1 // Multimap implementation -*- C++ -*-
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52 /** @file stl_multimap.h
53 * This is an internal header file, included by other library headers.
54 * You should not attempt to use it directly.
57 #ifndef _STL_MULTIMAP_H
58 #define _STL_MULTIMAP_H 1
60 #include <bits/concept_check.h>
61 #include <initializer_list>
63 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
66 * @brief A standard container made up of (key,value) pairs, which can be
67 * retrieved based on a key, in logarithmic time.
69 * @ingroup associative_containers
71 * Meets the requirements of a <a href="tables.html#65">container</a>, a
72 * <a href="tables.html#66">reversible container</a>, and an
73 * <a href="tables.html#69">associative container</a> (using equivalent
74 * keys). For a @c multimap<Key,T> the key_type is Key, the mapped_type
75 * is T, and the value_type is std::pair<const Key,T>.
77 * Multimaps support bidirectional iterators.
79 * The private tree data is declared exactly the same way for map and
80 * multimap; the distinction is made entirely in how the tree functions are
81 * called (*_unique versus *_equal, same as the standard).
83 template <typename _Key, typename _Tp,
84 typename _Compare = std::less<_Key>,
85 typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
89 typedef _Key key_type;
90 typedef _Tp mapped_type;
91 typedef std::pair<const _Key, _Tp> value_type;
92 typedef _Compare key_compare;
93 typedef _Alloc allocator_type;
96 // concept requirements
97 typedef typename _Alloc::value_type _Alloc_value_type;
98 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
99 __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
100 _BinaryFunctionConcept)
101 __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
105 : public std::binary_function<value_type, value_type, bool>
107 friend class multimap<_Key, _Tp, _Compare, _Alloc>;
111 value_compare(_Compare __c)
115 bool operator()(const value_type& __x, const value_type& __y) const
116 { return comp(__x.first, __y.first); }
120 /// This turns a red-black tree into a [multi]map.
121 typedef typename _Alloc::template rebind<value_type>::other
124 typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
125 key_compare, _Pair_alloc_type> _Rep_type;
126 /// The actual tree structure.
130 // many of these are specified differently in ISO, but the following are
131 // "functionally equivalent"
132 typedef typename _Pair_alloc_type::pointer pointer;
133 typedef typename _Pair_alloc_type::const_pointer const_pointer;
134 typedef typename _Pair_alloc_type::reference reference;
135 typedef typename _Pair_alloc_type::const_reference const_reference;
136 typedef typename _Rep_type::iterator iterator;
137 typedef typename _Rep_type::const_iterator const_iterator;
138 typedef typename _Rep_type::size_type size_type;
139 typedef typename _Rep_type::difference_type difference_type;
140 typedef typename _Rep_type::reverse_iterator reverse_iterator;
141 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
143 // [23.3.2] construct/copy/destroy
144 // (get_allocator() is also listed in this section)
146 * @brief Default constructor creates no elements.
152 * @brief Creates a %multimap with no elements.
153 * @param comp A comparison object.
154 * @param a An allocator object.
157 multimap(const _Compare& __comp,
158 const allocator_type& __a = allocator_type())
159 : _M_t(__comp, __a) { }
162 * @brief %Multimap copy constructor.
163 * @param x A %multimap of identical element and allocator types.
165 * The newly-created %multimap uses a copy of the allocation object
168 multimap(const multimap& __x)
171 #ifdef __GXX_EXPERIMENTAL_CXX0X__
173 * @brief %Multimap move constructor.
174 * @param x A %multimap of identical element and allocator types.
176 * The newly-created %multimap contains the exact contents of @a x.
177 * The contents of @a x are a valid, but unspecified %multimap.
179 multimap(multimap&& __x)
180 : _M_t(std::move(__x._M_t)) { }
183 * @brief Builds a %multimap from an initializer_list.
184 * @param l An initializer_list.
185 * @param comp A comparison functor.
186 * @param a An allocator object.
188 * Create a %multimap consisting of copies of the elements from
189 * the initializer_list. This is linear in N if the list is already
190 * sorted, and NlogN otherwise (where N is @a __l.size()).
