xref: /netbsd-src/external/gpl3/gcc/dist/libstdc++-v3/include/bits/stl_set.h (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 // Set 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) 1996,1997
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_set.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_SET_H
57 #define _STL_SET_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 unique keys, which can be
70    *  retrieved in logarithmic time.
71    *
72    *  @ingroup associative_containers
73    *
74    *  @tparam _Key  Type of key objects.
75    *  @tparam _Compare  Comparison function object type, defaults to less<_Key>.
76    *  @tparam _Alloc  Allocator type, defaults to allocator<_Key>.
77    *
78    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
79    *  <a href="tables.html#66">reversible container</a>, and an
80    *  <a href="tables.html#69">associative container</a> (using unique keys).
81    *
82    *  Sets support bidirectional iterators.
83    *
84    *  The private tree data is declared exactly the same way for set and
85    *  multiset; the distinction is made entirely in how the tree functions are
86    *  called (*_unique versus *_equal, same as the standard).
87   */
88   template<typename _Key, typename _Compare = std::less<_Key>,
89 	   typename _Alloc = std::allocator<_Key> >
90     class set
91     {
92       // concept requirements
93       typedef typename _Alloc::value_type                   _Alloc_value_type;
94       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
95       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
96 				_BinaryFunctionConcept)
97       __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
98 
99     public:
100       // typedefs:
101       //@{
102       /// Public 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 
110     private:
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       _Rep_type _M_t;  // Red-black tree representing set.
117 
118       typedef __gnu_cxx::__alloc_traits<_Key_alloc_type> _Alloc_traits;
119 
120     public:
121       //@{
122       ///  Iterator-related typedefs.
123       typedef typename _Alloc_traits::pointer		    pointer;
124       typedef typename _Alloc_traits::const_pointer	    const_pointer;
125       typedef typename _Alloc_traits::reference		    reference;
126       typedef typename _Alloc_traits::const_reference	    const_reference;
127       // _GLIBCXX_RESOLVE_LIB_DEFECTS
128       // DR 103. set::iterator is required to be modifiable,
129       // but this allows modification of keys.
130       typedef typename _Rep_type::const_iterator            iterator;
131       typedef typename _Rep_type::const_iterator            const_iterator;
132       typedef typename _Rep_type::const_reverse_iterator    reverse_iterator;
133       typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
134       typedef typename _Rep_type::size_type                 size_type;
135       typedef typename _Rep_type::difference_type           difference_type;
136       //@}
137 
138       // allocation/deallocation
139       /**
140        *  @brief  Default constructor creates no elements.
141        */
142       set()
143       _GLIBCXX_NOEXCEPT_IF(
144 	  is_nothrow_default_constructible<allocator_type>::value
145 	  && is_nothrow_default_constructible<key_compare>::value)
146       : _M_t() { }
147 
148       /**
149        *  @brief  Creates a %set with no elements.
150        *  @param  __comp  Comparator to use.
151        *  @param  __a  An allocator object.
152        */
153       explicit
154       set(const _Compare& __comp,
155 	  const allocator_type& __a = allocator_type())
156       : _M_t(__comp, _Key_alloc_type(__a)) { }
157 
158       /**
159        *  @brief  Builds a %set from a range.
160        *  @param  __first  An input iterator.
161        *  @param  __last  An input iterator.
162        *
163        *  Create a %set consisting of copies of the elements from
164        *  [__first,__last).  This is linear in N if the range is
165        *  already sorted, and NlogN otherwise (where N is
166        *  distance(__first,__last)).
167        */
168       template<typename _InputIterator>
169 	set(_InputIterator __first, _InputIterator __last)
170 	: _M_t()
171 	{ _M_t._M_insert_unique(__first, __last); }
172 
173       /**
174        *  @brief  Builds a %set from a range.
175        *  @param  __first  An input iterator.
176        *  @param  __last  An input iterator.
177        *  @param  __comp  A comparison functor.
178        *  @param  __a  An allocator object.
179        *
180        *  Create a %set consisting of copies of the elements from
181        *  [__first,__last).  This is linear in N if the range is
182        *  already sorted, and NlogN otherwise (where N is
183        *  distance(__first,__last)).
