1 // Multiset implementation -*- C++ -*-
2
3 // Copyright (C) 2001-2016 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
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_multiset.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{set}
54 */
55
56 #ifndef _STL_MULTISET_H
57 #define _STL_MULTISET_H 1
58
59 #include <bits/concept_check.h>
60 #if __cplusplus >= 201103L
61 #include <initializer_list>
62 #endif
63
_GLIBCXX_VISIBILITY(default)64 namespace std _GLIBCXX_VISIBILITY(default)
65 {
66 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
67
68 /**
69 * @brief A standard container made up of elements, which can be retrieved
70 * in logarithmic time.
71 *
72 * @ingroup associative_containers
73 *
74 *
75 * @tparam _Key Type of key objects.
76 * @tparam _Compare Comparison function object type, defaults to less<_Key>.
77 * @tparam _Alloc Allocator type, defaults to allocator<_Key>.
78 *
79 * Meets the requirements of a <a href="tables.html#65">container</a>, a
80 * <a href="tables.html#66">reversible container</a>, and an
81 * <a href="tables.html#69">associative container</a> (using equivalent
82 * keys). For a @c multiset<Key> the key_type and value_type are Key.
83 *
84 * Multisets support bidirectional iterators.
85 *
86 * The private tree data is declared exactly the same way for set and
87 * multiset; the distinction is made entirely in how the tree functions are
88 * called (*_unique versus *_equal, same as the standard).
89 */
90 template <typename _Key, typename _Compare = std::less<_Key>,
91 typename _Alloc = std::allocator<_Key> >
92 class multiset
93 {
94 // concept requirements
95 typedef typename _Alloc::value_type _Alloc_value_type;
96 __glibcxx_class_requires(_Key, _SGIAssignableConcept)
97 __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
98 _BinaryFunctionConcept)
99 __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
100
101 public:
102 // typedefs:
103 typedef _Key key_type;
104 typedef _Key value_type;
105 typedef _Compare key_compare;
106 typedef _Compare value_compare;
107 typedef _Alloc allocator_type;
108
109 private:
110 /// This turns a red-black tree into a [multi]set.
111 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
112 rebind<_Key>::other _Key_alloc_type;
113
114 typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
115 key_compare, _Key_alloc_type> _Rep_type;
116 /// The actual tree structure.
117 _Rep_type _M_t;
118
119 typedef __gnu_cxx::__alloc_traits<_Key_alloc_type> _Alloc_traits;
120
121 public:
122 typedef typename _Alloc_traits::pointer pointer;
123 typedef typename _Alloc_traits::const_pointer const_pointer;
124 typedef typename _Alloc_traits::reference reference;
125 typedef typename _Alloc_traits::const_reference const_reference;
126 // _GLIBCXX_RESOLVE_LIB_DEFECTS
127 // DR 103. set::iterator is required to be modifiable,
128 // but this allows modification of keys.
129 typedef typename _Rep_type::const_iterator iterator;
130 typedef typename _Rep_type::const_iterator const_iterator;
131 typedef typename _Rep_type::const_reverse_iterator reverse_iterator;
132 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
133 typedef typename _Rep_type::size_type size_type;
134 typedef typename _Rep_type::difference_type difference_type;
135
136 // allocation/deallocation
137 /**
138 * @brief Default constructor creates no elements.
139 */
140 multiset()
141 _GLIBCXX_NOEXCEPT_IF(
142 is_nothrow_default_constructible<allocator_type>::value
143 && is_nothrow_default_constructible<key_compare>::value)
144 : _M_t() { }
145
146 /**
147 * @brief Creates a %multiset with no elements.
148 * @param __comp Comparator to use.
149 * @param __a An allocator object.
150 */
151 explicit
152 multiset(const _Compare& __comp,
153 const allocator_type& __a = allocator_type())
154 : _M_t(__comp, _Key_alloc_type(__a)) { }
155
156 /**
157 * @brief Builds a %multiset from a range.
158 * @param __first An input iterator.
159 * @param __last An input iterator.
160 *
161 * Create a %multiset consisting of copies of the elements from
162 * [first,last). This is linear in N if the range is already sorted,
163 * and NlogN otherwise (where N is distance(__first,__last)).