192 multimap(initializer_list<value_type> __l,
193 const _Compare& __comp = _Compare(),
194 const allocator_type& __a = allocator_type())
196 { _M_t._M_insert_equal(__l.begin(), __l.end()); }
200 * @brief Builds a %multimap from a range.
201 * @param first An input iterator.
202 * @param last An input iterator.
204 * Create a %multimap consisting of copies of the elements from
205 * [first,last). This is linear in N if the range is already sorted,
206 * and NlogN otherwise (where N is distance(first,last)).
208 template<typename _InputIterator>
209 multimap(_InputIterator __first, _InputIterator __last)
211 { _M_t._M_insert_equal(__first, __last); }
214 * @brief Builds a %multimap from a range.
215 * @param first An input iterator.
216 * @param last An input iterator.
217 * @param comp A comparison functor.
218 * @param a An allocator object.
220 * Create a %multimap consisting of copies of the elements from
221 * [first,last). This is linear in N if the range is already sorted,
222 * and NlogN otherwise (where N is distance(first,last)).
224 template<typename _InputIterator>
225 multimap(_InputIterator __first, _InputIterator __last,
226 const _Compare& __comp,
227 const allocator_type& __a = allocator_type())
229 { _M_t._M_insert_equal(__first, __last); }
231 // FIXME There is no dtor declared, but we should have something generated
232 // by Doxygen. I don't know what tags to add to this paragraph to make
235 * The dtor only erases the elements, and note that if the elements
236 * themselves are pointers, the pointed-to memory is not touched in any
237 * way. Managing the pointer is the user's responsibility.
241 * @brief %Multimap assignment operator.
242 * @param x A %multimap of identical element and allocator types.
244 * All the elements of @a x are copied, but unlike the copy constructor,
245 * the allocator object is not copied.
248 operator=(const multimap& __x)
254 #ifdef __GXX_EXPERIMENTAL_CXX0X__
256 * @brief %Multimap move assignment operator.
257 * @param x A %multimap of identical element and allocator types.
259 * The contents of @a x are moved into this multimap (without copying).
260 * @a x is a valid, but unspecified multimap.
263 operator=(multimap&& __x)
273 * @brief %Multimap list assignment operator.
274 * @param l An initializer_list.
276 * This function fills a %multimap with copies of the elements
277 * in the initializer list @a l.
279 * Note that the assignment completely changes the %multimap and
280 * that the resulting %multimap's size is the same as the number
281 * of elements assigned. Old data may be lost.
284 operator=(initializer_list<value_type> __l)
287 this->insert(__l.begin(), __l.end());
292 /// Get a copy of the memory allocation object.
294 get_allocator() const
295 { return _M_t.get_allocator(); }
299 * Returns a read/write iterator that points to the first pair in the
300 * %multimap. Iteration is done in ascending order according to the
305 { return _M_t.begin(); }
308 * Returns a read-only (constant) iterator that points to the first pair
309 * in the %multimap. Iteration is done in ascending order according to
314 { return _M_t.begin(); }
317 * Returns a read/write iterator that points one past the last pair in
318 * the %multimap. Iteration is done in ascending order according to the
323 { return _M_t.end(); }
326 * Returns a read-only (constant) iterator that points one past the last
327 * pair in the %multimap. Iteration is done in ascending order according
332 { return _M_t.end(); }
335 * Returns a read/write reverse iterator that points to the last pair in
336 * the %multimap. Iteration is done in descending order according to the
341 { return _M_t.rbegin(); }
344 * Returns a read-only (constant) reverse iterator that points to the
345 * last pair in the %multimap. Iteration is done in descending order
346 * according to the keys.
348 const_reverse_iterator
350 { return _M_t.rbegin(); }
353 * Returns a read/write reverse iterator that points to one before the
354 * first pair in the %multimap. Iteration is done in descending order
355 * according to the keys.
359 { return _M_t.rend(); }
362 * Returns a read-only (constant) reverse iterator that points to one
363 * before the first pair in the %multimap. Iteration is done in
364 * descending order according to the keys.
366 const_reverse_iterator
368 { return _M_t.rend(); }
370 #ifdef __GXX_EXPERIMENTAL_CXX0X__
372 * Returns a read-only (constant) iterator that points to the first pair
373 * in the %multimap. Iteration is done in ascending order according to
378 { return _M_t.begin(); }
381 * Returns a read-only (constant) iterator that points one past the last
382 * pair in the %multimap. Iteration is done in ascending order according
387 { return _M_t.end(); }
390 * Returns a read-only (constant) reverse iterator that points to the
391 * last pair in the %multimap. Iteration is done in descending order
392 * according to the keys.