184        */
185       template<typename _InputIterator>
186 	set(_InputIterator __first, _InputIterator __last,
187 	    const _Compare& __comp,
188 	    const allocator_type& __a = allocator_type())
189 	: _M_t(__comp, _Key_alloc_type(__a))
190         { _M_t._M_insert_unique(__first, __last); }
191 
192       /**
193        *  @brief  %Set copy constructor.
194        *  @param  __x  A %set of identical element and allocator types.
195        *
196        *  The newly-created %set uses a copy of the allocation object used
197        *  by @a __x.
198        */
199       set(const set& __x)
200       : _M_t(__x._M_t) { }
201 
202 #if __cplusplus >= 201103L
203      /**
204        *  @brief %Set move constructor
205        *  @param __x  A %set of identical element and allocator types.
206        *
207        *  The newly-created %set contains the exact contents of @a x.
208        *  The contents of @a x are a valid, but unspecified %set.
209        */
210       set(set&& __x)
211       noexcept(is_nothrow_copy_constructible<_Compare>::value)
212       : _M_t(std::move(__x._M_t)) { }
213 
214       /**
215        *  @brief  Builds a %set from an initializer_list.
216        *  @param  __l  An initializer_list.
217        *  @param  __comp  A comparison functor.
218        *  @param  __a  An allocator object.
219        *
220        *  Create a %set consisting of copies of the elements in the list.
221        *  This is linear in N if the list is already sorted, and NlogN
222        *  otherwise (where N is @a __l.size()).
223        */
224       set(initializer_list<value_type> __l,
225 	  const _Compare& __comp = _Compare(),
226 	  const allocator_type& __a = allocator_type())
227       : _M_t(__comp, _Key_alloc_type(__a))
228       { _M_t._M_insert_unique(__l.begin(), __l.end()); }
229 
230       /// Allocator-extended default constructor.
231       explicit
232       set(const allocator_type& __a)
233       : _M_t(_Compare(), _Key_alloc_type(__a)) { }
234 
235       /// Allocator-extended copy constructor.
236       set(const set& __x, const allocator_type& __a)
237       : _M_t(__x._M_t, _Key_alloc_type(__a)) { }
238 
239       /// Allocator-extended move constructor.
240       set(set&& __x, const allocator_type& __a)
241       noexcept(is_nothrow_copy_constructible<_Compare>::value
242 	       && _Alloc_traits::_S_always_equal())
243       : _M_t(std::move(__x._M_t), _Key_alloc_type(__a)) { }
244 
245       /// Allocator-extended initialier-list constructor.
246       set(initializer_list<value_type> __l, const allocator_type& __a)
247       : _M_t(_Compare(), _Key_alloc_type(__a))
248       { _M_t._M_insert_unique(__l.begin(), __l.end()); }
249 
250       /// Allocator-extended range constructor.
251       template<typename _InputIterator>
252         set(_InputIterator __first, _InputIterator __last,
253 	    const allocator_type& __a)
254 	: _M_t(_Compare(), _Key_alloc_type(__a))
255         { _M_t._M_insert_unique(__first, __last); }
256 #endif
257 
258       /**
259        *  @brief  %Set assignment operator.
260        *  @param  __x  A %set of identical element and allocator types.
261        *
262        *  All the elements of @a __x are copied, but unlike the copy
263        *  constructor, the allocator object is not copied.
264        */
265       set&
266       operator=(const set& __x)
267       {
268 	_M_t = __x._M_t;
269 	return *this;
270       }
271 
272 #if __cplusplus >= 201103L
273       /// Move assignment operator.
274       set&
275       operator=(set&&) = default;
276 
277       /**
278        *  @brief  %Set list assignment operator.
279        *  @param  __l  An initializer_list.
280        *
281        *  This function fills a %set with copies of the elements in the
282        *  initializer list @a __l.
283        *
284        *  Note that the assignment completely changes the %set and
285        *  that the resulting %set's size is the same as the number
286        *  of elements assigned.  Old data may be lost.
287        */
288       set&
289       operator=(initializer_list<value_type> __l)
290       {
291 	_M_t._M_assign_unique(__l.begin(), __l.end());
292 	return *this;
293       }
294 #endif
295 
296       // accessors:
297 
298       ///  Returns the comparison object with which the %set was constructed.
