libstdc++
stl_multiset.h
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00001 // Multiset implementation -*- C++ -*-
00002 
00003 // Copyright (C) 2001-2017 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
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_multiset.h
00052  *  This is an internal header file, included by other library headers.
00053  *  Do not attempt to use it directly. @headername{set}
00054  */
00055 
00056 #ifndef _STL_MULTISET_H
00057 #define _STL_MULTISET_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_CONTAINER
00067 
00068   template<typename _Key, typename _Compare, typename _Alloc>
00069     class set;
00070 
00071   /**
00072    *  @brief A standard container made up of elements, which can be retrieved
00073    *  in logarithmic time.
00074    *
00075    *  @ingroup associative_containers
00076    *
00077    *
00078    *  @tparam _Key  Type of key objects.
00079    *  @tparam _Compare  Comparison function object type, defaults to less<_Key>.
00080    *  @tparam _Alloc  Allocator type, defaults to allocator<_Key>.
00081    *
00082    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
00083    *  <a href="tables.html#66">reversible container</a>, and an
00084    *  <a href="tables.html#69">associative container</a> (using equivalent
00085    *  keys).  For a @c multiset<Key> the key_type and value_type are Key.
00086    *
00087    *  Multisets support bidirectional iterators.
00088    *
00089    *  The private tree data is declared exactly the same way for set and
00090    *  multiset; the distinction is made entirely in how the tree functions are
00091    *  called (*_unique versus *_equal, same as the standard).
00092   */
00093   template <typename _Key, typename _Compare = std::less<_Key>,
00094             typename _Alloc = std::allocator<_Key> >
00095     class multiset
00096     {
00097 #ifdef _GLIBCXX_CONCEPT_CHECKS
00098       // concept requirements
00099       typedef typename _Alloc::value_type               _Alloc_value_type;
00100 # if __cplusplus < 201103L
00101       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
00102 # endif
00103       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
00104                                 _BinaryFunctionConcept)
00105       __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
00106 #endif
00107 
00108     public:
00109       // typedefs:
00110       typedef _Key     key_type;
00111       typedef _Key     value_type;
00112       typedef _Compare key_compare;
00113       typedef _Compare value_compare;
00114       typedef _Alloc   allocator_type;
00115 
00116     private:
00117       /// This turns a red-black tree into a [multi]set.
00118       typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
00119         rebind<_Key>::other _Key_alloc_type;
00120 
00121       typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
00122                        key_compare, _Key_alloc_type> _Rep_type;
00123       /// The actual tree structure.
00124       _Rep_type _M_t;
00125 
00126       typedef __gnu_cxx::__alloc_traits<_Key_alloc_type> _Alloc_traits;
00127 
00128     public:
00129       typedef typename _Alloc_traits::pointer            pointer;
00130       typedef typename _Alloc_traits::const_pointer      const_pointer;
00131       typedef typename _Alloc_traits::reference          reference;
00132       typedef typename _Alloc_traits::const_reference    const_reference;
00133       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00134       // DR 103. set::iterator is required to be modifiable,
00135       // but this allows modification of keys.
00136       typedef typename _Rep_type::const_iterator         iterator;
00137       typedef typename _Rep_type::const_iterator         const_iterator;
00138       typedef typename _Rep_type::const_reverse_iterator reverse_iterator;
00139       typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
00140       typedef typename _Rep_type::size_type              size_type;
00141       typedef typename _Rep_type::difference_type        difference_type;
00142 
00143 #if __cplusplus > 201402L
00144       using node_type = typename _Rep_type::node_type;
00145 #endif
00146 
00147       // allocation/deallocation
00148       /**
00149        *  @brief  Default constructor creates no elements.
00150        */
00151 #if __cplusplus < 201103L
00152       multiset() : _M_t() { }
00153 #else
00154       multiset() = default;
00155 #endif
00156 
00157       /**
00158        *  @brief  Creates a %multiset with no elements.
00159        *  @param  __comp  Comparator to use.
00160        *  @param  __a  An allocator object.
00161        */
00162       explicit
00163       multiset(const _Compare& __comp,
00164                const allocator_type& __a = allocator_type())
00165       : _M_t(__comp, _Key_alloc_type(__a)) { }
00166 
00167       /**
00168        *  @brief  Builds a %multiset from a range.
00169        *  @param  __first  An input iterator.
00170        *  @param  __last  An input iterator.
