xref: /netbsd-src/external/gpl3/gcc.old/dist/libstdc++-v3/include/bits/stl_multiset.h (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 // Multiset implementation -*- C++ -*-
2 
3 // Copyright (C) 2001-2015 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 
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 #if __cplusplus >= 201103L
142       noexcept(is_nothrow_default_constructible<allocator_type>::value
143                && is_nothrow_default_constructible<key_compare>::value)
144 #endif
145       : _M_t() { }
146 
147       /**
148        *  @brief  Creates a %multiset with no elements.
149        *  @param  __comp  Comparator to use.
150        *  @param  __a  An allocator object.
151        */
152       explicit
153       multiset(const _Compare& __comp,
154 	       const allocator_type& __a = allocator_type())
155       : _M_t(__comp, _Key_alloc_type(__a)) { }
156 
157       /**
158        *  @brief  Builds a %multiset from a range.
159        *  @param  __first  An input iterator.
160        *  @param  __last  An input iterator.
161        *
162        *  Create a %multiset consisting of copies of the elements from
163        *  [first,last).  This is linear in N if the range is already sorted,
164        *  and NlogN otherwise (where N is distance(__first,__last)).
165        */
166       template<typename _InputIterator>
167         multiset(_InputIterator __first, _InputIterator __last)
168 	: _M_t()
169         { _M_t._M_insert_equal(__first, __last); }
170 
171       /**
172        *  @brief  Builds a %multiset from a range.
173        *  @param  __first  An input iterator.
174        *  @param  __last  An input iterator.
175        *  @param  __comp  A comparison functor.
176        *  @param  __a  An allocator object.
177        *
178        *  Create a %multiset consisting of copies of the elements from
179        *  [__first,__last).  This is linear in N if the range is already sorted,
180        *  and NlogN otherwise (where N is distance(__first,__last)).
181        */
182       template<typename _InputIterator>
183         multiset(_InputIterator __first, _InputIterator __last,
184 		 const _Compare& __comp,
185 		 const allocator_type& __a = allocator_type())
186 	: _M_t(__comp, _Key_alloc_type(__a))
187         { _M_t._M_insert_equal(__first, __last); }
188 
189       /**
190        *  @brief  %Multiset copy constructor.
191        *  @param  __x  A %multiset of identical element and allocator types.
192        *
193        *  The newly-created %multiset uses a copy of the allocation object used
194        *  by @a __x.
195        */
196       multiset(const multiset& __x)
197       : _M_t(__x._M_t) { }
198 
199 #if __cplusplus >= 201103L
200      /**
201        *  @brief  %Multiset move constructor.
202        *  @param  __x  A %multiset of identical element and allocator types.
203        *
204        *  The newly-created %multiset contains the exact contents of @a __x.
205        *  The contents of @a __x are a valid, but unspecified %multiset.
206        */
207       multiset(multiset&& __x)
208       noexcept(is_nothrow_copy_constructible<_Compare>::value)
209       : _M_t(std::move(__x._M_t)) { }
210 
211       /**
212        *  @brief  Builds a %multiset from an initializer_list.
213        *  @param  __l  An initializer_list.
214        *  @param  __comp  A comparison functor.
215        *  @param  __a  An allocator object.
216        *
217        *  Create a %multiset consisting of copies of the elements from
218        *  the list.  This is linear in N if the list is already sorted,
219        *  and NlogN otherwise (where N is @a __l.size()).
220        */
221       multiset(initializer_list<value_type> __l,
222 	       const _Compare& __comp = _Compare(),
223 	       const allocator_type& __a = allocator_type())
224       : _M_t(__comp, _Key_alloc_type(__a))
225       { _M_t._M_insert_equal(__l.begin(), __l.end()); }
226 
227       /// Allocator-extended default constructor.
228       explicit
229       multiset(const allocator_type& __a)
230       : _M_t(_Compare(), _Key_alloc_type(__a)) { }
231 
232       /// Allocator-extended copy constructor.