299       key_compare
300       key_comp() const
301       { return _M_t.key_comp(); }
302       ///  Returns the comparison object with which the %set was constructed.
303       value_compare
304       value_comp() const
305       { return _M_t.key_comp(); }
306       ///  Returns the allocator object with which the %set was constructed.
307       allocator_type
308       get_allocator() const _GLIBCXX_NOEXCEPT
309       { return allocator_type(_M_t.get_allocator()); }
310 
311       /**
312        *  Returns a read-only (constant) iterator that points to the first
313        *  element in the %set.  Iteration is done in ascending order according
314        *  to the keys.
315        */
316       iterator
317       begin() const _GLIBCXX_NOEXCEPT
318       { return _M_t.begin(); }
319 
320       /**
321        *  Returns a read-only (constant) iterator that points one past the last
322        *  element in the %set.  Iteration is done in ascending order according
323        *  to the keys.
324        */
325       iterator
326       end() const _GLIBCXX_NOEXCEPT
327       { return _M_t.end(); }
328 
329       /**
330        *  Returns a read-only (constant) iterator that points to the last
331        *  element in the %set.  Iteration is done in descending order according
332        *  to the keys.
333        */
334       reverse_iterator
335       rbegin() const _GLIBCXX_NOEXCEPT
336       { return _M_t.rbegin(); }
337 
338       /**
339        *  Returns a read-only (constant) reverse iterator that points to the
340        *  last pair in the %set.  Iteration is done in descending order
341        *  according to the keys.
342        */
343       reverse_iterator
344       rend() const _GLIBCXX_NOEXCEPT
345       { return _M_t.rend(); }
346 
347 #if __cplusplus >= 201103L
348       /**
349        *  Returns a read-only (constant) iterator that points to the first
350        *  element in the %set.  Iteration is done in ascending order according
351        *  to the keys.
352        */
353       iterator
354       cbegin() const noexcept
355       { return _M_t.begin(); }
356 
357       /**
358        *  Returns a read-only (constant) iterator that points one past the last
359        *  element in the %set.  Iteration is done in ascending order according
360        *  to the keys.
361        */
362       iterator
363       cend() const noexcept
364       { return _M_t.end(); }
365 
366       /**
367        *  Returns a read-only (constant) iterator that points to the last
368        *  element in the %set.  Iteration is done in descending order according
369        *  to the keys.
370        */
371       reverse_iterator
372       crbegin() const noexcept
373       { return _M_t.rbegin(); }
374 
375       /**
376        *  Returns a read-only (constant) reverse iterator that points to the
377        *  last pair in the %set.  Iteration is done in descending order
378        *  according to the keys.
379        */
380       reverse_iterator
381       crend() const noexcept
382       { return _M_t.rend(); }
383 #endif
384 
385       ///  Returns true if the %set is empty.
386       bool
387       empty() const _GLIBCXX_NOEXCEPT
388       { return _M_t.empty(); }
389 
390       ///  Returns the size of the %set.
391       size_type
392       size() const _GLIBCXX_NOEXCEPT
393       { return _M_t.size(); }
394 
395       ///  Returns the maximum size of the %set.
396       size_type
397       max_size() const _GLIBCXX_NOEXCEPT
398       { return _M_t.max_size(); }
399 
400       /**
401        *  @brief  Swaps data with another %set.
402        *  @param  __x  A %set of the same element and allocator types.
403        *
404        *  This exchanges the elements between two sets in constant
405        *  time.  (It is only swapping a pointer, an integer, and an
406        *  instance of the @c Compare type (which itself is often
407        *  stateless and empty), so it should be quite fast.)  Note
408        *  that the global std::swap() function is specialized such
409        *  that std::swap(s1,s2) will feed to this function.
410        */
411       void
412       swap(set& __x)
413       _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
414       { _M_t.swap(__x._M_t); }
415 
416       // insert/erase
417 #if __cplusplus >= 201103L
418       /**
419        *  @brief Attempts to build and insert an element into the %set.
420        *  @param __args  Arguments used to generate an element.
421        *  @return  A pair, of which the first element is an iterator that points
422        *           to the possibly inserted element, and the second is a bool
423        *           that is true if the element was actually inserted.
