1// Multimap implementation -*- C++ -*-
2
3// Copyright (C) 2001-2014 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation. Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose. It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1996,1997
40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
45 * that both that copyright notice and this permission notice appear
46 * in supporting documentation. Silicon Graphics makes no
47 * representations about the suitability of this software for any
48 * purpose. It is provided "as is" without express or implied warranty.
49 */
50
51/** @file bits/stl_multimap.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{map}
54 */
55
56#ifndef _STL_MULTIMAP_H
57#define _STL_MULTIMAP_H 1
58
59#include <bits/concept_check.h>
60#if __cplusplus >= 201103L
61#include <initializer_list>
62#endif
63
64namespace std _GLIBCXX_VISIBILITY(default)
65{
66_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
67
68 /**
69 * @brief A standard container made up of (key,value) pairs, which can be
70 * retrieved based on a key, in logarithmic time.
71 *
72 * @ingroup associative_containers
73 *
74 * @tparam _Key Type of key objects.
75 * @tparam _Tp Type of mapped objects.
76 * @tparam _Compare Comparison function object type, defaults to less<_Key>.
77 * @tparam _Alloc Allocator type, defaults to
78 * allocator<pair<const _Key, _Tp>.
79 *
80 * Meets the requirements of a <a href="tables.html#65">container</a>, a
81 * <a href="tables.html#66">reversible container</a>, and an
82 * <a href="tables.html#69">associative container</a> (using equivalent
83 * keys). For a @c multimap<Key,T> the key_type is Key, the mapped_type
84 * is T, and the value_type is std::pair<const Key,T>.
85 *
86 * Multimaps support bidirectional iterators.
87 *
88 * The private tree data is declared exactly the same way for map and
89 * multimap; the distinction is made entirely in how the tree functions are
90 * called (*_unique versus *_equal, same as the standard).
91 */
92 template <typename _Key, typename _Tp,
93 typename _Compare = std::less<_Key>,
94 typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
95 class multimap
96 {
97 public:
98 typedef _Key key_type;
99 typedef _Tp mapped_type;
100 typedef std::pair<const _Key, _Tp> value_type;
101 typedef _Compare key_compare;
102 typedef _Alloc allocator_type;
103
104 private:
105 // concept requirements
106 typedef typename _Alloc::value_type _Alloc_value_type;
107 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
108 __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
109 _BinaryFunctionConcept)
110 __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
111
112 public:
113 class value_compare
114 : public std::binary_function<value_type, value_type, bool>
115 {
116 friend class multimap<_Key, _Tp, _Compare, _Alloc>;
117 protected:
118 _Compare comp;
119
120 value_compare(_Compare __c)
121 : comp(__c) { }
122
123 public:
124 bool operator()(const value_type& __x, const value_type& __y) const
125 { return comp(__x.first, __y.first); }
126 };
127
128 private:
129 /// This turns a red-black tree into a [multi]map.
130 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
131 rebind<value_type>::other _Pair_alloc_type;
132
133 typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
134 key_compare, _Pair_alloc_type> _Rep_type;
135 /// The actual tree structure.
136 _Rep_type _M_t;
137
138 typedef __gnu_cxx::__alloc_traits<_Pair_alloc_type> _Alloc_traits;
139
140 public:
141 // many of these are specified differently in ISO, but the following are
142 // "functionally equivalent"
143 typedef typename _Alloc_traits::pointer pointer;
144 typedef typename _Alloc_traits::const_pointer const_pointer;
145 typedef typename _Alloc_traits::reference reference;
146 typedef typename _Alloc_traits::const_reference const_reference;
147 typedef typename _Rep_type::iterator iterator;
148 typedef typename _Rep_type::const_iterator const_iterator;
149 typedef typename _Rep_type::size_type size_type;
150 typedef typename _Rep_type::difference_type difference_type;
151 typedef typename _Rep_type::reverse_iterator reverse_iterator;
152 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
153
154 // [23.3.2] construct/copy/destroy
155 // (get_allocator() is also listed in this section)
156
157 /**
158 * @brief Default constructor creates no elements.
