1 // Multimap implementation -*- C++ -*-
2 
3 // Copyright (C) 2001-2015 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /*
26  *
27  * Copyright (c) 1994
28  * Hewlett-Packard Company
29  *
30  * Permission to use, copy, modify, distribute and sell this software
31  * and its documentation for any purpose is hereby granted without fee,
32  * provided that the above copyright notice appear in all copies and
33  * that both that copyright notice and this permission notice appear
34  * in supporting documentation.  Hewlett-Packard Company makes no
35  * representations about the suitability of this software for any
36  * purpose.  It is provided "as is" without express or implied warranty.
37  *
38  *
39  * Copyright (c) 1996,1997
40  * Silicon Graphics Computer Systems, Inc.
41  *
42  * Permission to use, copy, modify, distribute and sell this software
43  * and its documentation for any purpose is hereby granted without fee,
44  * provided that the above copyright notice appear in all copies and
45  * that both that copyright notice and this permission notice appear
46  * in supporting documentation.  Silicon Graphics makes no
47  * representations about the suitability of this software for any
48  * purpose.  It is provided "as is" without express or implied warranty.
49  */
50 
51 /** @file bits/stl_multimap.h
52  *  This is an internal header file, included by other library headers.
53  *  Do not attempt to use it directly. @headername{map}
54  */
55 
56 #ifndef _STL_MULTIMAP_H
57 #define _STL_MULTIMAP_H 1
58 
59 #include <bits/concept_check.h>
60 #if __cplusplus >= 201103L
61 #include <initializer_list>
62 #endif
63 
_GLIBCXX_VISIBILITY(default)64 namespace std _GLIBCXX_VISIBILITY(default)
65 {
66 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
67 
68   /**
69    *  @brief A standard container made up of (key,value) pairs, which can be
70    *  retrieved based on a key, in logarithmic time.
71    *
72    *  @ingroup associative_containers
73    *
74    *  @tparam _Key  Type of key objects.
75    *  @tparam  _Tp  Type of mapped objects.
76    *  @tparam _Compare  Comparison function object type, defaults to less<_Key>.
77    *  @tparam _Alloc  Allocator type, defaults to
78    *                  allocator<pair<const _Key, _Tp>.
79    *
80    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
81    *  <a href="tables.html#66">reversible container</a>, and an
82    *  <a href="tables.html#69">associative container</a> (using equivalent
83    *  keys).  For a @c multimap<Key,T> the key_type is Key, the mapped_type
84    *  is T, and the value_type is std::pair<const Key,T>.
85    *
86    *  Multimaps support bidirectional iterators.
87    *
88    *  The private tree data is declared exactly the same way for map and
89    *  multimap; the distinction is made entirely in how the tree functions are
90    *  called (*_unique versus *_equal, same as the standard).
91   */
92   template <typename _Key, typename _Tp,
93 	    typename _Compare = std::less<_Key>,
94 	    typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
95     class multimap
96     {
97     public:
98       typedef _Key                                          key_type;
99       typedef _Tp                                           mapped_type;
100       typedef std::pair<const _Key, _Tp>                    value_type;
101       typedef _Compare                                      key_compare;
102       typedef _Alloc                                        allocator_type;
103 
104     private:
105       // concept requirements
106       typedef typename _Alloc::value_type                   _Alloc_value_type;
107       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
108       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
109 				_BinaryFunctionConcept)
110       __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
111 
112     public:
113       class value_compare
114       : public std::binary_function<value_type, value_type, bool>
115       {
116 	friend class multimap<_Key, _Tp, _Compare, _Alloc>;
117       protected:
118 	_Compare comp;
119 
120 	value_compare(_Compare __c)
121 	: comp(__c) { }
122 
123       public:
124 	bool operator()(const value_type& __x, const value_type& __y) const
125 	{ return comp(__x.first, __y.first); }
126       };
127 
128     private:
129       /// This turns a red-black tree into a [multi]map.
130       typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
131 	rebind<value_type>::other _Pair_alloc_type;
132 
133       typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
134 		       key_compare, _Pair_alloc_type> _Rep_type;
135       /// The actual tree structure.