424        *
425        *  This function attempts to build and insert an element into the %set.
426        *  A %set relies on unique keys and thus an element is only inserted if
427        *  it is not already present in the %set.
428        *
429        *  Insertion requires logarithmic time.
430        */
431       template<typename... _Args>
432 	std::pair<iterator, bool>
433 	emplace(_Args&&... __args)
434 	{ return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); }
435 
436       /**
437        *  @brief Attempts to insert an element into the %set.
438        *  @param  __pos  An iterator that serves as a hint as to where the
439        *                element should be inserted.
440        *  @param  __args  Arguments used to generate the element to be
441        *                 inserted.
442        *  @return An iterator that points to the element with key equivalent to
443        *          the one generated from @a __args (may or may not be the
444        *          element itself).
445        *
446        *  This function is not concerned about whether the insertion took place,
447        *  and thus does not return a boolean like the single-argument emplace()
448        *  does.  Note that the first parameter is only a hint and can
449        *  potentially improve the performance of the insertion process.  A bad
450        *  hint would cause no gains in efficiency.
451        *
452        *  For more on @a hinting, see:
453        *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
454        *
455        *  Insertion requires logarithmic time (if the hint is not taken).
456        */
457       template<typename... _Args>
458 	iterator
459 	emplace_hint(const_iterator __pos, _Args&&... __args)
460 	{
461 	  return _M_t._M_emplace_hint_unique(__pos,
462 					     std::forward<_Args>(__args)...);
463 	}
464 #endif
465 
466       /**
467        *  @brief Attempts to insert an element into the %set.
468        *  @param  __x  Element to be inserted.
469        *  @return  A pair, of which the first element is an iterator that points
470        *           to the possibly inserted element, and the second is a bool
471        *           that is true if the element was actually inserted.
472        *
473        *  This function attempts to insert an element into the %set.  A %set
474        *  relies on unique keys and thus an element is only inserted if it is
475        *  not already present in the %set.
476        *
477        *  Insertion requires logarithmic time.
478        */
479       std::pair<iterator, bool>
480       insert(const value_type& __x)
481       {
482 	std::pair<typename _Rep_type::iterator, bool> __p =
483 	  _M_t._M_insert_unique(__x);
484 	return std::pair<iterator, bool>(__p.first, __p.second);
485       }
486 
487 #if __cplusplus >= 201103L
488       std::pair<iterator, bool>
489       insert(value_type&& __x)
490       {
491 	std::pair<typename _Rep_type::iterator, bool> __p =
492 	  _M_t._M_insert_unique(std::move(__x));
493 	return std::pair<iterator, bool>(__p.first, __p.second);
494       }
495 #endif
496 
497       /**
498        *  @brief Attempts to insert an element into the %set.
499        *  @param  __position  An iterator that serves as a hint as to where the
500        *                    element should be inserted.
501        *  @param  __x  Element to be inserted.
502        *  @return An iterator that points to the element with key of
503        *           @a __x (may or may not be the element passed in).
504        *
505        *  This function is not concerned about whether the insertion took place,
506        *  and thus does not return a boolean like the single-argument insert()
507        *  does.  Note that the first parameter is only a hint and can
508        *  potentially improve the performance of the insertion process.  A bad
509        *  hint would cause no gains in efficiency.
510        *
511        *  For more on @a hinting, see:
512        *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
513        *
514        *  Insertion requires logarithmic time (if the hint is not taken).
515        */
516       iterator
517       insert(const_iterator __position, const value_type& __x)
518       { return _M_t._M_insert_unique_(__position, __x); }
519 
520 #if __cplusplus >= 201103L
521       iterator
522       insert(const_iterator __position, value_type&& __x)
523       { return _M_t._M_insert_unique_(__position, std::move(__x)); }
524 #endif
525 
526       /**
527        *  @brief A template function that attempts to insert a range
528        *  of elements.
529        *  @param  __first  Iterator pointing to the start of the range to be
530        *                   inserted.
531        *  @param  __last  Iterator pointing to the end of the range.
532        *
533        *  Complexity similar to that of the range constructor.
534        */
535       template<typename _InputIterator>
536 	void
537 	insert(_InputIterator __first, _InputIterator __last)
538 	{ _M_t._M_insert_unique(__first, __last); }
539 
540 #if __cplusplus >= 201103L
541       /**
542        *  @brief Attempts to insert a list of elements into the %set.
