       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00742       // DR 130. Associative erase should return an iterator.
00743       /**
00744        *  @brief Erases a [first,last) range of elements from a %multimap.
00745        *  @param  __first  Iterator pointing to the start of the range to be
00746        *                   erased.
00747        *  @param __last Iterator pointing to the end of the range to be
00748        *                erased .
00749        *  @return The iterator @a __last.
00750        *
00751        *  This function erases a sequence of elements from a %multimap.
00752        *  Note that this function only erases the elements, and that if
00753        *  the elements themselves are pointers, the pointed-to memory is not
00754        *  touched in any way.  Managing the pointer is the user's
00755        *  responsibility.
00756        */
00757       iterator
00758       erase(const_iterator __first, const_iterator __last)
00759       { return _M_t.erase(__first, __last); }
00760 #else
00761       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00762       // DR 130. Associative erase should return an iterator.
00763       /**
00764        *  @brief Erases a [first,last) range of elements from a %multimap.
00765        *  @param  __first  Iterator pointing to the start of the range to be
00766        *                 erased.
00767        *  @param __last Iterator pointing to the end of the range to
00768        *                be erased.
00769        *
00770        *  This function erases a sequence of elements from a %multimap.
00771        *  Note that this function only erases the elements, and that if
00772        *  the elements themselves are pointers, the pointed-to memory is not
00773        *  touched in any way.  Managing the pointer is the user's
00774        *  responsibility.
00775        */
00776       void
00777       erase(iterator __first, iterator __last)
00778       { _M_t.erase(__first, __last); }
00779 #endif
00780 
00781       /**
00782        *  @brief  Swaps data with another %multimap.
00783        *  @param  __x  A %multimap of the same element and allocator types.
00784        *
00785        *  This exchanges the elements between two multimaps in constant time.
00786        *  (It is only swapping a pointer, an integer, and an instance of
00787        *  the @c Compare type (which itself is often stateless and empty), so it
00788        *  should be quite fast.)
00789        *  Note that the global std::swap() function is specialized such that
00790        *  std::swap(m1,m2) will feed to this function.
00791        *
00792        *  Whether the allocators are swapped depends on the allocator traits.
00793        */
00794       void
00795       swap(multimap& __x)
00796       _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
00797       { _M_t.swap(__x._M_t); }
00798 
00799       /**
00800        *  Erases all elements in a %multimap.  Note that this function only
00801        *  erases the elements, and that if the elements themselves are pointers,
00802        *  the pointed-to memory is not touched in any way.  Managing the pointer
00803        *  is the user's responsibility.
00804        */
00805       void
00806       clear() _GLIBCXX_NOEXCEPT
00807       { _M_t.clear(); }
00808 
00809       // observers
00810       /**
00811        *  Returns the key comparison object out of which the %multimap
00812        *  was constructed.
00813        */
00814       key_compare
00815       key_comp() const
00816       { return _M_t.key_comp(); }
00817 
00818       /**
00819        *  Returns a value comparison object, built from the key comparison
00820        *  object out of which the %multimap was constructed.
00821        */
00822       value_compare
00823       value_comp() const
00824       { return value_compare(_M_t.key_comp()); }
00825 
00826       // multimap operations
00827 
00828       //@{
00829       /**
00830        *  @brief Tries to locate an element in a %multimap.
00831        *  @param  __x  Key of (key, value) pair to be located.
00832        *  @return  Iterator pointing to sought-after element,
00833        *           or end() if not found.
00834        *
00835        *  This function takes a key and tries to locate the element with which
00836        *  the key matches.  If successful the function returns an iterator
00837        *  pointing to the sought after %pair.  If unsuccessful it returns the
00838        *  past-the-end ( @c end() ) iterator.
00839        */
00840       iterator
00841       find(const key_type& __x)
00842       { return _M_t.find(__x); }
00843 
00844 #if __cplusplus > 201103L
00845       template<typename _Kt>
00846         auto
00847         find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
00848         { return _M_t._M_find_tr(__x); }
00849 #endif
00850       //@}
00851 
00852       //@{
00853       /**
00854        *  @brief Tries to locate an element in a %multimap.
