libstdc++
stl_set.h
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1 // Set implementation -*- C++ -*-
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25 /*
26  *
27  * Copyright (c) 1994
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41  *
42  * Permission to use, copy, modify, distribute and sell this software
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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_VERSION
67 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
68 
69  template<typename _Key, typename _Compare, typename _Alloc>
70  class multiset;
71 
72  /**
73  * @brief A standard container made up of unique keys, which can be
74  * retrieved in logarithmic time.
75  *
76  * @ingroup associative_containers
77  *
78  * @tparam _Key Type of key objects.
79  * @tparam _Compare Comparison function object type, defaults to less<_Key>.
80  * @tparam _Alloc Allocator type, defaults to allocator<_Key>.
81  *
82  * Meets the requirements of a <a href="tables.html#65">container</a>, a
83  * <a href="tables.html#66">reversible container</a>, and an
84  * <a href="tables.html#69">associative container</a> (using unique keys).
85  *
86  * Sets support bidirectional iterators.
87  *
88  * The private tree data is declared exactly the same way for set and
89  * multiset; the distinction is made entirely in how the tree functions are
90  * called (*_unique versus *_equal, same as the standard).
91  */
92  template<typename _Key, typename _Compare = std::less<_Key>,
93  typename _Alloc = std::allocator<_Key> >
94  class set
95  {
96 #ifdef _GLIBCXX_CONCEPT_CHECKS
97  // concept requirements
98  typedef typename _Alloc::value_type _Alloc_value_type;
99 # if __cplusplus < 201103L
100  __glibcxx_class_requires(_Key, _SGIAssignableConcept)
101 # endif
102  __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
103  _BinaryFunctionConcept)
104  __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
105 #endif
106 
107 #if __cplusplus >= 201103L
108  static_assert(is_same<typename remove_cv<_Key>::type, _Key>::value,
109  "std::set must have a non-const, non-volatile value_type");
110 # if __cplusplus > 201703L || defined __STRICT_ANSI__
112  "std::set must have the same value_type as its allocator");
113 # endif
114 #endif
115 
116  public:
117  // typedefs:
118  ///@{
119  /// Public typedefs.
120  typedef _Key key_type;
121  typedef _Key value_type;
122  typedef _Compare key_compare;
123  typedef _Compare value_compare;
124  typedef _Alloc allocator_type;
125  ///@}
126 
127  private:
129  rebind<_Key>::other _Key_alloc_type;
130 
131  typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
132  key_compare, _Key_alloc_type> _Rep_type;
133  _Rep_type _M_t; // Red-black tree representing set.
134 
136 
137  public:
138  ///@{
139  /// Iterator-related typedefs.
140  typedef typename _Alloc_traits::pointer pointer;
141  typedef typename _Alloc_traits::const_pointer const_pointer;
142  typedef typename _Alloc_traits::reference reference;
143  typedef typename _Alloc_traits::const_reference const_reference;
144  // _GLIBCXX_RESOLVE_LIB_DEFECTS
145  // DR 103. set::iterator is required to be modifiable,
146  // but this allows modification of keys.
147  typedef typename _Rep_type::const_iterator iterator;
148  typedef typename _Rep_type::const_iterator const_iterator;
151  typedef typename _Rep_type::size_type size_type;
152  typedef typename _Rep_type::difference_type difference_type;
153  ///@}
154 
155 #if __cplusplus > 201402L
156  using node_type = typename _Rep_type::node_type;
157  using insert_return_type = typename _Rep_type::insert_return_type;
158 #endif
159 
160  // allocation/deallocation
161  /**
162  * @brief Default constructor creates no elements.
163  */
164 #if __cplusplus < 201103L
165  set() : _M_t() { }
166 #else
167  set() = default;
168 #endif
169 
170  /**
171  * @brief Creates a %set with no elements.
172  * @param __comp Comparator to use.
173  * @param __a An allocator object.
174  */
175  explicit
176  set(const _Compare& __comp,
177  const allocator_type& __a = allocator_type())
178  : _M_t(__comp, _Key_alloc_type(__a)) { }
179 
180  /**
181  * @brief Builds a %set from a range.
182  * @param __first An input iterator.
183  * @param __last An input iterator.
184  *
185  * Create a %set consisting of copies of the elements from
186  * [__first,__last). This is linear in N if the range is
187  * already sorted, and NlogN otherwise (where N is
188  * distance(__first,__last)).