394 const_reverse_iterator
396 { return _M_t.rbegin(); }
399 * Returns a read-only (constant) reverse iterator that points to one
400 * before the first pair in the %multimap. Iteration is done in
401 * descending order according to the keys.
403 const_reverse_iterator
405 { return _M_t.rend(); }
409 /** Returns true if the %multimap is empty. */
412 { return _M_t.empty(); }
414 /** Returns the size of the %multimap. */
417 { return _M_t.size(); }
419 /** Returns the maximum size of the %multimap. */
422 { return _M_t.max_size(); }
426 * @brief Inserts a std::pair into the %multimap.
427 * @param x Pair to be inserted (see std::make_pair for easy creation
429 * @return An iterator that points to the inserted (key,value) pair.
431 * This function inserts a (key, value) pair into the %multimap.
432 * Contrary to a std::map the %multimap does not rely on unique keys and
433 * thus multiple pairs with the same key can be inserted.
435 * Insertion requires logarithmic time.
438 insert(const value_type& __x)
439 { return _M_t._M_insert_equal(__x); }
442 * @brief Inserts a std::pair into the %multimap.
443 * @param position An iterator that serves as a hint as to where the
444 * pair should be inserted.
445 * @param x Pair to be inserted (see std::make_pair for easy creation
447 * @return An iterator that points to the inserted (key,value) pair.
449 * This function inserts a (key, value) pair into the %multimap.
450 * Contrary to a std::map the %multimap does not rely on unique keys and
451 * thus multiple pairs with the same key can be inserted.
452 * Note that the first parameter is only a hint and can potentially
453 * improve the performance of the insertion process. A bad hint would
454 * cause no gains in efficiency.
456 * For more on @a hinting, see:
457 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
459 * Insertion requires logarithmic time (if the hint is not taken).
462 #ifdef __GXX_EXPERIMENTAL_CXX0X__
463 insert(const_iterator __position, const value_type& __x)
465 insert(iterator __position, const value_type& __x)
467 { return _M_t._M_insert_equal_(__position, __x); }
470 * @brief A template function that attempts to insert a range
472 * @param first Iterator pointing to the start of the range to be
474 * @param last Iterator pointing to the end of the range.
476 * Complexity similar to that of the range constructor.
478 template<typename _InputIterator>
480 insert(_InputIterator __first, _InputIterator __last)
481 { _M_t._M_insert_equal(__first, __last); }
483 #ifdef __GXX_EXPERIMENTAL_CXX0X__
485 * @brief Attempts to insert a list of std::pairs into the %multimap.
486 * @param list A std::initializer_list<value_type> of pairs to be
489 * Complexity similar to that of the range constructor.
492 insert(initializer_list<value_type> __l)
493 { this->insert(__l.begin(), __l.end()); }
496 #ifdef __GXX_EXPERIMENTAL_CXX0X__
497 // _GLIBCXX_RESOLVE_LIB_DEFECTS
498 // DR 130. Associative erase should return an iterator.
500 * @brief Erases an element from a %multimap.
501 * @param position An iterator pointing to the element to be erased.
502 * @return An iterator pointing to the element immediately following
503 * @a position prior to the element being erased. If no such
504 * element exists, end() is returned.
506 * This function erases an element, pointed to by the given iterator,
507 * from a %multimap. Note that this function only erases the element,
508 * and that if the element is itself a pointer, the pointed-to memory is
509 * not touched in any way. Managing the pointer is the user's
513 erase(const_iterator __position)
514 { return _M_t.erase(__position); }
517 * @brief Erases an element from a %multimap.
518 * @param position An iterator pointing to the element to be erased.
520 * This function erases an element, pointed to by the given iterator,
521 * from a %multimap. Note that this function only erases the element,
522 * and that if the element is itself a pointer, the pointed-to memory is
523 * not touched in any way. Managing the pointer is the user's
527 erase(iterator __position)
528 { _M_t.erase(__position); }
532 * @brief Erases elements according to the provided key.
