libstdc++
stl_multiset.h
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1 // Multiset implementation -*- C++ -*-
2 
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25 /*
26  *
27  * Copyright (c) 1994
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30  * Permission to use, copy, modify, distribute and sell this software
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43  * and its documentation for any purpose is hereby granted without fee,
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49  */
50 
51 /** @file bits/stl_multiset.h
52  * This is an internal header file, included by other library headers.
53  * Do not attempt to use it directly. @headername{set}
54  */
55 
56 #ifndef _STL_MULTISET_H
57 #define _STL_MULTISET_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_VERSION
67 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
68 
69  template<typename _Key, typename _Compare, typename _Alloc>
70  class set;
71 
72  /**
73  * @brief A standard container made up of elements, which can be retrieved
74  * in logarithmic time.
75  *
76  * @ingroup associative_containers
77  * @headerfile set
78  * @since C++98
79  *
80  * @tparam _Key Type of key objects.
81  * @tparam _Compare Comparison function object type, defaults to less<_Key>.
82  * @tparam _Alloc Allocator type, defaults to allocator<_Key>.
83  *
84  * Meets the requirements of a <a href="tables.html#65">container</a>, a
85  * <a href="tables.html#66">reversible container</a>, and an
86  * <a href="tables.html#69">associative container</a> (using equivalent
87  * keys). For a @c multiset<Key> the key_type and value_type are Key.
88  *
89  * Multisets support bidirectional iterators.
90  *
91  * The private tree data is declared exactly the same way for set and
92  * multiset; 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 _Compare = std::less<_Key>,
96  typename _Alloc = std::allocator<_Key> >
97  class multiset
98  {
99 #ifdef _GLIBCXX_CONCEPT_CHECKS
100  // concept requirements
101  typedef typename _Alloc::value_type _Alloc_value_type;
102 # if __cplusplus < 201103L
103  __glibcxx_class_requires(_Key, _SGIAssignableConcept)
104 # endif
105  __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
106  _BinaryFunctionConcept)
107  __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
108 #endif
109 
110 #if __cplusplus >= 201103L
111  static_assert(is_same<typename remove_cv<_Key>::type, _Key>::value,
112  "std::multiset must have a non-const, non-volatile value_type");
113 # if __cplusplus > 201703L || defined __STRICT_ANSI__
115  "std::multiset must have the same value_type as its allocator");
116 # endif
117 #endif
118 
119  public:
120  // typedefs:
121  typedef _Key key_type;
122  typedef _Key value_type;
123  typedef _Compare key_compare;
124  typedef _Compare value_compare;
125  typedef _Alloc allocator_type;
126 
127  private:
128  /// This turns a red-black tree into a [multi]set.
130  rebind<_Key>::other _Key_alloc_type;
131 
132  typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
133  key_compare, _Key_alloc_type> _Rep_type;
134  /// The actual tree structure.
135  _Rep_type _M_t;
136 
138 
139  public:
140  typedef typename _Alloc_traits::pointer pointer;
141  typedef typename _Alloc_traits::const_pointer const_pointer;
142  typedef typename _Alloc_traits::reference reference;
143  typedef typename _Alloc_traits::const_reference const_reference;
144  // _GLIBCXX_RESOLVE_LIB_DEFECTS
145  // DR 103. set::iterator is required to be modifiable,
146  // but this allows modification of keys.
147  typedef typename _Rep_type::const_iterator iterator;
148  typedef typename _Rep_type::const_iterator const_iterator;
151  typedef typename _Rep_type::size_type size_type;
152  typedef typename _Rep_type::difference_type difference_type;
153 
154 #if __cplusplus > 201402L
155  using node_type = typename _Rep_type::node_type;
156 #endif
157 
158  // allocation/deallocation
159  /**
160  * @brief Default constructor creates no elements.
161  */
162 #if __cplusplus < 201103L
163  multiset() : _M_t() { }
164 #else
165  multiset() = default;
166 #endif
167 
168  /**
169  * @brief Creates a %multiset with no elements.
170  * @param __comp Comparator to use.
171  * @param __a An allocator object.
172  */
173  explicit
174  multiset(const _Compare& __comp,
175  const allocator_type& __a = allocator_type())
176  : _M_t(__comp, _Key_alloc_type(__a)) { }
177 
178  /**
179  * @brief Builds a %multiset from a range.
180  * @param __first An input iterator.
181  * @param __last An input iterator.
182  *
183  * Create a %multiset consisting of copies of the elements from
184  * [first,last). This is linear in N if the range is already sorted,
185  * and NlogN otherwise (where N is distance(__first,__last)).
186  */
187  template<typename _InputIterator>
188  multiset(_InputIterator __first, _InputIterator __last)
189  : _M_t()
190  { _M_t._M_insert_range_equal(__first, __last); }
191 
192  /**
193  * @brief Builds a %multiset from a range.
194  * @param __first An input iterator.
195  * @param __last An input iterator.
196  * @param __comp A comparison functor.
197  * @param __a An allocator object.
198  *
199  * Create a %multiset consisting of copies of the elements from
200  * [__first,__last). This is linear in N if the range is already sorted,
201  * and NlogN otherwise (where N is distance(__first,__last)).
202  */
203  template<typename _InputIterator>
204  multiset(_InputIterator __first, _InputIterator __last,
205  const _Compare& __comp,
206  const allocator_type& __a = allocator_type())
207  : _M_t(__comp, _Key_alloc_type(__a))
208  { _M_t._M_insert_range_equal(__first, __last); }
209 
210  /**
211  * @brief %Multiset copy constructor.