189  */
190  template<typename _InputIterator>
191  set(_InputIterator __first, _InputIterator __last)
192  : _M_t()
193  { _M_t._M_insert_range_unique(__first, __last); }
194 
195  /**
196  * @brief Builds a %set from a range.
197  * @param __first An input iterator.
198  * @param __last An input iterator.
199  * @param __comp A comparison functor.
200  * @param __a An allocator object.
201  *
202  * Create a %set consisting of copies of the elements from
203  * [__first,__last). This is linear in N if the range is
204  * already sorted, and NlogN otherwise (where N is
205  * distance(__first,__last)).
206  */
207  template<typename _InputIterator>
208  set(_InputIterator __first, _InputIterator __last,
209  const _Compare& __comp,
210  const allocator_type& __a = allocator_type())
211  : _M_t(__comp, _Key_alloc_type(__a))
212  { _M_t._M_insert_range_unique(__first, __last); }
213 
214  /**
215  * @brief %Set copy constructor.
216  *
217  * Whether the allocator is copied depends on the allocator traits.
218  */
219 #if __cplusplus < 201103L
220  set(const set& __x)
221  : _M_t(__x._M_t) { }
222 #else
223  set(const set&) = default;
224 
225  /**
226  * @brief %Set move constructor
227  *
228  * The newly-created %set contains the exact contents of the moved
229  * instance. The moved instance is a valid, but unspecified, %set.
230  */
231  set(set&&) = default;
232 
233  /**
234  * @brief Builds a %set from an initializer_list.
235  * @param __l An initializer_list.
236  * @param __comp A comparison functor.
237  * @param __a An allocator object.
238  *
239  * Create a %set consisting of copies of the elements in the list.
240  * This is linear in N if the list is already sorted, and NlogN
241  * otherwise (where N is @a __l.size()).
242  */
244  const _Compare& __comp = _Compare(),
245  const allocator_type& __a = allocator_type())
246  : _M_t(__comp, _Key_alloc_type(__a))
247  { _M_t._M_insert_range_unique(__l.begin(), __l.end()); }
248 
249  /// Allocator-extended default constructor.
250  explicit
251  set(const allocator_type& __a)
252  : _M_t(_Key_alloc_type(__a)) { }
253 
254  /// Allocator-extended copy constructor.
255  set(const set& __x, const allocator_type& __a)
256  : _M_t(__x._M_t, _Key_alloc_type(__a)) { }
257 
258  /// Allocator-extended move constructor.
259  set(set&& __x, const allocator_type& __a)
261  && _Alloc_traits::_S_always_equal())
262  : _M_t(std::move(__x._M_t), _Key_alloc_type(__a)) { }
263 
264  /// Allocator-extended initialier-list constructor.
266  : _M_t(_Key_alloc_type(__a))
267  { _M_t._M_insert_range_unique(__l.begin(), __l.end()); }
268 
269  /// Allocator-extended range constructor.
270  template<typename _InputIterator>
271  set(_InputIterator __first, _InputIterator __last,
272  const allocator_type& __a)
273  : _M_t(_Key_alloc_type(__a))
274  { _M_t._M_insert_range_unique(__first, __last); }
275 
276  /**
277  * The dtor only erases the elements, and note that if the elements
278  * themselves are pointers, the pointed-to memory is not touched in any
279  * way. Managing the pointer is the user's responsibility.
280  */
281  ~set() = default;
282 #endif
283 
284  /**
285  * @brief %Set assignment operator.
286  *
287  * Whether the allocator is copied depends on the allocator traits.
288  */
289 #if __cplusplus < 201103L
290  set&
291  operator=(const set& __x)
292  {
293  _M_t = __x._M_t;
294  return *this;
295  }
296 #else
297  set&
298  operator=(const set&) = default;
299 
300  /// Move assignment operator.
301  set&
302  operator=(set&&) = default;
303 
304  /**
305  * @brief %Set list assignment operator.
306  * @param __l An initializer_list.
307  *
308  * This function fills a %set with copies of the elements in the
309  * initializer list @a __l.
310  *
311  * Note that the assignment completely changes the %set and
312  * that the resulting %set's size is the same as the number
313  * of elements assigned.
