1 // Multimap implementation -*- C++ -*-
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56 /** @file stl_multimap.h
57 * This is an internal header file, included by other library headers.
58 * You should not attempt to use it directly.
61 #ifndef __GLIBCPP_INTERNAL_MULTIMAP_H
62 #define __GLIBCPP_INTERNAL_MULTIMAP_H
64 #include <bits/concept_check.h>
68 // Forward declaration of operators < and ==, needed for friend declaration.
70 template <typename _Key, typename _Tp,
71 typename _Compare = less<_Key>,
72 typename _Alloc = allocator<pair<const _Key, _Tp> > >
75 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
76 inline bool operator==(const multimap<_Key,_Tp,_Compare,_Alloc>& __x,
77 const multimap<_Key,_Tp,_Compare,_Alloc>& __y);
79 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
80 inline bool operator<(const multimap<_Key,_Tp,_Compare,_Alloc>& __x,
81 const multimap<_Key,_Tp,_Compare,_Alloc>& __y);
84 * @brief A standard container made up of (key,value) pairs, which can be
85 * retrieved based on a key, in logarithmic time.
88 * @ingroup Assoc_containers
90 * Meets the requirements of a <a href="tables.html#65">container</a>, a
91 * <a href="tables.html#66">reversible container</a>, and an
92 * <a href="tables.html#69">associative container</a> (using equivalent
93 * keys). For a @c multimap<Key,T> the key_type is Key, the mapped_type
94 * is T, and the value_type is std::pair<const Key,T>.
96 * Multimaps support bidirectional iterators.
99 * The private tree data is declared exactly the same way for map and
100 * multimap; the distinction is made entirely in how the tree functions are
101 * called (*_unique versus *_equal, same as the standard).
104 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
107 // concept requirements
108 __glibcpp_class_requires(_Tp, _SGIAssignableConcept)
109 __glibcpp_class_requires4(_Compare, bool, _Key, _Key, _BinaryFunctionConcept)
112 typedef _Key key_type;
113 typedef _Tp mapped_type;
114 typedef pair<const _Key, _Tp> value_type;
115 typedef _Compare key_compare;
118 : public binary_function<value_type, value_type, bool>
120 friend class multimap<_Key,_Tp,_Compare,_Alloc>;
123 value_compare(_Compare __c) : comp(__c) {}
125 bool operator()(const value_type& __x, const value_type& __y) const
126 { return comp(__x.first, __y.first); }
130 /// @if maint This turns a red-black tree into a [multi]map. @endif
131 typedef _Rb_tree<key_type, value_type,
132 _Select1st<value_type>, key_compare, _Alloc> _Rep_type;
133 /// @if maint The actual tree structure. @endif
137 // many of these are specified differently in ISO, but the following are
138 // "functionally equivalent"
139 typedef typename _Rep_type::allocator_type allocator_type;
140 typedef typename _Rep_type::reference reference;
141 typedef typename _Rep_type::const_reference const_reference;
142 typedef typename _Rep_type::iterator iterator;
143 typedef typename _Rep_type::const_iterator const_iterator;
144 typedef typename _Rep_type::size_type size_type;
145 typedef typename _Rep_type::difference_type difference_type;
146 typedef typename _Rep_type::pointer pointer;
147 typedef typename _Rep_type::const_pointer const_pointer;
148 typedef typename _Rep_type::reverse_iterator reverse_iterator;
149 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
152 // [23.3.2] construct/copy/destroy
153 // (get_allocator() is also listed in this section)
155 * @brief Default constructor creates no elements.
157 multimap() : _M_t(_Compare(), allocator_type()) { }
159 // for some reason this was made a separate function
161 * @brief Default constructor creates no elements.
164 multimap(const _Compare& __comp, const allocator_type& __a = allocator_type())
165 : _M_t(__comp, __a) { }
168 * @brief %Multimap copy constructor.
169 * @param x A %multimap of identical element and allocator types.
171 * The newly-created %multimap uses a copy of the allocation object used
174 multimap(const multimap& __x)
178 * @brief Builds a %multimap from a range.
179 * @param first An input iterator.
180 * @param last An input iterator.
182 * Create a %multimap consisting of copies of the elements from
183 * [first,last). This is linear in N if the range is already sorted,
184 * and NlogN otherwise (where N is distance(first,last)).
186 template <typename _InputIterator>
187 multimap(_InputIterator __first, _InputIterator __last)
188 : _M_t(_Compare(), allocator_type())
189 { _M_t.insert_equal(__first, __last); }
192 * @brief Builds a %multimap from a range.
193 * @param first An input iterator.
