libstdc++
stl_multimap.h
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00001 // Multimap implementation -*- C++ -*-
00002 
00003 // Copyright (C) 2001-2018 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_equal(__l.begin(), __l.end()); }
00228 
00229       /// Allocator-extended default constructor.
00230       explicit
00231       multimap(const allocator_type& __a)
00232       : _M_t(_Compare(), _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(_Compare(), _Pair_alloc_type(__a))
00247       { _M_t._M_insert_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(_Compare(), _Pair_alloc_type(__a))
00254         { _M_t._M_insert_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_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_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       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, typename = typename
00548                std::enable_if<std::is_constructible<value_type,
00549                                                     _Pair&&>::value>::type>
00550         iterator
00551         insert(_Pair&& __x)
00552         { return _M_t._M_insert_equal(std::forward<_Pair>(__x)); }
00553 #endif
00554       // @}
00555 
00556       /**
00557        *  @brief Inserts a std::pair into the %multimap.
00558        *  @param  __position  An iterator that serves as a hint as to where the
00559        *                      pair should be inserted.
00560        *  @param  __x  Pair to be inserted (see std::make_pair for easy creation
00561        *               of pairs).
00562        *  @return An iterator that points to the inserted (key,value) pair.
00563        *
00564        *  This function inserts a (key, value) pair into the %multimap.
00565        *  Contrary to a std::map the %multimap does not rely on unique keys and
00566        *  thus multiple pairs with the same key can be inserted.
00567        *  Note that the first parameter is only a hint and can potentially
00568        *  improve the performance of the insertion process.  A bad hint would
00569        *  cause no gains in efficiency.
00570        *
00571        *  For more on @a hinting, see:
00572        *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
00573        *
00574        *  Insertion requires logarithmic time (if the hint is not taken).
00575        * @{
00576        */
00577       iterator
00578 #if __cplusplus >= 201103L
00579       insert(const_iterator __position, const value_type& __x)
00580 #else
00581       insert(iterator __position, const value_type& __x)
00582 #endif
00583       { return _M_t._M_insert_equal_(__position, __x); }
00584 
00585 #if __cplusplus >= 201103L
00586       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00587       // 2354. Unnecessary copying when inserting into maps with braced-init
00588       iterator
00589       insert(const_iterator __position, value_type&& __x)
00590       { return _M_t._M_insert_equal_(__position, std::move(__x)); }
00591 
00592       template<typename _Pair, typename = typename
00593                std::enable_if<std::is_constructible<value_type,
00594                                                     _Pair&&>::value>::type>
00595         iterator
00596         insert(const_iterator __position, _Pair&& __x)
00597         { return _M_t._M_insert_equal_(__position,
00598                                        std::forward<_Pair>(__x)); }
00599 #endif
00600       // @}
00601 
00602       /**
00603        *  @brief A template function that attempts to insert a range
00604        *  of elements.
00605        *  @param  __first  Iterator pointing to the start of the range to be
00606        *                   inserted.
00607        *  @param  __last  Iterator pointing to the end of the range.
00608        *
00609        *  Complexity similar to that of the range constructor.
00610        */
00611       template<typename _InputIterator>
00612         void
00613         insert(_InputIterator __first, _InputIterator __last)
00614         { _M_t._M_insert_equal(__first, __last); }
00615 
00616 #if __cplusplus >= 201103L
00617       /**
00618        *  @brief Attempts to insert a list of std::pairs into the %multimap.
00619        *  @param  __l  A std::initializer_list<value_type> of pairs to be
00620        *               inserted.
00621        *
00622        *  Complexity similar to that of the range constructor.
00623        */
00624       void
00625       insert(initializer_list<value_type> __l)
00626       { this->insert(__l.begin(), __l.end()); }
00627 #endif
00628 
00629 #if __cplusplus > 201402L
00630       /// Extract a node.
00631       node_type
00632       extract(const_iterator __pos)
00633       {
00634         __glibcxx_assert(__pos != end());
00635         return _M_t.extract(__pos);
00636       }
00637 
00638       /// Extract a node.