159 */
160 multimap()
161 : _M_t() { }
162
163 /**
164 * @brief Creates a %multimap with no elements.
165 * @param __comp A comparison object.
166 * @param __a An allocator object.
167 */
168 explicit
169 multimap(const _Compare& __comp,
170 const allocator_type& __a = allocator_type())
171 : _M_t(__comp, _Pair_alloc_type(__a)) { }
172
173 /**
174 * @brief %Multimap copy constructor.
175 * @param __x A %multimap of identical element and allocator types.
176 *
177 * The newly-created %multimap uses a copy of the allocation object
178 * used by @a __x.
179 */
180 multimap(const multimap& __x)
181 : _M_t(__x._M_t) { }
182
183#if __cplusplus >= 201103L
184 /**
185 * @brief %Multimap move constructor.
186 * @param __x A %multimap of identical element and allocator types.
187 *
188 * The newly-created %multimap contains the exact contents of @a __x.
189 * The contents of @a __x are a valid, but unspecified %multimap.
190 */
191 multimap(multimap&& __x)
192 noexcept(is_nothrow_copy_constructible<_Compare>::value)
193 : _M_t(std::move(__x._M_t)) { }
194
195 /**
196 * @brief Builds a %multimap from an initializer_list.
197 * @param __l An initializer_list.
198 * @param __comp A comparison functor.
199 * @param __a An allocator object.
200 *
201 * Create a %multimap consisting of copies of the elements from
202 * the initializer_list. This is linear in N if the list is already
203 * sorted, and NlogN otherwise (where N is @a __l.size()).
204 */
205 multimap(initializer_list<value_type> __l,
206 const _Compare& __comp = _Compare(),
207 const allocator_type& __a = allocator_type())
208 : _M_t(__comp, _Pair_alloc_type(__a))
209 { _M_t._M_insert_equal(__l.begin(), __l.end()); }
210
211 /// Allocator-extended default constructor.
212 explicit
213 multimap(const allocator_type& __a)
214 : _M_t(_Compare(), _Pair_alloc_type(__a)) { }
215
216 /// Allocator-extended copy constructor.
217 multimap(const multimap& __m, const allocator_type& __a)
218 : _M_t(__m._M_t, _Pair_alloc_type(__a)) { }
219
220 /// Allocator-extended move constructor.
221 multimap(multimap&& __m, const allocator_type& __a)
222 noexcept(is_nothrow_copy_constructible<_Compare>::value
223 && _Alloc_traits::_S_always_equal())
224 : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { }
225
226 /// Allocator-extended initialier-list constructor.
227 multimap(initializer_list<value_type> __l, const allocator_type& __a)
228 : _M_t(_Compare(), _Pair_alloc_type(__a))
229 { _M_t._M_insert_equal(__l.begin(), __l.end()); }
230
231 /// Allocator-extended range constructor.
232 template<typename _InputIterator>
233 multimap(_InputIterator __first, _InputIterator __last,
234 const allocator_type& __a)
235 : _M_t(_Compare(), _Pair_alloc_type(__a))
236 { _M_t._M_insert_equal(__first, __last); }
237#endif
238
239 /**
240 * @brief Builds a %multimap from a range.
241 * @param __first An input iterator.
242 * @param __last An input iterator.
243 *
244 * Create a %multimap consisting of copies of the elements from
245 * [__first,__last). This is linear in N if the range is already sorted,
246 * and NlogN otherwise (where N is distance(__first,__last)).
247 */
248 template<typename _InputIterator>
249 multimap(_InputIterator __first, _InputIterator __last)
250 : _M_t()
251 { _M_t._M_insert_equal(__first, __last); }
252
253 /**
254 * @brief Builds a %multimap from a range.
255 * @param __first An input iterator.