164 */
165 template<typename _InputIterator>
166 multiset(_InputIterator __first, _InputIterator __last)
167 : _M_t()
168 { _M_t._M_insert_equal(__first, __last); }
169
170 /**
171 * @brief Builds a %multiset from a range.
172 * @param __first An input iterator.
173 * @param __last An input iterator.
174 * @param __comp A comparison functor.
175 * @param __a An allocator object.
176 *
177 * Create a %multiset consisting of copies of the elements from
178 * [__first,__last). This is linear in N if the range is already sorted,
179 * and NlogN otherwise (where N is distance(__first,__last)).
180 */
181 template<typename _InputIterator>
182 multiset(_InputIterator __first, _InputIterator __last,
183 const _Compare& __comp,
184 const allocator_type& __a = allocator_type())
185 : _M_t(__comp, _Key_alloc_type(__a))
186 { _M_t._M_insert_equal(__first, __last); }
187
188 /**
189 * @brief %Multiset copy constructor.
190 * @param __x A %multiset of identical element and allocator types.
191 *
192 * The newly-created %multiset uses a copy of the allocation object used
193 * by @a __x.
194 */
195 multiset(const multiset& __x)
196 : _M_t(__x._M_t) { }
197
198 #if __cplusplus >= 201103L
199 /**
200 * @brief %Multiset move constructor.
201 * @param __x A %multiset of identical element and allocator types.
202 *
203 * The newly-created %multiset contains the exact contents of @a __x.
204 * The contents of @a __x are a valid, but unspecified %multiset.
205 */
206 multiset(multiset&& __x)
207 noexcept(is_nothrow_copy_constructible<_Compare>::value)
208 : _M_t(std::move(__x._M_t)) { }
209
210 /**
211 * @brief Builds a %multiset from an initializer_list.
212 * @param __l An initializer_list.
213 * @param __comp A comparison functor.
214 * @param __a An allocator object.
215 *
216 * Create a %multiset consisting of copies of the elements from
217 * the list. This is linear in N if the list is already sorted,
218 * and NlogN otherwise (where N is @a __l.size()).
219 */
220 multiset(initializer_list<value_type> __l,
221 const _Compare& __comp = _Compare(),
222 const allocator_type& __a = allocator_type())
223 : _M_t(__comp, _Key_alloc_type(__a))
224 { _M_t._M_insert_equal(__l.begin(), __l.end()); }
225
226 /// Allocator-extended default constructor.
227 explicit
228 multiset(const allocator_type& __a)
229 : _M_t(_Compare(), _Key_alloc_type(__a)) { }
230
231 /// Allocator-extended copy constructor.
232 multiset(const multiset& __m, const allocator_type& __a)
233 : _M_t(__m._M_t, _Key_alloc_type(__a)) { }
234
235 /// Allocator-extended move constructor.
236 multiset(multiset&& __m, const allocator_type& __a)
237 noexcept(is_nothrow_copy_constructible<_Compare>::value
238 && _Alloc_traits::_S_always_equal())
239 : _M_t(std::move(__m._M_t), _Key_alloc_type(__a)) { }
240
241 /// Allocator-extended initialier-list constructor.
242 multiset(initializer_list<value_type> __l, const allocator_type& __a)
243 : _M_t(_Compare(), _Key_alloc_type(__a))
244 { _M_t._M_insert_equal(__l.begin(), __l.end()); }
245
246 /// Allocator-extended range constructor.
247 template<typename _InputIterator>
248 multiset(_InputIterator __first, _InputIterator __last,
249 const allocator_type& __a)
250 : _M_t(_Compare(), _Key_alloc_type(__a))
251 { _M_t._M_insert_equal(__first, __last); }
252 #endif
253
254 /**
255 * @brief %Multiset assignment operator.
256 * @param __x A %multiset of identical element and allocator types.
257 *
258 * All the elements of @a __x are copied, but unlike the copy
259 * constructor, the allocator object is not copied.
260 */
261 multiset&
262 operator=(const multiset& __x)
263 {
264 _M_t = __x._M_t;
265 return *this;
266 }
267
268 #if __cplusplus >= 201103L
269 /// Move assignment operator.