212  *
213  * Whether the allocator is copied depends on the allocator traits.
214  */
215 #if __cplusplus < 201103L
216  multiset(const multiset& __x)
217  : _M_t(__x._M_t) { }
218 #else
219  multiset(const multiset&) = default;
220 
221  /**
222  * @brief %Multiset move constructor.
223  *
224  * The newly-created %multiset contains the exact contents of the
225  * moved instance. The moved instance is a valid, but unspecified
226  * %multiset.
227  */
228  multiset(multiset&&) = default;
229 
230  /**
231  * @brief Builds a %multiset from an initializer_list.
232  * @param __l An initializer_list.
233  * @param __comp A comparison functor.
234  * @param __a An allocator object.
235  *
236  * Create a %multiset consisting of copies of the elements from
237  * the list. This is linear in N if the list is already sorted,
238  * and NlogN otherwise (where N is @a __l.size()).
239  */
241  const _Compare& __comp = _Compare(),
242  const allocator_type& __a = allocator_type())
243  : _M_t(__comp, _Key_alloc_type(__a))
244  { _M_t._M_insert_range_equal(__l.begin(), __l.end()); }
245 
246  /// Allocator-extended default constructor.
247  explicit
248  multiset(const allocator_type& __a)
249  : _M_t(_Key_alloc_type(__a)) { }
250 
251  /// Allocator-extended copy constructor.
252  multiset(const multiset& __m,
253  const __type_identity_t<allocator_type>& __a)
254  : _M_t(__m._M_t, _Key_alloc_type(__a)) { }
255 
256  /// Allocator-extended move constructor.
257  multiset(multiset&& __m, const __type_identity_t<allocator_type>& __a)
259  && _Alloc_traits::_S_always_equal())
260  : _M_t(std::move(__m._M_t), _Key_alloc_type(__a)) { }
261 
262  /// Allocator-extended initialier-list constructor.
263  multiset(initializer_list<value_type> __l, const allocator_type& __a)
264  : _M_t(_Key_alloc_type(__a))
265  { _M_t._M_insert_range_equal(__l.begin(), __l.end()); }
266 
267  /// Allocator-extended range constructor.
268  template<typename _InputIterator>
269  multiset(_InputIterator __first, _InputIterator __last,
270  const allocator_type& __a)
271  : _M_t(_Key_alloc_type(__a))
272  { _M_t._M_insert_range_equal(__first, __last); }
273 
274  /**
275  * The dtor only erases the elements, and note that if the elements
276  * themselves are pointers, the pointed-to memory is not touched in any
277  * way. Managing the pointer is the user's responsibility.
278  */
279  ~multiset() = default;
280 #endif
281 
282  /**
283  * @brief %Multiset assignment operator.
284  *
285  * Whether the allocator is copied depends on the allocator traits.
286  */
287 #if __cplusplus < 201103L
288  multiset&
289  operator=(const multiset& __x)
290  {
291  _M_t = __x._M_t;
292  return *this;
293  }
294 #else
295  multiset&
296  operator=(const multiset&) = default;
297 
298  /// Move assignment operator.
299  multiset&
300  operator=(multiset&&) = default;
301 
302  /**
303  * @brief %Multiset list assignment operator.
304  * @param __l An initializer_list.
305  *
306  * This function fills a %multiset with copies of the elements in the
307  * initializer list @a __l.
308  *
309  * Note that the assignment completely changes the %multiset and
310  * that the resulting %multiset's size is the same as the number
311  * of elements assigned.
312  */
313  multiset&
315  {
316  _M_t._M_assign_equal(__l.begin(), __l.end());
317  return *this;
318  }
319 #endif
320 
321  // accessors:
322 
323  /// Returns the comparison object.
324  key_compare
325  key_comp() const
326  { return _M_t.key_comp(); }
327  /// Returns the comparison object.
328  value_compare
329  value_comp() const
330  { return _M_t.key_comp(); }
331  /// Returns the memory allocation object.
332  allocator_type
333  get_allocator() const _GLIBCXX_NOEXCEPT
334  { return allocator_type(_M_t.get_allocator()); }
335 
336  /**
337  * Returns a read-only (constant) iterator that points to the first
338  * element in the %multiset. Iteration is done in ascending order
339  * according to the keys.
340  */
341  iterator
342  begin() const _GLIBCXX_NOEXCEPT
343  { return _M_t.begin(); }
344 
345  /**
346  * Returns a read-only (constant) iterator that points one past the last
347  * element in the %multiset. Iteration is done in ascending order
348  * according to the keys.
349  */
350  iterator
351  end() const _GLIBCXX_NOEXCEPT
352  { return _M_t.end(); }
353 
354  /**
355  * Returns a read-only (constant) reverse iterator that points to the
356  * last element in the %multiset. Iteration is done in descending order
357  * according to the keys.
358  */
360  rbegin() const _GLIBCXX_NOEXCEPT
361  { return _M_t.rbegin(); }
362 
363  /**
364  * Returns a read-only (constant) reverse iterator that points to the
365  * last element in the %multiset. Iteration is done in descending order
366  * according to the keys.