256 * @param __last An input iterator.
257 * @param __comp A comparison functor.
258 * @param __a An allocator object.
259 *
260 * Create a %multimap consisting of copies of the elements from
261 * [__first,__last). This is linear in N if the range is already sorted,
262 * and NlogN otherwise (where N is distance(__first,__last)).
263 */
264 template<typename _InputIterator>
265 multimap(_InputIterator __first, _InputIterator __last,
266 const _Compare& __comp,
267 const allocator_type& __a = allocator_type())
268 : _M_t(__comp, _Pair_alloc_type(__a))
269 { _M_t._M_insert_equal(__first, __last); }
270
271 // FIXME There is no dtor declared, but we should have something generated
272 // by Doxygen. I don't know what tags to add to this paragraph to make
273 // that happen:
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
280 /**
281 * @brief %Multimap assignment operator.
282 * @param __x A %multimap of identical element and allocator types.
283 *
284 * All the elements of @a __x are copied, but unlike the copy
285 * constructor, the allocator object is not copied.
286 */
287 multimap&
288 operator=(const multimap& __x)
289 {
290 _M_t = __x._M_t;
291 return *this;
292 }
293
294#if __cplusplus >= 201103L
295 /**
296 * @brief %Multimap move assignment operator.
297 * @param __x A %multimap of identical element and allocator types.
298 *
299 * The contents of @a __x are moved into this multimap (without copying
300 * if the allocators compare equal or get moved on assignment).
301 * Afterwards @a __x is in a valid, but unspecified state.
302 */
303 multimap&
304 operator=(multimap&& __x) noexcept(_Alloc_traits::_S_nothrow_move())
305 {
306 if (!_M_t._M_move_assign(__x._M_t))
307 {
308 // The rvalue's allocator cannot be moved and is not equal,
309 // so we need to individually move each element.
310 clear();
311 insert(std::__make_move_if_noexcept_iterator(__x.begin()),
312 std::__make_move_if_noexcept_iterator(__x.end()));
313 __x.clear();
314 }
315 return *this;
316 }
317
318 /**
319 * @brief %Multimap list assignment operator.
320 * @param __l An initializer_list.
321 *
322 * This function fills a %multimap with copies of the elements
323 * in the initializer list @a __l.
324 *
325 * Note that the assignment completely changes the %multimap and
326 * that the resulting %multimap's size is the same as the number
327 * of elements assigned. Old data may be lost.
328 */
329 multimap&
330 operator=(initializer_list<value_type> __l)
331 {
332 this->clear();
333 this->insert(__l.begin(), __l.end());
334 return *this;
335 }
336#endif
337
338 /// Get a copy of the memory allocation object.
339 allocator_type
340 get_allocator() const _GLIBCXX_NOEXCEPT
341 { return allocator_type(_M_t.get_allocator()); }
342
343 // iterators
344 /**
345 * Returns a read/write iterator that points to the first pair in the
346 * %multimap. Iteration is done in ascending order according to the
347 * keys.
348 */
349 iterator
350 begin() _GLIBCXX_NOEXCEPT
351 { return _M_t.begin(); }
352
353 /**
354 * Returns a read-only (constant) iterator that points to the first pair
355 * in the %multimap. Iteration is done in ascending order according to
356 * the keys.
357 */
358 const_iterator
359 begin() const _GLIBCXX_NOEXCEPT
360 { return _M_t.begin(); }
361
362 /**
363 * Returns a read/write iterator that points one past the last pair in
364 * the %multimap. Iteration is done in ascending order according to the
365 * keys.
366 */
367 iterator
368 end() _GLIBCXX_NOEXCEPT
369 { return _M_t.end(); }
370
371 /**
372 * Returns a read-only (constant) iterator that points one past the last
373 * pair in the %multimap. Iteration is done in ascending order according
374 * to the keys.