136       _Rep_type _M_t;
137 
138       typedef __gnu_cxx::__alloc_traits<_Pair_alloc_type> _Alloc_traits;
139 
140     public:
141       // many of these are specified differently in ISO, but the following are
142       // "functionally equivalent"
143       typedef typename _Alloc_traits::pointer            pointer;
144       typedef typename _Alloc_traits::const_pointer      const_pointer;
145       typedef typename _Alloc_traits::reference          reference;
146       typedef typename _Alloc_traits::const_reference    const_reference;
147       typedef typename _Rep_type::iterator               iterator;
148       typedef typename _Rep_type::const_iterator         const_iterator;
149       typedef typename _Rep_type::size_type              size_type;
150       typedef typename _Rep_type::difference_type        difference_type;
151       typedef typename _Rep_type::reverse_iterator       reverse_iterator;
152       typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
153 
154       // [23.3.2] construct/copy/destroy
155       // (get_allocator() is also listed in this section)
156 
157       /**
158        *  @brief  Default constructor creates no elements.
159        */
160       multimap()
161 #if __cplusplus >= 201103L
162       noexcept(is_nothrow_default_constructible<allocator_type>::value
163                && is_nothrow_default_constructible<key_compare>::value)
164 #endif
165       : _M_t() { }
166 
167       /**
168        *  @brief  Creates a %multimap with no elements.
169        *  @param  __comp  A comparison object.
170        *  @param  __a  An allocator object.
171        */
172       explicit
173       multimap(const _Compare& __comp,
174 	       const allocator_type& __a = allocator_type())
175       : _M_t(__comp, _Pair_alloc_type(__a)) { }
176 
177       /**
178        *  @brief  %Multimap copy constructor.
179        *  @param  __x  A %multimap of identical element and allocator types.
180        *
181        *  The newly-created %multimap uses a copy of the allocation object
182        *  used by @a __x.
183        */
184       multimap(const multimap& __x)
185       : _M_t(__x._M_t) { }
186 
187 #if __cplusplus >= 201103L
188       /**
189        *  @brief  %Multimap move constructor.
190        *  @param   __x  A %multimap of identical element and allocator types.
191        *
192        *  The newly-created %multimap contains the exact contents of @a __x.
193        *  The contents of @a __x are a valid, but unspecified %multimap.
194        */
195       multimap(multimap&& __x)
196       noexcept(is_nothrow_copy_constructible<_Compare>::value)
197       : _M_t(std::move(__x._M_t)) { }
198 
199       /**
200        *  @brief  Builds a %multimap from an initializer_list.
201        *  @param  __l  An initializer_list.
202        *  @param  __comp  A comparison functor.
203        *  @param  __a  An allocator object.
204        *
205        *  Create a %multimap consisting of copies of the elements from
206        *  the initializer_list.  This is linear in N if the list is already
207        *  sorted, and NlogN otherwise (where N is @a __l.size()).
208        */
209       multimap(initializer_list<value_type> __l,
210 	       const _Compare& __comp = _Compare(),
211 	       const allocator_type& __a = allocator_type())
212       : _M_t(__comp, _Pair_alloc_type(__a))
213       { _M_t._M_insert_equal(__l.begin(), __l.end()); }
214 
215       /// Allocator-extended default constructor.
216       explicit
217       multimap(const allocator_type& __a)
218       : _M_t(_Compare(), _Pair_alloc_type(__a)) { }
219 
220       /// Allocator-extended copy constructor.
221       multimap(const multimap& __m, const allocator_type& __a)
222       : _M_t(__m._M_t, _Pair_alloc_type(__a)) { }
223 
224       /// Allocator-extended move constructor.
225       multimap(multimap&& __m, const allocator_type& __a)
226       noexcept(is_nothrow_copy_constructible<_Compare>::value
227 	       && _Alloc_traits::_S_always_equal())
228       : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { }
229 
230       /// Allocator-extended initialier-list constructor.
231       multimap(initializer_list<value_type> __l, const allocator_type& __a)
232       : _M_t(_Compare(), _Pair_alloc_type(__a))
233       { _M_t._M_insert_equal(__l.begin(), __l.end()); }
234 
235       /// Allocator-extended range constructor.
236       template<typename _InputIterator>
237         multimap(_InputIterator __first, _InputIterator __last,
238 		 const allocator_type& __a)
239 	: _M_t(_Compare(), _Pair_alloc_type(__a))
240         { _M_t._M_insert_equal(__first, __last); }
241 #endif
242 
243       /**
244        *  @brief  Builds a %multimap from a range.
245        *  @param  __first  An input iterator.
246        *  @param  __last  An input iterator.
247        *
248        *  Create a %multimap consisting of copies of the elements from
249        *  [__first,__last).  This is linear in N if the range is already sorted,
250        *  and NlogN otherwise (where N is distance(__first,__last)).