00171        *
00172        *  Create a %multiset consisting of copies of the elements from
00173        *  [first,last).  This is linear in N if the range is already sorted,
00174        *  and NlogN otherwise (where N is distance(__first,__last)).
00175        */
00176       template<typename _InputIterator>
00177         multiset(_InputIterator __first, _InputIterator __last)
00178         : _M_t()
00179         { _M_t._M_insert_equal(__first, __last); }
00180 
00181       /**
00182        *  @brief  Builds a %multiset from a range.
00183        *  @param  __first  An input iterator.
00184        *  @param  __last  An input iterator.
00185        *  @param  __comp  A comparison functor.
00186        *  @param  __a  An allocator object.
00187        *
00188        *  Create a %multiset consisting of copies of the elements from
00189        *  [__first,__last).  This is linear in N if the range is already sorted,
00190        *  and NlogN otherwise (where N is distance(__first,__last)).
00191        */
00192       template<typename _InputIterator>
00193         multiset(_InputIterator __first, _InputIterator __last,
00194                  const _Compare& __comp,
00195                  const allocator_type& __a = allocator_type())
00196         : _M_t(__comp, _Key_alloc_type(__a))
00197         { _M_t._M_insert_equal(__first, __last); }
00198 
00199       /**
00200        *  @brief  %Multiset copy constructor.
00201        *
00202        *  Whether the allocator is copied depends on the allocator traits.
00203        */
00204 #if __cplusplus < 201103L
00205       multiset(const multiset& __x)
00206       : _M_t(__x._M_t) { }
00207 #else
00208       multiset(const multiset&) = default;
00209 
00210      /**
00211        *  @brief  %Multiset move constructor.
00212        *
00213        *  The newly-created %multiset contains the exact contents of the
00214        *  moved instance. The moved instance is a valid, but unspecified
00215        *  %multiset.
00216        */
00217       multiset(multiset&&) = default;
00218 
00219       /**
00220        *  @brief  Builds a %multiset from an initializer_list.
00221        *  @param  __l  An initializer_list.
00222        *  @param  __comp  A comparison functor.
00223        *  @param  __a  An allocator object.
00224        *
00225        *  Create a %multiset consisting of copies of the elements from
00226        *  the list.  This is linear in N if the list is already sorted,
00227        *  and NlogN otherwise (where N is @a __l.size()).
00228        */
00229       multiset(initializer_list<value_type> __l,
00230                const _Compare& __comp = _Compare(),
00231                const allocator_type& __a = allocator_type())
00232       : _M_t(__comp, _Key_alloc_type(__a))
00233       { _M_t._M_insert_equal(__l.begin(), __l.end()); }
00234 
00235       /// Allocator-extended default constructor.
00236       explicit
00237       multiset(const allocator_type& __a)
00238       : _M_t(_Compare(), _Key_alloc_type(__a)) { }
00239 
00240       /// Allocator-extended copy constructor.
00241       multiset(const multiset& __m, const allocator_type& __a)
00242       : _M_t(__m._M_t, _Key_alloc_type(__a)) { }
00243 
00244       /// Allocator-extended move constructor.
00245       multiset(multiset&& __m, const allocator_type& __a)
00246       noexcept(is_nothrow_copy_constructible<_Compare>::value
00247                && _Alloc_traits::_S_always_equal())
00248       : _M_t(std::move(__m._M_t), _Key_alloc_type(__a)) { }
00249 
00250       /// Allocator-extended initialier-list constructor.
00251       multiset(initializer_list<value_type> __l, const allocator_type& __a)
00252       : _M_t(_Compare(), _Key_alloc_type(__a))
00253       { _M_t._M_insert_equal(__l.begin(), __l.end()); }
00254 
00255       /// Allocator-extended range constructor.
00256       template<typename _InputIterator>
00257         multiset(_InputIterator __first, _InputIterator __last,
00258                  const allocator_type& __a)
00259         : _M_t(_Compare(), _Key_alloc_type(__a))
00260         { _M_t._M_insert_equal(__first, __last); }
00261 
00262       /**
00263        *  The dtor only erases the elements, and note that if the elements
00264        *  themselves are pointers, the pointed-to memory is not touched in any
00265        *  way. Managing the pointer is the user's responsibility.
00266        */
00267       ~multiset() = default;
00268 #endif
00269 
00270       /**
00271        *  @brief  %Multiset assignment operator.