233       multiset(const multiset& __m, const allocator_type& __a)
234       : _M_t(__m._M_t, _Key_alloc_type(__a)) { }
235 
236       /// Allocator-extended move constructor.
237       multiset(multiset&& __m, const allocator_type& __a)
238       noexcept(is_nothrow_copy_constructible<_Compare>::value
239 	       && _Alloc_traits::_S_always_equal())
240       : _M_t(std::move(__m._M_t), _Key_alloc_type(__a)) { }
241 
242       /// Allocator-extended initialier-list constructor.
243       multiset(initializer_list<value_type> __l, const allocator_type& __a)
244       : _M_t(_Compare(), _Key_alloc_type(__a))
245       { _M_t._M_insert_equal(__l.begin(), __l.end()); }
246 
247       /// Allocator-extended range constructor.
248       template<typename _InputIterator>
249         multiset(_InputIterator __first, _InputIterator __last,
250 		 const allocator_type& __a)
251 	: _M_t(_Compare(), _Key_alloc_type(__a))
252         { _M_t._M_insert_equal(__first, __last); }
253 #endif
254 
255       /**
256        *  @brief  %Multiset assignment operator.
257        *  @param  __x  A %multiset of identical element and allocator types.
258        *
259        *  All the elements of @a __x are copied, but unlike the copy
260        *  constructor, the allocator object is not copied.
261        */
262       multiset&
263       operator=(const multiset& __x)
264       {
265 	_M_t = __x._M_t;
266 	return *this;
267       }
268 
269 #if __cplusplus >= 201103L
270       /// Move assignment operator.
271       multiset&
272       operator=(multiset&&) = default;
273 
274       /**
275        *  @brief  %Multiset list assignment operator.
276        *  @param  __l  An initializer_list.
277        *
278        *  This function fills a %multiset with copies of the elements in the
279        *  initializer list @a __l.
280        *
281        *  Note that the assignment completely changes the %multiset and
282        *  that the resulting %multiset's size is the same as the number
283        *  of elements assigned.  Old data may be lost.
284        */
285       multiset&
286       operator=(initializer_list<value_type> __l)
287       {
288 	_M_t._M_assign_equal(__l.begin(), __l.end());
289 	return *this;
290       }
291 #endif
292 
293       // accessors:
294 
295       ///  Returns the comparison object.
296       key_compare
297       key_comp() const
298       { return _M_t.key_comp(); }
299       ///  Returns the comparison object.
300       value_compare
301       value_comp() const
302       { return _M_t.key_comp(); }
303       ///  Returns the memory allocation object.
304       allocator_type
305       get_allocator() const _GLIBCXX_NOEXCEPT
306       { return allocator_type(_M_t.get_allocator()); }
307 
308       /**
309        *  Returns a read-only (constant) iterator that points to the first
310        *  element in the %multiset.  Iteration is done in ascending order
311        *  according to the keys.
312        */
313       iterator
314       begin() const _GLIBCXX_NOEXCEPT
315       { return _M_t.begin(); }
316 
317       /**
318        *  Returns a read-only (constant) iterator that points one past the last
319        *  element in the %multiset.  Iteration is done in ascending order
320        *  according to the keys.
321        */
322       iterator
323       end() const _GLIBCXX_NOEXCEPT
324       { return _M_t.end(); }
325 
326       /**
327        *  Returns a read-only (constant) reverse iterator that points to the
328        *  last element in the %multiset.  Iteration is done in descending order
329        *  according to the keys.
330        */
331       reverse_iterator
332       rbegin() const _GLIBCXX_NOEXCEPT
333       { return _M_t.rbegin(); }
334 
335       /**
336        *  Returns a read-only (constant) reverse iterator that points to the
337        *  last element in the %multiset.  Iteration is done in descending order
338        *  according to the keys.