194 * @param last An input iterator.
195 * @param comp A comparison functor.
196 * @param a An allocator object.
198 * Create a %multimap consisting of copies of the elements from
199 * [first,last). This is linear in N if the range is already sorted,
200 * and NlogN otherwise (where N is distance(first,last)).
202 template <typename _InputIterator>
203 multimap(_InputIterator __first, _InputIterator __last,
204 const _Compare& __comp,
205 const allocator_type& __a = allocator_type())
207 { _M_t.insert_equal(__first, __last); }
209 // FIXME There is no dtor declared, but we should have something generated
210 // by Doxygen. I don't know what tags to add to this paragraph to make
213 * The dtor only erases the elements, and note that if the elements
214 * themselves are pointers, the pointed-to memory is not touched in any
215 * way. Managing the pointer is the user's responsibilty.
219 * @brief %Multimap assignment operator.
220 * @param x A %multimap of identical element and allocator types.
222 * All the elements of @a x are copied, but unlike the copy constructor,
223 * the allocator object is not copied.
226 operator=(const multimap& __x)
232 /// Get a copy of the memory allocation object.
234 get_allocator() const { return _M_t.get_allocator(); }
238 * Returns a read/write iterator that points to the first pair in the
239 * %multimap. Iteration is done in ascending order according to the keys.
242 begin() { return _M_t.begin(); }
245 * Returns a read-only (constant) iterator that points to the first pair
246 * in the %multimap. Iteration is done in ascending order according to the
250 begin() const { return _M_t.begin(); }
253 * Returns a read/write iterator that points one past the last pair in the
254 * %multimap. Iteration is done in ascending order according to the keys.
257 end() { return _M_t.end(); }
260 * Returns a read-only (constant) iterator that points one past the last
261 * pair in the %multimap. Iteration is done in ascending order according
265 end() const { return _M_t.end(); }
268 * Returns a read/write reverse iterator that points to the last pair in
269 * the %multimap. Iteration is done in descending order according to the
273 rbegin() { return _M_t.rbegin(); }
276 * Returns a read-only (constant) reverse iterator that points to the last
277 * pair in the %multimap. Iteration is done in descending order according
280 const_reverse_iterator
281 rbegin() const { return _M_t.rbegin(); }
284 * Returns a read/write reverse iterator that points to one before the
285 * first pair in the %multimap. Iteration is done in descending order
286 * according to the keys.
289 rend() { return _M_t.rend(); }
292 * Returns a read-only (constant) reverse iterator that points to one
293 * before the first pair in the %multimap. Iteration is done in descending
294 * order according to the keys.
296 const_reverse_iterator
297 rend() const { return _M_t.rend(); }
300 /** Returns true if the %multimap is empty. */
302 empty() const { return _M_t.empty(); }
304 /** Returns the size of the %multimap. */
306 size() const { return _M_t.size(); }
308 /** Returns the maximum size of the %multimap. */
310 max_size() const { return _M_t.max_size(); }
314 * @brief Inserts a std::pair into the %multimap.
315 * @param x Pair to be inserted (see std::make_pair for easy creation of
317 * @return An iterator that points to the inserted (key,value) pair.
319 * This function inserts a (key, value) pair into the %multimap. Contrary
320 * to a std::map the %multimap does not rely on unique keys and thus
321 * multiple pairs with the same key can be inserted.
323 * Insertion requires logarithmic time.
326 insert(const value_type& __x) { return _M_t.insert_equal(__x); }
329 * @brief Inserts a std::pair into the %multimap.
330 * @param position An iterator that serves as a hint as to where the
331 * pair should be inserted.
332 * @param x Pair to be inserted (see std::make_pair for easy creation of
334 * @return An iterator that points to the inserted (key,value) pair.
336 * This function inserts a (key, value) pair into the %multimap. Contrary
337 * to a std::map the %multimap does not rely on unique keys and thus
338 * multiple pairs with the same key can be inserted.
339 * Note that the first parameter is only a hint and can potentially
340 * improve the performance of the insertion process. A bad hint would
341 * cause no gains in efficiency.
343 * See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4
344 * for more on "hinting".
346 * Insertion requires logarithmic time (if the hint is not taken).
349 insert(iterator __position, const value_type& __x)
350 { return _M_t.insert_equal(__position, __x); }
353 * @brief A template function that attemps to insert a range of elements.
354 * @param first Iterator pointing to the start of the range to be
356 * @param last Iterator pointing to the end of the range.
358 * Complexity similar to that of the range constructor.
360 template <typename _InputIterator>
362 insert(_InputIterator __first, _InputIterator __last)
363 { _M_t.insert_equal(__first, __last); }
366 * @brief Erases an element from a %multimap.