00855        *  @param  __x  Key of (key, value) pair to be located.
00856        *  @return  Read-only (constant) iterator pointing to sought-after
00857        *           element, or end() if not found.
00858        *
00859        *  This function takes a key and tries to locate the element with which
00860        *  the key matches.  If successful the function returns a constant
00861        *  iterator pointing to the sought after %pair.  If unsuccessful it
00862        *  returns the past-the-end ( @c end() ) iterator.
00863        */
00864       const_iterator
00865       find(const key_type& __x) const
00866       { return _M_t.find(__x); }
00867 
00868 #if __cplusplus > 201103L
00869       template<typename _Kt>
00870         auto
00871         find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
00872         { return _M_t._M_find_tr(__x); }
00873 #endif
00874       //@}
00875 
00876       //@{
00877       /**
00878        *  @brief Finds the number of elements with given key.
00879        *  @param  __x  Key of (key, value) pairs to be located.
00880        *  @return Number of elements with specified key.
00881        */
00882       size_type
00883       count(const key_type& __x) const
00884       { return _M_t.count(__x); }
00885 
00886 #if __cplusplus > 201103L
00887       template<typename _Kt>
00888         auto
00889         count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
00890         { return _M_t._M_count_tr(__x); }
00891 #endif
00892       //@}
00893 
00894 #if __cplusplus > 201703L
00895       //@{
00896       /**
00897        *  @brief  Finds whether an element with the given key exists.
00898        *  @param  __x  Key of (key, value) pairs to be located.
00899        *  @return  True if there is any element with the specified key.
00900        */
00901       bool
00902       contains(const key_type& __x) const
00903       { return _M_t.find(__x) != _M_t.end(); }
00904 
00905       template<typename _Kt>
00906         auto
00907         contains(const _Kt& __x) const
00908         -> decltype(_M_t._M_find_tr(__x), void(), true)
00909         { return _M_t._M_find_tr(__x) != _M_t.end(); }
00910       //@}
00911 #endif
00912 
00913       //@{
00914       /**
00915        *  @brief Finds the beginning of a subsequence matching given key.
00916        *  @param  __x  Key of (key, value) pair to be located.
00917        *  @return  Iterator pointing to first element equal to or greater
00918        *           than key, or end().
00919        *
00920        *  This function returns the first element of a subsequence of elements
00921        *  that matches the given key.  If unsuccessful it returns an iterator
00922        *  pointing to the first element that has a greater value than given key
00923        *  or end() if no such element exists.
00924        */
00925       iterator
00926       lower_bound(const key_type& __x)
00927       { return _M_t.lower_bound(__x); }
00928 
00929 #if __cplusplus > 201103L
00930       template<typename _Kt>
00931         auto
00932         lower_bound(const _Kt& __x)
00933         -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
00934         { return iterator(_M_t._M_lower_bound_tr(__x)); }
00935 #endif
00936       //@}
00937 
00938       //@{
00939       /**
00940        *  @brief Finds the beginning of a subsequence matching given key.
00941        *  @param  __x  Key of (key, value) pair to be located.
00942        *  @return  Read-only (constant) iterator pointing to first element
00943        *           equal to or greater than key, or end().
00944        *
00945        *  This function returns the first element of a subsequence of
00946        *  elements that matches the given key.  If unsuccessful the
00947        *  iterator will point to the next greatest element or, if no
00948        *  such greater element exists, to end().
00949        */
00950       const_iterator
00951       lower_bound(const key_type& __x) const
00952       { return _M_t.lower_bound(__x); }
00953 
00954 #if __cplusplus > 201103L
00955       template<typename _Kt>
00956         auto
00957         lower_bound(const _Kt& __x) const
00958         -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
00959         { return const_iterator(_M_t._M_lower_bound_tr(__x)); }
00960 #endif
00961       //@}
00962 
00963       //@{
00964       /**
00965        *  @brief Finds the end of a subsequence matching given key.
00966        *  @param  __x  Key of (key, value) pair to be located.
00967        *  @return Iterator pointing to the first element
00968        *          greater than key, or end().