339        */
340       reverse_iterator
341       rend() const _GLIBCXX_NOEXCEPT
342       { return _M_t.rend(); }
343 
344 #if __cplusplus >= 201103L
345       /**
346        *  Returns a read-only (constant) iterator that points to the first
347        *  element in the %multiset.  Iteration is done in ascending order
348        *  according to the keys.
349        */
350       iterator
351       cbegin() const noexcept
352       { return _M_t.begin(); }
353 
354       /**
355        *  Returns a read-only (constant) iterator that points one past the last
356        *  element in the %multiset.  Iteration is done in ascending order
357        *  according to the keys.
358        */
359       iterator
360       cend() const noexcept
361       { return _M_t.end(); }
362 
363       /**
364        *  Returns a read-only (constant) reverse iterator that points to the
365        *  last element in the %multiset.  Iteration is done in descending order
366        *  according to the keys.
367        */
368       reverse_iterator
369       crbegin() const noexcept
370       { return _M_t.rbegin(); }
371 
372       /**
373        *  Returns a read-only (constant) reverse iterator that points to the
374        *  last element in the %multiset.  Iteration is done in descending order
375        *  according to the keys.
376        */
377       reverse_iterator
378       crend() const noexcept
379       { return _M_t.rend(); }
380 #endif
381 
382       ///  Returns true if the %set is empty.
383       bool
384       empty() const _GLIBCXX_NOEXCEPT
385       { return _M_t.empty(); }
386 
387       ///  Returns the size of the %set.
388       size_type
389       size() const _GLIBCXX_NOEXCEPT
390       { return _M_t.size(); }
391 
392       ///  Returns the maximum size of the %set.
393       size_type
394       max_size() const _GLIBCXX_NOEXCEPT
395       { return _M_t.max_size(); }
396 
397       /**
398        *  @brief  Swaps data with another %multiset.
399        *  @param  __x  A %multiset of the same element and allocator types.
400        *
401        *  This exchanges the elements between two multisets in constant time.
402        *  (It is only swapping a pointer, an integer, and an instance of the @c
403        *  Compare type (which itself is often stateless and empty), so it should
404        *  be quite fast.)
405        *  Note that the global std::swap() function is specialized such that
406        *  std::swap(s1,s2) will feed to this function.
407        */
408       void
409       swap(multiset& __x)
410 #if __cplusplus >= 201103L
411       noexcept(_Alloc_traits::_S_nothrow_swap())
412 #endif
413       { _M_t.swap(__x._M_t); }
414 
415       // insert/erase
416 #if __cplusplus >= 201103L
417       /**
418        *  @brief Builds and inserts an element into the %multiset.
419        *  @param  __args  Arguments used to generate the element instance to be
420        *                 inserted.
421        *  @return An iterator that points to the inserted element.
422        *
423        *  This function inserts an element into the %multiset.  Contrary
424        *  to a std::set the %multiset does not rely on unique keys and thus
425        *  multiple copies of the same element can be inserted.
426        *
427        *  Insertion requires logarithmic time.
428        */
429       template<typename... _Args>
430 	iterator
431 	emplace(_Args&&... __args)
432 	{ return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); }
433 
434       /**
435        *  @brief Builds and inserts an element into the %multiset.
436        *  @param  __pos  An iterator that serves as a hint as to where the
437        *                element should be inserted.
438        *  @param  __args  Arguments used to generate the element instance to be
439        *                 inserted.
440        *  @return An iterator that points to the inserted element.
441        *
442        *  This function inserts an element into the %multiset.  Contrary
443        *  to a std::set the %multiset does not rely on unique keys and thus
444        *  multiple copies of the same element can be inserted.
445        *
446        *  Note that the first parameter is only a hint and can potentially
447        *  improve the performance of the insertion process.  A bad hint would
448        *  cause no gains in efficiency.
449        *
450        *  See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
451        *  for more on @a hinting.
452        *
453        *  Insertion requires logarithmic time (if the hint is not taken).
