libstdc++
stl_multimap.h
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1 // Multimap implementation -*- C++ -*-
2 
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25 /*
26  *
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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 
64 namespace std _GLIBCXX_VISIBILITY(default)
65 {
66 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
67 
68  template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
69  class map;
70 
71  /**
72  * @brief A standard container made up of (key,value) pairs, which can be
73  * retrieved based on a key, in logarithmic time.
74  *
75  * @ingroup associative_containers
76  *
77  * @tparam _Key Type of key objects.
78  * @tparam _Tp Type of mapped objects.
79  * @tparam _Compare Comparison function object type, defaults to less<_Key>.
80  * @tparam _Alloc Allocator type, defaults to
81  * allocator<pair<const _Key, _Tp>.
82  *
83  * Meets the requirements of a <a href="tables.html#65">container</a>, a
84  * <a href="tables.html#66">reversible container</a>, and an
85  * <a href="tables.html#69">associative container</a> (using equivalent
86  * keys). For a @c multimap<Key,T> the key_type is Key, the mapped_type
87  * is T, and the value_type is std::pair<const Key,T>.
88  *
89  * Multimaps support bidirectional iterators.
90  *
91  * The private tree data is declared exactly the same way for map and
92  * multimap; the distinction is made entirely in how the tree functions are
93  * called (*_unique versus *_equal, same as the standard).
94  */
95  template <typename _Key, typename _Tp,
96  typename _Compare = std::less<_Key>,
97  typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
98  class multimap
99  {
100  public:
101  typedef _Key key_type;
102  typedef _Tp mapped_type;
103  typedef std::pair<const _Key, _Tp> value_type;
104  typedef _Compare key_compare;
105  typedef _Alloc allocator_type;
106 
107  private:
108 #ifdef _GLIBCXX_CONCEPT_CHECKS
109  // concept requirements
110  typedef typename _Alloc::value_type _Alloc_value_type;
111 # if __cplusplus < 201103L
112  __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
113 # endif
114  __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
115  _BinaryFunctionConcept)
116  __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
117 #endif
118 
119  public:
120  class value_compare
121  : public std::binary_function<value_type, value_type, bool>
122  {
123  friend class multimap<_Key, _Tp, _Compare, _Alloc>;
124  protected:
125  _Compare comp;
126 
127  value_compare(_Compare __c)
128  : comp(__c) { }
129 
130  public:
131  bool operator()(const value_type& __x, const value_type& __y) const
132  { return comp(__x.first, __y.first); }
133  };
134 
135  private:
136  /// This turns a red-black tree into a [multi]map.
138  rebind<value_type>::other _Pair_alloc_type;
139 
140  typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
141  key_compare, _Pair_alloc_type> _Rep_type;
142  /// The actual tree structure.
143  _Rep_type _M_t;
144 
145  typedef __gnu_cxx::__alloc_traits<_Pair_alloc_type> _Alloc_traits;
146 
147  public:
148  // many of these are specified differently in ISO, but the following are
149  // "functionally equivalent"
150  typedef typename _Alloc_traits::pointer pointer;
151  typedef typename _Alloc_traits::const_pointer const_pointer;
152  typedef typename _Alloc_traits::reference reference;
153  typedef typename _Alloc_traits::const_reference const_reference;
154  typedef typename _Rep_type::iterator iterator;
155  typedef typename _Rep_type::const_iterator const_iterator;
156  typedef typename _Rep_type::size_type size_type;
157  typedef typename _Rep_type::difference_type difference_type;
158  typedef typename _Rep_type::reverse_iterator reverse_iterator;
159  typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
160 
161 #if __cplusplus > 201402L
162  using node_type = typename _Rep_type::node_type;
163 #endif
164 
165  // [23.3.2] construct/copy/destroy
166  // (get_allocator() is also listed in this section)
167 
168  /**
169  * @brief Default constructor creates no elements.
170  */
171 #if __cplusplus < 201103L
172  multimap() : _M_t() { }
173 #else
174  multimap() = default;
175 #endif
176 
177  /**
178  * @brief Creates a %multimap with no elements.
179  * @param __comp A comparison object.
180  * @param __a An allocator object.
181  */
182  explicit
183  multimap(const _Compare& __comp,
184  const allocator_type& __a = allocator_type())
185  : _M_t(__comp, _Pair_alloc_type(__a)) { }
186 
187  /**
188  * @brief %Multimap copy constructor.
189  *
190  * Whether the allocator is copied depends on the allocator traits.
191  */
192 #if __cplusplus < 201103L
193  multimap(const multimap& __x)
194  : _M_t(__x._M_t) { }
195 #else
196  multimap(const multimap&) = default;
197 
198  /**
199  * @brief %Multimap move constructor.
200  *
201  * The newly-created %multimap contains the exact contents of the
202  * moved instance. The moved instance is a valid, but unspecified
203  * %multimap.
204  */
205  multimap(multimap&&) = default;
206 
207  /**
208  * @brief Builds a %multimap from an initializer_list.
209  * @param __l An initializer_list.
210  * @param __comp A comparison functor.
211  * @param __a An allocator object.
212  *
213  * Create a %multimap consisting of copies of the elements from
214  * the initializer_list. This is linear in N if the list is already
215  * sorted, and NlogN otherwise (where N is @a __l.size()).
