1 // Multiset implementation -*- C++ -*-
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52 /** @file bits/stl_multiset.h
53 * This is an internal header file, included by other library headers.
54 * Do not attempt to use it directly. @headername{set}
57 #ifndef _STL_MULTISET_H
58 #define _STL_MULTISET_H 1
60 #include <bits/concept_check.h>
61 #include <initializer_list>
63 namespace std _GLIBCXX_VISIBILITY(default)
65 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
68 * @brief A standard container made up of elements, which can be retrieved
69 * in logarithmic time.
71 * @ingroup associative_containers
73 * Meets the requirements of a <a href="tables.html#65">container</a>, a
74 * <a href="tables.html#66">reversible container</a>, and an
75 * <a href="tables.html#69">associative container</a> (using equivalent
76 * keys). For a @c multiset<Key> the key_type and value_type are Key.
78 * Multisets support bidirectional iterators.
80 * The private tree data is declared exactly the same way for set and
81 * multiset; the distinction is made entirely in how the tree functions are
82 * called (*_unique versus *_equal, same as the standard).
84 template <typename _Key, typename _Compare = std::less<_Key>,
85 typename _Alloc = std::allocator<_Key> >
88 // concept requirements
89 typedef typename _Alloc::value_type _Alloc_value_type;
90 __glibcxx_class_requires(_Key, _SGIAssignableConcept)
91 __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
92 _BinaryFunctionConcept)
93 __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
97 typedef _Key key_type;
98 typedef _Key value_type;
99 typedef _Compare key_compare;
100 typedef _Compare value_compare;
101 typedef _Alloc allocator_type;
104 /// This turns a red-black tree into a [multi]set.
105 typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type;
107 typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
108 key_compare, _Key_alloc_type> _Rep_type;
109 /// The actual tree structure.
113 typedef typename _Key_alloc_type::pointer pointer;
114 typedef typename _Key_alloc_type::const_pointer const_pointer;
115 typedef typename _Key_alloc_type::reference reference;
116 typedef typename _Key_alloc_type::const_reference const_reference;
117 // _GLIBCXX_RESOLVE_LIB_DEFECTS
118 // DR 103. set::iterator is required to be modifiable,
119 // but this allows modification of keys.
120 typedef typename _Rep_type::const_iterator iterator;
121 typedef typename _Rep_type::const_iterator const_iterator;
122 typedef typename _Rep_type::const_reverse_iterator reverse_iterator;
123 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
124 typedef typename _Rep_type::size_type size_type;
125 typedef typename _Rep_type::difference_type difference_type;
127 // allocation/deallocation
129 * @brief Default constructor creates no elements.
135 * @brief Creates a %multiset with no elements.
136 * @param comp Comparator to use.
137 * @param a An allocator object.
140 multiset(const _Compare& __comp,
141 const allocator_type& __a = allocator_type())
142 : _M_t(__comp, __a) { }
145 * @brief Builds a %multiset from a range.
146 * @param first An input iterator.
147 * @param last An input iterator.
149 * Create a %multiset consisting of copies of the elements from
150 * [first,last). This is linear in N if the range is already sorted,
151 * and NlogN otherwise (where N is distance(first,last)).
153 template<typename _InputIterator>
154 multiset(_InputIterator __first, _InputIterator __last)
156 { _M_t._M_insert_equal(__first, __last); }
159 * @brief Builds a %multiset from a range.
160 * @param first An input iterator.
161 * @param last An input iterator.
162 * @param comp A comparison functor.
163 * @param a An allocator object.
165 * Create a %multiset consisting of copies of the elements from
166 * [first,last). This is linear in N if the range is already sorted,
167 * and NlogN otherwise (where N is distance(first,last)).
169 template<typename _InputIterator>
170 multiset(_InputIterator __first, _InputIterator __last,
171 const _Compare& __comp,
172 const allocator_type& __a = allocator_type())
174 { _M_t._M_insert_equal(__first, __last); }
177 * @brief %Multiset copy constructor.
178 * @param x A %multiset of identical element and allocator types.
180 * The newly-created %multiset uses a copy of the allocation object used
183 multiset(const multiset& __x)
186 #ifdef __GXX_EXPERIMENTAL_CXX0X__
188 * @brief %Multiset move constructor.
189 * @param x A %multiset of identical element and allocator types.
191 * The newly-created %multiset contains the exact contents of @a x.
192 * The contents of @a x are a valid, but unspecified %multiset.
194 multiset(multiset&& __x)
195 : _M_t(std::move(__x._M_t)) { }
198 * @brief Builds a %multiset from an initializer_list.
199 * @param l An initializer_list.
200 * @param comp A comparison functor.
201 * @param a An allocator object.
203 * Create a %multiset consisting of copies of the elements from
204 * the list. This is linear in N if the list is already sorted,
205 * and NlogN otherwise (where N is @a l.size()).