543        *  @param  __l  A std::initializer_list<value_type> of elements
544        *               to be inserted.
545        *
546        *  Complexity similar to that of the range constructor.
547        */
548       void
549       insert(initializer_list<value_type> __l)
550       { this->insert(__l.begin(), __l.end()); }
551 #endif
552 
553 #if __cplusplus >= 201103L
554       // _GLIBCXX_RESOLVE_LIB_DEFECTS
555       // DR 130. Associative erase should return an iterator.
556       /**
557        *  @brief Erases an element from a %set.
558        *  @param  __position  An iterator pointing to the element to be erased.
559        *  @return An iterator pointing to the element immediately following
560        *          @a __position prior to the element being erased. If no such
561        *          element exists, end() is returned.
562        *
563        *  This function erases an element, pointed to by the given iterator,
564        *  from a %set.  Note that this function only erases the element, and
565        *  that if the element is itself a pointer, the pointed-to memory is not
566        *  touched in any way.  Managing the pointer is the user's
567        *  responsibility.
568        */
569       _GLIBCXX_ABI_TAG_CXX11
570       iterator
571       erase(const_iterator __position)
572       { return _M_t.erase(__position); }
573 #else
574       /**
575        *  @brief Erases an element from a %set.
576        *  @param  position  An iterator pointing to the element to be erased.
577        *
578        *  This function erases an element, pointed to by the given iterator,
579        *  from a %set.  Note that this function only erases the element, and
580        *  that if the element is itself a pointer, the pointed-to memory is not
581        *  touched in any way.  Managing the pointer is the user's
582        *  responsibility.
583        */
584       void
585       erase(iterator __position)
586       { _M_t.erase(__position); }
587 #endif
588 
589       /**
590        *  @brief Erases elements according to the provided key.
591        *  @param  __x  Key of element to be erased.
592        *  @return  The number of elements erased.
593        *
594        *  This function erases all the elements located by the given key from
595        *  a %set.
596        *  Note that this function only erases the element, and that if
597        *  the element is itself a pointer, the pointed-to memory is not touched
598        *  in any way.  Managing the pointer is the user's responsibility.
599        */
600       size_type
601       erase(const key_type& __x)
602       { return _M_t.erase(__x); }
603 
604 #if __cplusplus >= 201103L
605       // _GLIBCXX_RESOLVE_LIB_DEFECTS
606       // DR 130. Associative erase should return an iterator.
607       /**
608        *  @brief Erases a [__first,__last) range of elements from a %set.
609        *  @param  __first  Iterator pointing to the start of the range to be
610        *                 erased.
611 
612        *  @param __last Iterator pointing to the end of the range to
613        *  be erased.
614        *  @return The iterator @a __last.
615        *
616        *  This function erases a sequence of elements from a %set.
617        *  Note that this function only erases the element, and that if
618        *  the element is itself a pointer, the pointed-to memory is not touched
619        *  in any way.  Managing the pointer is the user's responsibility.
620        */
621       _GLIBCXX_ABI_TAG_CXX11
622       iterator
623       erase(const_iterator __first, const_iterator __last)
624       { return _M_t.erase(__first, __last); }
625 #else
626       /**
627        *  @brief Erases a [first,last) range of elements from a %set.
628        *  @param  __first  Iterator pointing to the start of the range to be
629        *                 erased.
630        *  @param __last Iterator pointing to the end of the range to
631        *  be erased.
632        *
633        *  This function erases a sequence of elements from a %set.
634        *  Note that this function only erases the element, and that if
635        *  the element is itself a pointer, the pointed-to memory is not touched
636        *  in any way.  Managing the pointer is the user's responsibility.
637        */
638       void
639       erase(iterator __first, iterator __last)
640       { _M_t.erase(__first, __last); }
641 #endif
642 
643       /**
644        *  Erases all elements in a %set.  Note that this function only erases
645        *  the elements, and that if the elements themselves are pointers, the
646        *  pointed-to memory is not touched in any way.  Managing the pointer is
647        *  the user's responsibility.