00272        *
00273        *  Whether the allocator is copied depends on the allocator traits.
00274        */
00275 #if __cplusplus < 201103L
00276       multiset&
00277       operator=(const multiset& __x)
00278       {
00279         _M_t = __x._M_t;
00280         return *this;
00281       }
00282 #else
00283       multiset&
00284       operator=(const multiset&) = default;
00285 
00286       /// Move assignment operator.
00287       multiset&
00288       operator=(multiset&&) = default;
00289 
00290       /**
00291        *  @brief  %Multiset list assignment operator.
00292        *  @param  __l  An initializer_list.
00293        *
00294        *  This function fills a %multiset with copies of the elements in the
00295        *  initializer list @a __l.
00296        *
00297        *  Note that the assignment completely changes the %multiset and
00298        *  that the resulting %multiset's size is the same as the number
00299        *  of elements assigned.
00300        */
00301       multiset&
00302       operator=(initializer_list<value_type> __l)
00303       {
00304         _M_t._M_assign_equal(__l.begin(), __l.end());
00305         return *this;
00306       }
00307 #endif
00308 
00309       // accessors:
00310 
00311       ///  Returns the comparison object.
00312       key_compare
00313       key_comp() const
00314       { return _M_t.key_comp(); }
00315       ///  Returns the comparison object.
00316       value_compare
00317       value_comp() const
00318       { return _M_t.key_comp(); }
00319       ///  Returns the memory allocation object.
00320       allocator_type
00321       get_allocator() const _GLIBCXX_NOEXCEPT
00322       { return allocator_type(_M_t.get_allocator()); }
00323 
00324       /**
00325        *  Returns a read-only (constant) iterator that points to the first
00326        *  element in the %multiset.  Iteration is done in ascending order
00327        *  according to the keys.
00328        */
00329       iterator
00330       begin() const _GLIBCXX_NOEXCEPT
00331       { return _M_t.begin(); }
00332 
00333       /**
00334        *  Returns a read-only (constant) iterator that points one past the last
00335        *  element in the %multiset.  Iteration is done in ascending order
00336        *  according to the keys.
00337        */
00338       iterator
00339       end() const _GLIBCXX_NOEXCEPT
00340       { return _M_t.end(); }
00341 
00342       /**
00343        *  Returns a read-only (constant) reverse iterator that points to the
00344        *  last element in the %multiset.  Iteration is done in descending order
00345        *  according to the keys.
00346        */
00347       reverse_iterator
00348       rbegin() const _GLIBCXX_NOEXCEPT
00349       { return _M_t.rbegin(); }
00350 
00351       /**
00352        *  Returns a read-only (constant) reverse iterator that points to the
00353        *  last element in the %multiset.  Iteration is done in descending order
00354        *  according to the keys.
00355        */
00356       reverse_iterator
00357       rend() const _GLIBCXX_NOEXCEPT
00358       { return _M_t.rend(); }
00359 
00360 #if __cplusplus >= 201103L
00361       /**
00362        *  Returns a read-only (constant) iterator that points to the first
00363        *  element in the %multiset.  Iteration is done in ascending order
00364        *  according to the keys.
00365        */
00366       iterator
00367       cbegin() const noexcept
00368       { return _M_t.begin(); }
00369 
00370       /**
00371        *  Returns a read-only (constant) iterator that points one past the last
00372        *  element in the %multiset.  Iteration is done in ascending order
00373        *  according to the keys.
00374        */
00375       iterator
00376       cend() const noexcept
00377       { return _M_t.end(); }
00378 
00379       /**
00380        *  Returns a read-only (constant) reverse iterator that points to the
00381        *  last element in the %multiset.  Iteration is done in descending order
00382        *  according to the keys.
00383        */
00384       reverse_iterator
00385       crbegin() const noexcept
00386       { return _M_t.rbegin(); }
00387 
00388       /**
00389        *  Returns a read-only (constant) reverse iterator that points to the
00390        *  last element in the %multiset.  Iteration is done in descending order
00391        *  according to the keys.
00392        */
00393       reverse_iterator
00394       crend() const noexcept
00395       { return _M_t.rend(); }
00396 #endif
00397 
00398       ///  Returns true if the %set is empty.
00399       bool
00400       empty() const _GLIBCXX_NOEXCEPT
00401       { return _M_t.empty(); }
00402 
00403       ///  Returns the size of the %set.