207 multiset(initializer_list<value_type> __l,
208 const _Compare& __comp = _Compare(),
209 const allocator_type& __a = allocator_type())
211 { _M_t._M_insert_equal(__l.begin(), __l.end()); }
215 * @brief %Multiset assignment operator.
216 * @param x A %multiset of identical element and allocator types.
218 * All the elements of @a x are copied, but unlike the copy constructor,
219 * the allocator object is not copied.
222 operator=(const multiset& __x)
228 #ifdef __GXX_EXPERIMENTAL_CXX0X__
230 * @brief %Multiset move assignment operator.
231 * @param x A %multiset of identical element and allocator types.
233 * The contents of @a x are moved into this %multiset (without copying).
234 * @a x is a valid, but unspecified %multiset.
237 operator=(multiset&& __x)
247 * @brief %Multiset list assignment operator.
248 * @param l An initializer_list.
250 * This function fills a %multiset with copies of the elements in the
251 * initializer list @a l.
253 * Note that the assignment completely changes the %multiset and
254 * that the resulting %multiset's size is the same as the number
255 * of elements assigned. Old data may be lost.
258 operator=(initializer_list<value_type> __l)
261 this->insert(__l.begin(), __l.end());
268 /// Returns the comparison object.
271 { return _M_t.key_comp(); }
272 /// Returns the comparison object.
275 { return _M_t.key_comp(); }
276 /// Returns the memory allocation object.
278 get_allocator() const
279 { return _M_t.get_allocator(); }
282 * Returns a read-only (constant) iterator that points to the first
283 * element in the %multiset. Iteration is done in ascending order
284 * according to the keys.
288 { return _M_t.begin(); }
291 * Returns a read-only (constant) iterator that points one past the last
292 * element in the %multiset. Iteration is done in ascending order
293 * according to the keys.
297 { return _M_t.end(); }
300 * Returns a read-only (constant) reverse iterator that points to the
301 * last element in the %multiset. Iteration is done in descending order
302 * according to the keys.
306 { return _M_t.rbegin(); }
309 * Returns a read-only (constant) reverse iterator that points to the
310 * last element in the %multiset. Iteration is done in descending order
311 * according to the keys.
315 { return _M_t.rend(); }
317 #ifdef __GXX_EXPERIMENTAL_CXX0X__
319 * Returns a read-only (constant) iterator that points to the first
320 * element in the %multiset. Iteration is done in ascending order
321 * according to the keys.
325 { return _M_t.begin(); }
328 * Returns a read-only (constant) iterator that points one past the last
329 * element in the %multiset. Iteration is done in ascending order
330 * according to the keys.
334 { return _M_t.end(); }
337 * Returns a read-only (constant) reverse iterator that points to the
338 * last element in the %multiset. Iteration is done in descending order
339 * according to the keys.
343 { return _M_t.rbegin(); }
346 * Returns a read-only (constant) reverse iterator that points to the
347 * last element in the %multiset. Iteration is done in descending order
348 * according to the keys.
352 { return _M_t.rend(); }
355 /// Returns true if the %set is empty.
358 { return _M_t.empty(); }
360 /// Returns the size of the %set.
363 { return _M_t.size(); }
365 /// Returns the maximum size of the %set.
368 { return _M_t.max_size(); }
371 * @brief Swaps data with another %multiset.
372 * @param x A %multiset of the same element and allocator types.
374 * This exchanges the elements between two multisets in constant time.
375 * (It is only swapping a pointer, an integer, and an instance of the @c
376 * Compare type (which itself is often stateless and empty), so it should
378 * Note that the global std::swap() function is specialized such that
379 * std::swap(s1,s2) will feed to this function.
383 { _M_t.swap(__x._M_t); }
387 * @brief Inserts an element into the %multiset.
388 * @param x Element to be inserted.
389 * @return An iterator that points to the inserted element.
391 * This function inserts an element into the %multiset. Contrary
392 * to a std::set the %multiset does not rely on unique keys and thus
393 * multiple copies of the same element can be inserted.
395 * Insertion requires logarithmic time.
398 insert(const value_type& __x)
399 { return _M_t._M_insert_equal(__x); }
401 #ifdef __GXX_EXPERIMENTAL_CXX0X__
403 insert(value_type&& __x)
404 { return _M_t._M_insert_equal(std::move(__x)); }
408 * @brief Inserts an element into the %multiset.
409 * @param position An iterator that serves as a hint as to where the
410 * element should be inserted.
411 * @param x Element to be inserted.
412 * @return An iterator that points to the inserted element.
414 * This function inserts an element into the %multiset. Contrary
415 * to a std::set the %multiset does not rely on unique keys and thus
416 * multiple copies of the same element can be inserted.