251        */
252       template<typename _InputIterator>
253         multimap(_InputIterator __first, _InputIterator __last)
254 	: _M_t()
255         { _M_t._M_insert_equal(__first, __last); }
256 
257       /**
258        *  @brief  Builds a %multimap from a range.
259        *  @param  __first  An input iterator.
260        *  @param  __last  An input iterator.
261        *  @param  __comp  A comparison functor.
262        *  @param  __a  An allocator object.
263        *
264        *  Create a %multimap consisting of copies of the elements from
265        *  [__first,__last).  This is linear in N if the range is already sorted,
266        *  and NlogN otherwise (where N is distance(__first,__last)).
267        */
268       template<typename _InputIterator>
269         multimap(_InputIterator __first, _InputIterator __last,
270 		 const _Compare& __comp,
271 		 const allocator_type& __a = allocator_type())
272 	: _M_t(__comp, _Pair_alloc_type(__a))
273         { _M_t._M_insert_equal(__first, __last); }
274 
275       // FIXME There is no dtor declared, but we should have something generated
276       // by Doxygen.  I don't know what tags to add to this paragraph to make
277       // that happen:
278       /**
279        *  The dtor only erases the elements, and note that if the elements
280        *  themselves are pointers, the pointed-to memory is not touched in any
281        *  way.  Managing the pointer is the user's responsibility.
282        */
283 
284       /**
285        *  @brief  %Multimap assignment operator.
286        *  @param  __x  A %multimap of identical element and allocator types.
287        *
288        *  All the elements of @a __x are copied, but unlike the copy
289        *  constructor, the allocator object is not copied.
290        */
291       multimap&
292       operator=(const multimap& __x)
293       {
294 	_M_t = __x._M_t;
295 	return *this;
296       }
297 
298 #if __cplusplus >= 201103L
299       /// Move assignment operator.
300       multimap&
301       operator=(multimap&&) = default;
302 
303       /**
304        *  @brief  %Multimap list assignment operator.
305        *  @param  __l  An initializer_list.
306        *
307        *  This function fills a %multimap with copies of the elements
308        *  in the initializer list @a __l.
309        *
310        *  Note that the assignment completely changes the %multimap and
311        *  that the resulting %multimap's size is the same as the number
312        *  of elements assigned.  Old data may be lost.
313        */
314       multimap&
315       operator=(initializer_list<value_type> __l)
316       {
317 	_M_t._M_assign_equal(__l.begin(), __l.end());
318 	return *this;
319       }
320 #endif
321 
322       /// Get a copy of the memory allocation object.
323       allocator_type
324       get_allocator() const _GLIBCXX_NOEXCEPT
325       { return allocator_type(_M_t.get_allocator()); }
326 
327       // iterators
328       /**
329        *  Returns a read/write iterator that points to the first pair in the
330        *  %multimap.  Iteration is done in ascending order according to the
331        *  keys.
332        */
333       iterator
334       begin() _GLIBCXX_NOEXCEPT
335       { return _M_t.begin(); }
336 
337       /**
338        *  Returns a read-only (constant) iterator that points to the first pair
339        *  in the %multimap.  Iteration is done in ascending order according to
340        *  the keys.
341        */
342       const_iterator
343       begin() const _GLIBCXX_NOEXCEPT
344       { return _M_t.begin(); }
345 
346       /**
347        *  Returns a read/write iterator that points one past the last pair in
348        *  the %multimap.  Iteration is done in ascending order according to the
349        *  keys.
350        */
351       iterator
352       end() _GLIBCXX_NOEXCEPT
353       { return _M_t.end(); }
354 
355       /**
356        *  Returns a read-only (constant) iterator that points one past the last
357        *  pair in the %multimap.  Iteration is done in ascending order according
358        *  to the keys.
359        */
360       const_iterator
361       end() const _GLIBCXX_NOEXCEPT
362       { return _M_t.end(); }
363 
364       /**
365        *  Returns a read/write reverse iterator that points to the last pair in
366        *  the %multimap.  Iteration is done in descending order according to the
367        *  keys.
368        */
369       reverse_iterator
370       rbegin() _GLIBCXX_NOEXCEPT
371       { return _M_t.rbegin(); }
372 
373       /**
374        *  Returns a read-only (constant) reverse iterator that points to the
375        *  last pair in the %multimap.  Iteration is done in descending order
376        *  according to the keys.
377        */
378       const_reverse_iterator
379       rbegin() const _GLIBCXX_NOEXCEPT
380       { return _M_t.rbegin(); }
381 
382       /**
383        *  Returns a read/write reverse iterator that points to one before the
384        *  first pair in the %multimap.  Iteration is done in descending order
385        *  according to the keys.