533 * @param x Key of element to be erased.
534 * @return The number of elements erased.
536 * This function erases all elements located by the given key from a
538 * Note that this function only erases the element, and that if
539 * the element is itself a pointer, the pointed-to memory is not touched
540 * in any way. Managing the pointer is the user's responsibility.
543 erase(const key_type& __x)
544 { return _M_t.erase(__x); }
546 #ifdef __GXX_EXPERIMENTAL_CXX0X__
547 // _GLIBCXX_RESOLVE_LIB_DEFECTS
548 // DR 130. Associative erase should return an iterator.
550 * @brief Erases a [first,last) range of elements from a %multimap.
551 * @param first Iterator pointing to the start of the range to be
553 * @param last Iterator pointing to the end of the range to be erased.
554 * @return The iterator @a last.
556 * This function erases a sequence of elements from a %multimap.
557 * Note that this function only erases the elements, and that if
558 * the elements themselves are pointers, the pointed-to memory is not
559 * touched in any way. Managing the pointer is the user's
563 erase(const_iterator __first, const_iterator __last)
564 { return _M_t.erase(__first, __last); }
566 // _GLIBCXX_RESOLVE_LIB_DEFECTS
567 // DR 130. Associative erase should return an iterator.
569 * @brief Erases a [first,last) range of elements from a %multimap.
570 * @param first Iterator pointing to the start of the range to be
572 * @param last Iterator pointing to the end of the range to be erased.
574 * This function erases a sequence of elements from a %multimap.
575 * Note that this function only erases the elements, and that if
576 * the elements themselves are pointers, the pointed-to memory is not
577 * touched in any way. Managing the pointer is the user's
581 erase(iterator __first, iterator __last)
582 { _M_t.erase(__first, __last); }
586 * @brief Swaps data with another %multimap.
587 * @param x A %multimap of the same element and allocator types.
589 * This exchanges the elements between two multimaps in constant time.
590 * (It is only swapping a pointer, an integer, and an instance of
591 * the @c Compare type (which itself is often stateless and empty), so it
592 * should be quite fast.)
593 * Note that the global std::swap() function is specialized such that
594 * std::swap(m1,m2) will feed to this function.
598 { _M_t.swap(__x._M_t); }
601 * Erases all elements in a %multimap. Note that this function only
602 * erases the elements, and that if the elements themselves are pointers,
603 * the pointed-to memory is not touched in any way. Managing the pointer
604 * is the user's responsibility.
612 * Returns the key comparison object out of which the %multimap
617 { return _M_t.key_comp(); }
620 * Returns a value comparison object, built from the key comparison
621 * object out of which the %multimap was constructed.
625 { return value_compare(_M_t.key_comp()); }
627 // multimap operations
629 * @brief Tries to locate an element in a %multimap.
630 * @param x Key of (key, value) pair to be located.
631 * @return Iterator pointing to sought-after element,
632 * or end() if not found.
634 * This function takes a key and tries to locate the element with which
635 * the key matches. If successful the function returns an iterator
636 * pointing to the sought after %pair. If unsuccessful it returns the
637 * past-the-end ( @c end() ) iterator.
640 find(const key_type& __x)
641 { return _M_t.find(__x); }
644 * @brief Tries to locate an element in a %multimap.
645 * @param x Key of (key, value) pair to be located.
646 * @return Read-only (constant) iterator pointing to sought-after
647 * element, or end() if not found.
649 * This function takes a key and tries to locate the element with which
650 * the key matches. If successful the function returns a constant
651 * iterator pointing to the sought after %pair. If unsuccessful it
652 * returns the past-the-end ( @c end() ) iterator.
655 find(const key_type& __x) const
656 { return _M_t.find(__x); }
659 * @brief Finds the number of elements with given key.
660 * @param x Key of (key, value) pairs to be located.
661 * @return Number of elements with specified key.
664 count(const key_type& __x) const
665 { return _M_t.count(__x); }
668 * @brief Finds the beginning of a subsequence matching given key.
669 * @param x Key of (key, value) pair to be located.
670 * @return Iterator pointing to first element equal to or greater
671 * than key, or end().
673 * This function returns the first element of a subsequence of elements
674 * that matches the given key. If unsuccessful it returns an iterator
675 * pointing to the first element that has a greater value than given key
676 * or end() if no such element exists.