00639       node_type
00640       extract(const key_type& __x)
00641       { return _M_t.extract(__x); }
00642 
00643       /// Re-insert an extracted node.
00644       iterator
00645       insert(node_type&& __nh)
00646       { return _M_t._M_reinsert_node_equal(std::move(__nh)); }
00647 
00648       /// Re-insert an extracted node.
00649       iterator
00650       insert(const_iterator __hint, node_type&& __nh)
00651       { return _M_t._M_reinsert_node_hint_equal(__hint, std::move(__nh)); }
00652 
00653       template<typename, typename>
00654         friend class std::_Rb_tree_merge_helper;
00655 
00656       template<typename _C2>
00657         void
00658         merge(multimap<_Key, _Tp, _C2, _Alloc>& __source)
00659         {
00660           using _Merge_helper = _Rb_tree_merge_helper<multimap, _C2>;
00661           _M_t._M_merge_equal(_Merge_helper::_S_get_tree(__source));
00662         }
00663 
00664       template<typename _C2>
00665         void
00666         merge(multimap<_Key, _Tp, _C2, _Alloc>&& __source)
00667         { merge(__source); }
00668 
00669       template<typename _C2>
00670         void
00671         merge(map<_Key, _Tp, _C2, _Alloc>& __source)
00672         {
00673           using _Merge_helper = _Rb_tree_merge_helper<multimap, _C2>;
00674           _M_t._M_merge_equal(_Merge_helper::_S_get_tree(__source));
00675         }
00676 
00677       template<typename _C2>
00678         void
00679         merge(map<_Key, _Tp, _C2, _Alloc>&& __source)
00680         { merge(__source); }
00681 #endif // C++17
00682 
00683 #if __cplusplus >= 201103L
00684       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00685       // DR 130. Associative erase should return an iterator.
00686       /**
00687        *  @brief Erases an element from a %multimap.
00688        *  @param  __position  An iterator pointing to the element to be erased.
00689        *  @return An iterator pointing to the element immediately following
00690        *          @a position prior to the element being erased. If no such
00691        *          element exists, end() is returned.
00692        *
00693        *  This function erases an element, pointed to by the given iterator,
00694        *  from a %multimap.  Note that this function only erases the element,
00695        *  and that if the element is itself a pointer, the pointed-to memory is
00696        *  not touched in any way.  Managing the pointer is the user's
00697        *  responsibility.
00698        *
00699        * @{
00700        */
00701       iterator
00702       erase(const_iterator __position)
00703       { return _M_t.erase(__position); }
00704 
00705       // LWG 2059.
00706       _GLIBCXX_ABI_TAG_CXX11
00707       iterator
00708       erase(iterator __position)
00709       { return _M_t.erase(__position); }
00710       // @}
00711 #else
00712       /**
00713        *  @brief Erases an element from a %multimap.
00714        *  @param  __position  An iterator pointing to the element to be erased.
00715        *
00716        *  This function erases an element, pointed to by the given iterator,
00717        *  from a %multimap.  Note that this function only erases the element,
00718        *  and that if the element is itself a pointer, the pointed-to memory is
00719        *  not touched in any way.  Managing the pointer is the user's
00720        *  responsibility.
00721        */
00722       void
00723       erase(iterator __position)
00724       { _M_t.erase(__position); }
00725 #endif
00726 
00727       /**
00728        *  @brief Erases elements according to the provided key.
00729        *  @param  __x  Key of element to be erased.
00730        *  @return  The number of elements erased.
00731        *
00732        *  This function erases all elements located by the given key from a
00733        *  %multimap.
00734        *  Note that this function only erases the element, and that if
00735        *  the element is itself a pointer, the pointed-to memory is not touched
00736        *  in any way.  Managing the pointer is the user's responsibility.
00737        */
00738       size_type
00739       erase(const key_type& __x)
00740       { return _M_t.erase(__x); }
00741 
00742 #if __cplusplus >= 201103L
00743       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00744       // DR 130. Associative erase should return an iterator.