216  */
218  const _Compare& __comp = _Compare(),
219  const allocator_type& __a = allocator_type())
220  : _M_t(__comp, _Pair_alloc_type(__a))
221  { _M_t._M_insert_equal(__l.begin(), __l.end()); }
222 
223  /// Allocator-extended default constructor.
224  explicit
225  multimap(const allocator_type& __a)
226  : _M_t(_Compare(), _Pair_alloc_type(__a)) { }
227 
228  /// Allocator-extended copy constructor.
229  multimap(const multimap& __m, const allocator_type& __a)
230  : _M_t(__m._M_t, _Pair_alloc_type(__a)) { }
231 
232  /// Allocator-extended move constructor.
233  multimap(multimap&& __m, const allocator_type& __a)
234  noexcept(is_nothrow_copy_constructible<_Compare>::value
235  && _Alloc_traits::_S_always_equal())
236  : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { }
237 
238  /// Allocator-extended initialier-list constructor.
239  multimap(initializer_list<value_type> __l, const allocator_type& __a)
240  : _M_t(_Compare(), _Pair_alloc_type(__a))
241  { _M_t._M_insert_equal(__l.begin(), __l.end()); }
242 
243  /// Allocator-extended range constructor.
244  template<typename _InputIterator>
245  multimap(_InputIterator __first, _InputIterator __last,
246  const allocator_type& __a)
247  : _M_t(_Compare(), _Pair_alloc_type(__a))
248  { _M_t._M_insert_equal(__first, __last); }
249 #endif
250 
251  /**
252  * @brief Builds a %multimap from a range.
253  * @param __first An input iterator.
254  * @param __last An input iterator.
255  *
256  * Create a %multimap consisting of copies of the elements from
257  * [__first,__last). This is linear in N if the range is already sorted,
258  * and NlogN otherwise (where N is distance(__first,__last)).
259  */
260  template<typename _InputIterator>
261  multimap(_InputIterator __first, _InputIterator __last)
262  : _M_t()
263  { _M_t._M_insert_equal(__first, __last); }
264 
265  /**
266  * @brief Builds a %multimap from a range.
267  * @param __first An input iterator.
268  * @param __last An input iterator.
269  * @param __comp A comparison functor.
270  * @param __a An allocator object.
271  *
272  * Create a %multimap consisting of copies of the elements from
273  * [__first,__last). This is linear in N if the range is already sorted,
274  * and NlogN otherwise (where N is distance(__first,__last)).
275  */
276  template<typename _InputIterator>
277  multimap(_InputIterator __first, _InputIterator __last,
278  const _Compare& __comp,
279  const allocator_type& __a = allocator_type())
280  : _M_t(__comp, _Pair_alloc_type(__a))
281  { _M_t._M_insert_equal(__first, __last); }
282 
283 #if __cplusplus >= 201103L
284  /**
285  * The dtor only erases the elements, and note that if the elements
286  * themselves are pointers, the pointed-to memory is not touched in any
287  * way. Managing the pointer is the user's responsibility.
288  */
289  ~multimap() = default;
290 #endif
291 
292  /**
293  * @brief %Multimap assignment operator.
294  *
295  * Whether the allocator is copied depends on the allocator traits.
296  */
297 #if __cplusplus < 201103L
298  multimap&
299  operator=(const multimap& __x)
300  {
301  _M_t = __x._M_t;
302  return *this;
303  }
304 #else
305  multimap&
306  operator=(const multimap&) = default;
307 
308  /// Move assignment operator.
309  multimap&
310  operator=(multimap&&) = default;
311 
312  /**
313  * @brief %Multimap list assignment operator.
314  * @param __l An initializer_list.
315  *
316  * This function fills a %multimap with copies of the elements
317  * in the initializer list @a __l.
318  *
319  * Note that the assignment completely changes the %multimap and
320  * that the resulting %multimap's size is the same as the number
321  * of elements assigned.
322  */
323  multimap&
325  {
326  _M_t._M_assign_equal(__l.begin(), __l.end());
327  return *this;
328  }
329 #endif
330 
331  /// Get a copy of the memory allocation object.
332  allocator_type
333  get_allocator() const _GLIBCXX_NOEXCEPT
334  { return allocator_type(_M_t.get_allocator()); }
335 
336  // iterators
337  /**
338  * Returns a read/write iterator that points to the first pair in the
339  * %multimap. Iteration is done in ascending order according to the
340  * keys.
341  */
342  iterator
343  begin() _GLIBCXX_NOEXCEPT
344  { return _M_t.begin(); }
345 
346  /**
347  * Returns a read-only (constant) iterator that points to the first pair
348  * in the %multimap. Iteration is done in ascending order according to
349  * the keys.
350  */
351  const_iterator
352  begin() const _GLIBCXX_NOEXCEPT
353  { return _M_t.begin(); }
354 
355  /**
356  * Returns a read/write iterator that points one past the last pair in
357  * the %multimap. Iteration is done in ascending order according to the
358  * keys.
359  */
360  iterator
361  end() _GLIBCXX_NOEXCEPT
362  { return _M_t.end(); }
363 
364  /**
365  * Returns a read-only (constant) iterator that points one past the last
366  * pair in the %multimap. Iteration is done in ascending order according
367  * to the keys.
368  */
369  const_iterator
370  end() const _GLIBCXX_NOEXCEPT
371  { return _M_t.end(); }
372 
373  /**
374  * Returns a read/write reverse iterator that points to the last pair in
375  * the %multimap. Iteration is done in descending order according to the
376  * keys.