375 */
376 const_iterator
377 end() const _GLIBCXX_NOEXCEPT
378 { return _M_t.end(); }
379
380 /**
381 * Returns a read/write reverse iterator that points to the last pair in
382 * the %multimap. Iteration is done in descending order according to the
383 * keys.
384 */
385 reverse_iterator
386 rbegin() _GLIBCXX_NOEXCEPT
387 { return _M_t.rbegin(); }
388
389 /**
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.
393 */
394 const_reverse_iterator
395 rbegin() const _GLIBCXX_NOEXCEPT
396 { return _M_t.rbegin(); }
397
398 /**
399 * Returns a read/write reverse iterator that points to one before the
400 * first pair in the %multimap. Iteration is done in descending order
401 * according to the keys.
402 */
403 reverse_iterator
404 rend() _GLIBCXX_NOEXCEPT
405 { return _M_t.rend(); }
406
407 /**
408 * Returns a read-only (constant) reverse iterator that points to one
409 * before the first pair in the %multimap. Iteration is done in
410 * descending order according to the keys.
411 */
412 const_reverse_iterator
413 rend() const _GLIBCXX_NOEXCEPT
414 { return _M_t.rend(); }
415
416#if __cplusplus >= 201103L
417 /**
418 * Returns a read-only (constant) iterator that points to the first pair
419 * in the %multimap. Iteration is done in ascending order according to
420 * the keys.
421 */
422 const_iterator
423 cbegin() const noexcept
424 { return _M_t.begin(); }
425
426 /**
427 * Returns a read-only (constant) iterator that points one past the last
428 * pair in the %multimap. Iteration is done in ascending order according
429 * to the keys.
430 */
431 const_iterator
432 cend() const noexcept
433 { return _M_t.end(); }
434
435 /**
436 * Returns a read-only (constant) reverse iterator that points to the
437 * last pair in the %multimap. Iteration is done in descending order
438 * according to the keys.
439 */
440 const_reverse_iterator
441 crbegin() const noexcept
442 { return _M_t.rbegin(); }
443
444 /**
445 * Returns a read-only (constant) reverse iterator that points to one
446 * before the first pair in the %multimap. Iteration is done in
447 * descending order according to the keys.
448 */
449 const_reverse_iterator
450 crend() const noexcept
451 { return _M_t.rend(); }
452#endif
453
454 // capacity
455 /** Returns true if the %multimap is empty. */
456 bool
457 empty() const _GLIBCXX_NOEXCEPT
458 { return _M_t.empty(); }
459
460 /** Returns the size of the %multimap. */
461 size_type
462 size() const _GLIBCXX_NOEXCEPT
463 { return _M_t.size(); }
464
465 /** Returns the maximum size of the %multimap. */
466 size_type
467 max_size() const _GLIBCXX_NOEXCEPT
468 { return _M_t.max_size(); }
469
470 // modifiers
471#if __cplusplus >= 201103L
472 /**
473 * @brief Build and insert a std::pair into the %multimap.
474 *
475 * @param __args Arguments used to generate a new pair instance (see
476 * std::piecewise_contruct for passing arguments to each
477 * part of the pair constructor).
478 *
479 * @return An iterator that points to the inserted (key,value) pair.
480 *
481 * This function builds and inserts a (key, value) %pair into the
482 * %multimap.
483 * Contrary to a std::map the %multimap does not rely on unique keys and
484 * thus multiple pairs with the same key can be inserted.
485 *
486 * Insertion requires logarithmic time.
487 */
488 template<typename... _Args>
489 iterator
490 emplace(_Args&&... __args)
491 { return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); }
492
493 /**
494 * @brief Builds and inserts a std::pair into the %multimap.
495 *
496 * @param __pos An iterator that serves as a hint as to where the pair
497 * should be inserted.
498 * @param __args Arguments used to generate a new pair instance (see
499 * std::piecewise_contruct for passing arguments to each
500 * part of the pair constructor).
501 * @return An iterator that points to the inserted (key,value) pair.