00745       /**
00746        *  @brief Erases a [first,last) range of elements from a %multimap.
00747        *  @param  __first  Iterator pointing to the start of the range to be
00748        *                   erased.
00749        *  @param __last Iterator pointing to the end of the range to be
00750        *                erased .
00751        *  @return The iterator @a __last.
00752        *
00753        *  This function erases a sequence of elements from a %multimap.
00754        *  Note that this function only erases the elements, and that if
00755        *  the elements themselves are pointers, the pointed-to memory is not
00756        *  touched in any way.  Managing the pointer is the user's
00757        *  responsibility.
00758        */
00759       iterator
00760       erase(const_iterator __first, const_iterator __last)
00761       { return _M_t.erase(__first, __last); }
00762 #else
00763       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00764       // DR 130. Associative erase should return an iterator.
00765       /**
00766        *  @brief Erases a [first,last) range of elements from a %multimap.
00767        *  @param  __first  Iterator pointing to the start of the range to be
00768        *                 erased.
00769        *  @param __last Iterator pointing to the end of the range to
00770        *                be erased.
00771        *
00772        *  This function erases a sequence of elements from a %multimap.
00773        *  Note that this function only erases the elements, and that if
00774        *  the elements themselves are pointers, the pointed-to memory is not
00775        *  touched in any way.  Managing the pointer is the user's
00776        *  responsibility.
00777        */
00778       void
00779       erase(iterator __first, iterator __last)
00780       { _M_t.erase(__first, __last); }
00781 #endif
00782 
00783       /**
00784        *  @brief  Swaps data with another %multimap.
00785        *  @param  __x  A %multimap of the same element and allocator types.
00786        *
00787        *  This exchanges the elements between two multimaps in constant time.
00788        *  (It is only swapping a pointer, an integer, and an instance of
00789        *  the @c Compare type (which itself is often stateless and empty), so it
00790        *  should be quite fast.)
00791        *  Note that the global std::swap() function is specialized such that
00792        *  std::swap(m1,m2) will feed to this function.
00793        *
00794        *  Whether the allocators are swapped depends on the allocator traits.
00795        */
00796       void
00797       swap(multimap& __x)
00798       _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
00799       { _M_t.swap(__x._M_t); }
00800 
00801       /**
00802        *  Erases all elements in a %multimap.  Note that this function only
00803        *  erases the elements, and that if the elements themselves are pointers,
00804        *  the pointed-to memory is not touched in any way.  Managing the pointer
00805        *  is the user's responsibility.
00806        */
00807       void
00808       clear() _GLIBCXX_NOEXCEPT
00809       { _M_t.clear(); }
00810 
00811       // observers
00812       /**
00813        *  Returns the key comparison object out of which the %multimap
00814        *  was constructed.
00815        */
00816       key_compare
00817       key_comp() const
00818       { return _M_t.key_comp(); }
00819 
00820       /**
00821        *  Returns a value comparison object, built from the key comparison
00822        *  object out of which the %multimap was constructed.
00823        */
00824       value_compare
00825       value_comp() const
00826       { return value_compare(_M_t.key_comp()); }
00827 
00828       // multimap operations
00829 
00830       //@{
00831       /**
00832        *  @brief Tries to locate an element in a %multimap.
00833        *  @param  __x  Key of (key, value) pair to be located.
00834        *  @return  Iterator pointing to sought-after element,
00835        *           or end() if not found.
00836        *
00837        *  This function takes a key and tries to locate the element with which
00838        *  the key matches.  If successful the function returns an iterator
00839        *  pointing to the sought after %pair.  If unsuccessful it returns the
00840        *  past-the-end ( @c end() ) iterator.
00841        */
00842       iterator
00843       find(const key_type& __x)
00844       { return _M_t.find(__x); }
00845 
00846 #if __cplusplus > 201103L
00847       template<typename _Kt>
00848         auto
00849         find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
00850         { return _M_t._M_find_tr(__x); }
00851 #endif
00852       //@}
00853 
00854       //@{
00855       /**
00856        *  @brief Tries to locate an element in a %multimap.