377  */
379  rbegin() _GLIBCXX_NOEXCEPT
380  { return _M_t.rbegin(); }
381 
382  /**
383  * Returns a read-only (constant) reverse iterator that points to the
384  * last pair in the %multimap. Iteration is done in descending order
385  * according to the keys.
386  */
387  const_reverse_iterator
388  rbegin() const _GLIBCXX_NOEXCEPT
389  { return _M_t.rbegin(); }
390 
391  /**
392  * Returns a read/write reverse iterator that points to one before the
393  * first pair in the %multimap. Iteration is done in descending order
394  * according to the keys.
395  */
397  rend() _GLIBCXX_NOEXCEPT
398  { return _M_t.rend(); }
399 
400  /**
401  * Returns a read-only (constant) reverse iterator that points to one
402  * before the first pair in the %multimap. Iteration is done in
403  * descending order according to the keys.
404  */
405  const_reverse_iterator
406  rend() const _GLIBCXX_NOEXCEPT
407  { return _M_t.rend(); }
408 
409 #if __cplusplus >= 201103L
410  /**
411  * Returns a read-only (constant) iterator that points to the first pair
412  * in the %multimap. Iteration is done in ascending order according to
413  * the keys.
414  */
415  const_iterator
416  cbegin() const noexcept
417  { return _M_t.begin(); }
418 
419  /**
420  * Returns a read-only (constant) iterator that points one past the last
421  * pair in the %multimap. Iteration is done in ascending order according
422  * to the keys.
423  */
424  const_iterator
425  cend() const noexcept
426  { return _M_t.end(); }
427 
428  /**
429  * Returns a read-only (constant) reverse iterator that points to the
430  * last pair in the %multimap. Iteration is done in descending order
431  * according to the keys.
432  */
433  const_reverse_iterator
435  { return _M_t.rbegin(); }
436 
437  /**
438  * Returns a read-only (constant) reverse iterator that points to one
439  * before the first pair in the %multimap. Iteration is done in
440  * descending order according to the keys.
441  */
442  const_reverse_iterator
443  crend() const noexcept
444  { return _M_t.rend(); }
445 #endif
446 
447  // capacity
448  /** Returns true if the %multimap is empty. */
449  bool
450  empty() const _GLIBCXX_NOEXCEPT
451  { return _M_t.empty(); }
452 
453  /** Returns the size of the %multimap. */
454  size_type
455  size() const _GLIBCXX_NOEXCEPT
456  { return _M_t.size(); }
457 
458  /** Returns the maximum size of the %multimap. */
459  size_type
460  max_size() const _GLIBCXX_NOEXCEPT
461  { return _M_t.max_size(); }
462 
463  // modifiers
464 #if __cplusplus >= 201103L
465  /**
466  * @brief Build and insert a std::pair into the %multimap.
467  *
468  * @param __args Arguments used to generate a new pair instance (see
469  * std::piecewise_contruct for passing arguments to each
470  * part of the pair constructor).
471  *
472  * @return An iterator that points to the inserted (key,value) pair.
473  *
474  * This function builds and inserts a (key, value) %pair into the
475  * %multimap.
476  * Contrary to a std::map the %multimap does not rely on unique keys and
477  * thus multiple pairs with the same key can be inserted.
478  *
479  * Insertion requires logarithmic time.
480  */
481  template<typename... _Args>
482  iterator
483  emplace(_Args&&... __args)
484  { return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); }
485 
486  /**
487  * @brief Builds and inserts a std::pair into the %multimap.
488  *
489  * @param __pos An iterator that serves as a hint as to where the pair
490  * should be inserted.
491  * @param __args Arguments used to generate a new pair instance (see
492  * std::piecewise_contruct for passing arguments to each
493  * part of the pair constructor).
494  * @return An iterator that points to the inserted (key,value) pair.
495  *
496  * This function inserts a (key, value) pair into the %multimap.
497  * Contrary to a std::map the %multimap does not rely on unique keys and
498  * thus multiple pairs with the same key can be inserted.
499  * Note that the first parameter is only a hint and can potentially
500  * improve the performance of the insertion process. A bad hint would
501  * cause no gains in efficiency.
502  *
503  * For more on @a hinting, see:
504  * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
505  *
506  * Insertion requires logarithmic time (if the hint is not taken).
507  */
508  template<typename... _Args>
509  iterator
510  emplace_hint(const_iterator __pos, _Args&&... __args)
511  {
512  return _M_t._M_emplace_hint_equal(__pos,
513  std::forward<_Args>(__args)...);
514  }
515 #endif
516 
517  /**
518  * @brief Inserts a std::pair into the %multimap.
519  * @param __x Pair to be inserted (see std::make_pair for easy creation
520  * of pairs).
521  * @return An iterator that points to the inserted (key,value) pair.
522  *
523  * This function inserts a (key, value) pair into the %multimap.
524  * Contrary to a std::map the %multimap does not rely on unique keys and
525  * thus multiple pairs with the same key can be inserted.
526  *
527  * Insertion requires logarithmic time.