367 * @param position An iterator pointing to the element to be erased.
369 * This function erases an element, pointed to by the given iterator, from
370 * a %multimap. Note that this function only erases the element, and that
371 * if the element is itself a pointer, the pointed-to memory is not
372 * touched in any way. Managing the pointer is the user's responsibilty.
375 erase(iterator __position) { _M_t.erase(__position); }
378 * @brief Erases elements according to the provided key.
379 * @param x Key of element to be erased.
380 * @return The number of elements erased.
382 * This function erases all elements located by the given key from a
384 * Note that this function only erases the element, and that if
385 * the element is itself a pointer, the pointed-to memory is not touched
386 * in any way. Managing the pointer is the user's responsibilty.
389 erase(const key_type& __x) { return _M_t.erase(__x); }
392 * @brief Erases a [first,last) range of elements from a %multimap.
393 * @param first Iterator pointing to the start of the range to be erased.
394 * @param last Iterator pointing to the end of the range to be erased.
396 * This function erases a sequence of elements from a %multimap.
397 * Note that this function only erases the elements, and that if
398 * the elements themselves are pointers, the pointed-to memory is not
399 * touched in any way. Managing the pointer is the user's responsibilty.
402 erase(iterator __first, iterator __last) { _M_t.erase(__first, __last); }
405 * @brief Swaps data with another %multimap.
406 * @param x A %multimap of the same element and allocator types.
408 * This exchanges the elements between two multimaps in constant time.
409 * (It is only swapping a pointer, an integer, and an instance of
410 * the @c Compare type (which itself is often stateless and empty), so it
411 * should be quite fast.)
412 * Note that the global std::swap() function is specialized such that
413 * std::swap(m1,m2) will feed to this function.
416 swap(multimap& __x) { _M_t.swap(__x._M_t); }
419 * Erases all elements in a %multimap. Note that this function only erases
420 * the elements, and that if the elements themselves are pointers, the
421 * pointed-to memory is not touched in any way. Managing the pointer is
422 * the user's responsibilty.
425 clear() { _M_t.clear(); }
429 * Returns the key comparison object out of which the %multimap
433 key_comp() const { return _M_t.key_comp(); }
436 * Returns a value comparison object, built from the key comparison
437 * object out of which the %multimap was constructed.
440 value_comp() const { return value_compare(_M_t.key_comp()); }
442 // multimap operations
444 * @brief Tries to locate an element in a %multimap.
445 * @param x Key of (key, value) pair to be located.
446 * @return Iterator pointing to sought-after element,
447 * or end() if not found.
449 * This function takes a key and tries to locate the element with which
450 * the key matches. If successful the function returns an iterator
451 * pointing to the sought after %pair. If unsuccessful it returns the
452 * past-the-end ( @c end() ) iterator.
455 find(const key_type& __x) { return _M_t.find(__x); }
458 * @brief Tries to locate an element in a %multimap.
459 * @param x Key of (key, value) pair to be located.
460 * @return Read-only (constant) iterator pointing to sought-after
461 * element, or end() if not found.
463 * This function takes a key and tries to locate the element with which
464 * the key matches. If successful the function returns a constant iterator
465 * pointing to the sought after %pair. If unsuccessful it returns the
466 * past-the-end ( @c end() ) iterator.
469 find(const key_type& __x) const { return _M_t.find(__x); }
472 * @brief Finds the number of elements with given key.
473 * @param x Key of (key, value) pairs to be located.
474 * @return Number of elements with specified key.
477 count(const key_type& __x) const { return _M_t.count(__x); }
480 * @brief Finds the beginning of a subsequence matching given key.
481 * @param x Key of (key, value) pair to be located.
482 * @return Iterator pointing to first element matching given key, or
483 * end() if not found.
485 * This function returns the first element of a subsequence of elements
486 * that matches the given key. If unsuccessful it returns an iterator
487 * pointing to the first element that has a greater value than given key
488 * or end() if no such element exists.
491 lower_bound(const key_type& __x) { return _M_t.lower_bound(__x); }
494 * @brief Finds the beginning of a subsequence matching given key.
495 * @param x Key of (key, value) pair to be located.
496 * @return Read-only (constant) iterator pointing to first element
497 * matching given key, or end() if not found.
499 * This function returns the first element of a subsequence of elements
500 * that matches the given key. If unsuccessful the iterator will point
501 * to the next greatest element or, if no such greater element exists, to
505 lower_bound(const key_type& __x) const { return _M_t.lower_bound(__x); }
508 * @brief Finds the end of a subsequence matching given key.