648        */
649       void
650       clear() _GLIBCXX_NOEXCEPT
651       { _M_t.clear(); }
652 
653       // set operations:
654 
655       //@{
656       /**
657        *  @brief  Finds the number of elements.
658        *  @param  __x  Element to located.
659        *  @return  Number of elements with specified key.
660        *
661        *  This function only makes sense for multisets; for set the result will
662        *  either be 0 (not present) or 1 (present).
663        */
664       size_type
665       count(const key_type& __x) const
666       { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
667 
668 #if __cplusplus > 201103L
669       template<typename _Kt>
670 	auto
671 	count(const _Kt& __x) const
672 	-> decltype(_M_t._M_count_tr(__x))
673 	{ return _M_t._M_count_tr(__x); }
674 #endif
675       //@}
676 
677       // _GLIBCXX_RESOLVE_LIB_DEFECTS
678       // 214.  set::find() missing const overload
679       //@{
680       /**
681        *  @brief Tries to locate an element in a %set.
682        *  @param  __x  Element to be located.
683        *  @return  Iterator pointing to sought-after element, or end() if not
684        *           found.
685        *
686        *  This function takes a key and tries to locate the element with which
687        *  the key matches.  If successful the function returns an iterator
688        *  pointing to the sought after element.  If unsuccessful it returns the
689        *  past-the-end ( @c end() ) iterator.
690        */
691       iterator
692       find(const key_type& __x)
693       { return _M_t.find(__x); }
694 
695       const_iterator
696       find(const key_type& __x) const
697       { return _M_t.find(__x); }
698 
699 #if __cplusplus > 201103L
700       template<typename _Kt>
701 	auto
702 	find(const _Kt& __x)
703 	-> decltype(iterator{_M_t._M_find_tr(__x)})
704 	{ return iterator{_M_t._M_find_tr(__x)}; }
705 
706       template<typename _Kt>
707 	auto
708 	find(const _Kt& __x) const
709 	-> decltype(const_iterator{_M_t._M_find_tr(__x)})
710 	{ return const_iterator{_M_t._M_find_tr(__x)}; }
711 #endif
712       //@}
713 
714       //@{
715       /**
716        *  @brief Finds the beginning of a subsequence matching given key.
717        *  @param  __x  Key to be located.
718        *  @return  Iterator pointing to first element equal to or greater
719        *           than key, or end().
720        *
721        *  This function returns the first element of a subsequence of elements
722        *  that matches the given key.  If unsuccessful it returns an iterator
723        *  pointing to the first element that has a greater value than given key
724        *  or end() if no such element exists.
725        */
726       iterator
727       lower_bound(const key_type& __x)
728       { return _M_t.lower_bound(__x); }
729 
730       const_iterator
731       lower_bound(const key_type& __x) const
732       { return _M_t.lower_bound(__x); }
733 
734 #if __cplusplus > 201103L
735       template<typename _Kt>
736 	auto
737 	lower_bound(const _Kt& __x)
738 	-> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
739 	{ return iterator(_M_t._M_lower_bound_tr(__x)); }
740 
741       template<typename _Kt>
742 	auto
743 	lower_bound(const _Kt& __x) const
744 	-> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
745 	{ return const_iterator(_M_t._M_lower_bound_tr(__x)); }
746 #endif
747       //@}
748 
749       //@{
750       /**
751        *  @brief Finds the end of a subsequence matching given key.
752        *  @param  __x  Key to be located.
753        *  @return Iterator pointing to the first element
754        *          greater than key, or end().
755        */
756       iterator
757       upper_bound(const key_type& __x)
758       { return _M_t.upper_bound(__x); }
759 
760       const_iterator
761       upper_bound(const key_type& __x) const
762       { return _M_t.upper_bound(__x); }
763 
764 #if __cplusplus > 201103L
765       template<typename _Kt>
766 	auto
767 	upper_bound(const _Kt& __x)
768 	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
769 	{ return iterator(_M_t._M_upper_bound_tr(__x)); }
770 
771       template<typename _Kt>
772 	auto
773 	upper_bound(const _Kt& __x) const
774 	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
775 	{ return const_iterator(_M_t._M_upper_bound_tr(__x)); }
776 #endif
777       //@}
778 
779       //@{
780       /**
781        *  @brief Finds a subsequence matching given key.