386        */
387       reverse_iterator
388       rend() _GLIBCXX_NOEXCEPT
389       { return _M_t.rend(); }
390 
391       /**
392        *  Returns a read-only (constant) reverse iterator that points to one
393        *  before the first pair in the %multimap.  Iteration is done in
394        *  descending order according to the keys.
395        */
396       const_reverse_iterator
397       rend() const _GLIBCXX_NOEXCEPT
398       { return _M_t.rend(); }
399 
400 #if __cplusplus >= 201103L
401       /**
402        *  Returns a read-only (constant) iterator that points to the first pair
403        *  in the %multimap.  Iteration is done in ascending order according to
404        *  the keys.
405        */
406       const_iterator
407       cbegin() const noexcept
408       { return _M_t.begin(); }
409 
410       /**
411        *  Returns a read-only (constant) iterator that points one past the last
412        *  pair in the %multimap.  Iteration is done in ascending order according
413        *  to the keys.
414        */
415       const_iterator
416       cend() const noexcept
417       { return _M_t.end(); }
418 
419       /**
420        *  Returns a read-only (constant) reverse iterator that points to the
421        *  last pair in the %multimap.  Iteration is done in descending order
422        *  according to the keys.
423        */
424       const_reverse_iterator
425       crbegin() const noexcept
426       { return _M_t.rbegin(); }
427 
428       /**
429        *  Returns a read-only (constant) reverse iterator that points to one
430        *  before the first pair in the %multimap.  Iteration is done in
431        *  descending order according to the keys.
432        */
433       const_reverse_iterator
434       crend() const noexcept
435       { return _M_t.rend(); }
436 #endif
437 
438       // capacity
439       /** Returns true if the %multimap is empty.  */
440       bool
441       empty() const _GLIBCXX_NOEXCEPT
442       { return _M_t.empty(); }
443 
444       /** Returns the size of the %multimap.  */
445       size_type
446       size() const _GLIBCXX_NOEXCEPT
447       { return _M_t.size(); }
448 
449       /** Returns the maximum size of the %multimap.  */
450       size_type
451       max_size() const _GLIBCXX_NOEXCEPT
452       { return _M_t.max_size(); }
453 
454       // modifiers
455 #if __cplusplus >= 201103L
456       /**
457        *  @brief Build and insert a std::pair into the %multimap.
458        *
459        *  @param __args  Arguments used to generate a new pair instance (see
460        *	        std::piecewise_contruct for passing arguments to each
461        *	        part of the pair constructor).
462        *
463        *  @return An iterator that points to the inserted (key,value) pair.
464        *
465        *  This function builds and inserts a (key, value) %pair into the
466        *  %multimap.
467        *  Contrary to a std::map the %multimap does not rely on unique keys and
468        *  thus multiple pairs with the same key can be inserted.
469        *
470        *  Insertion requires logarithmic time.
471        */
472       template<typename... _Args>
473 	iterator
474 	emplace(_Args&&... __args)
475 	{ return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); }
476 
477       /**
478        *  @brief Builds and inserts a std::pair into the %multimap.
479        *
480        *  @param  __pos  An iterator that serves as a hint as to where the pair
481        *                should be inserted.
482        *  @param  __args  Arguments used to generate a new pair instance (see
483        *	         std::piecewise_contruct for passing arguments to each
484        *	         part of the pair constructor).
485        *  @return An iterator that points to the inserted (key,value) pair.
486        *
487        *  This function inserts a (key, value) pair into the %multimap.
488        *  Contrary to a std::map the %multimap does not rely on unique keys and
489        *  thus multiple pairs with the same key can be inserted.
490        *  Note that the first parameter is only a hint and can potentially
491        *  improve the performance of the insertion process.  A bad hint would
492        *  cause no gains in efficiency.
493        *
494        *  For more on @a hinting, see:
495        *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
496        *
497        *  Insertion requires logarithmic time (if the hint is not taken).
498        */
499       template<typename... _Args>
500 	iterator
501 	emplace_hint(const_iterator __pos, _Args&&... __args)
502 	{
503 	  return _M_t._M_emplace_hint_equal(__pos,
504 					    std::forward<_Args>(__args)...);
505 	}
506 #endif
507 
508       /**
509        *  @brief Inserts a std::pair into the %multimap.
510        *  @param  __x  Pair to be inserted (see std::make_pair for easy creation
511        *             of pairs).