00969        */
00970       iterator
00971       upper_bound(const key_type& __x)
00972       { return _M_t.upper_bound(__x); }
00973 
00974 #if __cplusplus > 201103L
00975       template<typename _Kt>
00976         auto
00977         upper_bound(const _Kt& __x)
00978         -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
00979         { return iterator(_M_t._M_upper_bound_tr(__x)); }
00980 #endif
00981       //@}
00982 
00983       //@{
00984       /**
00985        *  @brief Finds the end of a subsequence matching given key.
00986        *  @param  __x  Key of (key, value) pair to be located.
00987        *  @return  Read-only (constant) iterator pointing to first iterator
00988        *           greater than key, or end().
00989        */
00990       const_iterator
00991       upper_bound(const key_type& __x) const
00992       { return _M_t.upper_bound(__x); }
00993 
00994 #if __cplusplus > 201103L
00995       template<typename _Kt>
00996         auto
00997         upper_bound(const _Kt& __x) const
00998         -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
00999         { return const_iterator(_M_t._M_upper_bound_tr(__x)); }
01000 #endif
01001       //@}
01002 
01003       //@{
01004       /**
01005        *  @brief Finds a subsequence matching given key.
01006        *  @param  __x  Key of (key, value) pairs to be located.
01007        *  @return  Pair of iterators that possibly points to the subsequence
01008        *           matching given key.
01009        *
01010        *  This function is equivalent to
01011        *  @code
01012        *    std::make_pair(c.lower_bound(val),
01013        *                   c.upper_bound(val))
01014        *  @endcode
01015        *  (but is faster than making the calls separately).
01016        */
01017       std::pair<iterator, iterator>
01018       equal_range(const key_type& __x)
01019       { return _M_t.equal_range(__x); }
01020 
01021 #if __cplusplus > 201103L
01022       template<typename _Kt>
01023         auto
01024         equal_range(const _Kt& __x)
01025         -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
01026         { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
01027 #endif
01028       //@}
01029 
01030       //@{
01031       /**
01032        *  @brief Finds a subsequence matching given key.
01033        *  @param  __x  Key of (key, value) pairs to be located.
01034        *  @return  Pair of read-only (constant) iterators that possibly points
01035        *           to the subsequence matching given key.
01036        *
01037        *  This function is equivalent to
01038        *  @code
01039        *    std::make_pair(c.lower_bound(val),
01040        *                   c.upper_bound(val))
01041        *  @endcode
01042        *  (but is faster than making the calls separately).
01043        */
01044       std::pair<const_iterator, const_iterator>
01045       equal_range(const key_type& __x) const
01046       { return _M_t.equal_range(__x); }
01047 
01048 #if __cplusplus > 201103L
01049       template<typename _Kt>
01050         auto
01051         equal_range(const _Kt& __x) const
01052         -> decltype(pair<const_iterator, const_iterator>(
01053               _M_t._M_equal_range_tr(__x)))
01054         {
01055           return pair<const_iterator, const_iterator>(
01056               _M_t._M_equal_range_tr(__x));
01057         }
01058 #endif
01059       //@}
01060 
01061       template<typename _K1, typename _T1, typename _C1, typename _A1>
01062         friend bool
01063         operator==(const multimap<_K1, _T1, _C1, _A1>&,
01064                    const multimap<_K1, _T1, _C1, _A1>&);
01065 
01066       template<typename _K1, typename _T1, typename _C1, typename _A1>
01067         friend bool
01068         operator<(const multimap<_K1, _T1, _C1, _A1>&,
01069                   const multimap<_K1, _T1, _C1, _A1>&);
01070   };
01071 
01072 #if __cpp_deduction_guides >= 201606
01073 
01074   template<typename _InputIterator,
01075            typename _Compare = less<__iter_key_t<_InputIterator>>,
01076            typename _Allocator = allocator<__iter_to_alloc_t<_InputIterator>>,
01077            typename = _RequireInputIter<_InputIterator>,
01078            typename = _RequireNotAllocator<_Compare>,
01079            typename = _RequireAllocator<_Allocator>>
01080     multimap(_InputIterator, _InputIterator,
01081              _Compare = _Compare(), _Allocator = _Allocator())
01082     -> multimap<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
01083                 _Compare, _Allocator>;
01084 
01085   template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
01086            typename _Allocator = allocator<pair<const _Key, _Tp>>,
01087            typename = _RequireNotAllocator<_Compare>,
01088            typename = _RequireAllocator<_Allocator>>
01089     multimap(initializer_list<pair<_Key, _Tp>>,