00404       size_type
00405       size() const _GLIBCXX_NOEXCEPT
00406       { return _M_t.size(); }
00407 
00408       ///  Returns the maximum size of the %set.
00409       size_type
00410       max_size() const _GLIBCXX_NOEXCEPT
00411       { return _M_t.max_size(); }
00412 
00413       /**
00414        *  @brief  Swaps data with another %multiset.
00415        *  @param  __x  A %multiset of the same element and allocator types.
00416        *
00417        *  This exchanges the elements between two multisets in constant time.
00418        *  (It is only swapping a pointer, an integer, and an instance of the @c
00419        *  Compare type (which itself is often stateless and empty), so it should
00420        *  be quite fast.)
00421        *  Note that the global std::swap() function is specialized such that
00422        *  std::swap(s1,s2) will feed to this function.
00423        *
00424        *  Whether the allocators are swapped depends on the allocator traits.
00425        */
00426       void
00427       swap(multiset& __x)
00428       _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
00429       { _M_t.swap(__x._M_t); }
00430 
00431       // insert/erase
00432 #if __cplusplus >= 201103L
00433       /**
00434        *  @brief Builds and inserts an element into the %multiset.
00435        *  @param  __args  Arguments used to generate the element instance to be
00436        *                 inserted.
00437        *  @return An iterator that points to the inserted element.
00438        *
00439        *  This function inserts an element into the %multiset.  Contrary
00440        *  to a std::set the %multiset does not rely on unique keys and thus
00441        *  multiple copies of the same element can be inserted.
00442        *
00443        *  Insertion requires logarithmic time.
00444        */
00445       template<typename... _Args>
00446         iterator
00447         emplace(_Args&&... __args)
00448         { return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); }
00449 
00450       /**
00451        *  @brief Builds and inserts an element into the %multiset.
00452        *  @param  __pos  An iterator that serves as a hint as to where the
00453        *                element should be inserted.
00454        *  @param  __args  Arguments used to generate the element instance to be
00455        *                 inserted.
00456        *  @return An iterator that points to the inserted element.
00457        *
00458        *  This function inserts an element into the %multiset.  Contrary
00459        *  to a std::set the %multiset does not rely on unique keys and thus
00460        *  multiple copies of the same element can be inserted.
00461        *
00462        *  Note that the first parameter is only a hint and can potentially
00463        *  improve the performance of the insertion process.  A bad hint would
00464        *  cause no gains in efficiency.
00465        *
00466        *  See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
00467        *  for more on @a hinting.
00468        *
00469        *  Insertion requires logarithmic time (if the hint is not taken).
00470        */
00471       template<typename... _Args>
00472         iterator
00473         emplace_hint(const_iterator __pos, _Args&&... __args)
00474         {
00475           return _M_t._M_emplace_hint_equal(__pos,
00476                                             std::forward<_Args>(__args)...);
00477         }
00478 #endif
00479 
00480       /**
00481        *  @brief Inserts an element into the %multiset.
00482        *  @param  __x  Element to be inserted.
00483        *  @return An iterator that points to the inserted element.
00484        *
00485        *  This function inserts an element into the %multiset.  Contrary
00486        *  to a std::set the %multiset does not rely on unique keys and thus
00487        *  multiple copies of the same element can be inserted.
00488        *
00489        *  Insertion requires logarithmic time.
00490        */
00491       iterator
00492       insert(const value_type& __x)
00493       { return _M_t._M_insert_equal(__x); }
00494 
00495 #if __cplusplus >= 201103L
00496       iterator
00497       insert(value_type&& __x)
00498       { return _M_t._M_insert_equal(std::move(__x)); }
00499 #endif
00500 
00501       /**
00502        *  @brief Inserts an element into the %multiset.
00503        *  @param  __position  An iterator that serves as a hint as to where the
00504        *                    element should be inserted.
00505        *  @param  __x  Element to be inserted.
00506        *  @return An iterator that points to the inserted element.
00507        *
00508        *  This function inserts an element into the %multiset.  Contrary
00509        *  to a std::set the %multiset does not rely on unique keys and thus
00510        *  multiple copies of the same element can be inserted.
00511        *
00512        *  Note that the first parameter is only a hint and can potentially
00513        *  improve the performance of the insertion process.  A bad hint would
00514        *  cause no gains in efficiency.
00515        *
00516        *  See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
00517        *  for more on @a hinting.