00857        *  @param  __x  Key of (key, value) pair to be located.
00858        *  @return  Read-only (constant) iterator pointing to sought-after
00859        *           element, or end() if not found.
00860        *
00861        *  This function takes a key and tries to locate the element with which
00862        *  the key matches.  If successful the function returns a constant
00863        *  iterator pointing to the sought after %pair.  If unsuccessful it
00864        *  returns the past-the-end ( @c end() ) iterator.
00865        */
00866       const_iterator
00867       find(const key_type& __x) const
00868       { return _M_t.find(__x); }
00869 
00870 #if __cplusplus > 201103L
00871       template<typename _Kt>
00872         auto
00873         find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
00874         { return _M_t._M_find_tr(__x); }
00875 #endif
00876       //@}
00877 
00878       //@{
00879       /**
00880        *  @brief Finds the number of elements with given key.
00881        *  @param  __x  Key of (key, value) pairs to be located.
00882        *  @return Number of elements with specified key.
00883        */
00884       size_type
00885       count(const key_type& __x) const
00886       { return _M_t.count(__x); }
00887 
00888 #if __cplusplus > 201103L
00889       template<typename _Kt>
00890         auto
00891         count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
00892         { return _M_t._M_count_tr(__x); }
00893 #endif
00894       //@}
00895 
00896       //@{
00897       /**
00898        *  @brief Finds the beginning of a subsequence matching given key.
00899        *  @param  __x  Key of (key, value) pair to be located.
00900        *  @return  Iterator pointing to first element equal to or greater
00901        *           than key, or end().
00902        *
00903        *  This function returns the first element of a subsequence of elements
00904        *  that matches the given key.  If unsuccessful it returns an iterator
00905        *  pointing to the first element that has a greater value than given key
00906        *  or end() if no such element exists.
00907        */
00908       iterator
00909       lower_bound(const key_type& __x)
00910       { return _M_t.lower_bound(__x); }
00911 
00912 #if __cplusplus > 201103L
00913       template<typename _Kt>
00914         auto
00915         lower_bound(const _Kt& __x)
00916         -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
00917         { return iterator(_M_t._M_lower_bound_tr(__x)); }
00918 #endif
00919       //@}
00920 
00921       //@{
00922       /**
00923        *  @brief Finds the beginning of a subsequence matching given key.
00924        *  @param  __x  Key of (key, value) pair to be located.
00925        *  @return  Read-only (constant) iterator pointing to first element
00926        *           equal to or greater than key, or end().
00927        *
00928        *  This function returns the first element of a subsequence of
00929        *  elements that matches the given key.  If unsuccessful the
00930        *  iterator will point to the next greatest element or, if no
00931        *  such greater element exists, to end().
00932        */
00933       const_iterator
00934       lower_bound(const key_type& __x) const
00935       { return _M_t.lower_bound(__x); }
00936 
00937 #if __cplusplus > 201103L
00938       template<typename _Kt>
00939         auto
00940         lower_bound(const _Kt& __x) const
00941         -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
00942         { return const_iterator(_M_t._M_lower_bound_tr(__x)); }
00943 #endif
00944       //@}
00945 
00946       //@{
00947       /**
00948        *  @brief Finds the end of a subsequence matching given key.
00949        *  @param  __x  Key of (key, value) pair to be located.
00950        *  @return Iterator pointing to the first element
00951        *          greater than key, or end().
00952        */
00953       iterator
00954       upper_bound(const key_type& __x)
00955       { return _M_t.upper_bound(__x); }
00956 
00957 #if __cplusplus > 201103L
00958       template<typename _Kt>
00959         auto
00960         upper_bound(const _Kt& __x)
00961         -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
00962         { return iterator(_M_t._M_upper_bound_tr(__x)); }
00963 #endif
00964       //@}
00965 
00966       //@{
00967       /**
00968        *  @brief Finds the end of a subsequence matching given key.