509 * @param x Key of (key, value) pair to be located.
510 * @return Iterator pointing to last element matching given key.
513 upper_bound(const key_type& __x) { return _M_t.upper_bound(__x); }
516 * @brief Finds the end of a subsequence matching given key.
517 * @param x Key of (key, value) pair to be located.
518 * @return Read-only (constant) iterator pointing to last element matching
522 upper_bound(const key_type& __x) const { return _M_t.upper_bound(__x); }
525 * @brief Finds a subsequence matching given key.
526 * @param x Key of (key, value) pairs to be located.
527 * @return Pair of iterators that possibly points to the subsequence
528 * matching given key.
530 * This function returns a pair of which the first
531 * element possibly points to the first element matching the given key
532 * and the second element possibly points to the last element matching the
533 * given key. If unsuccessful the first element of the returned pair will
534 * contain an iterator pointing to the next greatest element or, if no such
535 * greater element exists, to end().
537 pair<iterator,iterator>
538 equal_range(const key_type& __x) { return _M_t.equal_range(__x); }
541 * @brief Finds a subsequence matching given key.
542 * @param x Key of (key, value) pairs to be located.
543 * @return Pair of read-only (constant) iterators that possibly points to
544 * the subsequence matching given key.
546 * This function returns a pair of which the first
547 * element possibly points to the first element matching the given key
548 * and the second element possibly points to the last element matching the
549 * given key. If unsuccessful the first element of the returned pair will
550 * contain an iterator pointing to the next greatest element or, if no such
551 * a greater element exists, to end().
553 pair<const_iterator,const_iterator>
554 equal_range(const key_type& __x) const { return _M_t.equal_range(__x); }
556 template <typename _K1, typename _T1, typename _C1, typename _A1>
557 friend bool operator== (const multimap<_K1,_T1,_C1,_A1>&,
558 const multimap<_K1,_T1,_C1,_A1>&);
559 template <typename _K1, typename _T1, typename _C1, typename _A1>
560 friend bool operator< (const multimap<_K1,_T1,_C1,_A1>&,
561 const multimap<_K1,_T1,_C1,_A1>&);
566 * @brief Multimap equality comparison.
567 * @param x A %multimap.
568 * @param y A %multimap of the same type as @a x.
569 * @return True iff the size and elements of the maps are equal.
571 * This is an equivalence relation. It is linear in the size of the
572 * multimaps. Multimaps are considered equivalent if their sizes are equal,
573 * and if corresponding elements compare equal.
575 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
577 operator==(const multimap<_Key,_Tp,_Compare,_Alloc>& __x,
578 const multimap<_Key,_Tp,_Compare,_Alloc>& __y)
580 return __x._M_t == __y._M_t;
584 * @brief Multimap ordering relation.
585 * @param x A %multimap.
586 * @param y A %multimap of the same type as @a x.
587 * @return True iff @a x is lexographically less than @a y.
589 * This is a total ordering relation. It is linear in the size of the
590 * multimaps. The elements must be comparable with @c <.
592 * See std::lexographical_compare() for how the determination is made.
594 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
596 operator<(const multimap<_Key,_Tp,_Compare,_Alloc>& __x,
597 const multimap<_Key,_Tp,_Compare,_Alloc>& __y)
598 { return __x._M_t < __y._M_t; }
600 /// Based on operator==
601 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
603 operator!=(const multimap<_Key,_Tp,_Compare,_Alloc>& __x,
604 const multimap<_Key,_Tp,_Compare,_Alloc>& __y)
605 { return !(__x == __y); }
607 /// Based on operator<
608 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
610 operator>(const multimap<_Key,_Tp,_Compare,_Alloc>& __x,
611 const multimap<_Key,_Tp,_Compare,_Alloc>& __y)
612 { return __y < __x; }
614 /// Based on operator<
615 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
617 operator<=(const multimap<_Key,_Tp,_Compare,_Alloc>& __x,
618 const multimap<_Key,_Tp,_Compare,_Alloc>& __y)
619 { return !(__y < __x); }
621 /// Based on operator<
622 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
624 operator>=(const multimap<_Key,_Tp,_Compare,_Alloc>& __x,
625 const multimap<_Key,_Tp,_Compare,_Alloc>& __y)
626 { return !(__x < __y); }
628 /// See std::multimap::swap().
629 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
631 swap(multimap<_Key,_Tp,_Compare,_Alloc>& __x,
632 multimap<_Key,_Tp,_Compare,_Alloc>& __y)
636 #endif /* __GLIBCPP_INTERNAL_MULTIMAP_H */