314  */
315  set&
317  {
318  _M_t._M_assign_unique(__l.begin(), __l.end());
319  return *this;
320  }
321 #endif
322 
323  // accessors:
324 
325  /// Returns the comparison object with which the %set was constructed.
327  key_comp() const
328  { return _M_t.key_comp(); }
329  /// Returns the comparison object with which the %set was constructed.
331  value_comp() const
332  { return _M_t.key_comp(); }
333  /// Returns the allocator object with which the %set was constructed.
335  get_allocator() const _GLIBCXX_NOEXCEPT
336  { return allocator_type(_M_t.get_allocator()); }
337 
338  /**
339  * Returns a read-only (constant) iterator that points to the first
340  * element in the %set. Iteration is done in ascending order according
341  * to the keys.
342  */
343  iterator
344  begin() const _GLIBCXX_NOEXCEPT
345  { return _M_t.begin(); }
346 
347  /**
348  * Returns a read-only (constant) iterator that points one past the last
349  * element in the %set. Iteration is done in ascending order according
350  * to the keys.
351  */
352  iterator
353  end() const _GLIBCXX_NOEXCEPT
354  { return _M_t.end(); }
355 
356  /**
357  * Returns a read-only (constant) iterator that points to the last
358  * element in the %set. Iteration is done in descending order according
359  * to the keys.
360  */
362  rbegin() const _GLIBCXX_NOEXCEPT
363  { return _M_t.rbegin(); }
364 
365  /**
366  * Returns a read-only (constant) reverse iterator that points to the
367  * last pair in the %set. Iteration is done in descending order
368  * according to the keys.
369  */
371  rend() const _GLIBCXX_NOEXCEPT
372  { return _M_t.rend(); }
373 
374 #if __cplusplus >= 201103L
375  /**
376  * Returns a read-only (constant) iterator that points to the first
377  * element in the %set. Iteration is done in ascending order according
378  * to the keys.
379  */
380  iterator
381  cbegin() const noexcept
382  { return _M_t.begin(); }
383 
384  /**
385  * Returns a read-only (constant) iterator that points one past the last
386  * element in the %set. Iteration is done in ascending order according
387  * to the keys.
388  */
389  iterator
390  cend() const noexcept
391  { return _M_t.end(); }
392 
393  /**
394  * Returns a read-only (constant) iterator that points to the last
395  * element in the %set. Iteration is done in descending order according
396  * to the keys.
397  */
399  crbegin() const noexcept
400  { return _M_t.rbegin(); }
401 
402  /**
403  * Returns a read-only (constant) reverse iterator that points to the
404  * last pair in the %set. Iteration is done in descending order
405  * according to the keys.
406  */
408  crend() const noexcept
409  { return _M_t.rend(); }
410 #endif
411 
412  /// Returns true if the %set is empty.
413  _GLIBCXX_NODISCARD bool
414  empty() const _GLIBCXX_NOEXCEPT
415  { return _M_t.empty(); }
416 
417  /// Returns the size of the %set.
418  size_type
419  size() const _GLIBCXX_NOEXCEPT
420  { return _M_t.size(); }
421 
422  /// Returns the maximum size of the %set.
423  size_type
424  max_size() const _GLIBCXX_NOEXCEPT
425  { return _M_t.max_size(); }
426 
427  /**
428  * @brief Swaps data with another %set.
429  * @param __x A %set of the same element and allocator types.
430  *
431  * This exchanges the elements between two sets in constant
432  * time. (It is only swapping a pointer, an integer, and an
433  * instance of the @c Compare type (which itself is often
434  * stateless and empty), so it should be quite fast.) Note
435  * that the global std::swap() function is specialized such
436  * that std::swap(s1,s2) will feed to this function.
437  *
438  * Whether the allocators are swapped depends on the allocator traits.
439  */
440  void
441  swap(set& __x)
442  _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
443  { _M_t.swap(__x._M_t); }
444 
445  // insert/erase
446 #if __cplusplus >= 201103L
447  /**
448  * @brief Attempts to build and insert an element into the %set.
449  * @param __args Arguments used to generate an element.
450  * @return A pair, of which the first element is an iterator that points
451  * to the possibly inserted element, and the second is a bool
452  * that is true if the element was actually inserted.
453  *
454  * This function attempts to build and insert an element into the %set.
455  * A %set relies on unique keys and thus an element is only inserted if
456  * it is not already present in the %set.
457  *
458  * Insertion requires logarithmic time.