00969        *  @param  __x  Key of (key, value) pair to be located.
00970        *  @return  Read-only (constant) iterator pointing to first iterator
00971        *           greater than key, or end().
00972        */
00973       const_iterator
00974       upper_bound(const key_type& __x) const
00975       { return _M_t.upper_bound(__x); }
00976 
00977 #if __cplusplus > 201103L
00978       template<typename _Kt>
00979         auto
00980         upper_bound(const _Kt& __x) const
00981         -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
00982         { return const_iterator(_M_t._M_upper_bound_tr(__x)); }
00983 #endif
00984       //@}
00985 
00986       //@{
00987       /**
00988        *  @brief Finds a subsequence matching given key.
00989        *  @param  __x  Key of (key, value) pairs to be located.
00990        *  @return  Pair of iterators that possibly points to the subsequence
00991        *           matching given key.
00992        *
00993        *  This function is equivalent to
00994        *  @code
00995        *    std::make_pair(c.lower_bound(val),
00996        *                   c.upper_bound(val))
00997        *  @endcode
00998        *  (but is faster than making the calls separately).
00999        */
01000       std::pair<iterator, iterator>
01001       equal_range(const key_type& __x)
01002       { return _M_t.equal_range(__x); }
01003 
01004 #if __cplusplus > 201103L
01005       template<typename _Kt>
01006         auto
01007         equal_range(const _Kt& __x)
01008         -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
01009         { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
01010 #endif
01011       //@}
01012 
01013       //@{
01014       /**
01015        *  @brief Finds a subsequence matching given key.
01016        *  @param  __x  Key of (key, value) pairs to be located.
01017        *  @return  Pair of read-only (constant) iterators that possibly points
01018        *           to the subsequence matching given key.
01019        *
01020        *  This function is equivalent to
01021        *  @code
01022        *    std::make_pair(c.lower_bound(val),
01023        *                   c.upper_bound(val))
01024        *  @endcode
01025        *  (but is faster than making the calls separately).
01026        */
01027       std::pair<const_iterator, const_iterator>
01028       equal_range(const key_type& __x) const
01029       { return _M_t.equal_range(__x); }
01030 
01031 #if __cplusplus > 201103L
01032       template<typename _Kt>
01033         auto
01034         equal_range(const _Kt& __x) const
01035         -> decltype(pair<const_iterator, const_iterator>(
01036               _M_t._M_equal_range_tr(__x)))
01037         {
01038           return pair<const_iterator, const_iterator>(
01039               _M_t._M_equal_range_tr(__x));
01040         }
01041 #endif
01042       //@}
01043 
01044       template<typename _K1, typename _T1, typename _C1, typename _A1>
01045         friend bool
01046         operator==(const multimap<_K1, _T1, _C1, _A1>&,
01047                    const multimap<_K1, _T1, _C1, _A1>&);
01048 
01049       template<typename _K1, typename _T1, typename _C1, typename _A1>
01050         friend bool
01051         operator<(const multimap<_K1, _T1, _C1, _A1>&,
01052                   const multimap<_K1, _T1, _C1, _A1>&);
01053   };
01054 
01055 #if __cpp_deduction_guides >= 201606
01056 
01057   template<typename _InputIterator,
01058            typename _Compare = less<__iter_key_t<_InputIterator>>,
01059            typename _Allocator = allocator<__iter_to_alloc_t<_InputIterator>>,
01060            typename = _RequireInputIter<_InputIterator>,
01061            typename = _RequireAllocator<_Allocator>>
01062     multimap(_InputIterator, _InputIterator,
01063              _Compare = _Compare(), _Allocator = _Allocator())
01064     -> multimap<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
01065                 _Compare, _Allocator>;
01066 
01067   template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
01068            typename _Allocator = allocator<pair<const _Key, _Tp>>,
01069            typename = _RequireAllocator<_Allocator>>
01070     multimap(initializer_list<pair<_Key, _Tp>>,
01071              _Compare = _Compare(), _Allocator = _Allocator())
01072     -> multimap<_Key, _Tp, _Compare, _Allocator>;
01073 
01074   template<typename _InputIterator, typename _Allocator,
01075            typename = _RequireInputIter<_InputIterator>,
01076            typename = _RequireAllocator<_Allocator>>
01077     multimap(_InputIterator, _InputIterator, _Allocator)
01078     -> multimap<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
01079                 less<__iter_key_t<_InputIterator>>, _Allocator>;
01080 
01081   template<typename _Key, typename _Tp, typename _Allocator,
01082            typename = _RequireAllocator<_Allocator>>
01083     multimap(initializer_list<pair<_Key, _Tp>>, _Allocator)
01084     -> multimap<_Key, _Tp, less<_Key>, _Allocator>;
01085 
01086 #endif
01087 
01088   /**
01089    *  @brief  Multimap equality comparison.