00518        *
00519        *  Insertion requires logarithmic time (if the hint is not taken).
00520        */
00521       iterator
00522       insert(const_iterator __position, const value_type& __x)
00523       { return _M_t._M_insert_equal_(__position, __x); }
00524 
00525 #if __cplusplus >= 201103L
00526       iterator
00527       insert(const_iterator __position, value_type&& __x)
00528       { return _M_t._M_insert_equal_(__position, std::move(__x)); }
00529 #endif
00530 
00531       /**
00532        *  @brief A template function that tries to insert a range of elements.
00533        *  @param  __first  Iterator pointing to the start of the range to be
00534        *                   inserted.
00535        *  @param  __last  Iterator pointing to the end of the range.
00536        *
00537        *  Complexity similar to that of the range constructor.
00538        */
00539       template<typename _InputIterator>
00540         void
00541         insert(_InputIterator __first, _InputIterator __last)
00542         { _M_t._M_insert_equal(__first, __last); }
00543 
00544 #if __cplusplus >= 201103L
00545       /**
00546        *  @brief Attempts to insert a list of elements into the %multiset.
00547        *  @param  __l  A std::initializer_list<value_type> of elements
00548        *               to be inserted.
00549        *
00550        *  Complexity similar to that of the range constructor.
00551        */
00552       void
00553       insert(initializer_list<value_type> __l)
00554       { this->insert(__l.begin(), __l.end()); }
00555 #endif
00556 
00557 #if __cplusplus > 201402L
00558       /// Extract a node.
00559       node_type
00560       extract(const_iterator __pos)
00561       {
00562         __glibcxx_assert(__pos != end());
00563         return _M_t.extract(__pos);
00564       }
00565 
00566       /// Extract a node.
00567       node_type
00568       extract(const key_type& __x)
00569       { return _M_t.extract(__x); }
00570 
00571       /// Re-insert an extracted node.
00572       iterator
00573       insert(node_type&& __nh)
00574       { return _M_t._M_reinsert_node_equal(std::move(__nh)); }
00575 
00576       /// Re-insert an extracted node.
00577       iterator
00578       insert(const_iterator __hint, node_type&& __nh)
00579       { return _M_t._M_reinsert_node_hint_equal(__hint, std::move(__nh)); }
00580 
00581       template<typename, typename>
00582         friend class _Rb_tree_merge_helper;
00583 
00584       template<typename _Compare1>
00585         void
00586         merge(multiset<_Key, _Compare1, _Alloc>& __source)
00587         {
00588           using _Merge_helper = _Rb_tree_merge_helper<multiset, _Compare1>;
00589           _M_t._M_merge_equal(_Merge_helper::_S_get_tree(__source));
00590         }
00591 
00592       template<typename _Compare1>
00593         void
00594         merge(multiset<_Key, _Compare1, _Alloc>&& __source)
00595         { merge(__source); }
00596 
00597       template<typename _Compare1>
00598         void
00599         merge(set<_Key, _Compare1, _Alloc>& __source)
00600         {
00601           using _Merge_helper = _Rb_tree_merge_helper<multiset, _Compare1>;
00602           _M_t._M_merge_equal(_Merge_helper::_S_get_tree(__source));
00603         }
00604 
00605       template<typename _Compare1>
00606         void
00607         merge(set<_Key, _Compare1, _Alloc>&& __source)
00608         { merge(__source); }
00609 #endif // C++17
00610 
00611 #if __cplusplus >= 201103L
00612       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00613       // DR 130. Associative erase should return an iterator.
00614       /**
00615        *  @brief Erases an element from a %multiset.
00616        *  @param  __position  An iterator pointing to the element to be erased.
00617        *  @return An iterator pointing to the element immediately following
00618        *          @a position prior to the element being erased. If no such
00619        *          element exists, end() is returned.
00620        *
00621        *  This function erases an element, pointed to by the given iterator,
00622        *  from a %multiset.  Note that this function only erases the element,
00623        *  and that if the element is itself a pointer, the pointed-to memory is
00624        *  not touched in any way.  Managing the pointer is the user's
00625        *  responsibility.
00626        */
00627       _GLIBCXX_ABI_TAG_CXX11
00628       iterator
00629       erase(const_iterator __position)
00630       { return _M_t.erase(__position); }
00631 #else
00632       /**
00633        *  @brief Erases an element from a %multiset.