528  * @{
529  */
530  iterator
531  insert(const value_type& __x)
532  { return _M_t._M_insert_equal(__x); }
533 
534 #if __cplusplus >= 201103L
535  // _GLIBCXX_RESOLVE_LIB_DEFECTS
536  // 2354. Unnecessary copying when inserting into maps with braced-init
537  iterator
538  insert(value_type&& __x)
539  { return _M_t._M_insert_equal(std::move(__x)); }
540 
541  template<typename _Pair, typename = typename
542  std::enable_if<std::is_constructible<value_type,
543  _Pair&&>::value>::type>
544  iterator
545  insert(_Pair&& __x)
546  { return _M_t._M_insert_equal(std::forward<_Pair>(__x)); }
547 #endif
548  // @}
549 
550  /**
551  * @brief Inserts a std::pair into the %multimap.
552  * @param __position An iterator that serves as a hint as to where the
553  * pair should be inserted.
554  * @param __x Pair to be inserted (see std::make_pair for easy creation
555  * of pairs).
556  * @return An iterator that points to the inserted (key,value) pair.
557  *
558  * This function inserts a (key, value) pair into the %multimap.
559  * Contrary to a std::map the %multimap does not rely on unique keys and
560  * thus multiple pairs with the same key can be inserted.
561  * Note that the first parameter is only a hint and can potentially
562  * improve the performance of the insertion process. A bad hint would
563  * cause no gains in efficiency.
564  *
565  * For more on @a hinting, see:
566  * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
567  *
568  * Insertion requires logarithmic time (if the hint is not taken).
569  * @{
570  */
571  iterator
572 #if __cplusplus >= 201103L
573  insert(const_iterator __position, const value_type& __x)
574 #else
575  insert(iterator __position, const value_type& __x)
576 #endif
577  { return _M_t._M_insert_equal_(__position, __x); }
578 
579 #if __cplusplus >= 201103L
580  // _GLIBCXX_RESOLVE_LIB_DEFECTS
581  // 2354. Unnecessary copying when inserting into maps with braced-init
582  iterator
583  insert(const_iterator __position, value_type&& __x)
584  { return _M_t._M_insert_equal_(__position, std::move(__x)); }
585 
586  template<typename _Pair, typename = typename
587  std::enable_if<std::is_constructible<value_type,
588  _Pair&&>::value>::type>
589  iterator
590  insert(const_iterator __position, _Pair&& __x)
591  { return _M_t._M_insert_equal_(__position,
592  std::forward<_Pair>(__x)); }
593 #endif
594  // @}
595 
596  /**
597  * @brief A template function that attempts to insert a range
598  * of elements.
599  * @param __first Iterator pointing to the start of the range to be
600  * inserted.
601  * @param __last Iterator pointing to the end of the range.
602  *
603  * Complexity similar to that of the range constructor.
604  */
605  template<typename _InputIterator>
606  void
607  insert(_InputIterator __first, _InputIterator __last)
608  { _M_t._M_insert_equal(__first, __last); }
609 
610 #if __cplusplus >= 201103L
611  /**
612  * @brief Attempts to insert a list of std::pairs into the %multimap.
613  * @param __l A std::initializer_list<value_type> of pairs to be
614  * inserted.
615  *
616  * Complexity similar to that of the range constructor.
617  */
618  void
620  { this->insert(__l.begin(), __l.end()); }
621 #endif
622 
623 #if __cplusplus > 201402L
624  /// Extract a node.
625  node_type
626  extract(const_iterator __pos)
627  {
628  __glibcxx_assert(__pos != end());
629  return _M_t.extract(__pos);
630  }
631 
632  /// Extract a node.
633  node_type
634  extract(const key_type& __x)
635  { return _M_t.extract(__x); }
636 
637  /// Re-insert an extracted node.
638  iterator
639  insert(node_type&& __nh)
640  { return _M_t._M_reinsert_node_equal(std::move(__nh)); }
641 
642  /// Re-insert an extracted node.
643  iterator
644  insert(const_iterator __hint, node_type&& __nh)
645  { return _M_t._M_reinsert_node_hint_equal(__hint, std::move(__nh)); }
646 
647  template<typename, typename>
648  friend class _Rb_tree_merge_helper;
649 
650  template<typename _C2>
651  void
652  merge(multimap<_Key, _Tp, _C2, _Alloc>& __source)
653  {
654  using _Merge_helper = _Rb_tree_merge_helper<multimap, _C2>;
655  _M_t._M_merge_equal(_Merge_helper::_S_get_tree(__source));
656  }
657 
658  template<typename _C2>
659  void
660  merge(multimap<_Key, _Tp, _C2, _Alloc>&& __source)
661  { merge(__source); }
662 
663  template<typename _C2>
664  void
665  merge(map<_Key, _Tp, _C2, _Alloc>& __source)
666  {
667  using _Merge_helper = _Rb_tree_merge_helper<multimap, _C2>;
668  _M_t._M_merge_equal(_Merge_helper::_S_get_tree(__source));
669  }
670 
671  template<typename _C2>
672  void
673  merge(map<_Key, _Tp, _C2, _Alloc>&& __source)
674  { merge(__source); }
675 #endif // C++17
676 
677 #if __cplusplus >= 201103L
678  // _GLIBCXX_RESOLVE_LIB_DEFECTS
679  // DR 130. Associative erase should return an iterator.
680  /**
681  * @brief Erases an element from a %multimap.
682  * @param __position An iterator pointing to the element to be erased.
683  * @return An iterator pointing to the element immediately following
684  * @a position prior to the element being erased. If no such
685  * element exists, end() is returned.