367  */
369  rend() const _GLIBCXX_NOEXCEPT
370  { return _M_t.rend(); }
371 
372 #if __cplusplus >= 201103L
373  /**
374  * Returns a read-only (constant) iterator that points to the first
375  * element in the %multiset. Iteration is done in ascending order
376  * according to the keys.
377  */
378  iterator
379  cbegin() const noexcept
380  { return _M_t.begin(); }
381 
382  /**
383  * Returns a read-only (constant) iterator that points one past the last
384  * element in the %multiset. Iteration is done in ascending order
385  * according to the keys.
386  */
387  iterator
388  cend() const noexcept
389  { return _M_t.end(); }
390 
391  /**
392  * Returns a read-only (constant) reverse iterator that points to the
393  * last element in the %multiset. Iteration is done in descending order
394  * according to the keys.
395  */
397  crbegin() const noexcept
398  { return _M_t.rbegin(); }
399 
400  /**
401  * Returns a read-only (constant) reverse iterator that points to the
402  * last element in the %multiset. Iteration is done in descending order
403  * according to the keys.
404  */
406  crend() const noexcept
407  { return _M_t.rend(); }
408 #endif
409 
410  /// Returns true if the %set is empty.
411  _GLIBCXX_NODISCARD bool
412  empty() const _GLIBCXX_NOEXCEPT
413  { return _M_t.empty(); }
414 
415  /// Returns the size of the %set.
416  size_type
417  size() const _GLIBCXX_NOEXCEPT
418  { return _M_t.size(); }
419 
420  /// Returns the maximum size of the %set.
421  size_type
422  max_size() const _GLIBCXX_NOEXCEPT
423  { return _M_t.max_size(); }
424 
425  /**
426  * @brief Swaps data with another %multiset.
427  * @param __x A %multiset of the same element and allocator types.
428  *
429  * This exchanges the elements between two multisets in constant time.
430  * (It is only swapping a pointer, an integer, and an instance of the @c
431  * Compare type (which itself is often stateless and empty), so it should
432  * be quite fast.)
433  * Note that the global std::swap() function is specialized such that
434  * std::swap(s1,s2) will feed to this function.
435  *
436  * Whether the allocators are swapped depends on the allocator traits.
437  */
438  void
440  _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
441  { _M_t.swap(__x._M_t); }
442 
443  // insert/erase
444 #if __cplusplus >= 201103L
445  /**
446  * @brief Builds and inserts an element into the %multiset.
447  * @param __args Arguments used to generate the element instance to be
448  * inserted.
449  * @return An iterator that points to the inserted element.
450  *
451  * This function inserts an element into the %multiset. Contrary
452  * to a std::set the %multiset does not rely on unique keys and thus
453  * multiple copies of the same element can be inserted.
454  *
455  * Insertion requires logarithmic time.
456  */
457  template<typename... _Args>
458  iterator
459  emplace(_Args&&... __args)
460  { return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); }
461 
462  /**
463  * @brief Builds and inserts an element into the %multiset.
464  * @param __pos An iterator that serves as a hint as to where the
465  * element should be inserted.
466  * @param __args Arguments used to generate the element instance to be
467  * inserted.
468  * @return An iterator that points to the inserted element.
469  *
470  * This function inserts an element into the %multiset. Contrary
471  * to a std::set the %multiset does not rely on unique keys and thus
472  * multiple copies of the same element can be inserted.
473  *
474  * Note that the first parameter is only a hint and can potentially
475  * improve the performance of the insertion process. A bad hint would
476  * cause no gains in efficiency.
477  *
478  * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
479  * for more on @a hinting.
480  *
481  * Insertion requires logarithmic time (if the hint is not taken).
482  */
483  template<typename... _Args>
484  iterator
485  emplace_hint(const_iterator __pos, _Args&&... __args)
486  {
487  return _M_t._M_emplace_hint_equal(__pos,
488  std::forward<_Args>(__args)...);
489  }
490 #endif
491 
492  /**
493  * @brief Inserts an element into the %multiset.
494  * @param __x Element to be inserted.
495  * @return An iterator that points to the inserted element.
496  *
497  * This function inserts an element into the %multiset. Contrary
498  * to a std::set the %multiset does not rely on unique keys and thus
499  * multiple copies of the same element can be inserted.
500  *
501  * Insertion requires logarithmic time.
502  */
503  iterator
504  insert(const value_type& __x)
505  { return _M_t._M_insert_equal(__x); }
506 
507 #if __cplusplus >= 201103L
508  iterator
509  insert(value_type&& __x)
510  { return _M_t._M_insert_equal(std::move(__x)); }
511 #endif
512 
513  /**
514  * @brief Inserts an element into the %multiset.
515  * @param __position An iterator that serves as a hint as to where the
516  * element should be inserted.
517  * @param __x Element to be inserted.
518  * @return An iterator that points to the inserted element.
519  *
520  * This function inserts an element into the %multiset. Contrary
521  * to a std::set the %multiset does not rely on unique keys and thus
522  * multiple copies of the same element can be inserted.
523  *
524  * Note that the first parameter is only a hint and can potentially
525  * improve the performance of the insertion process. A bad hint would
526  * cause no gains in efficiency.
527  *
528  * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
529  * for more on @a hinting.
530  *
531  * Insertion requires logarithmic time (if the hint is not taken).