01090              _Compare = _Compare(), _Allocator = _Allocator())
01091     -> multimap<_Key, _Tp, _Compare, _Allocator>;
01092 
01093   template<typename _InputIterator, typename _Allocator,
01094            typename = _RequireInputIter<_InputIterator>,
01095            typename = _RequireAllocator<_Allocator>>
01096     multimap(_InputIterator, _InputIterator, _Allocator)
01097     -> multimap<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
01098                 less<__iter_key_t<_InputIterator>>, _Allocator>;
01099 
01100   template<typename _Key, typename _Tp, typename _Allocator,
01101            typename = _RequireAllocator<_Allocator>>
01102     multimap(initializer_list<pair<_Key, _Tp>>, _Allocator)
01103     -> multimap<_Key, _Tp, less<_Key>, _Allocator>;
01104 
01105 #endif
01106 
01107   /**
01108    *  @brief  Multimap equality comparison.
01109    *  @param  __x  A %multimap.
01110    *  @param  __y  A %multimap of the same type as @a __x.
01111    *  @return  True iff the size and elements of the maps are equal.
01112    *
01113    *  This is an equivalence relation.  It is linear in the size of the
01114    *  multimaps.  Multimaps are considered equivalent if their sizes are equal,
01115    *  and if corresponding elements compare equal.
01116   */
01117   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01118     inline bool
01119     operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01120                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01121     { return __x._M_t == __y._M_t; }
01122 
01123   /**
01124    *  @brief  Multimap ordering relation.
01125    *  @param  __x  A %multimap.
01126    *  @param  __y  A %multimap of the same type as @a __x.
01127    *  @return  True iff @a x is lexicographically less than @a y.
01128    *
01129    *  This is a total ordering relation.  It is linear in the size of the
01130    *  multimaps.  The elements must be comparable with @c <.
01131    *
01132    *  See std::lexicographical_compare() for how the determination is made.
01133   */
01134   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01135     inline bool
01136     operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01137               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01138     { return __x._M_t < __y._M_t; }
01139 
01140   /// Based on operator==
01141   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01142     inline bool
01143     operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01144                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01145     { return !(__x == __y); }
01146 
01147   /// Based on operator<
01148   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01149     inline bool
01150     operator>(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01151               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01152     { return __y < __x; }
01153 
01154   /// Based on operator<
01155   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01156     inline bool
01157     operator<=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01158                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01159     { return !(__y < __x); }
01160 
01161   /// Based on operator<
01162   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01163     inline bool
01164     operator>=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01165                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01166     { return !(__x < __y); }
01167 
01168   /// See std::multimap::swap().
01169   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01170     inline void
01171     swap(multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01172          multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01173     _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
01174     { __x.swap(__y); }
01175 
01176 _GLIBCXX_END_NAMESPACE_CONTAINER
01177 
01178 #if __cplusplus > 201402L
01179   // Allow std::multimap access to internals of compatible maps.
01180   template<typename _Key, typename _Val, typename _Cmp1, typename _Alloc,
01181            typename _Cmp2>
01182     struct
01183     _Rb_tree_merge_helper<_GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp1, _Alloc>,
01184                           _Cmp2>
01185     {
01186     private:
01187       friend class _GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp1, _Alloc>;
01188 
01189       static auto&
01190       _S_get_tree(_GLIBCXX_STD_C::map<_Key, _Val, _Cmp2, _Alloc>& __map)
01191       { return __map._M_t; }
01192 
01193       static auto&
01194       _S_get_tree(_GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp2, _Alloc>& __map)
01195       { return __map._M_t; }
01196     };
01197 #endif // C++17
01198 
01199 _GLIBCXX_END_NAMESPACE_VERSION
01200 } // namespace std
01201 
01202 #endif /* _STL_MULTIMAP_H */