270 multiset&
271 operator=(multiset&&) = default;
272
273 /**
274 * @brief %Multiset list assignment operator.
275 * @param __l An initializer_list.
276 *
277 * This function fills a %multiset with copies of the elements in the
278 * initializer list @a __l.
279 *
280 * Note that the assignment completely changes the %multiset and
281 * that the resulting %multiset's size is the same as the number
282 * of elements assigned. Old data may be lost.
283 */
284 multiset&
285 operator=(initializer_list<value_type> __l)
286 {
287 _M_t._M_assign_equal(__l.begin(), __l.end());
288 return *this;
289 }
290 #endif
291
292 // accessors:
293
294 /// Returns the comparison object.
295 key_compare
296 key_comp() const
297 { return _M_t.key_comp(); }
298 /// Returns the comparison object.
299 value_compare
300 value_comp() const
301 { return _M_t.key_comp(); }
302 /// Returns the memory allocation object.
303 allocator_type
304 get_allocator() const _GLIBCXX_NOEXCEPT
305 { return allocator_type(_M_t.get_allocator()); }
306
307 /**
308 * Returns a read-only (constant) iterator that points to the first
309 * element in the %multiset. Iteration is done in ascending order
310 * according to the keys.
311 */
312 iterator
313 begin() const _GLIBCXX_NOEXCEPT
314 { return _M_t.begin(); }
315
316 /**
317 * Returns a read-only (constant) iterator that points one past the last
318 * element in the %multiset. Iteration is done in ascending order
319 * according to the keys.
320 */
321 iterator
322 end() const _GLIBCXX_NOEXCEPT
323 { return _M_t.end(); }
324
325 /**
326 * Returns a read-only (constant) reverse iterator that points to the
327 * last element in the %multiset. Iteration is done in descending order
328 * according to the keys.
329 */
330 reverse_iterator
331 rbegin() const _GLIBCXX_NOEXCEPT
332 { return _M_t.rbegin(); }
333
334 /**
335 * Returns a read-only (constant) reverse iterator that points to the
336 * last element in the %multiset. Iteration is done in descending order
337 * according to the keys.
338 */
339 reverse_iterator
340 rend() const _GLIBCXX_NOEXCEPT
341 { return _M_t.rend(); }
342
343 #if __cplusplus >= 201103L
344 /**
345 * Returns a read-only (constant) iterator that points to the first
346 * element in the %multiset. Iteration is done in ascending order
347 * according to the keys.
348 */
349 iterator
350 cbegin() const noexcept
351 { return _M_t.begin(); }
352
353 /**
354 * Returns a read-only (constant) iterator that points one past the last
355 * element in the %multiset. Iteration is done in ascending order
356 * according to the keys.
357 */
358 iterator
359 cend() const noexcept
360 { return _M_t.end(); }
361
362 /**
363 * Returns a read-only (constant) reverse iterator that points to the
364 * last element in the %multiset. Iteration is done in descending order
365 * according to the keys.
366 */
367 reverse_iterator
368 crbegin() const noexcept
369 { return _M_t.rbegin(); }
370
371 /**
372 * Returns a read-only (constant) reverse iterator that points to the
373 * last element in the %multiset. Iteration is done in descending order
374 * according to the keys.
375 */
376 reverse_iterator
377 crend() const noexcept
378 { return _M_t.rend(); }
379 #endif
380
381 /// Returns true if the %set is empty.
382 bool
383 empty() const _GLIBCXX_NOEXCEPT
384 { return _M_t.empty(); }
385
386 /// Returns the size of the %set.
387 size_type
388 size() const _GLIBCXX_NOEXCEPT
389 { return _M_t.size(); }
390
391 /// Returns the maximum size of the %set.
392 size_type
393 max_size() const _GLIBCXX_NOEXCEPT
394 { return _M_t.max_size(); }
395
396 /**
397 * @brief Swaps data with another %multiset.
398 * @param __x A %multiset of the same element and allocator types.
399 *
400 * This exchanges the elements between two multisets in constant time.