418 * Note that the first parameter is only a hint and can potentially
419 * improve the performance of the insertion process. A bad hint would
420 * cause no gains in efficiency.
422 * See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
423 * for more on @a hinting.
425 * Insertion requires logarithmic time (if the hint is not taken).
428 insert(const_iterator __position, const value_type& __x)
429 { return _M_t._M_insert_equal_(__position, __x); }
431 #ifdef __GXX_EXPERIMENTAL_CXX0X__
433 insert(const_iterator __position, value_type&& __x)
434 { return _M_t._M_insert_equal_(__position, std::move(__x)); }
438 * @brief A template function that tries to insert a range of elements.
439 * @param first Iterator pointing to the start of the range to be
441 * @param last Iterator pointing to the end of the range.
443 * Complexity similar to that of the range constructor.
445 template<typename _InputIterator>
447 insert(_InputIterator __first, _InputIterator __last)
448 { _M_t._M_insert_equal(__first, __last); }
450 #ifdef __GXX_EXPERIMENTAL_CXX0X__
452 * @brief Attempts to insert a list of elements into the %multiset.
453 * @param list A std::initializer_list<value_type> of elements
456 * Complexity similar to that of the range constructor.
459 insert(initializer_list<value_type> __l)
460 { this->insert(__l.begin(), __l.end()); }
463 #ifdef __GXX_EXPERIMENTAL_CXX0X__
464 // _GLIBCXX_RESOLVE_LIB_DEFECTS
465 // DR 130. Associative erase should return an iterator.
467 * @brief Erases an element from a %multiset.
468 * @param position An iterator pointing to the element to be erased.
469 * @return An iterator pointing to the element immediately following
470 * @a position prior to the element being erased. If no such
471 * element exists, end() is returned.
473 * This function erases an element, pointed to by the given iterator,
474 * from a %multiset. Note that this function only erases the element,
475 * and that if the element is itself a pointer, the pointed-to memory is
476 * not touched in any way. Managing the pointer is the user's
480 erase(const_iterator __position)
481 { return _M_t.erase(__position); }
484 * @brief Erases an element from a %multiset.
485 * @param position An iterator pointing to the element to be erased.
487 * This function erases an element, pointed to by the given iterator,
488 * from a %multiset. Note that this function only erases the element,
489 * and that if the element is itself a pointer, the pointed-to memory is
490 * not touched in any way. Managing the pointer is the user's
494 erase(iterator __position)
495 { _M_t.erase(__position); }
499 * @brief Erases elements according to the provided key.
500 * @param x Key of element to be erased.
501 * @return The number of elements erased.
503 * This function erases all elements located by the given key from a
505 * Note that this function only erases the element, and that if
506 * the element is itself a pointer, the pointed-to memory is not touched
507 * in any way. Managing the pointer is the user's responsibility.
510 erase(const key_type& __x)
511 { return _M_t.erase(__x); }
513 #ifdef __GXX_EXPERIMENTAL_CXX0X__
514 // _GLIBCXX_RESOLVE_LIB_DEFECTS
515 // DR 130. Associative erase should return an iterator.
517 * @brief Erases a [first,last) range of elements from a %multiset.
518 * @param first Iterator pointing to the start of the range to be
520 * @param last Iterator pointing to the end of the range to be erased.
521 * @return The iterator @a last.
523 * This function erases a sequence of elements from a %multiset.
524 * Note that this function only erases the elements, and that if
525 * the elements themselves are pointers, the pointed-to memory is not
526 * touched in any way. Managing the pointer is the user's
530 erase(const_iterator __first, const_iterator __last)
531 { return _M_t.erase(__first, __last); }
534 * @brief Erases a [first,last) range of elements from a %multiset.
535 * @param first Iterator pointing to the start of the range to be
537 * @param last Iterator pointing to the end of the range to be erased.
539 * This function erases a sequence of elements from a %multiset.
540 * Note that this function only erases the elements, and that if
541 * the elements themselves are pointers, the pointed-to memory is not
542 * touched in any way. Managing the pointer is the user's
546 erase(iterator __first, iterator __last)
547 { _M_t.erase(__first, __last); }
551 * Erases all elements in a %multiset. Note that this function only
552 * erases the elements, and that if the elements themselves are pointers,
553 * the pointed-to memory is not touched in any way. Managing the pointer
554 * is the user's responsibility.
560 // multiset operations:
563 * @brief Finds the number of elements with given key.
564 * @param x Key of elements to be located.
565 * @return Number of elements with specified key.
568 count(const key_type& __x) const
569 { return _M_t.count(__x); }
571 // _GLIBCXX_RESOLVE_LIB_DEFECTS
572 // 214. set::find() missing const overload
575 * @brief Tries to locate an element in a %set.
576 * @param x Element to be located.