532  */
533  iterator
534  insert(const_iterator __position, const value_type& __x)
535  { return _M_t._M_insert_equal_(__position, __x); }
536 
537 #if __cplusplus >= 201103L
538  iterator
539  insert(const_iterator __position, value_type&& __x)
540  { return _M_t._M_insert_equal_(__position, std::move(__x)); }
541 #endif
542 
543  /**
544  * @brief A template function that tries to insert a range of elements.
545  * @param __first Iterator pointing to the start of the range to be
546  * inserted.
547  * @param __last Iterator pointing to the end of the range.
548  *
549  * Complexity similar to that of the range constructor.
550  */
551  template<typename _InputIterator>
552  void
553  insert(_InputIterator __first, _InputIterator __last)
554  { _M_t._M_insert_range_equal(__first, __last); }
555 
556 #if __cplusplus >= 201103L
557  /**
558  * @brief Attempts to insert a list of elements into the %multiset.
559  * @param __l A std::initializer_list<value_type> of elements
560  * to be inserted.
561  *
562  * Complexity similar to that of the range constructor.
563  */
564  void
566  { this->insert(__l.begin(), __l.end()); }
567 #endif
568 
569 #if __cplusplus > 201402L
570  /// Extract a node.
571  node_type
572  extract(const_iterator __pos)
573  {
574  __glibcxx_assert(__pos != end());
575  return _M_t.extract(__pos);
576  }
577 
578  /// Extract a node.
579  node_type
580  extract(const key_type& __x)
581  { return _M_t.extract(__x); }
582 
583  /// Re-insert an extracted node.
584  iterator
585  insert(node_type&& __nh)
586  { return _M_t._M_reinsert_node_equal(std::move(__nh)); }
587 
588  /// Re-insert an extracted node.
589  iterator
590  insert(const_iterator __hint, node_type&& __nh)
591  { return _M_t._M_reinsert_node_hint_equal(__hint, std::move(__nh)); }
592 
593  template<typename, typename>
594  friend struct std::_Rb_tree_merge_helper;
595 
596  template<typename _Compare1>
597  void
598  merge(multiset<_Key, _Compare1, _Alloc>& __source)
599  {
600  using _Merge_helper = _Rb_tree_merge_helper<multiset, _Compare1>;
601  _M_t._M_merge_equal(_Merge_helper::_S_get_tree(__source));
602  }
603 
604  template<typename _Compare1>
605  void
606  merge(multiset<_Key, _Compare1, _Alloc>&& __source)
607  { merge(__source); }
608 
609  template<typename _Compare1>
610  void
611  merge(set<_Key, _Compare1, _Alloc>& __source)
612  {
613  using _Merge_helper = _Rb_tree_merge_helper<multiset, _Compare1>;
614  _M_t._M_merge_equal(_Merge_helper::_S_get_tree(__source));
615  }
616 
617  template<typename _Compare1>
618  void
619  merge(set<_Key, _Compare1, _Alloc>&& __source)
620  { merge(__source); }
621 #endif // C++17
622 
623 #if __cplusplus >= 201103L
624  // _GLIBCXX_RESOLVE_LIB_DEFECTS
625  // DR 130. Associative erase should return an iterator.
626  /**
627  * @brief Erases an element from a %multiset.
628  * @param __position An iterator pointing to the element to be erased.
629  * @return An iterator pointing to the element immediately following
630  * @a position prior to the element being erased. If no such
631  * element exists, end() is returned.
632  *
633  * This function erases an element, pointed to by the given iterator,
634  * from a %multiset. Note that this function only erases the element,
635  * and that if the element is itself a pointer, the pointed-to memory is
636  * not touched in any way. Managing the pointer is the user's
637  * responsibility.
638  */
639  _GLIBCXX_ABI_TAG_CXX11
640  iterator
641  erase(const_iterator __position)
642  { return _M_t.erase(__position); }
643 #else
644  /**
645  * @brief Erases an element from a %multiset.
646  * @param __position An iterator pointing to the element to be erased.
647  *
648  * This function erases an element, pointed to by the given iterator,
649  * from a %multiset. Note that this function only erases the element,
650  * and that if the element is itself a pointer, the pointed-to memory is
651  * not touched in any way. Managing the pointer is the user's
652  * responsibility.
653  */
654  void
655  erase(iterator __position)
656  { _M_t.erase(__position); }
657 #endif
658 
659  /**
660  * @brief Erases elements according to the provided key.
661  * @param __x Key of element to be erased.
662  * @return The number of elements erased.
663  *
664  * This function erases all elements located by the given key from a
665  * %multiset.
666  * Note that this function only erases the element, and that if
667  * the element is itself a pointer, the pointed-to memory is not touched
668  * in any way. Managing the pointer is the user's responsibility.
669  */
670  size_type
671  erase(const key_type& __x)
672  { return _M_t.erase(__x); }
673 
674 #if __cplusplus >= 201103L
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 %multiset.
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  * @return The iterator @a last.
684  *
685  * This function erases a sequence of elements from a %multiset.
686  * Note that this function only erases the elements, and that if
687  * the elements themselves are pointers, the pointed-to memory is not
688  * touched in any way. Managing the pointer is the user's
689  * responsibility.
690  */
691  _GLIBCXX_ABI_TAG_CXX11
692  iterator
693  erase(const_iterator __first, const_iterator __last)
694  { return _M_t.erase(__first, __last); }
695 #else
696  /**
697  * @brief Erases a [first,last) range of elements from a %multiset.
698  * @param first Iterator pointing to the start of the range to be
699  * erased.