401 * (It is only swapping a pointer, an integer, and an instance of the @c
402 * Compare type (which itself is often stateless and empty), so it should
403 * be quite fast.)
404 * Note that the global std::swap() function is specialized such that
405 * std::swap(s1,s2) will feed to this function.
406 */
407 void
408 swap(multiset& __x)
409 _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
410 { _M_t.swap(__x._M_t); }
411
412 // insert/erase
413 #if __cplusplus >= 201103L
414 /**
415 * @brief Builds and inserts an element into the %multiset.
416 * @param __args Arguments used to generate the element instance to be
417 * inserted.
418 * @return An iterator that points to the inserted element.
419 *
420 * This function inserts an element into the %multiset. Contrary
421 * to a std::set the %multiset does not rely on unique keys and thus
422 * multiple copies of the same element can be inserted.
423 *
424 * Insertion requires logarithmic time.
425 */
426 template<typename... _Args>
427 iterator
428 emplace(_Args&&... __args)
429 { return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); }
430
431 /**
432 * @brief Builds and inserts an element into the %multiset.
433 * @param __pos An iterator that serves as a hint as to where the
434 * element should be inserted.
435 * @param __args Arguments used to generate the element instance to be
436 * inserted.
437 * @return An iterator that points to the inserted element.
438 *
439 * This function inserts an element into the %multiset. Contrary
440 * to a std::set the %multiset does not rely on unique keys and thus
441 * multiple copies of the same element can be inserted.
442 *
443 * Note that the first parameter is only a hint and can potentially
444 * improve the performance of the insertion process. A bad hint would
445 * cause no gains in efficiency.
446 *
447 * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
448 * for more on @a hinting.
449 *
450 * Insertion requires logarithmic time (if the hint is not taken).
451 */
452 template<typename... _Args>
453 iterator
454 emplace_hint(const_iterator __pos, _Args&&... __args)
455 {
456 return _M_t._M_emplace_hint_equal(__pos,
457 std::forward<_Args>(__args)...);
458 }
459 #endif
460
461 /**
462 * @brief Inserts an element into the %multiset.
463 * @param __x Element to be inserted.
464 * @return An iterator that points to the inserted element.
465 *
466 * This function inserts an element into the %multiset. Contrary
467 * to a std::set the %multiset does not rely on unique keys and thus
468 * multiple copies of the same element can be inserted.
469 *
470 * Insertion requires logarithmic time.
471 */
472 iterator
473 insert(const value_type& __x)
474 { return _M_t._M_insert_equal(__x); }
475
476 #if __cplusplus >= 201103L
477 iterator
478 insert(value_type&& __x)
479 { return _M_t._M_insert_equal(std::move(__x)); }
480 #endif
481
482 /**
483 * @brief Inserts an element into the %multiset.
484 * @param __position An iterator that serves as a hint as to where the
485 * element should be inserted.
486 * @param __x Element to be inserted.
487 * @return An iterator that points to the inserted element.
488 *
489 * This function inserts an element into the %multiset. Contrary
490 * to a std::set the %multiset does not rely on unique keys and thus
491 * multiple copies of the same element can be inserted.
492 *
493 * Note that the first parameter is only a hint and can potentially
494 * improve the performance of the insertion process. A bad hint would
495 * cause no gains in efficiency.
496 *
497 * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
498 * for more on @a hinting.
499 *
500 * Insertion requires logarithmic time (if the hint is not taken).
501 */
502 iterator
503 insert(const_iterator __position, const value_type& __x)
504 { return _M_t._M_insert_equal_(__position, __x); }
505
506 #if __cplusplus >= 201103L
507 iterator
508 insert(const_iterator __position, value_type&& __x)
509 { return _M_t._M_insert_equal_(__position, std::move(__x)); }
510 #endif
511
512 /**
513 * @brief A template function that tries to insert a range of elements.
514 * @param __first Iterator pointing to the start of the range to be
515 * inserted.
516 * @param __last Iterator pointing to the end of the range.
517 *
518 * Complexity similar to that of the range constructor.