577 * @return Iterator pointing to sought-after element, or end() if not
580 * This function takes a key and tries to locate the element with which
581 * the key matches. If successful the function returns an iterator
582 * pointing to the sought after element. If unsuccessful it returns the
583 * past-the-end ( @c end() ) iterator.
586 find(const key_type& __x)
587 { return _M_t.find(__x); }
590 find(const key_type& __x) const
591 { return _M_t.find(__x); }
596 * @brief Finds the beginning of a subsequence matching given key.
597 * @param x Key to be located.
598 * @return Iterator pointing to first element equal to or greater
599 * than key, or end().
601 * This function returns the first element of a subsequence of elements
602 * that matches the given key. If unsuccessful it returns an iterator
603 * pointing to the first element that has a greater value than given key
604 * or end() if no such element exists.
607 lower_bound(const key_type& __x)
608 { return _M_t.lower_bound(__x); }
611 lower_bound(const key_type& __x) const
612 { return _M_t.lower_bound(__x); }
617 * @brief Finds the end of a subsequence matching given key.
618 * @param x Key to be located.
619 * @return Iterator pointing to the first element
620 * greater than key, or end().
623 upper_bound(const key_type& __x)
624 { return _M_t.upper_bound(__x); }
627 upper_bound(const key_type& __x) const
628 { return _M_t.upper_bound(__x); }
633 * @brief Finds a subsequence matching given key.
634 * @param x Key to be located.
635 * @return Pair of iterators that possibly points to the subsequence
636 * matching given key.
638 * This function is equivalent to
640 * std::make_pair(c.lower_bound(val),
641 * c.upper_bound(val))
643 * (but is faster than making the calls separately).
645 * This function probably only makes sense for multisets.
647 std::pair<iterator, iterator>
648 equal_range(const key_type& __x)
649 { return _M_t.equal_range(__x); }
651 std::pair<const_iterator, const_iterator>
652 equal_range(const key_type& __x) const
653 { return _M_t.equal_range(__x); }
655 template<typename _K1, typename _C1, typename _A1>
657 operator==(const multiset<_K1, _C1, _A1>&,
658 const multiset<_K1, _C1, _A1>&);
660 template<typename _K1, typename _C1, typename _A1>
662 operator< (const multiset<_K1, _C1, _A1>&,
663 const multiset<_K1, _C1, _A1>&);
667 * @brief Multiset equality comparison.
668 * @param x A %multiset.
669 * @param y A %multiset of the same type as @a x.
670 * @return True iff the size and elements of the multisets are equal.
672 * This is an equivalence relation. It is linear in the size of the
674 * Multisets are considered equivalent if their sizes are equal, and if
675 * corresponding elements compare equal.
677 template<typename _Key, typename _Compare, typename _Alloc>
679 operator==(const multiset<_Key, _Compare, _Alloc>& __x,
680 const multiset<_Key, _Compare, _Alloc>& __y)
681 { return __x._M_t == __y._M_t; }
684 * @brief Multiset ordering relation.
685 * @param x A %multiset.
686 * @param y A %multiset of the same type as @a x.
687 * @return True iff @a x is lexicographically less than @a y.
689 * This is a total ordering relation. It is linear in the size of the
690 * maps. The elements must be comparable with @c <.
692 * See std::lexicographical_compare() for how the determination is made.
694 template<typename _Key, typename _Compare, typename _Alloc>
696 operator<(const multiset<_Key, _Compare, _Alloc>& __x,
697 const multiset<_Key, _Compare, _Alloc>& __y)
698 { return __x._M_t < __y._M_t; }
700 /// Returns !(x == y).
701 template<typename _Key, typename _Compare, typename _Alloc>
703 operator!=(const multiset<_Key, _Compare, _Alloc>& __x,
704 const multiset<_Key, _Compare, _Alloc>& __y)
705 { return !(__x == __y); }
708 template<typename _Key, typename _Compare, typename _Alloc>
710 operator>(const multiset<_Key,_Compare,_Alloc>& __x,
711 const multiset<_Key,_Compare,_Alloc>& __y)
712 { return __y < __x; }
715 template<typename _Key, typename _Compare, typename _Alloc>
717 operator<=(const multiset<_Key, _Compare, _Alloc>& __x,
718 const multiset<_Key, _Compare, _Alloc>& __y)
719 { return !(__y < __x); }
722 template<typename _Key, typename _Compare, typename _Alloc>
724 operator>=(const multiset<_Key, _Compare, _Alloc>& __x,
725 const multiset<_Key, _Compare, _Alloc>& __y)
726 { return !(__x < __y); }
728 /// See std::multiset::swap().
729 template<typename _Key, typename _Compare, typename _Alloc>
731 swap(multiset<_Key, _Compare, _Alloc>& __x,
732 multiset<_Key, _Compare, _Alloc>& __y)
735 _GLIBCXX_END_NAMESPACE_CONTAINER
738 #endif /* _STL_MULTISET_H */