700  * @param last Iterator pointing to the end of the range to be erased.
701  *
702  * This function erases a sequence of elements from a %multiset.
703  * Note that this function only erases the elements, and that if
704  * the elements themselves are pointers, the pointed-to memory is not
705  * touched in any way. Managing the pointer is the user's
706  * responsibility.
707  */
708  void
709  erase(iterator __first, iterator __last)
710  { _M_t.erase(__first, __last); }
711 #endif
712 
713  /**
714  * Erases all elements in a %multiset. 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  // multiset operations:
724 
725  ///@{
726  /**
727  * @brief Finds the number of elements with given key.
728  * @param __x Key of elements to be located.
729  * @return Number of elements with specified key.
730  */
731  size_type
732  count(const key_type& __x) const
733  { return _M_t.count(__x); }
734 
735 #if __cplusplus > 201103L
736  template<typename _Kt>
737  auto
738  count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
739  { return _M_t._M_count_tr(__x); }
740 #endif
741  ///@}
742 
743 #if __cplusplus > 201703L
744  ///@{
745  /**
746  * @brief Finds whether an element with the given key exists.
747  * @param __x Key of elements to be located.
748  * @return True if there is any element with the specified key.
749  */
750  bool
751  contains(const key_type& __x) const
752  { return _M_t.find(__x) != _M_t.end(); }
753 
754  template<typename _Kt>
755  auto
756  contains(const _Kt& __x) const
757  -> decltype(_M_t._M_find_tr(__x), void(), true)
758  { return _M_t._M_find_tr(__x) != _M_t.end(); }
759  ///@}
760 #endif
761 
762  // _GLIBCXX_RESOLVE_LIB_DEFECTS
763  // 214. set::find() missing const overload
764  ///@{
765  /**
766  * @brief Tries to locate an element in a %set.
767  * @param __x Element to be located.
768  * @return Iterator pointing to sought-after element, or end() if not
769  * found.
770  *
771  * This function takes a key and tries to locate the element with which
772  * the key matches. If successful the function returns an iterator
773  * pointing to the sought after element. If unsuccessful it returns the
774  * past-the-end ( @c end() ) iterator.
775  */
776  iterator
777  find(const key_type& __x)
778  { return _M_t.find(__x); }
779 
780  const_iterator
781  find(const key_type& __x) const
782  { return _M_t.find(__x); }
783 
784 #if __cplusplus > 201103L
785  template<typename _Kt>
786  auto
787  find(const _Kt& __x)
788  -> decltype(iterator{_M_t._M_find_tr(__x)})
789  { return iterator{_M_t._M_find_tr(__x)}; }
790 
791  template<typename _Kt>
792  auto
793  find(const _Kt& __x) const
794  -> decltype(const_iterator{_M_t._M_find_tr(__x)})
795  { return const_iterator{_M_t._M_find_tr(__x)}; }
796 #endif
797  ///@}
798 
799  ///@{
800  /**
801  * @brief Finds the beginning of a subsequence matching given key.
802  * @param __x Key to be located.
803  * @return Iterator pointing to first element equal to or greater
804  * than key, or end().
805  *
806  * This function returns the first element of a subsequence of elements
807  * that matches the given key. If unsuccessful it returns an iterator
808  * pointing to the first element that has a greater value than given key
809  * or end() if no such element exists.
810  */
811  iterator
812  lower_bound(const key_type& __x)
813  { return _M_t.lower_bound(__x); }
814 
815  const_iterator
816  lower_bound(const key_type& __x) const
817  { return _M_t.lower_bound(__x); }
818 
819 #if __cplusplus > 201103L
820  template<typename _Kt>
821  auto
822  lower_bound(const _Kt& __x)
823  -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
824  { return iterator(_M_t._M_lower_bound_tr(__x)); }
825 
826  template<typename _Kt>
827  auto
828  lower_bound(const _Kt& __x) const
829  -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
830  { return iterator(_M_t._M_lower_bound_tr(__x)); }
831 #endif
832  ///@}
833 
834  ///@{
835  /**
836  * @brief Finds the end of a subsequence matching given key.
837  * @param __x Key to be located.
838  * @return Iterator pointing to the first element
839  * greater than key, or end().
840  */
841  iterator
842  upper_bound(const key_type& __x)
843  { return _M_t.upper_bound(__x); }
844 
845  const_iterator
846  upper_bound(const key_type& __x) const
847  { return _M_t.upper_bound(__x); }
848 
849 #if __cplusplus > 201103L
850  template<typename _Kt>
851  auto
852  upper_bound(const _Kt& __x)
853  -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
854  { return iterator(_M_t._M_upper_bound_tr(__x)); }
855 
856  template<typename _Kt>
857  auto
858  upper_bound(const _Kt& __x) const
859  -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
860  { return iterator(_M_t._M_upper_bound_tr(__x)); }
861 #endif
862  ///@}
863 
864  ///@{
865  /**
866  * @brief Finds a subsequence matching given key.
867  * @param __x Key to be located.
868  * @return Pair of iterators that possibly points to the subsequence
869  * matching given key.
870  *
871  * This function is equivalent to
872  * @code
873  * std::make_pair(c.lower_bound(val),
874  * c.upper_bound(val))
875  * @endcode
876  * (but is faster than making the calls separately).
877  *
878  * This function probably only makes sense for multisets.