519 */
520 template<typename _InputIterator>
521 void
522 insert(_InputIterator __first, _InputIterator __last)
523 { _M_t._M_insert_equal(__first, __last); }
524
525 #if __cplusplus >= 201103L
526 /**
527 * @brief Attempts to insert a list of elements into the %multiset.
528 * @param __l A std::initializer_list<value_type> of elements
529 * to be inserted.
530 *
531 * Complexity similar to that of the range constructor.
532 */
533 void
534 insert(initializer_list<value_type> __l)
535 { this->insert(__l.begin(), __l.end()); }
536 #endif
537
538 #if __cplusplus >= 201103L
539 // _GLIBCXX_RESOLVE_LIB_DEFECTS
540 // DR 130. Associative erase should return an iterator.
541 /**
542 * @brief Erases an element from a %multiset.
543 * @param __position An iterator pointing to the element to be erased.
544 * @return An iterator pointing to the element immediately following
545 * @a position prior to the element being erased. If no such
546 * element exists, end() is returned.
547 *
548 * This function erases an element, pointed to by the given iterator,
549 * from a %multiset. Note that this function only erases the element,
550 * and that if the element is itself a pointer, the pointed-to memory is
551 * not touched in any way. Managing the pointer is the user's
552 * responsibility.
553 */
554 _GLIBCXX_ABI_TAG_CXX11
555 iterator
556 erase(const_iterator __position)
557 { return _M_t.erase(__position); }
558 #else
559 /**
560 * @brief Erases an element from a %multiset.
561 * @param __position An iterator pointing to the element to be erased.
562 *
563 * This function erases an element, pointed to by the given iterator,
564 * from a %multiset. Note that this function only erases the element,
565 * and that if the element is itself a pointer, the pointed-to memory is
566 * not touched in any way. Managing the pointer is the user's
567 * responsibility.
568 */
569 void
570 erase(iterator __position)
571 { _M_t.erase(__position); }
572 #endif
573
574 /**
575 * @brief Erases elements according to the provided key.
576 * @param __x Key of element to be erased.
577 * @return The number of elements erased.
578 *
579 * This function erases all elements located by the given key from a
580 * %multiset.
581 * Note that this function only erases the element, and that if
582 * the element is itself a pointer, the pointed-to memory is not touched
583 * in any way. Managing the pointer is the user's responsibility.
584 */
585 size_type
586 erase(const key_type& __x)
587 { return _M_t.erase(__x); }
588
589 #if __cplusplus >= 201103L
590 // _GLIBCXX_RESOLVE_LIB_DEFECTS
591 // DR 130. Associative erase should return an iterator.
592 /**
593 * @brief Erases a [first,last) range of elements from a %multiset.
594 * @param __first Iterator pointing to the start of the range to be
595 * erased.
596 * @param __last Iterator pointing to the end of the range to
597 * be erased.
598 * @return The iterator @a last.
599 *
600 * This function erases a sequence of elements from a %multiset.
601 * Note that this function only erases the elements, and that if
602 * the elements themselves are pointers, the pointed-to memory is not
603 * touched in any way. Managing the pointer is the user's
604 * responsibility.
605 */
606 _GLIBCXX_ABI_TAG_CXX11
607 iterator
608 erase(const_iterator __first, const_iterator __last)
609 { return _M_t.erase(__first, __last); }
610 #else
611 /**
612 * @brief Erases a [first,last) range of elements from a %multiset.
613 * @param first Iterator pointing to the start of the range to be
614 * erased.
615 * @param last Iterator pointing to the end of the range to be erased.
616 *
617 * This function erases a sequence of elements from a %multiset.
618 * Note that this function only erases the elements, and that if
619 * the elements themselves are pointers, the pointed-to memory is not
620 * touched in any way. Managing the pointer is the user's
621 * responsibility.
622 */
623 void
624 erase(iterator __first, iterator __last)
625 { _M_t.erase(__first, __last); }
626 #endif
627
628 /**
629 * Erases all elements in a %multiset. Note that this function only
630 * erases the elements, and that if the elements themselves are pointers,
631 * the pointed-to memory is not touched in any way. Managing the pointer
632 * is the user's responsibility.