00634        *  @param  __position  An iterator pointing to the element to be erased.
00635        *
00636        *  This function erases an element, pointed to by the given iterator,
00637        *  from a %multiset.  Note that this function only erases the element,
00638        *  and that if the element is itself a pointer, the pointed-to memory is
00639        *  not touched in any way.  Managing the pointer is the user's
00640        *  responsibility.
00641        */
00642       void
00643       erase(iterator __position)
00644       { _M_t.erase(__position); }
00645 #endif
00646 
00647       /**
00648        *  @brief Erases elements according to the provided key.
00649        *  @param  __x  Key of element to be erased.
00650        *  @return  The number of elements erased.
00651        *
00652        *  This function erases all elements located by the given key from a
00653        *  %multiset.
00654        *  Note that this function only erases the element, and that if
00655        *  the element is itself a pointer, the pointed-to memory is not touched
00656        *  in any way.  Managing the pointer is the user's responsibility.
00657        */
00658       size_type
00659       erase(const key_type& __x)
00660       { return _M_t.erase(__x); }
00661 
00662 #if __cplusplus >= 201103L
00663       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00664       // DR 130. Associative erase should return an iterator.
00665       /**
00666        *  @brief Erases a [first,last) range of elements from a %multiset.
00667        *  @param  __first  Iterator pointing to the start of the range to be
00668        *                   erased.
00669        *  @param __last Iterator pointing to the end of the range to
00670        *                be erased.
00671        *  @return The iterator @a last.
00672        *
00673        *  This function erases a sequence of elements from a %multiset.
00674        *  Note that this function only erases the elements, and that if
00675        *  the elements themselves are pointers, the pointed-to memory is not
00676        *  touched in any way.  Managing the pointer is the user's
00677        *  responsibility.
00678        */
00679       _GLIBCXX_ABI_TAG_CXX11
00680       iterator
00681       erase(const_iterator __first, const_iterator __last)
00682       { return _M_t.erase(__first, __last); }
00683 #else
00684       /**
00685        *  @brief Erases a [first,last) range of elements from a %multiset.
00686        *  @param  first  Iterator pointing to the start of the range to be
00687        *                 erased.
00688        *  @param  last  Iterator pointing to the end of the range to be erased.
00689        *
00690        *  This function erases a sequence of elements from a %multiset.
00691        *  Note that this function only erases the elements, and that if
00692        *  the elements themselves are pointers, the pointed-to memory is not
00693        *  touched in any way.  Managing the pointer is the user's
00694        *  responsibility.
00695        */
00696       void
00697       erase(iterator __first, iterator __last)
00698       { _M_t.erase(__first, __last); }
00699 #endif
00700 
00701       /**
00702        *  Erases all elements in a %multiset.  Note that this function only
00703        *  erases the elements, and that if the elements themselves are pointers,
00704        *  the pointed-to memory is not touched in any way.  Managing the pointer
00705        *  is the user's responsibility.
00706        */
00707       void
00708       clear() _GLIBCXX_NOEXCEPT
00709       { _M_t.clear(); }
00710 
00711       // multiset operations:
00712 
00713       //@{
00714       /**
00715        *  @brief Finds the number of elements with given key.
00716        *  @param  __x  Key of elements to be located.
00717        *  @return Number of elements with specified key.
00718        */
00719       size_type
00720       count(const key_type& __x) const
00721       { return _M_t.count(__x); }
00722 
00723 #if __cplusplus > 201103L
00724       template<typename _Kt>
00725         auto
00726         count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
00727         { return _M_t._M_count_tr(__x); }
00728 #endif
00729       //@}
00730 
00731       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00732       // 214.  set::find() missing const overload
00733       //@{
00734       /**
00735        *  @brief Tries to locate an element in a %set.
00736        *  @param  __x  Element to be located.
00737        *  @return  Iterator pointing to sought-after element, or end() if not
00738        *           found.
00739        *
00740        *  This function takes a key and tries to locate the element with which
00741        *  the key matches.  If successful the function returns an iterator
00742        *  pointing to the sought after element.  If unsuccessful it returns the
00743        *  past-the-end ( @c end() ) iterator.