879  */
881  equal_range(const key_type& __x)
882  { return _M_t.equal_range(__x); }
883 
885  equal_range(const key_type& __x) const
886  { return _M_t.equal_range(__x); }
887 
888 #if __cplusplus > 201103L
889  template<typename _Kt>
890  auto
891  equal_range(const _Kt& __x)
892  -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
893  { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
894 
895  template<typename _Kt>
896  auto
897  equal_range(const _Kt& __x) const
898  -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
899  { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
900 #endif
901  ///@}
902 
903  template<typename _K1, typename _C1, typename _A1>
904  friend bool
905  operator==(const multiset<_K1, _C1, _A1>&,
906  const multiset<_K1, _C1, _A1>&);
907 
908 #if __cpp_lib_three_way_comparison
909  template<typename _K1, typename _C1, typename _A1>
910  friend __detail::__synth3way_t<_K1>
911  operator<=>(const multiset<_K1, _C1, _A1>&,
912  const multiset<_K1, _C1, _A1>&);
913 #else
914  template<typename _K1, typename _C1, typename _A1>
915  friend bool
916  operator< (const multiset<_K1, _C1, _A1>&,
917  const multiset<_K1, _C1, _A1>&);
918 #endif
919  };
920 
921 #if __cpp_deduction_guides >= 201606
922 
923  template<typename _InputIterator,
924  typename _Compare =
925  less<typename iterator_traits<_InputIterator>::value_type>,
926  typename _Allocator =
927  allocator<typename iterator_traits<_InputIterator>::value_type>,
928  typename = _RequireInputIter<_InputIterator>,
929  typename = _RequireNotAllocator<_Compare>,
930  typename = _RequireAllocator<_Allocator>>
931  multiset(_InputIterator, _InputIterator,
932  _Compare = _Compare(), _Allocator = _Allocator())
933  -> multiset<typename iterator_traits<_InputIterator>::value_type,
934  _Compare, _Allocator>;
935 
936  template<typename _Key,
937  typename _Compare = less<_Key>,
938  typename _Allocator = allocator<_Key>,
939  typename = _RequireNotAllocator<_Compare>,
940  typename = _RequireAllocator<_Allocator>>
941  multiset(initializer_list<_Key>,
942  _Compare = _Compare(), _Allocator = _Allocator())
943  -> multiset<_Key, _Compare, _Allocator>;
944 
945  template<typename _InputIterator, typename _Allocator,
946  typename = _RequireInputIter<_InputIterator>,
947  typename = _RequireAllocator<_Allocator>>
948  multiset(_InputIterator, _InputIterator, _Allocator)
949  -> multiset<typename iterator_traits<_InputIterator>::value_type,
950  less<typename iterator_traits<_InputIterator>::value_type>,
951  _Allocator>;
952 
953  template<typename _Key, typename _Allocator,
954  typename = _RequireAllocator<_Allocator>>
955  multiset(initializer_list<_Key>, _Allocator)
956  -> multiset<_Key, less<_Key>, _Allocator>;
957 
958 #endif // deduction guides
959 
960  /**
961  * @brief Multiset equality comparison.
962  * @param __x A %multiset.
963  * @param __y A %multiset of the same type as @a __x.
964  * @return True iff the size and elements of the multisets are equal.
965  *
966  * This is an equivalence relation. It is linear in the size of the
967  * multisets.
968  * Multisets are considered equivalent if their sizes are equal, and if
969  * corresponding elements compare equal.
970  */
971  template<typename _Key, typename _Compare, typename _Alloc>
972  inline bool
973  operator==(const multiset<_Key, _Compare, _Alloc>& __x,
975  { return __x._M_t == __y._M_t; }
976 
977 #if __cpp_lib_three_way_comparison
978  /**
979  * @brief Multiset ordering relation.
980  * @param __x A `multiset`.
981  * @param __y A `multiset` of the same type as `x`.
982  * @return A value indicating whether `__x` is less than, equal to,
983  * greater than, or incomparable with `__y`.
984  *
985  * This is a total ordering relation. It is linear in the size of the
986  * maps. The elements must be comparable with @c <.
987  *
988  * See `std::lexicographical_compare_three_way()` for how the determination
989  * is made. This operator is used to synthesize relational operators like
990  * `<` and `>=` etc.
991  */
992  template<typename _Key, typename _Compare, typename _Alloc>
993  inline __detail::__synth3way_t<_Key>
994  operator<=>(const multiset<_Key, _Compare, _Alloc>& __x,
995  const multiset<_Key, _Compare, _Alloc>& __y)
996  { return __x._M_t <=> __y._M_t; }
997 #else
998  /**
999  * @brief Multiset ordering relation.
1000  * @param __x A %multiset.
1001  * @param __y A %multiset of the same type as @a __x.
1002  * @return True iff @a __x is lexicographically less than @a __y.
1003  *
1004  * This is a total ordering relation. It is linear in the size of the
1005  * sets. The elements must be comparable with @c <.
1006  *
1007  * See std::lexicographical_compare() for how the determination is made.
1008  */
1009  template<typename _Key, typename _Compare, typename _Alloc>
1010  inline bool
1011  operator<(const multiset<_Key, _Compare, _Alloc>& __x,
1013  { return __x._M_t < __y._M_t; }
1014 
1015  /// Returns !(x == y).
1016  template<typename _Key, typename _Compare, typename _Alloc>
1017  inline bool
1018  operator!=(const multiset<_Key, _Compare, _Alloc>& __x,
1020  { return !(__x == __y); }
1021 
1022  /// Returns y < x.