502 *
503 * This function inserts a (key, value) pair into the %multimap.
504 * Contrary to a std::map the %multimap does not rely on unique keys and
505 * thus multiple pairs with the same key can be inserted.
506 * Note that the first parameter is only a hint and can potentially
507 * improve the performance of the insertion process. A bad hint would
508 * cause no gains in efficiency.
509 *
510 * For more on @a hinting, see:
511 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
512 *
513 * Insertion requires logarithmic time (if the hint is not taken).
514 */
515 template<typename... _Args>
516 iterator
517 emplace_hint(const_iterator __pos, _Args&&... __args)
518 {
519 return _M_t._M_emplace_hint_equal(__pos,
520 std::forward<_Args>(__args)...);
521 }
522#endif
523
524 /**
525 * @brief Inserts a std::pair into the %multimap.
526 * @param __x Pair to be inserted (see std::make_pair for easy creation
527 * of pairs).
528 * @return An iterator that points to the inserted (key,value) pair.
529 *
530 * This function inserts a (key, value) pair into the %multimap.
531 * Contrary to a std::map the %multimap does not rely on unique keys and
532 * thus multiple pairs with the same key can be inserted.
533 *
534 * Insertion requires logarithmic time.
535 */
536 iterator
537 insert(const value_type& __x)
538 { return _M_t._M_insert_equal(__x); }
539
540#if __cplusplus >= 201103L
541 template<typename _Pair, typename = typename
542 std::enable_if<std::is_constructible<value_type,
543 _Pair&&>::value>::type>
544 iterator
545 insert(_Pair&& __x)
546 { return _M_t._M_insert_equal(std::forward<_Pair>(__x)); }
547#endif
548
549 /**
550 * @brief Inserts a std::pair into the %multimap.
551 * @param __position An iterator that serves as a hint as to where the
552 * pair should be inserted.
553 * @param __x Pair to be inserted (see std::make_pair for easy creation
554 * of pairs).
555 * @return An iterator that points to the inserted (key,value) pair.
556 *
557 * This function inserts a (key, value) pair into the %multimap.
558 * Contrary to a std::map the %multimap does not rely on unique keys and
559 * thus multiple pairs with the same key can be inserted.
560 * Note that the first parameter is only a hint and can potentially
561 * improve the performance of the insertion process. A bad hint would
562 * cause no gains in efficiency.
563 *
564 * For more on @a hinting, see:
565 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
566 *
567 * Insertion requires logarithmic time (if the hint is not taken).
568 */
569 iterator
570#if __cplusplus >= 201103L
571 insert(const_iterator __position, const value_type& __x)
572#else
573 insert(iterator __position, const value_type& __x)
574#endif
575 { return _M_t._M_insert_equal_(__position, __x); }
576
577#if __cplusplus >= 201103L
578 template<typename _Pair, typename = typename
579 std::enable_if<std::is_constructible<value_type,
580 _Pair&&>::value>::type>
581 iterator
582 insert(const_iterator __position, _Pair&& __x)
583 { return _M_t._M_insert_equal_(__position,
584 std::forward<_Pair>(__x)); }
585#endif
586
587 /**
588 * @brief A template function that attempts to insert a range
589 * of elements.
590 * @param __first Iterator pointing to the start of the range to be
591 * inserted.
592 * @param __last Iterator pointing to the end of the range.
593 *
594 * Complexity similar to that of the range constructor.
595 */
596 template<typename _InputIterator>
597 void
598 insert(_InputIterator __first, _InputIterator __last)
599 { _M_t._M_insert_equal(__first, __last); }
600
601#if __cplusplus >= 201103L
602 /**
603 * @brief Attempts to insert a list of std::pairs into the %multimap.
604 * @param __l A std::initializer_list<value_type> of pairs to be
605 * inserted.
606 *
607 * Complexity similar to that of the range constructor.