633 */
634 void
635 clear() _GLIBCXX_NOEXCEPT
636 { _M_t.clear(); }
637
638 // multiset operations:
639
640 //@{
641 /**
642 * @brief Finds the number of elements with given key.
643 * @param __x Key of elements to be located.
644 * @return Number of elements with specified key.
645 */
646 size_type
647 count(const key_type& __x) const
648 { return _M_t.count(__x); }
649
650 #if __cplusplus > 201103L
651 template<typename _Kt>
652 auto
653 count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
654 { return _M_t._M_count_tr(__x); }
655 #endif
656 //@}
657
658 // _GLIBCXX_RESOLVE_LIB_DEFECTS
659 // 214. set::find() missing const overload
660 //@{
661 /**
662 * @brief Tries to locate an element in a %set.
663 * @param __x Element to be located.
664 * @return Iterator pointing to sought-after element, or end() if not
665 * found.
666 *
667 * This function takes a key and tries to locate the element with which
668 * the key matches. If successful the function returns an iterator
669 * pointing to the sought after element. If unsuccessful it returns the
670 * past-the-end ( @c end() ) iterator.
671 */
672 iterator
673 find(const key_type& __x)
674 { return _M_t.find(__x); }
675
676 const_iterator
677 find(const key_type& __x) const
678 { return _M_t.find(__x); }
679
680 #if __cplusplus > 201103L
681 template<typename _Kt>
682 auto
683 find(const _Kt& __x)
684 -> decltype(iterator{_M_t._M_find_tr(__x)})
685 { return iterator{_M_t._M_find_tr(__x)}; }
686
687 template<typename _Kt>
688 auto
689 find(const _Kt& __x) const
690 -> decltype(const_iterator{_M_t._M_find_tr(__x)})
691 { return const_iterator{_M_t._M_find_tr(__x)}; }
692 #endif
693 //@}
694
695 //@{
696 /**
697 * @brief Finds the beginning of a subsequence matching given key.
698 * @param __x Key to be located.
699 * @return Iterator pointing to first element equal to or greater
700 * than key, or end().
701 *
702 * This function returns the first element of a subsequence of elements
703 * that matches the given key. If unsuccessful it returns an iterator
704 * pointing to the first element that has a greater value than given key
705 * or end() if no such element exists.
706 */
707 iterator
708 lower_bound(const key_type& __x)
709 { return _M_t.lower_bound(__x); }
710
711 const_iterator
712 lower_bound(const key_type& __x) const
713 { return _M_t.lower_bound(__x); }
714
715 #if __cplusplus > 201103L
716 template<typename _Kt>
717 auto
718 lower_bound(const _Kt& __x)
719 -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
720 { return iterator(_M_t._M_lower_bound_tr(__x)); }
721
722 template<typename _Kt>
723 auto
724 lower_bound(const _Kt& __x) const
725 -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
726 { return iterator(_M_t._M_lower_bound_tr(__x)); }
727 #endif
728 //@}
729
730 //@{
731 /**
732 * @brief Finds the end of a subsequence matching given key.
733 * @param __x Key to be located.
734 * @return Iterator pointing to the first element
735 * greater than key, or end().
736 */
737 iterator
738 upper_bound(const key_type& __x)
739 { return _M_t.upper_bound(__x); }
740
741 const_iterator
742 upper_bound(const key_type& __x) const
743 { return _M_t.upper_bound(__x); }
744
745 #if __cplusplus > 201103L
746 template<typename _Kt>
747 auto
748 upper_bound(const _Kt& __x)
749 -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
750 { return iterator(_M_t._M_upper_bound_tr(__x)); }
751
752 template<typename _Kt>
753 auto
754 upper_bound(const _Kt& __x) const
755 -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
756 { return iterator(_M_t._M_upper_bound_tr(__x)); }
757 #endif
758 //@}
759
760 //@{
761 /**
762 * @brief Finds a subsequence matching given key.
763 * @param __x Key to be located.
764 * @return Pair of iterators that possibly points to the subsequence
765 * matching given key.
766 *
767 * This function is equivalent to
768 * @code
769 * std::make_pair(c.lower_bound(val),
770 * c.upper_bound(val))
771 * @endcode
772 * (but is faster than making the calls separately).