1023  template<typename _Key, typename _Compare, typename _Alloc>
1024  inline bool
1025  operator>(const multiset<_Key,_Compare,_Alloc>& __x,
1026  const multiset<_Key,_Compare,_Alloc>& __y)
1027  { return __y < __x; }
1028 
1029  /// Returns !(y < x)
1030  template<typename _Key, typename _Compare, typename _Alloc>
1031  inline bool
1032  operator<=(const multiset<_Key, _Compare, _Alloc>& __x,
1034  { return !(__y < __x); }
1035 
1036  /// Returns !(x < y)
1037  template<typename _Key, typename _Compare, typename _Alloc>
1038  inline bool
1039  operator>=(const multiset<_Key, _Compare, _Alloc>& __x,
1041  { return !(__x < __y); }
1042 #endif // three-way comparison
1043 
1044  /// See std::multiset::swap().
1045  template<typename _Key, typename _Compare, typename _Alloc>
1046  inline void
1049  _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
1050  { __x.swap(__y); }
1051 
1052 _GLIBCXX_END_NAMESPACE_CONTAINER
1053 
1054 #if __cplusplus > 201402L
1055  // Allow std::multiset access to internals of compatible sets.
1056  template<typename _Val, typename _Cmp1, typename _Alloc, typename _Cmp2>
1057  struct
1058  _Rb_tree_merge_helper<_GLIBCXX_STD_C::multiset<_Val, _Cmp1, _Alloc>,
1059  _Cmp2>
1060  {
1061  private:
1062  friend class _GLIBCXX_STD_C::multiset<_Val, _Cmp1, _Alloc>;
1063 
1064  static auto&
1065  _S_get_tree(_GLIBCXX_STD_C::set<_Val, _Cmp2, _Alloc>& __set)
1066  { return __set._M_t; }
1067 
1068  static auto&
1069  _S_get_tree(_GLIBCXX_STD_C::multiset<_Val, _Cmp2, _Alloc>& __set)
1070  { return __set._M_t; }
1071  };
1072 #endif // C++17
1073 
1074 _GLIBCXX_END_NAMESPACE_VERSION
1075 } // namespace std
1076 
1077 #endif /* _STL_MULTISET_H */
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition: move.h:97
void swap(any &__x, any &__y) noexcept
Exchange the states of two any objects.
Definition: any:429
ISO C++ entities toplevel namespace is std.
initializer_list
is_same
Definition: type_traits:1399
is_nothrow_copy_constructible
Definition: type_traits:1133
Node handle type for maps.
Definition: node_handle.h:253
Struct holding two objects of arbitrary type.
Definition: stl_pair.h:189
Common iterator class.
A standard container made up of elements, which can be retrieved in logarithmic time.
Definition: stl_multiset.h:98
iterator emplace(_Args &&... __args)
Builds and inserts an element into the multiset.
Definition: stl_multiset.h:459
multiset(_InputIterator __first, _InputIterator __last, const allocator_type &__a)
Allocator-extended range constructor.
Definition: stl_multiset.h:269
iterator emplace_hint(const_iterator __pos, _Args &&... __args)
Builds and inserts an element into the multiset.
Definition: stl_multiset.h:485
multiset & operator=(const multiset &)=default
Multiset assignment operator.
reverse_iterator crend() const noexcept
Definition: stl_multiset.h:406
auto find(const _Kt &__x) const -> decltype(const_iterator{_M_t._M_find_tr(__x)})
Tries to locate an element in a set.
Definition: stl_multiset.h:793
iterator insert(node_type &&__nh)
Re-insert an extracted node.
Definition: stl_multiset.h:585
_GLIBCXX_ABI_TAG_CXX11 iterator erase(const_iterator __first, const_iterator __last)
Erases a [first,last) range of elements from a multiset.
Definition: stl_multiset.h:693
reverse_iterator crbegin() const noexcept
Definition: stl_multiset.h:397
multiset(const _Compare &__comp, const allocator_type &__a=allocator_type())
Creates a multiset with no elements.
Definition: stl_multiset.h:174
auto contains(const _Kt &__x) const -> decltype(_M_t._M_find_tr(__x), void(), true)
Finds whether an element with the given key exists.
Definition: stl_multiset.h:756
auto count(const _Kt &__x) const -> decltype(_M_t._M_count_tr(__x))
Finds the number of elements with given key.
Definition: stl_multiset.h:738
void swap(multiset &__x) noexcept(/*conditional */)
Swaps data with another multiset.
Definition: stl_multiset.h:439
iterator cbegin() const noexcept
Definition: stl_multiset.h:379
value_compare value_comp() const
Returns the comparison object.
Definition: stl_multiset.h:329
multiset(initializer_list< value_type > __l, const allocator_type &__a)
Allocator-extended initialier-list constructor.
Definition: stl_multiset.h:263
multiset(const multiset &__m, const __type_identity_t< allocator_type > &__a)
Allocator-extended copy constructor.
Definition: stl_multiset.h:252
auto upper_bound(const _Kt &__x) const -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
Finds the end of a subsequence matching given key.
Definition: stl_multiset.h:858
multiset & operator=(multiset &&)=default
Move assignment operator.
bool empty() const noexcept
Returns true if the set is empty.
Definition: stl_multiset.h:412
node_type extract(const_iterator __pos)
Extract a node.