00744        */
00745       iterator
00746       find(const key_type& __x)
00747       { return _M_t.find(__x); }
00748 
00749       const_iterator
00750       find(const key_type& __x) const
00751       { return _M_t.find(__x); }
00752 
00753 #if __cplusplus > 201103L
00754       template<typename _Kt>
00755         auto
00756         find(const _Kt& __x)
00757         -> decltype(iterator{_M_t._M_find_tr(__x)})
00758         { return iterator{_M_t._M_find_tr(__x)}; }
00759 
00760       template<typename _Kt>
00761         auto
00762         find(const _Kt& __x) const
00763         -> decltype(const_iterator{_M_t._M_find_tr(__x)})
00764         { return const_iterator{_M_t._M_find_tr(__x)}; }
00765 #endif
00766       //@}
00767 
00768       //@{
00769       /**
00770        *  @brief Finds the beginning of a subsequence matching given key.
00771        *  @param  __x  Key to be located.
00772        *  @return  Iterator pointing to first element equal to or greater
00773        *           than key, or end().
00774        *
00775        *  This function returns the first element of a subsequence of elements
00776        *  that matches the given key.  If unsuccessful it returns an iterator
00777        *  pointing to the first element that has a greater value than given key
00778        *  or end() if no such element exists.
00779        */
00780       iterator
00781       lower_bound(const key_type& __x)
00782       { return _M_t.lower_bound(__x); }
00783 
00784       const_iterator
00785       lower_bound(const key_type& __x) const
00786       { return _M_t.lower_bound(__x); }
00787 
00788 #if __cplusplus > 201103L
00789       template<typename _Kt>
00790         auto
00791         lower_bound(const _Kt& __x)
00792         -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
00793         { return iterator(_M_t._M_lower_bound_tr(__x)); }
00794 
00795       template<typename _Kt>
00796         auto
00797         lower_bound(const _Kt& __x) const
00798         -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
00799         { return iterator(_M_t._M_lower_bound_tr(__x)); }
00800 #endif
00801       //@}
00802 
00803       //@{
00804       /**
00805        *  @brief Finds the end of a subsequence matching given key.
00806        *  @param  __x  Key to be located.
00807        *  @return Iterator pointing to the first element
00808        *          greater than key, or end().
00809        */
00810       iterator
00811       upper_bound(const key_type& __x)
00812       { return _M_t.upper_bound(__x); }
00813 
00814       const_iterator
00815       upper_bound(const key_type& __x) const
00816       { return _M_t.upper_bound(__x); }
00817 
00818 #if __cplusplus > 201103L
00819       template<typename _Kt>
00820         auto
00821         upper_bound(const _Kt& __x)
00822         -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
00823         { return iterator(_M_t._M_upper_bound_tr(__x)); }
00824 
00825       template<typename _Kt>
00826         auto
00827         upper_bound(const _Kt& __x) const
00828         -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
00829         { return iterator(_M_t._M_upper_bound_tr(__x)); }
00830 #endif
00831       //@}
00832 
00833       //@{
00834       /**
00835        *  @brief Finds a subsequence matching given key.
00836        *  @param  __x  Key to be located.
00837        *  @return  Pair of iterators that possibly points to the subsequence
00838        *           matching given key.
00839        *
00840        *  This function is equivalent to
00841        *  @code
00842        *    std::make_pair(c.lower_bound(val),
00843        *                   c.upper_bound(val))
00844        *  @endcode
00845        *  (but is faster than making the calls separately).
00846        *
00847        *  This function probably only makes sense for multisets.
00848        */
00849       std::pair<iterator, iterator>
00850       equal_range(const key_type& __x)
00851       { return _M_t.equal_range(__x); }
00852 
00853       std::pair<const_iterator, const_iterator>
00854       equal_range(const key_type& __x) const
00855       { return _M_t.equal_range(__x); }
00856 
00857 #if __cplusplus > 201103L
00858       template<typename _Kt>
00859         auto
00860         equal_range(const _Kt& __x)
00861         -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
00862         { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
00863 
00864       template<typename _Kt>
00865         auto
00866         equal_range(const _Kt& __x) const
00867         -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
00868         { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
00869 #endif
00870       //@}
00871 
00872       template<typename _K1, typename _C1, typename _A1>
00873         friend bool
00874         operator==(const multiset<_K1, _C1, _A1>&,
00875                    const multiset<_K1, _C1, _A1>&);
00876 
00877       template<typename _K1, typename _C1, typename _A1>
00878         friend bool
00879         operator< (const multiset<_K1, _C1, _A1>&,
00880                    const multiset<_K1, _C1, _A1>&);
00881     };
00882 
00883   /**
00884    *  @brief  Multiset equality comparison.