512        *  @return An iterator that points to the inserted (key,value) pair.
513        *
514        *  This function inserts a (key, value) pair into the %multimap.
515        *  Contrary to a std::map the %multimap does not rely on unique keys and
516        *  thus multiple pairs with the same key can be inserted.
517        *
518        *  Insertion requires logarithmic time.
519        */
520       iterator
521       insert(const value_type& __x)
522       { return _M_t._M_insert_equal(__x); }
523 
524 #if __cplusplus >= 201103L
525       template<typename _Pair, typename = typename
526 	       std::enable_if<std::is_constructible<value_type,
527 						    _Pair&&>::value>::type>
528         iterator
529         insert(_Pair&& __x)
530         { return _M_t._M_insert_equal(std::forward<_Pair>(__x)); }
531 #endif
532 
533       /**
534        *  @brief Inserts a std::pair into the %multimap.
535        *  @param  __position  An iterator that serves as a hint as to where the
536        *                      pair should be inserted.
537        *  @param  __x  Pair to be inserted (see std::make_pair for easy creation
538        *               of pairs).
539        *  @return An iterator that points to the inserted (key,value) pair.
540        *
541        *  This function inserts a (key, value) pair into the %multimap.
542        *  Contrary to a std::map the %multimap does not rely on unique keys and
543        *  thus multiple pairs with the same key can be inserted.
544        *  Note that the first parameter is only a hint and can potentially
545        *  improve the performance of the insertion process.  A bad hint would
546        *  cause no gains in efficiency.
547        *
548        *  For more on @a hinting, see:
549        *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
550        *
551        *  Insertion requires logarithmic time (if the hint is not taken).
552        */
553       iterator
554 #if __cplusplus >= 201103L
555       insert(const_iterator __position, const value_type& __x)
556 #else
557       insert(iterator __position, const value_type& __x)
558 #endif
559       { return _M_t._M_insert_equal_(__position, __x); }
560 
561 #if __cplusplus >= 201103L
562       template<typename _Pair, typename = typename
563 	       std::enable_if<std::is_constructible<value_type,
564 						    _Pair&&>::value>::type>
565         iterator
566         insert(const_iterator __position, _Pair&& __x)
567         { return _M_t._M_insert_equal_(__position,
568 				       std::forward<_Pair>(__x)); }
569 #endif
570 
571       /**
572        *  @brief A template function that attempts to insert a range
573        *  of elements.
574        *  @param  __first  Iterator pointing to the start of the range to be
575        *                   inserted.
576        *  @param  __last  Iterator pointing to the end of the range.
577        *
578        *  Complexity similar to that of the range constructor.
579        */
580       template<typename _InputIterator>
581         void
582         insert(_InputIterator __first, _InputIterator __last)
583         { _M_t._M_insert_equal(__first, __last); }
584 
585 #if __cplusplus >= 201103L
586       /**
587        *  @brief Attempts to insert a list of std::pairs into the %multimap.
588        *  @param  __l  A std::initializer_list<value_type> of pairs to be
589        *               inserted.
590        *
591        *  Complexity similar to that of the range constructor.
592        */
593       void
594       insert(initializer_list<value_type> __l)
595       { this->insert(__l.begin(), __l.end()); }
596 #endif
597 
598 #if __cplusplus >= 201103L
599       // _GLIBCXX_RESOLVE_LIB_DEFECTS
600       // DR 130. Associative erase should return an iterator.
601       /**
602        *  @brief Erases an element from a %multimap.
603        *  @param  __position  An iterator pointing to the element to be erased.
604        *  @return An iterator pointing to the element immediately following
605        *          @a position prior to the element being erased. If no such
606        *          element exists, end() is returned.
607        *
608        *  This function erases an element, pointed to by the given iterator,
609        *  from a %multimap.  Note that this function only erases the element,
610        *  and that if the element is itself a pointer, the pointed-to memory is
611        *  not touched in any way.  Managing the pointer is the user's
612        *  responsibility.
613        */
614       iterator
615       erase(const_iterator __position)
616       { return _M_t.erase(__position); }
617 
618       // LWG 2059.
619       _GLIBCXX_ABI_TAG_CXX11
620       iterator
621       erase(iterator __position)
622       { return _M_t.erase(__position); }
623 #else
624       /**
625        *  @brief Erases an element from a %multimap.
626        *  @param  __position  An iterator pointing to the element to be erased.
627        *
628        *  This function erases an element, pointed to by the given iterator,
629        *  from a %multimap.  Note that this function only erases the element,
630        *  and that if the element is itself a pointer, the pointed-to memory is
631        *  not touched in any way.  Managing the pointer is the user's
632        *  responsibility.