773 *
774 * This function probably only makes sense for multisets.
775 */
776 std::pair<iterator, iterator>
777 equal_range(const key_type& __x)
778 { return _M_t.equal_range(__x); }
779
780 std::pair<const_iterator, const_iterator>
781 equal_range(const key_type& __x) const
782 { return _M_t.equal_range(__x); }
783
784 #if __cplusplus > 201103L
785 template<typename _Kt>
786 auto
787 equal_range(const _Kt& __x)
788 -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
789 { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
790
791 template<typename _Kt>
792 auto
793 equal_range(const _Kt& __x) const
794 -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
795 { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
796 #endif
797 //@}
798
799 template<typename _K1, typename _C1, typename _A1>
800 friend bool
801 operator==(const multiset<_K1, _C1, _A1>&,
802 const multiset<_K1, _C1, _A1>&);
803
804 template<typename _K1, typename _C1, typename _A1>
805 friend bool
806 operator< (const multiset<_K1, _C1, _A1>&,
807 const multiset<_K1, _C1, _A1>&);
808 };
809
810 /**
811 * @brief Multiset equality comparison.
812 * @param __x A %multiset.
813 * @param __y A %multiset of the same type as @a __x.
814 * @return True iff the size and elements of the multisets are equal.
815 *
816 * This is an equivalence relation. It is linear in the size of the
817 * multisets.
818 * Multisets are considered equivalent if their sizes are equal, and if
819 * corresponding elements compare equal.
820 */
821 template<typename _Key, typename _Compare, typename _Alloc>
822 inline bool
823 operator==(const multiset<_Key, _Compare, _Alloc>& __x,
824 const multiset<_Key, _Compare, _Alloc>& __y)
825 { return __x._M_t == __y._M_t; }
826
827 /**
828 * @brief Multiset ordering relation.
829 * @param __x A %multiset.
830 * @param __y A %multiset of the same type as @a __x.
831 * @return True iff @a __x is lexicographically less than @a __y.
832 *
833 * This is a total ordering relation. It is linear in the size of the
834 * sets. The elements must be comparable with @c <.
835 *
836 * See std::lexicographical_compare() for how the determination is made.
837 */
838 template<typename _Key, typename _Compare, typename _Alloc>
839 inline bool
840 operator<(const multiset<_Key, _Compare, _Alloc>& __x,
841 const multiset<_Key, _Compare, _Alloc>& __y)
842 { return __x._M_t < __y._M_t; }
843
844 /// Returns !(x == y).
845 template<typename _Key, typename _Compare, typename _Alloc>
846 inline bool
847 operator!=(const multiset<_Key, _Compare, _Alloc>& __x,
848 const multiset<_Key, _Compare, _Alloc>& __y)
849 { return !(__x == __y); }
850
851 /// Returns y < x.
852 template<typename _Key, typename _Compare, typename _Alloc>
853 inline bool
854 operator>(const multiset<_Key,_Compare,_Alloc>& __x,
855 const multiset<_Key,_Compare,_Alloc>& __y)
856 { return __y < __x; }
857
858 /// Returns !(y < x)
859 template<typename _Key, typename _Compare, typename _Alloc>
860 inline bool
861 operator<=(const multiset<_Key, _Compare, _Alloc>& __x,
862 const multiset<_Key, _Compare, _Alloc>& __y)
863 { return !(__y < __x); }
864
865 /// Returns !(x < y)
866 template<typename _Key, typename _Compare, typename _Alloc>
867 inline bool
868 operator>=(const multiset<_Key, _Compare, _Alloc>& __x,
869 const multiset<_Key, _Compare, _Alloc>& __y)
870 { return !(__x < __y); }
871
872 /// See std::multiset::swap().
873 template<typename _Key, typename _Compare, typename _Alloc>
874 inline void
875 swap(multiset<_Key, _Compare, _Alloc>& __x,
876 multiset<_Key, _Compare, _Alloc>& __y)
877 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
878 { __x.swap(__y); }
879
880 _GLIBCXX_END_NAMESPACE_CONTAINER
881 } // namespace std
882
883 #endif /* _STL_MULTISET_H */
884