686  *
687  * This function erases an element, pointed to by the given iterator,
688  * from a %multimap. Note that this function only erases the element,
689  * and that if the element is itself a pointer, the pointed-to memory is
690  * not touched in any way. Managing the pointer is the user's
691  * responsibility.
692  *
693  * @{
694  */
695  iterator
696  erase(const_iterator __position)
697  { return _M_t.erase(__position); }
698 
699  // LWG 2059.
700  _GLIBCXX_ABI_TAG_CXX11
701  iterator
702  erase(iterator __position)
703  { return _M_t.erase(__position); }
704  // @}
705 #else
706  /**
707  * @brief Erases an element from a %multimap.
708  * @param __position An iterator pointing to the element to be erased.
709  *
710  * This function erases an element, pointed to by the given iterator,
711  * from a %multimap. Note that this function only erases the element,
712  * and that if the element is itself a pointer, the pointed-to memory is
713  * not touched in any way. Managing the pointer is the user's
714  * responsibility.
715  */
716  void
717  erase(iterator __position)
718  { _M_t.erase(__position); }
719 #endif
720 
721  /**
722  * @brief Erases elements according to the provided key.
723  * @param __x Key of element to be erased.
724  * @return The number of elements erased.
725  *
726  * This function erases all elements located by the given key from a
727  * %multimap.
728  * Note that this function only erases the element, and that if
729  * the element is itself a pointer, the pointed-to memory is not touched
730  * in any way. Managing the pointer is the user's responsibility.
731  */
732  size_type
733  erase(const key_type& __x)
734  { return _M_t.erase(__x); }
735 
736 #if __cplusplus >= 201103L
737  // _GLIBCXX_RESOLVE_LIB_DEFECTS
738  // DR 130. Associative erase should return an iterator.
739  /**
740  * @brief Erases a [first,last) range of elements from a %multimap.
741  * @param __first Iterator pointing to the start of the range to be
742  * erased.
743  * @param __last Iterator pointing to the end of the range to be
744  * erased .
745  * @return The iterator @a __last.
746  *
747  * This function erases a sequence of elements from a %multimap.
748  * Note that this function only erases the elements, and that if
749  * the elements themselves are pointers, the pointed-to memory is not
750  * touched in any way. Managing the pointer is the user's
751  * responsibility.
752  */
753  iterator
754  erase(const_iterator __first, const_iterator __last)
755  { return _M_t.erase(__first, __last); }
756 #else
757  // _GLIBCXX_RESOLVE_LIB_DEFECTS
758  // DR 130. Associative erase should return an iterator.
759  /**
760  * @brief Erases a [first,last) range of elements from a %multimap.
761  * @param __first Iterator pointing to the start of the range to be
762  * erased.
763  * @param __last Iterator pointing to the end of the range to
764  * be erased.
765  *
766  * This function erases a sequence of elements from a %multimap.
767  * Note that this function only erases the elements, and that if
768  * the elements themselves are pointers, the pointed-to memory is not
769  * touched in any way. Managing the pointer is the user's
770  * responsibility.
771  */
772  void
773  erase(iterator __first, iterator __last)
774  { _M_t.erase(__first, __last); }
775 #endif
776 
777  /**
778  * @brief Swaps data with another %multimap.
779  * @param __x A %multimap of the same element and allocator types.
780  *
781  * This exchanges the elements between two multimaps in constant time.
782  * (It is only swapping a pointer, an integer, and an instance of
783  * the @c Compare type (which itself is often stateless and empty), so it
784  * should be quite fast.)
785  * Note that the global std::swap() function is specialized such that
786  * std::swap(m1,m2) will feed to this function.
787  *
788  * Whether the allocators are swapped depends on the allocator traits.
789  */
790  void
791  swap(multimap& __x)
792  _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
793  { _M_t.swap(__x._M_t); }
794 
795  /**
796  * Erases all elements in a %multimap. Note that this function only
797  * erases the elements, and that if the elements themselves are pointers,
798  * the pointed-to memory is not touched in any way. Managing the pointer
799  * is the user's responsibility.
800  */
801  void
802  clear() _GLIBCXX_NOEXCEPT
803  { _M_t.clear(); }
804 
805  // observers
806  /**
807  * Returns the key comparison object out of which the %multimap
808  * was constructed.
809  */
810  key_compare
811  key_comp() const
812  { return _M_t.key_comp(); }
813 
814  /**
815  * Returns a value comparison object, built from the key comparison
816  * object out of which the %multimap was constructed.
817  */
818  value_compare
819  value_comp() const
820  { return value_compare(_M_t.key_comp()); }
821 
822  // multimap operations
823 
824  //@{
825  /**
826  * @brief Tries to locate an element in a %multimap.
827  * @param __x Key of (key, value) pair to be located.
828  * @return Iterator pointing to sought-after element,
829  * or end() if not found.
830  *
831  * This function takes a key and tries to locate the element with which
832  * the key matches. If successful the function returns an iterator
833  * pointing to the sought after %pair. If unsuccessful it returns the
834  * past-the-end ( @c end() ) iterator.
835  */
836  iterator
837  find(const key_type& __x)
838  { return _M_t.find(__x); }
839 
840 #if __cplusplus > 201103L
841  template<typename _Kt>
842  auto
843  find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
844  { return _M_t._M_find_tr(__x); }
845 #endif
846  //@}
847 
848  //@{
849  /**
850  * @brief Tries to locate an element in a %multimap.