633        */
634       void
635       erase(iterator __position)
636       { _M_t.erase(__position); }
637 #endif
638 
639       /**
640        *  @brief Erases elements according to the provided key.
641        *  @param  __x  Key of element to be erased.
642        *  @return  The number of elements erased.
643        *
644        *  This function erases all elements located by the given key from a
645        *  %multimap.
646        *  Note that this function only erases the element, and that if
647        *  the element is itself a pointer, the pointed-to memory is not touched
648        *  in any way.  Managing the pointer is the user's responsibility.
649        */
650       size_type
651       erase(const key_type& __x)
652       { return _M_t.erase(__x); }
653 
654 #if __cplusplus >= 201103L
655       // _GLIBCXX_RESOLVE_LIB_DEFECTS
656       // DR 130. Associative erase should return an iterator.
657       /**
658        *  @brief Erases a [first,last) range of elements from a %multimap.
659        *  @param  __first  Iterator pointing to the start of the range to be
660        *                   erased.
661        *  @param __last Iterator pointing to the end of the range to be
662        *                erased .
663        *  @return The iterator @a __last.
664        *
665        *  This function erases a sequence of elements from a %multimap.
666        *  Note that this function only erases the elements, and that if
667        *  the elements themselves are pointers, the pointed-to memory is not
668        *  touched in any way.  Managing the pointer is the user's
669        *  responsibility.
670        */
671       iterator
672       erase(const_iterator __first, const_iterator __last)
673       { return _M_t.erase(__first, __last); }
674 #else
675       // _GLIBCXX_RESOLVE_LIB_DEFECTS
676       // DR 130. Associative erase should return an iterator.
677       /**
678        *  @brief Erases a [first,last) range of elements from a %multimap.
679        *  @param  __first  Iterator pointing to the start of the range to be
680        *                 erased.
681        *  @param __last Iterator pointing to the end of the range to
682        *                be erased.
683        *
684        *  This function erases a sequence of elements from a %multimap.
685        *  Note that this function only erases the elements, and that if
686        *  the elements themselves are pointers, the pointed-to memory is not
687        *  touched in any way.  Managing the pointer is the user's
688        *  responsibility.
689        */
690       void
691       erase(iterator __first, iterator __last)
692       { _M_t.erase(__first, __last); }
693 #endif
694 
695       /**
696        *  @brief  Swaps data with another %multimap.
697        *  @param  __x  A %multimap of the same element and allocator types.
698        *
699        *  This exchanges the elements between two multimaps in constant time.
700        *  (It is only swapping a pointer, an integer, and an instance of
701        *  the @c Compare type (which itself is often stateless and empty), so it
702        *  should be quite fast.)
703        *  Note that the global std::swap() function is specialized such that
704        *  std::swap(m1,m2) will feed to this function.
705        */
706       void
707       swap(multimap& __x)
708 #if __cplusplus >= 201103L
709       noexcept(_Alloc_traits::_S_nothrow_swap())
710 #endif
711       { _M_t.swap(__x._M_t); }
712 
713       /**
714        *  Erases all elements in a %multimap.  Note that this function only
715        *  erases the elements, and that if the elements themselves are pointers,
716        *  the pointed-to memory is not touched in any way.  Managing the pointer
717        *  is the user's responsibility.
718        */
719       void
720       clear() _GLIBCXX_NOEXCEPT
721       { _M_t.clear(); }
722 
723       // observers
724       /**
725        *  Returns the key comparison object out of which the %multimap
726        *  was constructed.
727        */
728       key_compare
729       key_comp() const
730       { return _M_t.key_comp(); }
731 
732       /**
733        *  Returns a value comparison object, built from the key comparison
734        *  object out of which the %multimap was constructed.
735        */
736       value_compare
737       value_comp() const
738       { return value_compare(_M_t.key_comp()); }
739 
740       // multimap operations
741 
742       //@{
743       /**
744        *  @brief Tries to locate an element in a %multimap.
745        *  @param  __x  Key of (key, value) pair to be located.
746        *  @return  Iterator pointing to sought-after element,
747        *           or end() if not found.
748        *
749        *  This function takes a key and tries to locate the element with which
750        *  the key matches.  If successful the function returns an iterator
751        *  pointing to the sought after %pair.  If unsuccessful it returns the
752        *  past-the-end ( @c end() ) iterator.