608 */
609 void
610 insert(initializer_list<value_type> __l)
611 { this->insert(__l.begin(), __l.end()); }
612#endif
613
614#if __cplusplus >= 201103L
615 // _GLIBCXX_RESOLVE_LIB_DEFECTS
616 // DR 130. Associative erase should return an iterator.
617 /**
618 * @brief Erases an element from a %multimap.
619 * @param __position An iterator pointing to the element to be erased.
620 * @return An iterator pointing to the element immediately following
621 * @a position prior to the element being erased. If no such
622 * element exists, end() is returned.
623 *
624 * This function erases an element, pointed to by the given iterator,
625 * from a %multimap. Note that this function only erases the element,
626 * and that if the element is itself a pointer, the pointed-to memory is
627 * not touched in any way. Managing the pointer is the user's
628 * responsibility.
629 */
630 iterator
631 erase(const_iterator __position)
632 { return _M_t.erase(__position); }
633
634 // LWG 2059.
635 _GLIBCXX_ABI_TAG_CXX11
636 iterator
637 erase(iterator __position)
638 { return _M_t.erase(__position); }
639#else
640 /**
641 * @brief Erases an element from a %multimap.
642 * @param __position An iterator pointing to the element to be erased.
643 *
644 * This function erases an element, pointed to by the given iterator,
645 * from a %multimap. Note that this function only erases the element,
646 * and that if the element is itself a pointer, the pointed-to memory is
647 * not touched in any way. Managing the pointer is the user's
648 * responsibility.
649 */
650 void
651 erase(iterator __position)
652 { _M_t.erase(__position); }
653#endif
654
655 /**
656 * @brief Erases elements according to the provided key.
657 * @param __x Key of element to be erased.
658 * @return The number of elements erased.
659 *
660 * This function erases all elements located by the given key from a
661 * %multimap.
662 * Note that this function only erases the element, and that if
663 * the element is itself a pointer, the pointed-to memory is not touched
664 * in any way. Managing the pointer is the user's responsibility.
665 */
666 size_type
667 erase(const key_type& __x)
668 { return _M_t.erase(__x); }
669
670#if __cplusplus >= 201103L
671 // _GLIBCXX_RESOLVE_LIB_DEFECTS
672 // DR 130. Associative erase should return an iterator.
673 /**
674 * @brief Erases a [first,last) range of elements from a %multimap.
675 * @param __first Iterator pointing to the start of the range to be
676 * erased.
677 * @param __last Iterator pointing to the end of the range to be
678 * erased .
679 * @return The iterator @a __last.
680 *
681 * This function erases a sequence of elements from a %multimap.
682 * Note that this function only erases the elements, and that if
683 * the elements themselves are pointers, the pointed-to memory is not
684 * touched in any way. Managing the pointer is the user's
685 * responsibility.
686 */
687 iterator
688 erase(const_iterator __first, const_iterator __last)
689 { return _M_t.erase(__first, __last); }
690#else
691 // _GLIBCXX_RESOLVE_LIB_DEFECTS
692 // DR 130. Associative erase should return an iterator.
693 /**
694 * @brief Erases a [first,last) range of elements from a %multimap.
695 * @param __first Iterator pointing to the start of the range to be
696 * erased.
697 * @param __last Iterator pointing to the end of the range to
698 * be erased.
699 *
700 * This function erases a sequence of elements from a %multimap.
701 * Note that this function only erases the elements, and that if
702 * the elements themselves are pointers, the pointed-to memory is not
703 * touched in any way. Managing the pointer is the user's
704 * responsibility.
705 */
706 void
707 erase(iterator __first, iterator __last)
708 { _M_t.erase(__first, __last); }
709#endif
710
711 /**
712 * @brief Swaps data with another %multimap.
713 * @param __x A %multimap of the same element and allocator types.
714 *
715 * This exchanges the elements between two multimaps in constant time.
716 * (It is only swapping a pointer, an integer, and an instance of
717 * the @c Compare type (which itself is often stateless and empty), so it
718 * should be quite fast.)