454        */
455       template<typename... _Args>
456 	iterator
457 	emplace_hint(const_iterator __pos, _Args&&... __args)
458 	{
459 	  return _M_t._M_emplace_hint_equal(__pos,
460 					    std::forward<_Args>(__args)...);
461 	}
462 #endif
463 
464       /**
465        *  @brief Inserts an element into the %multiset.
466        *  @param  __x  Element to be inserted.
467        *  @return An iterator that points to the inserted element.
468        *
469        *  This function inserts an element into the %multiset.  Contrary
470        *  to a std::set the %multiset does not rely on unique keys and thus
471        *  multiple copies of the same element can be inserted.
472        *
473        *  Insertion requires logarithmic time.
474        */
475       iterator
476       insert(const value_type& __x)
477       { return _M_t._M_insert_equal(__x); }
478 
479 #if __cplusplus >= 201103L
480       iterator
481       insert(value_type&& __x)
482       { return _M_t._M_insert_equal(std::move(__x)); }
483 #endif
484 
485       /**
486        *  @brief Inserts an element into the %multiset.
487        *  @param  __position  An iterator that serves as a hint as to where the
488        *                    element should be inserted.
489        *  @param  __x  Element to be inserted.
490        *  @return An iterator that points to the inserted element.
491        *
492        *  This function inserts an element into the %multiset.  Contrary
493        *  to a std::set the %multiset does not rely on unique keys and thus
494        *  multiple copies of the same element can be inserted.
495        *
496        *  Note that the first parameter is only a hint and can potentially
497        *  improve the performance of the insertion process.  A bad hint would
498        *  cause no gains in efficiency.
499        *
500        *  See https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
501        *  for more on @a hinting.
502        *
503        *  Insertion requires logarithmic time (if the hint is not taken).
504        */
505       iterator
506       insert(const_iterator __position, const value_type& __x)
507       { return _M_t._M_insert_equal_(__position, __x); }
508 
509 #if __cplusplus >= 201103L
510       iterator
511       insert(const_iterator __position, value_type&& __x)
512       { return _M_t._M_insert_equal_(__position, std::move(__x)); }
513 #endif
514 
515       /**
516        *  @brief A template function that tries to insert a range of elements.
517        *  @param  __first  Iterator pointing to the start of the range to be
518        *                   inserted.
519        *  @param  __last  Iterator pointing to the end of the range.
520        *
521        *  Complexity similar to that of the range constructor.
522        */
523       template<typename _InputIterator>
524         void
525         insert(_InputIterator __first, _InputIterator __last)
526         { _M_t._M_insert_equal(__first, __last); }
527 
528 #if __cplusplus >= 201103L
529       /**
530        *  @brief Attempts to insert a list of elements into the %multiset.
531        *  @param  __l  A std::initializer_list<value_type> of elements
532        *               to be inserted.
533        *
534        *  Complexity similar to that of the range constructor.
535        */
536       void
537       insert(initializer_list<value_type> __l)
538       { this->insert(__l.begin(), __l.end()); }
539 #endif
540 
541 #if __cplusplus >= 201103L
542       // _GLIBCXX_RESOLVE_LIB_DEFECTS
543       // DR 130. Associative erase should return an iterator.
544       /**
545        *  @brief Erases an element from a %multiset.
546        *  @param  __position  An iterator pointing to the element to be erased.
547        *  @return An iterator pointing to the element immediately following
548        *          @a position prior to the element being erased. If no such
549        *          element exists, end() is returned.
550        *
551        *  This function erases an element, pointed to by the given iterator,
552        *  from a %multiset.  Note that this function only erases the element,
553        *  and that if the element is itself a pointer, the pointed-to memory is
554        *  not touched in any way.  Managing the pointer is the user's
555        *  responsibility.
556        */
557       _GLIBCXX_ABI_TAG_CXX11
558       iterator
559       erase(const_iterator __position)
560       { return _M_t.erase(__position); }
561 #else
562       /**
563        *  @brief Erases an element from a %multiset.