753        */
754       iterator
755       find(const key_type& __x)
756       { return _M_t.find(__x); }
757 
758 #if __cplusplus > 201103L
759       template<typename _Kt>
760 	auto
761 	find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
762 	{ return _M_t._M_find_tr(__x); }
763 #endif
764       //@}
765 
766       //@{
767       /**
768        *  @brief Tries to locate an element in a %multimap.
769        *  @param  __x  Key of (key, value) pair to be located.
770        *  @return  Read-only (constant) iterator pointing to sought-after
771        *           element, or end() if not found.
772        *
773        *  This function takes a key and tries to locate the element with which
774        *  the key matches.  If successful the function returns a constant
775        *  iterator pointing to the sought after %pair.  If unsuccessful it
776        *  returns the past-the-end ( @c end() ) iterator.
777        */
778       const_iterator
779       find(const key_type& __x) const
780       { return _M_t.find(__x); }
781 
782 #if __cplusplus > 201103L
783       template<typename _Kt>
784 	auto
785 	find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
786 	{ return _M_t._M_find_tr(__x); }
787 #endif
788       //@}
789 
790       //@{
791       /**
792        *  @brief Finds the number of elements with given key.
793        *  @param  __x  Key of (key, value) pairs to be located.
794        *  @return Number of elements with specified key.
795        */
796       size_type
797       count(const key_type& __x) const
798       { return _M_t.count(__x); }
799 
800 #if __cplusplus > 201103L
801       template<typename _Kt>
802 	auto
803 	count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
804 	{ return _M_t._M_count_tr(__x); }
805 #endif
806       //@}
807 
808       //@{
809       /**
810        *  @brief Finds the beginning of a subsequence matching given key.
811        *  @param  __x  Key of (key, value) pair to be located.
812        *  @return  Iterator pointing to first element equal to or greater
813        *           than key, or end().
814        *
815        *  This function returns the first element of a subsequence of elements
816        *  that matches the given key.  If unsuccessful it returns an iterator
817        *  pointing to the first element that has a greater value than given key
818        *  or end() if no such element exists.
819        */
820       iterator
821       lower_bound(const key_type& __x)
822       { return _M_t.lower_bound(__x); }
823 
824 #if __cplusplus > 201103L
825       template<typename _Kt>
826 	auto
827 	lower_bound(const _Kt& __x)
828 	-> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
829 	{ return iterator(_M_t._M_lower_bound_tr(__x)); }
830 #endif
831       //@}
832 
833       //@{
834       /**
835        *  @brief Finds the beginning of a subsequence matching given key.
836        *  @param  __x  Key of (key, value) pair to be located.
837        *  @return  Read-only (constant) iterator pointing to first element
838        *           equal to or greater than key, or end().
839        *
840        *  This function returns the first element of a subsequence of
841        *  elements that matches the given key.  If unsuccessful the
842        *  iterator will point to the next greatest element or, if no
843        *  such greater element exists, to end().
844        */
845       const_iterator
846       lower_bound(const key_type& __x) const
847       { return _M_t.lower_bound(__x); }
848 
849 #if __cplusplus > 201103L
850       template<typename _Kt>
851 	auto
852 	lower_bound(const _Kt& __x) const
853 	-> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
854 	{ return const_iterator(_M_t._M_lower_bound_tr(__x)); }
855 #endif
856       //@}
857 
858       //@{
859       /**
860        *  @brief Finds the end of a subsequence matching given key.
861        *  @param  __x  Key of (key, value) pair to be located.
862        *  @return Iterator pointing to the first element
863        *          greater than key, or end().
864        */
865       iterator
866       upper_bound(const key_type& __x)
867       { return _M_t.upper_bound(__x); }
868 
869 #if __cplusplus > 201103L
870       template<typename _Kt>
871 	auto
872 	upper_bound(const _Kt& __x)
873 	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
874 	{ return iterator(_M_t._M_upper_bound_tr(__x)); }
875 #endif
876       //@}
877 
878       //@{
879       /**
880        *  @brief Finds the end of a subsequence matching given key.
881        *  @param  __x  Key of (key, value) pair to be located.
882        *  @return  Read-only (constant) iterator pointing to first iterator
883        *           greater than key, or end().
884        */
885       const_iterator
886       upper_bound(const key_type& __x) const
887       { return _M_t.upper_bound(__x); }
888 
889 #if __cplusplus > 201103L
890       template<typename _Kt>
891 	auto
892 	upper_bound(const _Kt& __x) const
893 	-> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
894 	{ return const_iterator(_M_t._M_upper_bound_tr(__x)); }
895 #endif
896       //@}
897 
898       //@{
899       /**
900        *  @brief Finds a subsequence matching given key.