719 * Note that the global std::swap() function is specialized such that
720 * std::swap(m1,m2) will feed to this function.
721 */
722 void
723 swap(multimap& __x)
724#if __cplusplus >= 201103L
725 noexcept(_Alloc_traits::_S_nothrow_swap())
726#endif
727 { _M_t.swap(__x._M_t); }
728
729 /**
730 * Erases all elements in a %multimap. Note that this function only
731 * erases the elements, and that if the elements themselves are pointers,
732 * the pointed-to memory is not touched in any way. Managing the pointer
733 * is the user's responsibility.
734 */
735 void
736 clear() _GLIBCXX_NOEXCEPT
737 { _M_t.clear(); }
738
739 // observers
740 /**
741 * Returns the key comparison object out of which the %multimap
742 * was constructed.
743 */
744 key_compare
745 key_comp() const
746 { return _M_t.key_comp(); }
747
748 /**
749 * Returns a value comparison object, built from the key comparison
750 * object out of which the %multimap was constructed.
751 */
752 value_compare
753 value_comp() const
754 { return value_compare(_M_t.key_comp()); }
755
756 // multimap operations
757 /**
758 * @brief Tries to locate an element in a %multimap.
759 * @param __x Key of (key, value) pair to be located.
760 * @return Iterator pointing to sought-after element,
761 * or end() if not found.
762 *
763 * This function takes a key and tries to locate the element with which
764 * the key matches. If successful the function returns an iterator
765 * pointing to the sought after %pair. If unsuccessful it returns the
766 * past-the-end ( @c end() ) iterator.
767 */
768 iterator
769 find(const key_type& __x)
770 { return _M_t.find(__x); }
771
772 /**
773 * @brief Tries to locate an element in a %multimap.
774 * @param __x Key of (key, value) pair to be located.
775 * @return Read-only (constant) iterator pointing to sought-after
776 * element, or end() if not found.
777 *
778 * This function takes a key and tries to locate the element with which
779 * the key matches. If successful the function returns a constant
780 * iterator pointing to the sought after %pair. If unsuccessful it
781 * returns the past-the-end ( @c end() ) iterator.
782 */
783 const_iterator
784 find(const key_type& __x) const
785 { return _M_t.find(__x); }
786
787 /**
788 * @brief Finds the number of elements with given key.
789 * @param __x Key of (key, value) pairs to be located.
790 * @return Number of elements with specified key.
791 */
792 size_type
793 count(const key_type& __x) const
794 { return _M_t.count(__x); }
795
796 /**
797 * @brief Finds the beginning of a subsequence matching given key.
798 * @param __x Key of (key, value) pair to be located.
799 * @return Iterator pointing to first element equal to or greater
800 * than key, or end().
801 *
802 * This function returns the first element of a subsequence of elements
803 * that matches the given key. If unsuccessful it returns an iterator
804 * pointing to the first element that has a greater value than given key
805 * or end() if no such element exists.
806 */
807 iterator
808 lower_bound(const key_type& __x)
809 { return _M_t.lower_bound(__x); }
810
811 /**
812 * @brief Finds the beginning of a subsequence matching given key.
813 * @param __x Key of (key, value) pair to be located.
814 * @return Read-only (constant) iterator pointing to first element
815 * equal to or greater than key, or end().
816 *
817 * This function returns the first element of a subsequence of
818 * elements that matches the given key. If unsuccessful the
819 * iterator will point to the next greatest element or, if no
820 * such greater element exists, to end().
821 */
822 const_iterator
823 lower_bound(const key_type& __x) const
824 { return _M_t.lower_bound(__x); }
825
826 /**
827 * @brief Finds the end of a subsequence matching given key.
828 * @param __x Key of (key, value) pair to be located.
829 * @return Iterator pointing to the first element
830 * greater than key, or end().
831 */
832 iterator
833 upper_bound(const key_type& __x)
834 { return _M_t.upper_bound(__x); }
835
836 /**
837 * @brief Finds the end of a subsequence matching given key.