Definition: stl_multiset.h:572
const_iterator upper_bound(const key_type &__x) const
Finds the end of a subsequence matching given key.
Definition: stl_multiset.h:846
multiset()=default
Default constructor creates no elements.
iterator insert(const value_type &__x)
Inserts an element into the multiset.
Definition: stl_multiset.h:504
reverse_iterator rbegin() const noexcept
Definition: stl_multiset.h:360
reverse_iterator rend() const noexcept
Definition: stl_multiset.h:369
void insert(initializer_list< value_type > __l)
Attempts to insert a list of elements into the multiset.
Definition: stl_multiset.h:565
void insert(_InputIterator __first, _InputIterator __last)
A template function that tries to insert a range of elements.
Definition: stl_multiset.h:553
~multiset()=default
multiset(multiset &&)=default
Multiset move constructor.
auto upper_bound(const _Kt &__x) -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
Finds the end of a subsequence matching given key.
Definition: stl_multiset.h:852
iterator find(const key_type &__x)
Tries to locate an element in a set.
Definition: stl_multiset.h:777
multiset & operator=(initializer_list< value_type > __l)
Multiset list assignment operator.
Definition: stl_multiset.h:314
auto find(const _Kt &__x) -> decltype(iterator{_M_t._M_find_tr(__x)})
Tries to locate an element in a set.
Definition: stl_multiset.h:787
node_type extract(const key_type &__x)
Extract a node.
Definition: stl_multiset.h:580
auto lower_bound(const _Kt &__x) const -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
Finds the beginning of a subsequence matching given key.
Definition: stl_multiset.h:828
size_type count(const key_type &__x) const
Finds the number of elements with given key.
Definition: stl_multiset.h:732
size_type size() const noexcept
Returns the size of the set.
Definition: stl_multiset.h:417
const_iterator lower_bound(const key_type &__x) const
Finds the beginning of a subsequence matching given key.
Definition: stl_multiset.h:816
_GLIBCXX_ABI_TAG_CXX11 iterator erase(const_iterator __position)
Erases an element from a multiset.
Definition: stl_multiset.h:641
iterator cend() const noexcept
Definition: stl_multiset.h:388
std::pair< const_iterator, const_iterator > equal_range(const key_type &__x) const
Finds a subsequence matching given key.
Definition: stl_multiset.h:885
multiset(multiset &&__m, const __type_identity_t< allocator_type > &__a) noexcept(is_nothrow_copy_constructible< _Compare >::value &&_Alloc_traits::_S_always_equal())
Allocator-extended move constructor.
Definition: stl_multiset.h:257
allocator_type get_allocator() const noexcept
Returns the memory allocation object.
Definition: stl_multiset.h:333
iterator upper_bound(const key_type &__x)
Finds the end of a subsequence matching given key.
Definition: stl_multiset.h:842
auto equal_range(const _Kt &__x) const -> decltype(pair< iterator, iterator >(_M_t._M_equal_range_tr(__x)))
Finds a subsequence matching given key.
Definition: stl_multiset.h:897
size_type erase(const key_type &__x)
Erases elements according to the provided key.
Definition: stl_multiset.h:671
key_compare key_comp() const
Returns the comparison object.
Definition: stl_multiset.h:325
multiset(_InputIterator __first, _InputIterator __last)
Builds a multiset from a range.
Definition: stl_multiset.h:188
iterator lower_bound(const key_type &__x)
Finds the beginning of a subsequence matching given key.
Definition: stl_multiset.h:812
iterator insert(const_iterator __hint, node_type &&__nh)
Re-insert an extracted node.
Definition: stl_multiset.h:590
void clear() noexcept
Definition: stl_multiset.h:720
iterator insert(const_iterator __position, const value_type &__x)
Inserts an element into the multiset.
Definition: stl_multiset.h:534
bool contains(const key_type &__x) const
Finds whether an element with the given key exists.
Definition: stl_multiset.h:751
iterator begin() const noexcept
Definition: stl_multiset.h:342
multiset(initializer_list< value_type > __l, const _Compare &__comp=_Compare(), const allocator_type &__a=allocator_type())
Builds a multiset from an initializer_list.
Definition: stl_multiset.h:240
auto equal_range(const _Kt &__x) -> decltype(pair< iterator, iterator >(_M_t._M_equal_range_tr(__x)))
Finds a subsequence matching given key.
Definition: stl_multiset.h:891
const_iterator find(const key_type &__x) const
Tries to locate an element in a set.
Definition: stl_multiset.h:781
auto lower_bound(const _Kt &__x) -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
Finds the beginning of a subsequence matching given key.
Definition: stl_multiset.h:822
multiset(_InputIterator __first, _InputIterator __last, const _Compare &__comp, const allocator_type &__a=allocator_type())
Builds a multiset from a range.
Definition: stl_multiset.h:204
multiset(const allocator_type &__a)
Allocator-extended default constructor.
Definition: stl_multiset.h:248
size_type max_size() const noexcept
Returns the maximum size of the set.
Definition: stl_multiset.h:422
multiset(const multiset &)=default
Multiset copy constructor.
std::pair< iterator, iterator > equal_range(const key_type &__x)
Finds a subsequence matching given key.
Definition: stl_multiset.h:881
iterator end() const noexcept
Definition: stl_multiset.h:351
Uniform interface to C++98 and C++11 allocators.