564        *  @param  __position  An iterator pointing to the element to be erased.
565        *
566        *  This function erases an element, pointed to by the given iterator,
567        *  from a %multiset.  Note that this function only erases the element,
568        *  and that if the element is itself a pointer, the pointed-to memory is
569        *  not touched in any way.  Managing the pointer is the user's
570        *  responsibility.
571        */
572       void
573       erase(iterator __position)
574       { _M_t.erase(__position); }
575 #endif
576 
577       /**
578        *  @brief Erases elements according to the provided key.
579        *  @param  __x  Key of element to be erased.
580        *  @return  The number of elements erased.
581        *
582        *  This function erases all elements located by the given key from a
583        *  %multiset.
584        *  Note that this function only erases the element, and that if
585        *  the element is itself a pointer, the pointed-to memory is not touched
586        *  in any way.  Managing the pointer is the user's responsibility.
587        */
588       size_type
589       erase(const key_type& __x)
590       { return _M_t.erase(__x); }
591 
592 #if __cplusplus >= 201103L
593       // _GLIBCXX_RESOLVE_LIB_DEFECTS
594       // DR 130. Associative erase should return an iterator.
595       /**
596        *  @brief Erases a [first,last) range of elements from a %multiset.
597        *  @param  __first  Iterator pointing to the start of the range to be
598        *                   erased.
599        *  @param __last Iterator pointing to the end of the range to
600        *                be erased.
601        *  @return The iterator @a last.
602        *
603        *  This function erases a sequence of elements from a %multiset.
604        *  Note that this function only erases the elements, and that if
605        *  the elements themselves are pointers, the pointed-to memory is not
606        *  touched in any way.  Managing the pointer is the user's
607        *  responsibility.
608        */
609       _GLIBCXX_ABI_TAG_CXX11
610       iterator
611       erase(const_iterator __first, const_iterator __last)
612       { return _M_t.erase(__first, __last); }
613 #else
614       /**
615        *  @brief Erases a [first,last) range of elements from a %multiset.
616        *  @param  first  Iterator pointing to the start of the range to be
617        *                 erased.
618        *  @param  last  Iterator pointing to the end of the range to be erased.
619        *
620        *  This function erases a sequence of elements from a %multiset.
621        *  Note that this function only erases the elements, and that if
622        *  the elements themselves are pointers, the pointed-to memory is not
623        *  touched in any way.  Managing the pointer is the user's
624        *  responsibility.
625        */
626       void
627       erase(iterator __first, iterator __last)
628       { _M_t.erase(__first, __last); }
629 #endif
630 
631       /**
632        *  Erases all elements in a %multiset.  Note that this function only
633        *  erases the elements, and that if the elements themselves are pointers,
634        *  the pointed-to memory is not touched in any way.  Managing the pointer
635        *  is the user's responsibility.
636        */
637       void
638       clear() _GLIBCXX_NOEXCEPT
639       { _M_t.clear(); }
640 
641       // multiset operations:
642 
643       //@{
644       /**
645        *  @brief Finds the number of elements with given key.
646        *  @param  __x  Key of elements to be located.
647        *  @return Number of elements with specified key.
648        */
649       size_type
650       count(const key_type& __x) const
651       { return _M_t.count(__x); }
652 
653 #if __cplusplus > 201103L
654       template<typename _Kt>
655 	auto
656 	count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
657 	{ return _M_t._M_count_tr(__x); }
658 #endif
659       //@}
660 
661       // _GLIBCXX_RESOLVE_LIB_DEFECTS
662       // 214.  set::find() missing const overload
663       //@{
664       /**
665        *  @brief Tries to locate an element in a %set.
666        *  @param  __x  Element to be located.
667        *  @return  Iterator pointing to sought-after element, or end() if not
668        *           found.