851  * @param __x Key of (key, value) pair to be located.
852  * @return Read-only (constant) iterator pointing to sought-after
853  * element, or end() if not found.
854  *
855  * This function takes a key and tries to locate the element with which
856  * the key matches. If successful the function returns a constant
857  * iterator pointing to the sought after %pair. If unsuccessful it
858  * returns the past-the-end ( @c end() ) iterator.
859  */
860  const_iterator
861  find(const key_type& __x) const
862  { return _M_t.find(__x); }
863 
864 #if __cplusplus > 201103L
865  template<typename _Kt>
866  auto
867  find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
868  { return _M_t._M_find_tr(__x); }
869 #endif
870  //@}
871 
872  //@{
873  /**
874  * @brief Finds the number of elements with given key.
875  * @param __x Key of (key, value) pairs to be located.
876  * @return Number of elements with specified key.
877  */
878  size_type
879  count(const key_type& __x) const
880  { return _M_t.count(__x); }
881 
882 #if __cplusplus > 201103L
883  template<typename _Kt>
884  auto
885  count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
886  { return _M_t._M_count_tr(__x); }
887 #endif
888  //@}
889 
890  //@{
891  /**
892  * @brief Finds the beginning of a subsequence matching given key.
893  * @param __x Key of (key, value) pair to be located.
894  * @return Iterator pointing to first element equal to or greater
895  * than key, or end().
896  *
897  * This function returns the first element of a subsequence of elements
898  * that matches the given key. If unsuccessful it returns an iterator
899  * pointing to the first element that has a greater value than given key
900  * or end() if no such element exists.
901  */
902  iterator
903  lower_bound(const key_type& __x)
904  { return _M_t.lower_bound(__x); }
905 
906 #if __cplusplus > 201103L
907  template<typename _Kt>
908  auto
909  lower_bound(const _Kt& __x)
910  -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
911  { return iterator(_M_t._M_lower_bound_tr(__x)); }
912 #endif
913  //@}
914 
915  //@{
916  /**
917  * @brief Finds the beginning of a subsequence matching given key.
918  * @param __x Key of (key, value) pair to be located.
919  * @return Read-only (constant) iterator pointing to first element
920  * equal to or greater than key, or end().
921  *
922  * This function returns the first element of a subsequence of
923  * elements that matches the given key. If unsuccessful the
924  * iterator will point to the next greatest element or, if no
925  * such greater element exists, to end().
926  */
927  const_iterator
928  lower_bound(const key_type& __x) const
929  { return _M_t.lower_bound(__x); }
930 
931 #if __cplusplus > 201103L
932  template<typename _Kt>
933  auto
934  lower_bound(const _Kt& __x) const
935  -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
936  { return const_iterator(_M_t._M_lower_bound_tr(__x)); }
937 #endif
938  //@}
939 
940  //@{
941  /**
942  * @brief Finds the end of a subsequence matching given key.
943  * @param __x Key of (key, value) pair to be located.
944  * @return Iterator pointing to the first element
945  * greater than key, or end().
946  */
947  iterator
948  upper_bound(const key_type& __x)
949  { return _M_t.upper_bound(__x); }
950 
951 #if __cplusplus > 201103L
952  template<typename _Kt>
953  auto
954  upper_bound(const _Kt& __x)
955  -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
956  { return iterator(_M_t._M_upper_bound_tr(__x)); }
957 #endif
958  //@}
959 
960  //@{
961  /**
962  * @brief Finds the end of a subsequence matching given key.
963  * @param __x Key of (key, value) pair to be located.
964  * @return Read-only (constant) iterator pointing to first iterator
965  * greater than key, or end().
966  */
967  const_iterator
968  upper_bound(const key_type& __x) const
969  { return _M_t.upper_bound(__x); }
970 
971 #if __cplusplus > 201103L
972  template<typename _Kt>
973  auto
974  upper_bound(const _Kt& __x) const
975  -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
976  { return const_iterator(_M_t._M_upper_bound_tr(__x)); }
977 #endif
978  //@}
979 
980  //@{
981  /**
982  * @brief Finds a subsequence matching given key.
983  * @param __x Key of (key, value) pairs to be located.
984  * @return Pair of iterators that possibly points to the subsequence
985  * matching given key.
986  *
987  * This function is equivalent to
988  * @code
989  * std::make_pair(c.lower_bound(val),
990  * c.upper_bound(val))
991  * @endcode
992  * (but is faster than making the calls separately).
993  */
995  equal_range(const key_type& __x)
996  { return _M_t.equal_range(__x); }
997 
998 #if __cplusplus > 201103L
999  template<typename _Kt>
1000  auto
1001  equal_range(const _Kt& __x)
1002  -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
1003  { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
1004 #endif
1005  //@}
1006 
1007  //@{
1008  /**
1009  * @brief Finds a subsequence matching given key.
1010  * @param __x Key of (key, value) pairs to be located.
1011  * @return Pair of read-only (constant) iterators that possibly points
1012  * to the subsequence matching given key.
1013  *
1014  * This function is equivalent to
1015  * @code
1016  * std::make_pair(c.lower_bound(val),
1017  * c.upper_bound(val))
1018  * @endcode
1019  * (but is faster than making the calls separately).