459  */
460  template<typename... _Args>
462  emplace(_Args&&... __args)
463  { return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); }
464 
465  /**
466  * @brief Attempts to insert an element into the %set.
467  * @param __pos An iterator that serves as a hint as to where the
468  * element should be inserted.
469  * @param __args Arguments used to generate the element to be
470  * inserted.
471  * @return An iterator that points to the element with key equivalent to
472  * the one generated from @a __args (may or may not be the
473  * element itself).
474  *
475  * This function is not concerned about whether the insertion took place,
476  * and thus does not return a boolean like the single-argument emplace()
477  * does. Note that the first parameter is only a hint and can
478  * potentially improve the performance of the insertion process. A bad
479  * hint would cause no gains in efficiency.
480  *
481  * For more on @a hinting, see:
482  * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
483  *
484  * Insertion requires logarithmic time (if the hint is not taken).
485  */
486  template<typename... _Args>
487  iterator
488  emplace_hint(const_iterator __pos, _Args&&... __args)
489  {
490  return _M_t._M_emplace_hint_unique(__pos,
491  std::forward<_Args>(__args)...);
492  }
493 #endif
494 
495  /**
496  * @brief Attempts to insert an element into the %set.
497  * @param __x Element to be inserted.
498  * @return A pair, of which the first element is an iterator that points
499  * to the possibly inserted element, and the second is a bool
500  * that is true if the element was actually inserted.
501  *
502  * This function attempts to insert an element into the %set. A %set
503  * relies on unique keys and thus an element is only inserted if it is
504  * not already present in the %set.
505  *
506  * Insertion requires logarithmic time.
507  */
509  insert(const value_type& __x)
510  {
512  _M_t._M_insert_unique(__x);
513  return std::pair<iterator, bool>(__p.first, __p.second);
514  }
515 
516 #if __cplusplus >= 201103L
518  insert(value_type&& __x)
519  {
521  _M_t._M_insert_unique(std::move(__x));
522  return std::pair<iterator, bool>(__p.first, __p.second);
523  }
524 #endif
525 
526  /**
527  * @brief Attempts to insert an element into the %set.
528  * @param __position An iterator that serves as a hint as to where the
529  * element should be inserted.
530  * @param __x Element to be inserted.
531  * @return An iterator that points to the element with key of
532  * @a __x (may or may not be the element passed in).
533  *
534  * This function is not concerned about whether the insertion took place,
535  * and thus does not return a boolean like the single-argument insert()
536  * does. Note that the first parameter is only a hint and can
537  * potentially improve the performance of the insertion process. A bad
538  * hint would cause no gains in efficiency.
539  *
540  * For more on @a hinting, see:
541  * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
542  *
543  * Insertion requires logarithmic time (if the hint is not taken).
544  */
545  iterator
546  insert(const_iterator __position, const value_type& __x)
547  { return _M_t._M_insert_unique_(__position, __x); }
548 
549 #if __cplusplus >= 201103L
550  iterator
551  insert(const_iterator __position, value_type&& __x)
552  { return _M_t._M_insert_unique_(__position, std::move(__x)); }
553 #endif
554 
555  /**
556  * @brief A template function that attempts to insert a range
557  * of elements.
558  * @param __first Iterator pointing to the start of the range to be
559  * inserted.
560  * @param __last Iterator pointing to the end of the range.
561  *
562  * Complexity similar to that of the range constructor.
563  */
564  template<typename _InputIterator>
565  void
566  insert(_InputIterator __first, _InputIterator __last)
567  { _M_t._M_insert_range_unique(__first, __last); }
568 
569 #if __cplusplus >= 201103L
570  /**
571  * @brief Attempts to insert a list of elements into the %set.
572  * @param __l A std::initializer_list<value_type> of elements
573  * to be inserted.
574  *
575  * Complexity similar to that of the range constructor.
576  */
577  void
579  { this->insert(__l.begin(), __l.end()); }
580 #endif
581 
582 #if __cplusplus > 201402L
583  /// Extract a node.
584  node_type
586  {
587  __glibcxx_assert(__pos != end());
588  return _M_t.extract(__pos);
589  }
590 
591  /// Extract a node.
592  node_type
593  extract(const key_type& __x)
594  { return _M_t.extract(__x); }
595 
596  /// Re-insert an extracted node.