782        *  @param  __x  Key to be located.
783        *  @return  Pair of iterators that possibly points to the subsequence
784        *           matching given key.
785        *
786        *  This function is equivalent to
787        *  @code
788        *    std::make_pair(c.lower_bound(val),
789        *                   c.upper_bound(val))
790        *  @endcode
791        *  (but is faster than making the calls separately).
792        *
793        *  This function probably only makes sense for multisets.
794        */
795       std::pair<iterator, iterator>
796       equal_range(const key_type& __x)
797       { return _M_t.equal_range(__x); }
798 
799       std::pair<const_iterator, const_iterator>
800       equal_range(const key_type& __x) const
801       { return _M_t.equal_range(__x); }
802 
803 #if __cplusplus > 201103L
804       template<typename _Kt>
805 	auto
806 	equal_range(const _Kt& __x)
807 	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
808 	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
809 
810       template<typename _Kt>
811 	auto
812 	equal_range(const _Kt& __x) const
813 	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
814 	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
815 #endif
816       //@}
817 
818       template<typename _K1, typename _C1, typename _A1>
819 	friend bool
820 	operator==(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
821 
822       template<typename _K1, typename _C1, typename _A1>
823 	friend bool
824 	operator<(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
825     };
826 
827 
828   /**
829    *  @brief  Set equality comparison.
830    *  @param  __x  A %set.
831    *  @param  __y  A %set of the same type as @a x.
832    *  @return  True iff the size and elements of the sets are equal.
833    *
834    *  This is an equivalence relation.  It is linear in the size of the sets.
835    *  Sets are considered equivalent if their sizes are equal, and if
836    *  corresponding elements compare equal.
837   */
838   template<typename _Key, typename _Compare, typename _Alloc>
839     inline bool
840     operator==(const set<_Key, _Compare, _Alloc>& __x,
841 	       const set<_Key, _Compare, _Alloc>& __y)
842     { return __x._M_t == __y._M_t; }
843 
844   /**
845    *  @brief  Set ordering relation.
846    *  @param  __x  A %set.
847    *  @param  __y  A %set of the same type as @a x.
848    *  @return  True iff @a __x is lexicographically less than @a __y.
849    *
850    *  This is a total ordering relation.  It is linear in the size of the
851    *  sets.  The elements must be comparable with @c <.
852    *
853    *  See std::lexicographical_compare() for how the determination is made.
854   */
855   template<typename _Key, typename _Compare, typename _Alloc>
856     inline bool
857     operator<(const set<_Key, _Compare, _Alloc>& __x,
858 	      const set<_Key, _Compare, _Alloc>& __y)
859     { return __x._M_t < __y._M_t; }
860 
861   ///  Returns !(x == y).
862   template<typename _Key, typename _Compare, typename _Alloc>
863     inline bool
864     operator!=(const set<_Key, _Compare, _Alloc>& __x,
865 	       const set<_Key, _Compare, _Alloc>& __y)
866     { return !(__x == __y); }
867 
868   ///  Returns y < x.
869   template<typename _Key, typename _Compare, typename _Alloc>
870     inline bool
871     operator>(const set<_Key, _Compare, _Alloc>& __x,
872 	      const set<_Key, _Compare, _Alloc>& __y)
873     { return __y < __x; }
874 
875   ///  Returns !(y < x)
876   template<typename _Key, typename _Compare, typename _Alloc>
877     inline bool
878     operator<=(const set<_Key, _Compare, _Alloc>& __x,
879 	       const set<_Key, _Compare, _Alloc>& __y)
880     { return !(__y < __x); }
881 
882   ///  Returns !(x < y)
883   template<typename _Key, typename _Compare, typename _Alloc>
884     inline bool
885     operator>=(const set<_Key, _Compare, _Alloc>& __x,
886 	       const set<_Key, _Compare, _Alloc>& __y)
887     { return !(__x < __y); }
888 
889   /// See std::set::swap().
890   template<typename _Key, typename _Compare, typename _Alloc>
891     inline void
892     swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>& __y)
893     _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
894     { __x.swap(__y); }
895 
896 _GLIBCXX_END_NAMESPACE_CONTAINER
897 } //namespace std
898 #endif /* _STL_SET_H */
899