1020  */
1022  equal_range(const key_type& __x) const
1023  { return _M_t.equal_range(__x); }
1024 
1025 #if __cplusplus > 201103L
1026  template<typename _Kt>
1027  auto
1028  equal_range(const _Kt& __x) const
1030  _M_t._M_equal_range_tr(__x)))
1031  {
1033  _M_t._M_equal_range_tr(__x));
1034  }
1035 #endif
1036  //@}
1037 
1038  template<typename _K1, typename _T1, typename _C1, typename _A1>
1039  friend bool
1040  operator==(const multimap<_K1, _T1, _C1, _A1>&,
1042 
1043  template<typename _K1, typename _T1, typename _C1, typename _A1>
1044  friend bool
1045  operator<(const multimap<_K1, _T1, _C1, _A1>&,
1047  };
1048 
1049  /**
1050  * @brief Multimap equality comparison.
1051  * @param __x A %multimap.
1052  * @param __y A %multimap of the same type as @a __x.
1053  * @return True iff the size and elements of the maps are equal.
1054  *
1055  * This is an equivalence relation. It is linear in the size of the
1056  * multimaps. Multimaps are considered equivalent if their sizes are equal,
1057  * and if corresponding elements compare equal.
1058  */
1059  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1060  inline bool
1063  { return __x._M_t == __y._M_t; }
1064 
1065  /**
1066  * @brief Multimap ordering relation.
1067  * @param __x A %multimap.
1068  * @param __y A %multimap of the same type as @a __x.
1069  * @return True iff @a x is lexicographically less than @a y.
1070  *
1071  * This is a total ordering relation. It is linear in the size of the
1072  * multimaps. The elements must be comparable with @c <.
1073  *
1074  * See std::lexicographical_compare() for how the determination is made.
1075  */
1076  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1077  inline bool
1078  operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
1080  { return __x._M_t < __y._M_t; }
1081 
1082  /// Based on operator==
1083  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1084  inline bool
1087  { return !(__x == __y); }
1088 
1089  /// Based on operator<
1090  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1091  inline bool
1094  { return __y < __x; }
1095 
1096  /// Based on operator<
1097  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1098  inline bool
1099  operator<=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
1101  { return !(__y < __x); }
1102 
1103  /// Based on operator<
1104  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1105  inline bool
1108  { return !(__x < __y); }
1109 
1110  /// See std::multimap::swap().
1111  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1112  inline void
1115  _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
1116  { __x.swap(__y); }
1117 
1118 _GLIBCXX_END_NAMESPACE_CONTAINER
1119 
1120 #if __cplusplus > 201402L
1121 _GLIBCXX_BEGIN_NAMESPACE_VERSION
1122  // Allow std::multimap access to internals of compatible maps.
1123  template<typename _Key, typename _Val, typename _Cmp1, typename _Alloc,
1124  typename _Cmp2>
1125  struct
1126  _Rb_tree_merge_helper<_GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp1, _Alloc>,
1127  _Cmp2>
1128  {
1129  private:
1130  friend class _GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp1, _Alloc>;
1131 
1132  static auto&
1133  _S_get_tree(_GLIBCXX_STD_C::map<_Key, _Val, _Cmp2, _Alloc>& __map)
1134  { return __map._M_t; }
1135 
1136  static auto&
1137  _S_get_tree(_GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp2, _Alloc>& __map)
1138  { return __map._M_t; }
1139  };
1140 _GLIBCXX_END_NAMESPACE_VERSION
1141 #endif // C++17
1142 
1143 } // namespace std
1144 
1145 #endif /* _STL_MULTIMAP_H */
const_reverse_iterator rbegin() const noexcept
Definition: stl_multimap.h:388
const_iterator cend() const noexcept
Definition: stl_multimap.h:425
multimap(const multimap &__m, const allocator_type &__a)
Allocator-extended copy constructor.
Definition: stl_multimap.h:229
const_reverse_iterator rend() const noexcept
Definition: stl_multimap.h:406
value_compare value_comp() const
Definition: stl_multimap.h:819
const_iterator begin() const noexcept
Definition: stl_multimap.h:352
std::pair< const_iterator, const_iterator > equal_range(const key_type &__x) const
Finds a subsequence matching given key.
const_iterator find(const key_type &__x) const
Tries to locate an element in a multimap.
Definition: stl_multimap.h:861
size_type erase(const key_type &__x)
Erases elements according to the provided key.
Definition: stl_multimap.h:733
auto find(const _Kt &__x) -> decltype(_M_t._M_find_tr(__x))
Tries to locate an element in a multimap.
Definition: stl_multimap.h:843
iterator insert(const value_type &__x)
Inserts a std::pair into the multimap.
Definition: stl_multimap.h:531
multimap(_InputIterator __first, _InputIterator __last, const allocator_type &__a)
Allocator-extended range constructor.
Definition: stl_multimap.h:245
const_iterator cbegin() const noexcept
Definition: stl_multimap.h:416
multimap()=default
Default constructor creates no elements.
A standard container made up of (key,value) pairs, which can be retrieved based on a key...
Definition: stl_map.h:71
std::pair< iterator, iterator > equal_range(const key_type &__x)
Finds a subsequence matching given key.
Definition: stl_multimap.h:995
auto lower_bound(const _Kt &__x) const -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
Finds the beginning of a subsequence matching given key.