00885    *  @param  __x  A %multiset.
00886    *  @param  __y  A %multiset of the same type as @a __x.
00887    *  @return  True iff the size and elements of the multisets are equal.
00888    *
00889    *  This is an equivalence relation.  It is linear in the size of the
00890    *  multisets.
00891    *  Multisets are considered equivalent if their sizes are equal, and if
00892    *  corresponding elements compare equal.
00893   */
00894   template<typename _Key, typename _Compare, typename _Alloc>
00895     inline bool
00896     operator==(const multiset<_Key, _Compare, _Alloc>& __x,
00897                const multiset<_Key, _Compare, _Alloc>& __y)
00898     { return __x._M_t == __y._M_t; }
00899 
00900   /**
00901    *  @brief  Multiset ordering relation.
00902    *  @param  __x  A %multiset.
00903    *  @param  __y  A %multiset of the same type as @a __x.
00904    *  @return  True iff @a __x is lexicographically less than @a __y.
00905    *
00906    *  This is a total ordering relation.  It is linear in the size of the
00907    *  sets.  The elements must be comparable with @c <.
00908    *
00909    *  See std::lexicographical_compare() for how the determination is made.
00910   */
00911   template<typename _Key, typename _Compare, typename _Alloc>
00912     inline bool
00913     operator<(const multiset<_Key, _Compare, _Alloc>& __x,
00914               const multiset<_Key, _Compare, _Alloc>& __y)
00915     { return __x._M_t < __y._M_t; }
00916 
00917   ///  Returns !(x == y).
00918   template<typename _Key, typename _Compare, typename _Alloc>
00919     inline bool
00920     operator!=(const multiset<_Key, _Compare, _Alloc>& __x,
00921                const multiset<_Key, _Compare, _Alloc>& __y)
00922     { return !(__x == __y); }
00923 
00924   ///  Returns y < x.
00925   template<typename _Key, typename _Compare, typename _Alloc>
00926     inline bool
00927     operator>(const multiset<_Key,_Compare,_Alloc>& __x,
00928               const multiset<_Key,_Compare,_Alloc>& __y)
00929     { return __y < __x; }
00930 
00931   ///  Returns !(y < x)
00932   template<typename _Key, typename _Compare, typename _Alloc>
00933     inline bool
00934     operator<=(const multiset<_Key, _Compare, _Alloc>& __x,
00935                const multiset<_Key, _Compare, _Alloc>& __y)
00936     { return !(__y < __x); }
00937 
00938   ///  Returns !(x < y)
00939   template<typename _Key, typename _Compare, typename _Alloc>
00940     inline bool
00941     operator>=(const multiset<_Key, _Compare, _Alloc>& __x,
00942                const multiset<_Key, _Compare, _Alloc>& __y)
00943     { return !(__x < __y); }
00944 
00945   /// See std::multiset::swap().
00946   template<typename _Key, typename _Compare, typename _Alloc>
00947     inline void
00948     swap(multiset<_Key, _Compare, _Alloc>& __x,
00949          multiset<_Key, _Compare, _Alloc>& __y)
00950     _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
00951     { __x.swap(__y); }
00952 
00953 _GLIBCXX_END_NAMESPACE_CONTAINER
00954 
00955 #if __cplusplus > 201402L
00956 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00957   // Allow std::multiset access to internals of compatible sets.
00958   template<typename _Val, typename _Cmp1, typename _Alloc, typename _Cmp2>
00959     struct
00960     _Rb_tree_merge_helper<_GLIBCXX_STD_C::multiset<_Val, _Cmp1, _Alloc>,
00961                           _Cmp2>
00962     {
00963     private:
00964       friend class _GLIBCXX_STD_C::multiset<_Val, _Cmp1, _Alloc>;
00965 
00966       static auto&
00967       _S_get_tree(_GLIBCXX_STD_C::set<_Val, _Cmp2, _Alloc>& __set)
00968       { return __set._M_t; }
00969 
00970       static auto&
00971       _S_get_tree(_GLIBCXX_STD_C::multiset<_Val, _Cmp2, _Alloc>& __set)
00972       { return __set._M_t; }
00973     };
00974 _GLIBCXX_END_NAMESPACE_VERSION
00975 #endif // C++17
00976 
00977 } // namespace std
00978 
00979 #endif /* _STL_MULTISET_H */