901        *  @param  __x  Key of (key, value) pairs to be located.
902        *  @return  Pair of iterators that possibly points to the subsequence
903        *           matching given key.
904        *
905        *  This function is equivalent to
906        *  @code
907        *    std::make_pair(c.lower_bound(val),
908        *                   c.upper_bound(val))
909        *  @endcode
910        *  (but is faster than making the calls separately).
911        */
912       std::pair<iterator, iterator>
913       equal_range(const key_type& __x)
914       { return _M_t.equal_range(__x); }
915 
916 #if __cplusplus > 201103L
917       template<typename _Kt>
918 	auto
919 	equal_range(const _Kt& __x)
920 	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
921 	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
922 #endif
923       //@}
924 
925       //@{
926       /**
927        *  @brief Finds a subsequence matching given key.
928        *  @param  __x  Key of (key, value) pairs to be located.
929        *  @return  Pair of read-only (constant) iterators that possibly points
930        *           to the subsequence matching given key.
931        *
932        *  This function is equivalent to
933        *  @code
934        *    std::make_pair(c.lower_bound(val),
935        *                   c.upper_bound(val))
936        *  @endcode
937        *  (but is faster than making the calls separately).
938        */
939       std::pair<const_iterator, const_iterator>
940       equal_range(const key_type& __x) const
941       { return _M_t.equal_range(__x); }
942 
943 #if __cplusplus > 201103L
944       template<typename _Kt>
945 	auto
946 	equal_range(const _Kt& __x) const
947 	-> decltype(pair<const_iterator, const_iterator>(
948 	      _M_t._M_equal_range_tr(__x)))
949 	{
950 	  return pair<const_iterator, const_iterator>(
951 	      _M_t._M_equal_range_tr(__x));
952 	}
953 #endif
954       //@}
955 
956       template<typename _K1, typename _T1, typename _C1, typename _A1>
957         friend bool
958         operator==(const multimap<_K1, _T1, _C1, _A1>&,
959 		   const multimap<_K1, _T1, _C1, _A1>&);
960 
961       template<typename _K1, typename _T1, typename _C1, typename _A1>
962         friend bool
963         operator<(const multimap<_K1, _T1, _C1, _A1>&,
964 		  const multimap<_K1, _T1, _C1, _A1>&);
965   };
966 
967   /**
968    *  @brief  Multimap equality comparison.
969    *  @param  __x  A %multimap.
970    *  @param  __y  A %multimap of the same type as @a __x.
971    *  @return  True iff the size and elements of the maps are equal.
972    *
973    *  This is an equivalence relation.  It is linear in the size of the
974    *  multimaps.  Multimaps are considered equivalent if their sizes are equal,
975    *  and if corresponding elements compare equal.
976   */
977   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
978     inline bool
979     operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
980                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
981     { return __x._M_t == __y._M_t; }
982 
983   /**
984    *  @brief  Multimap ordering relation.
985    *  @param  __x  A %multimap.
986    *  @param  __y  A %multimap of the same type as @a __x.
987    *  @return  True iff @a x is lexicographically less than @a y.
988    *
989    *  This is a total ordering relation.  It is linear in the size of the
990    *  multimaps.  The elements must be comparable with @c <.
991    *
992    *  See std::lexicographical_compare() for how the determination is made.
993   */
994   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
995     inline bool
996     operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
997               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
998     { return __x._M_t < __y._M_t; }
999 
1000   /// Based on operator==
1001   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1002     inline bool
1003     operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
1004                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
1005     { return !(__x == __y); }
1006 
1007   /// Based on operator<
1008   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1009     inline bool
1010     operator>(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
1011               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
1012     { return __y < __x; }
1013 
1014   /// Based on operator<
1015   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1016     inline bool
1017     operator<=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
1018                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
1019     { return !(__y < __x); }
1020 
1021   /// Based on operator<
1022   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1023     inline bool
1024     operator>=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
1025                const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
1026     { return !(__x < __y); }
1027 
1028   /// See std::multimap::swap().
1029   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1030     inline void
1031     swap(multimap<_Key, _Tp, _Compare, _Alloc>& __x,
1032          multimap<_Key, _Tp, _Compare, _Alloc>& __y)
1033     { __x.swap(__y); }
1034 
1035 _GLIBCXX_END_NAMESPACE_CONTAINER
1036 } // namespace std
1037 
1038 #endif /* _STL_MULTIMAP_H */
1039