669        *
670        *  This function takes a key and tries to locate the element with which
671        *  the key matches.  If successful the function returns an iterator
672        *  pointing to the sought after element.  If unsuccessful it returns the
673        *  past-the-end ( @c end() ) iterator.
674        */
675       iterator
676       find(const key_type& __x)
677       { return _M_t.find(__x); }
678 
679       const_iterator
680       find(const key_type& __x) const
681       { return _M_t.find(__x); }
682 
683 #if __cplusplus > 201103L
684       template<typename _Kt>
685 	auto
686 	find(const _Kt& __x)
687 	-> decltype(iterator{_M_t._M_find_tr(__x)})
688 	{ return iterator{_M_t._M_find_tr(__x)}; }
689 
690       template<typename _Kt>
691 	auto
692 	find(const _Kt& __x) const
693 	-> decltype(const_iterator{_M_t._M_find_tr(__x)})
694 	{ return const_iterator{_M_t._M_find_tr(__x)}; }
695 #endif
696       //@}
697 
698       //@{
699       /**
700        *  @brief Finds the beginning of a subsequence matching given key.
701        *  @param  __x  Key to be located.
702        *  @return  Iterator pointing to first element equal to or greater
703        *           than key, or end().
704        *
705        *  This function returns the first element of a subsequence of elements
706        *  that matches the given key.  If unsuccessful it returns an iterator
707        *  pointing to the first element that has a greater value than given key
708        *  or end() if no such element exists.
709        */
710       iterator
711       lower_bound(const key_type& __x)
712       { return _M_t.lower_bound(__x); }
713 
714       const_iterator
715       lower_bound(const key_type& __x) const
716       { return _M_t.lower_bound(__x); }
717 
718 #if __cplusplus > 201103L
719       template<typename _Kt>
720 	auto
721 	lower_bound(const _Kt& __x)
722 	-> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
723 	{ return iterator(_M_t._M_lower_bound_tr(__x)); }
724 
725       template<typename _Kt>
726 	auto
727 	lower_bound(const _Kt& __x) const
728 	-> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
729 	{ return iterator(_M_t._M_lower_bound_tr(__x)); }
730 #endif
731       //@}
732 
733       //@{
734       /**
735        *  @brief Finds the end of a subsequence matching given key.
736        *  @param  __x  Key to be located.
737        *  @return Iterator pointing to the first element
738        *          greater than key, or end().
739        */
740       iterator
741       upper_bound(const key_type& __x)
742       { return _M_t.upper_bound(__x); }
743 
744       const_iterator
745       upper_bound(const key_type& __x) const
746       { return _M_t.upper_bound(__x); }
747 
748 #if __cplusplus > 201103L
749       template<typename _Kt>
750 	auto
751 	upper_bound(const _Kt& __x)
752 	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
753 	{ return iterator(_M_t._M_upper_bound_tr(__x)); }
754 
755       template<typename _Kt>
756 	auto
757 	upper_bound(const _Kt& __x) const
758 	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
759 	{ return iterator(_M_t._M_upper_bound_tr(__x)); }
760 #endif
761       //@}
762 
763       //@{
764       /**
765        *  @brief Finds a subsequence matching given key.
766        *  @param  __x  Key to be located.
767        *  @return  Pair of iterators that possibly points to the subsequence
768        *           matching given key.
769        *
770        *  This function is equivalent to
771        *  @code
772        *    std::make_pair(c.lower_bound(val),
773        *                   c.upper_bound(val))
774        *  @endcode
775        *  (but is faster than making the calls separately).
776        *
777        *  This function probably only makes sense for multisets.