597  insert_return_type
598  insert(node_type&& __nh)
599  { return _M_t._M_reinsert_node_unique(std::move(__nh)); }
600 
601  /// Re-insert an extracted node.
602  iterator
603  insert(const_iterator __hint, node_type&& __nh)
604  { return _M_t._M_reinsert_node_hint_unique(__hint, std::move(__nh)); }
605 
606  template<typename, typename>
607  friend struct std::_Rb_tree_merge_helper;
608 
609  template<typename _Compare1>
610  void
611  merge(set<_Key, _Compare1, _Alloc>& __source)
612  {
613  using _Merge_helper = _Rb_tree_merge_helper<set, _Compare1>;
614  _M_t._M_merge_unique(_Merge_helper::_S_get_tree(__source));
615  }
616 
617  template<typename _Compare1>
618  void
619  merge(set<_Key, _Compare1, _Alloc>&& __source)
620  { merge(__source); }
621 
622  template<typename _Compare1>
623  void
624  merge(multiset<_Key, _Compare1, _Alloc>& __source)
625  {
626  using _Merge_helper = _Rb_tree_merge_helper<set, _Compare1>;
627  _M_t._M_merge_unique(_Merge_helper::_S_get_tree(__source));
628  }
629 
630  template<typename _Compare1>
631  void
632  merge(multiset<_Key, _Compare1, _Alloc>&& __source)
633  { merge(__source); }
634 #endif // C++17
635 
636 #if __cplusplus >= 201103L
637  // _GLIBCXX_RESOLVE_LIB_DEFECTS
638  // DR 130. Associative erase should return an iterator.
639  /**
640  * @brief Erases an element from a %set.
641  * @param __position An iterator pointing to the element to be erased.
642  * @return An iterator pointing to the element immediately following
643  * @a __position prior to the element being erased. If no such
644  * element exists, end() is returned.
645  *
646  * This function erases an element, pointed to by the given iterator,
647  * from a %set. Note that this function only erases the element, and
648  * that if the element is itself a pointer, the pointed-to memory is not
649  * touched in any way. Managing the pointer is the user's
650  * responsibility.
651  */
652  _GLIBCXX_ABI_TAG_CXX11
653  iterator
654  erase(const_iterator __position)
655  { return _M_t.erase(__position); }
656 #else
657  /**
658  * @brief Erases an element from a %set.
659  * @param position An iterator pointing to the element to be erased.
660  *
661  * This function erases an element, pointed to by the given iterator,
662  * from a %set. Note that this function only erases the element, and
663  * that if the element is itself a pointer, the pointed-to memory is not
664  * touched in any way. Managing the pointer is the user's
665  * responsibility.
666  */
667  void
668  erase(iterator __position)
669  { _M_t.erase(__position); }
670 #endif
671 
672  /**
673  * @brief Erases elements according to the provided key.
674  * @param __x Key of element to be erased.
675  * @return The number of elements erased.
676  *
677  * This function erases all the elements located by the given key from
678  * a %set.
679  * Note that this function only erases the element, and that if
680  * the element is itself a pointer, the pointed-to memory is not touched
681  * in any way. Managing the pointer is the user's responsibility.
682  */
683  size_type
684  erase(const key_type& __x)
685  { return _M_t.erase(__x); }
686 
687 #if __cplusplus >= 201103L
688  // _GLIBCXX_RESOLVE_LIB_DEFECTS
689  // DR 130. Associative erase should return an iterator.
690  /**
691  * @brief Erases a [__first,__last) range of elements from a %set.
692  * @param __first Iterator pointing to the start of the range to be
693  * erased.
694 
695  * @param __last Iterator pointing to the end of the range to
696  * be erased.
697  * @return The iterator @a __last.
698  *
699  * This function erases a sequence of elements from a %set.
700  * Note that this function only erases the element, and that if
701  * the element is itself a pointer, the pointed-to memory is not touched
702  * in any way. Managing the pointer is the user's responsibility.
703  */
704  _GLIBCXX_ABI_TAG_CXX11
705  iterator
707  { return _M_t.erase(__first, __last); }
708 #else
709  /**
710  * @brief Erases a [first,last) range of elements from a %set.
711  * @param __first Iterator pointing to the start of the range to be
712  * erased.
713  * @param __last Iterator pointing to the end of the range to
714  * be erased.
715  *
716  * This function erases a sequence of elements from a %set.