679 lower_bound(const key_type& __x)
680 { return _M_t.lower_bound(__x); }
683 * @brief Finds the beginning of a subsequence matching given key.
684 * @param x Key of (key, value) pair to be located.
685 * @return Read-only (constant) iterator pointing to first element
686 * equal to or greater than key, or end().
688 * This function returns the first element of a subsequence of elements
689 * that matches the given key. If unsuccessful the iterator will point
690 * to the next greatest element or, if no such greater element exists, to
694 lower_bound(const key_type& __x) const
695 { return _M_t.lower_bound(__x); }
698 * @brief Finds the end of a subsequence matching given key.
699 * @param x Key of (key, value) pair to be located.
700 * @return Iterator pointing to the first element
701 * greater than key, or end().
704 upper_bound(const key_type& __x)
705 { return _M_t.upper_bound(__x); }
708 * @brief Finds the end of a subsequence matching given key.
709 * @param x Key of (key, value) pair to be located.
710 * @return Read-only (constant) iterator pointing to first iterator
711 * greater than key, or end().
714 upper_bound(const key_type& __x) const
715 { return _M_t.upper_bound(__x); }
718 * @brief Finds a subsequence matching given key.
719 * @param x Key of (key, value) pairs to be located.
720 * @return Pair of iterators that possibly points to the subsequence
721 * matching given key.
723 * This function is equivalent to
725 * std::make_pair(c.lower_bound(val),
726 * c.upper_bound(val))
728 * (but is faster than making the calls separately).
730 std::pair<iterator, iterator>
731 equal_range(const key_type& __x)
732 { return _M_t.equal_range(__x); }
735 * @brief Finds a subsequence matching given key.
736 * @param x Key of (key, value) pairs to be located.
737 * @return Pair of read-only (constant) iterators that possibly points
738 * to the subsequence matching given key.
740 * This function is equivalent to
742 * std::make_pair(c.lower_bound(val),
743 * c.upper_bound(val))
745 * (but is faster than making the calls separately).
747 std::pair<const_iterator, const_iterator>
748 equal_range(const key_type& __x) const
749 { return _M_t.equal_range(__x); }
751 template<typename _K1, typename _T1, typename _C1, typename _A1>
753 operator==(const multimap<_K1, _T1, _C1, _A1>&,
754 const multimap<_K1, _T1, _C1, _A1>&);
756 template<typename _K1, typename _T1, typename _C1, typename _A1>
758 operator<(const multimap<_K1, _T1, _C1, _A1>&,
759 const multimap<_K1, _T1, _C1, _A1>&);
763 * @brief Multimap equality comparison.
764 * @param x A %multimap.
765 * @param y A %multimap of the same type as @a x.
766 * @return True iff the size and elements of the maps are equal.
768 * This is an equivalence relation. It is linear in the size of the
769 * multimaps. Multimaps are considered equivalent if their sizes are equal,
770 * and if corresponding elements compare equal.
772 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
774 operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
775 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
776 { return __x._M_t == __y._M_t; }
779 * @brief Multimap ordering relation.
780 * @param x A %multimap.
781 * @param y A %multimap of the same type as @a x.
782 * @return True iff @a x is lexicographically less than @a y.
784 * This is a total ordering relation. It is linear in the size of the
785 * multimaps. The elements must be comparable with @c <.
787 * See std::lexicographical_compare() for how the determination is made.
789 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
791 operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
792 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
793 { return __x._M_t < __y._M_t; }
795 /// Based on operator==
796 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
798 operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
799 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
800 { return !(__x == __y); }
802 /// Based on operator<
803 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
805 operator>(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
806 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
807 { return __y < __x; }
809 /// Based on operator<
810 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
812 operator<=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
813 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
814 { return !(__y < __x); }
816 /// Based on operator<
817 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
819 operator>=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
820 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
821 { return !(__x < __y); }
823 /// See std::multimap::swap().
824 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
826 swap(multimap<_Key, _Tp, _Compare, _Alloc>& __x,
827 multimap<_Key, _Tp, _Compare, _Alloc>& __y)
830 _GLIBCXX_END_NESTED_NAMESPACE
832 #endif /* _STL_MULTIMAP_H */