Definition: stl_multimap.h:934
multimap & operator=(const multimap &)=default
Multimap assignment operator.
iterator find(const key_type &__x)
Tries to locate an element in a multimap.
Definition: stl_multimap.h:837
void clear() noexcept
Definition: stl_multimap.h:802
iterator emplace_hint(const_iterator __pos, _Args &&...__args)
Builds and inserts a std::pair into the multimap.
Definition: stl_multimap.h:510
const_iterator upper_bound(const key_type &__x) const
Finds the end of a subsequence matching given key.
Definition: stl_multimap.h:968
multimap(initializer_list< value_type > __l, const allocator_type &__a)
Allocator-extended initialier-list constructor.
Definition: stl_multimap.h:239
iterator erase(const_iterator __position)
Erases an element from a multimap.
Definition: stl_multimap.h:696
multimap(const _Compare &__comp, const allocator_type &__a=allocator_type())
Creates a multimap with no elements.
Definition: stl_multimap.h:183
allocator_type get_allocator() const noexcept
Get a copy of the memory allocation object.
Definition: stl_multimap.h:333
The standard allocator, as per [20.4].
Definition: allocator.h:108
iterator emplace(_Args &&...__args)
Build and insert a std::pair into the multimap.
Definition: stl_multimap.h:483
iterator end() noexcept
Definition: stl_multimap.h:361
size_type size() const noexcept
Definition: stl_multimap.h:455
bool empty() const noexcept
Definition: stl_multimap.h:450
auto equal_range(const _Kt &__x) const -> decltype(pair< const_iterator, const_iterator >(_M_t._M_equal_range_tr(__x)))
Finds a subsequence matching given key.
auto find(const _Kt &__x) const -> decltype(_M_t._M_find_tr(__x))
Tries to locate an element in a multimap.
Definition: stl_multimap.h:867
const_iterator lower_bound(const key_type &__x) const
Finds the beginning of a subsequence matching given key.
Definition: stl_multimap.h:928
multimap(_InputIterator __first, _InputIterator __last)
Builds a multimap from a range.
Definition: stl_multimap.h:261
size_type count(const key_type &__x) const
Finds the number of elements with given key.
Definition: stl_multimap.h:879
auto count(const _Kt &__x) const -> decltype(_M_t._M_count_tr(__x))
Finds the number of elements with given key.
Definition: stl_multimap.h:885
initializer_list
const_reverse_iterator crend() const noexcept
Definition: stl_multimap.h:443
const_reverse_iterator crbegin() const noexcept
Definition: stl_multimap.h:434
void insert(_InputIterator __first, _InputIterator __last)
A template function that attempts to insert a range of elements.
Definition: stl_multimap.h:607
iterator insert(_Pair &&__x)
Inserts a std::pair into the multimap.
Definition: stl_multimap.h:545
iterator insert(const_iterator __position, _Pair &&__x)
Inserts a std::pair into the multimap.
Definition: stl_multimap.h:590
iterator upper_bound(const key_type &__x)
Finds the end of a subsequence matching given key.
Definition: stl_multimap.h:948
multimap(_InputIterator __first, _InputIterator __last, const _Compare &__comp, const allocator_type &__a=allocator_type())
Builds a multimap from a range.
Definition: stl_multimap.h:277
multimap(initializer_list< value_type > __l, const _Compare &__comp=_Compare(), const allocator_type &__a=allocator_type())
Builds a multimap from an initializer_list.
Definition: stl_multimap.h:217
size_type max_size() const noexcept
Definition: stl_multimap.h:460
_GLIBCXX_ABI_TAG_CXX11 iterator erase(iterator __position)
Erases an element from a multimap.
Definition: stl_multimap.h:702
iterator insert(value_type &&__x)
Inserts a std::pair into the multimap.
Definition: stl_multimap.h:538
reverse_iterator rbegin() noexcept
Definition: stl_multimap.h:379
iterator insert(const_iterator __position, value_type &&__x)
Inserts a std::pair into the multimap.
Definition: stl_multimap.h:583
iterator lower_bound(const key_type &__x)
Finds the beginning of a subsequence matching given key.
Definition: stl_multimap.h:903
iterator erase(const_iterator __first, const_iterator __last)
Erases a [first,last) range of elements from a multimap.
Definition: stl_multimap.h:754
void noexcept()
Swaps data with another multimap.
Definition: stl_multimap.h:792
iterator begin() noexcept
Definition: stl_multimap.h:343
const_iterator end() const noexcept
Definition: stl_multimap.h:370
void insert(initializer_list< value_type > __l)
Attempts to insert a list of std::pairs into the multimap.
Definition: stl_multimap.h:619
~multimap()=default
Struct holding two objects of arbitrary type.
Definition: stl_pair.h:198
reverse_iterator rend() noexcept
Definition: stl_multimap.h:397
key_compare key_comp() const
Definition: stl_multimap.h:811
multimap & operator=(initializer_list< value_type > __l)
Multimap list assignment operator.
Definition: stl_multimap.h:324
One of the comparison functors.
Definition: stl_function.h:340
auto upper_bound(const _Kt &__x) const -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
Finds the end of a subsequence matching given key.
Definition: stl_multimap.h:974
Uniform interface to C++98 and C++11 allocators.
multimap(const allocator_type &__a)
Allocator-extended default constructor.
Definition: stl_multimap.h:225
Common iterator class.