838 * @param __x Key of (key, value) pair to be located.
839 * @return Read-only (constant) iterator pointing to first iterator
840 * greater than key, or end().
841 */
842 const_iterator
843 upper_bound(const key_type& __x) const
844 { return _M_t.upper_bound(__x); }
845
846 /**
847 * @brief Finds a subsequence matching given key.
848 * @param __x Key of (key, value) pairs to be located.
849 * @return Pair of iterators that possibly points to the subsequence
850 * matching given key.
851 *
852 * This function is equivalent to
853 * @code
854 * std::make_pair(c.lower_bound(val),
855 * c.upper_bound(val))
856 * @endcode
857 * (but is faster than making the calls separately).
858 */
859 std::pair<iterator, iterator>
860 equal_range(const key_type& __x)
861 { return _M_t.equal_range(__x); }
862
863 /**
864 * @brief Finds a subsequence matching given key.
865 * @param __x Key of (key, value) pairs to be located.
866 * @return Pair of read-only (constant) iterators that possibly points
867 * to the subsequence matching given key.
868 *
869 * This function is equivalent to
870 * @code
871 * std::make_pair(c.lower_bound(val),
872 * c.upper_bound(val))
873 * @endcode
874 * (but is faster than making the calls separately).
875 */
876 std::pair<const_iterator, const_iterator>
877 equal_range(const key_type& __x) const
878 { return _M_t.equal_range(__x); }
879
880 template<typename _K1, typename _T1, typename _C1, typename _A1>
881 friend bool
882 operator==(const multimap<_K1, _T1, _C1, _A1>&,
883 const multimap<_K1, _T1, _C1, _A1>&);
884
885 template<typename _K1, typename _T1, typename _C1, typename _A1>
886 friend bool
887 operator<(const multimap<_K1, _T1, _C1, _A1>&,
888 const multimap<_K1, _T1, _C1, _A1>&);
889 };
890
891 /**
892 * @brief Multimap equality comparison.
893 * @param __x A %multimap.
894 * @param __y A %multimap of the same type as @a __x.
895 * @return True iff the size and elements of the maps are equal.
896 *
897 * This is an equivalence relation. It is linear in the size of the
898 * multimaps. Multimaps are considered equivalent if their sizes are equal,
899 * and if corresponding elements compare equal.
900 */
901 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
902 inline bool
903 operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
904 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
905 { return __x._M_t == __y._M_t; }
906
907 /**
908 * @brief Multimap ordering relation.
909 * @param __x A %multimap.
910 * @param __y A %multimap of the same type as @a __x.
911 * @return True iff @a x is lexicographically less than @a y.
912 *
913 * This is a total ordering relation. It is linear in the size of the
914 * multimaps. The elements must be comparable with @c <.
915 *
916 * See std::lexicographical_compare() for how the determination is made.
917 */
918 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
919 inline bool
920 operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
921 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
922 { return __x._M_t < __y._M_t; }
923
924 /// Based on operator==
925 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
926 inline bool
927 operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
928 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
929 { return !(__x == __y); }
930
931 /// Based on operator<
932 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
933 inline bool
934 operator>(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
935 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
936 { return __y < __x; }
937
938 /// Based on operator<
939 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
940 inline bool
941 operator<=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
942 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
943 { return !(__y < __x); }
944
945 /// Based on operator<
946 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
947 inline bool
948 operator>=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
949 const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
950 { return !(__x < __y); }
951
952 /// See std::multimap::swap().
953 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
954 inline void
955 swap(multimap<_Key, _Tp, _Compare, _Alloc>& __x,
956 multimap<_Key, _Tp, _Compare, _Alloc>& __y)
957 { __x.swap(__y); }
958
959_GLIBCXX_END_NAMESPACE_CONTAINER
960} // namespace std
961
962#endif /* _STL_MULTIMAP_H */
963