778        */
779       std::pair<iterator, iterator>
780       equal_range(const key_type& __x)
781       { return _M_t.equal_range(__x); }
782 
783       std::pair<const_iterator, const_iterator>
784       equal_range(const key_type& __x) const
785       { return _M_t.equal_range(__x); }
786 
787 #if __cplusplus > 201103L
788       template<typename _Kt>
789 	auto
790 	equal_range(const _Kt& __x)
791 	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
792 	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
793 
794       template<typename _Kt>
795 	auto
796 	equal_range(const _Kt& __x) const
797 	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
798 	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
799 #endif
800       //@}
801 
802       template<typename _K1, typename _C1, typename _A1>
803         friend bool
804         operator==(const multiset<_K1, _C1, _A1>&,
805 		   const multiset<_K1, _C1, _A1>&);
806 
807       template<typename _K1, typename _C1, typename _A1>
808         friend bool
809         operator< (const multiset<_K1, _C1, _A1>&,
810 		   const multiset<_K1, _C1, _A1>&);
811     };
812 
813   /**
814    *  @brief  Multiset equality comparison.
815    *  @param  __x  A %multiset.
816    *  @param  __y  A %multiset of the same type as @a __x.
817    *  @return  True iff the size and elements of the multisets are equal.
818    *
819    *  This is an equivalence relation.  It is linear in the size of the
820    *  multisets.
821    *  Multisets are considered equivalent if their sizes are equal, and if
822    *  corresponding elements compare equal.
823   */
824   template<typename _Key, typename _Compare, typename _Alloc>
825     inline bool
826     operator==(const multiset<_Key, _Compare, _Alloc>& __x,
827 	       const multiset<_Key, _Compare, _Alloc>& __y)
828     { return __x._M_t == __y._M_t; }
829 
830   /**
831    *  @brief  Multiset ordering relation.
832    *  @param  __x  A %multiset.
833    *  @param  __y  A %multiset of the same type as @a __x.
834    *  @return  True iff @a __x is lexicographically less than @a __y.
835    *
836    *  This is a total ordering relation.  It is linear in the size of the
837    *  sets.  The elements must be comparable with @c <.
838    *
839    *  See std::lexicographical_compare() for how the determination is made.
840   */
841   template<typename _Key, typename _Compare, typename _Alloc>
842     inline bool
843     operator<(const multiset<_Key, _Compare, _Alloc>& __x,
844 	      const multiset<_Key, _Compare, _Alloc>& __y)
845     { return __x._M_t < __y._M_t; }
846 
847   ///  Returns !(x == y).
848   template<typename _Key, typename _Compare, typename _Alloc>
849     inline bool
850     operator!=(const multiset<_Key, _Compare, _Alloc>& __x,
851 	       const multiset<_Key, _Compare, _Alloc>& __y)
852     { return !(__x == __y); }
853 
854   ///  Returns y < x.
855   template<typename _Key, typename _Compare, typename _Alloc>
856     inline bool
857     operator>(const multiset<_Key,_Compare,_Alloc>& __x,
858 	      const multiset<_Key,_Compare,_Alloc>& __y)
859     { return __y < __x; }
860 
861   ///  Returns !(y < x)
862   template<typename _Key, typename _Compare, typename _Alloc>
863     inline bool
864     operator<=(const multiset<_Key, _Compare, _Alloc>& __x,
865 	       const multiset<_Key, _Compare, _Alloc>& __y)
866     { return !(__y < __x); }
867 
868   ///  Returns !(x < y)
869   template<typename _Key, typename _Compare, typename _Alloc>
870     inline bool
871     operator>=(const multiset<_Key, _Compare, _Alloc>& __x,
872 	       const multiset<_Key, _Compare, _Alloc>& __y)
873     { return !(__x < __y); }
874 
875   /// See std::multiset::swap().
876   template<typename _Key, typename _Compare, typename _Alloc>
877     inline void
878     swap(multiset<_Key, _Compare, _Alloc>& __x,
879 	 multiset<_Key, _Compare, _Alloc>& __y)
880     { __x.swap(__y); }
881 
882 _GLIBCXX_END_NAMESPACE_CONTAINER
883 } // namespace std
884 
885 #endif /* _STL_MULTISET_H */
886