01090    *  @param  __x  A %multimap.
01091    *  @param  __y  A %multimap of the same type as @a __x.
01092    *  @return  True iff the size and elements of the maps are equal.
01093    *
01094    *  This is an equivalence relation.  It is linear in the size of the
01095    *  multimaps.  Multimaps are considered equivalent if their sizes are equal,
01096    *  and if corresponding elements compare equal.
01097   */
01098   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01099     inline bool
01100     operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01101                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01102     { return __x._M_t == __y._M_t; }
01103 
01104   /**
01105    *  @brief  Multimap ordering relation.
01106    *  @param  __x  A %multimap.
01107    *  @param  __y  A %multimap of the same type as @a __x.
01108    *  @return  True iff @a x is lexicographically less than @a y.
01109    *
01110    *  This is a total ordering relation.  It is linear in the size of the
01111    *  multimaps.  The elements must be comparable with @c <.
01112    *
01113    *  See std::lexicographical_compare() for how the determination is made.
01114   */
01115   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01116     inline bool
01117     operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01118               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01119     { return __x._M_t < __y._M_t; }
01120 
01121   /// Based on operator==
01122   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01123     inline bool
01124     operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01125                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01126     { return !(__x == __y); }
01127 
01128   /// Based on operator<
01129   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01130     inline bool
01131     operator>(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01132               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01133     { return __y < __x; }
01134 
01135   /// Based on operator<
01136   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01137     inline bool
01138     operator<=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01139                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01140     { return !(__y < __x); }
01141 
01142   /// Based on operator<
01143   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01144     inline bool
01145     operator>=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01146                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01147     { return !(__x < __y); }
01148 
01149   /// See std::multimap::swap().
01150   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
01151     inline void
01152     swap(multimap<_Key, _Tp, _Compare, _Alloc>& __x,
01153          multimap<_Key, _Tp, _Compare, _Alloc>& __y)
01154     _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
01155     { __x.swap(__y); }
01156 
01157 _GLIBCXX_END_NAMESPACE_CONTAINER
01158 
01159 #if __cplusplus > 201402L
01160   // Allow std::multimap access to internals of compatible maps.
01161   template<typename _Key, typename _Val, typename _Cmp1, typename _Alloc,
01162            typename _Cmp2>
01163     struct
01164     _Rb_tree_merge_helper<_GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp1, _Alloc>,
01165                           _Cmp2>
01166     {
01167     private:
01168       friend class _GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp1, _Alloc>;
01169 
01170       static auto&
01171       _S_get_tree(_GLIBCXX_STD_C::map<_Key, _Val, _Cmp2, _Alloc>& __map)
01172       { return __map._M_t; }
01173 
01174       static auto&
01175       _S_get_tree(_GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp2, _Alloc>& __map)
01176       { return __map._M_t; }
01177     };
01178 #endif // C++17
01179 
01180 _GLIBCXX_END_NAMESPACE_VERSION
01181 } // namespace std
01182 
01183 #endif /* _STL_MULTIMAP_H */