717  * Note that this function only erases the element, and that if
718  * the element is itself a pointer, the pointed-to memory is not touched
719  * in any way. Managing the pointer is the user's responsibility.
720  */
721  void
722  erase(iterator __first, iterator __last)
723  { _M_t.erase(__first, __last); }
724 #endif
725 
726  /**
727  * Erases all elements in a %set. Note that this function only erases
728  * the elements, and that if the elements themselves are pointers, the
729  * pointed-to memory is not touched in any way. Managing the pointer is
730  * the user's responsibility.
731  */
732  void
733  clear() _GLIBCXX_NOEXCEPT
734  { _M_t.clear(); }
735 
736  // set operations:
737 
738  ///@{
739  /**
740  * @brief Finds the number of elements.
741  * @param __x Element to located.
742  * @return Number of elements with specified key.
743  *
744  * This function only makes sense for multisets; for set the result will
745  * either be 0 (not present) or 1 (present).
746  */
747  size_type
748  count(const key_type& __x) const
749  { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
750 
751 #if __cplusplus > 201103L
752  template<typename _Kt>
753  auto
754  count(const _Kt& __x) const
755  -> decltype(_M_t._M_count_tr(__x))
756  { return _M_t._M_count_tr(__x); }
757 #endif
758  ///@}
759 
760 #if __cplusplus > 201703L
761  ///@{
762  /**
763  * @brief Finds whether an element with the given key exists.
764  * @param __x Key of elements to be located.
765  * @return True if there is an element with the specified key.
766  */
767  bool
768  contains(const key_type& __x) const
769  { return _M_t.find(__x) != _M_t.end(); }
770 
771  template<typename _Kt>
772  auto
773  contains(const _Kt& __x) const
774  -> decltype(_M_t._M_find_tr(__x), void(), true)
775  { return _M_t._M_find_tr(__x) != _M_t.end(); }
776  ///@}
777 #endif
778 
779  // _GLIBCXX_RESOLVE_LIB_DEFECTS
780  // 214. set::find() missing const overload
781  ///@{
782  /**
783  * @brief Tries to locate an element in a %set.
784  * @param __x Element to be located.
785  * @return Iterator pointing to sought-after element, or end() if not
786  * found.
787  *
788  * This function takes a key and tries to locate the element with which
789  * the key matches. If successful the function returns an iterator
790  * pointing to the sought after element. If unsuccessful it returns the
791  * past-the-end ( @c end() ) iterator.
792  */
793  iterator
794  find(const key_type& __x)
795  { return _M_t.find(__x); }
796 
798  find(const key_type& __x) const
799  { return _M_t.find(__x); }
800 
801 #if __cplusplus > 201103L
802  template<typename _Kt>
803  auto
804  find(const _Kt& __x)
805  -> decltype(iterator{_M_t._M_find_tr(__x)})
806  { return iterator{_M_t._M_find_tr(__x)}; }
807 
808  template<typename _Kt>
809  auto
810  find(const _Kt& __x) const
811  -> decltype(const_iterator{_M_t._M_find_tr(__x)})
812  { return const_iterator{_M_t._M_find_tr(__x)}; }
813 #endif
814  ///@}
815 
816  ///@{
817  /**
818  * @brief Finds the beginning of a subsequence matching given key.
819  * @param __x Key to be located.
820  * @return Iterator pointing to first element equal to or greater
821  * than key, or end().
822  *
823  * This function returns the first element of a subsequence of elements
824  * that matches the given key. If unsuccessful it returns an iterator
825  * pointing to the first element that has a greater value than given key
826  * or end() if no such element exists.
827  */
828  iterator
829  lower_bound(const key_type& __x)
830  { return _M_t.lower_bound(__x); }
831 
833  lower_bound(const key_type& __x) const
834  { return _M_t.lower_bound(__x); }
835 
836 #if __cplusplus > 201103L
837  template<typename _Kt>
838  auto
839  lower_bound(const _Kt& __x)
840  -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
841  { return iterator(_M_t._M_lower_bound_tr(__x)); }
842 
843  template<typename _Kt>
844  auto
845  lower_bound(const _Kt& __x) const
846  -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
847  { return const_iterator(_M_t._M_lower_bound_tr(__x)); }
848 #endif
849  ///@}
850 
851  ///@{
852  /**
853  * @brief Finds the end of a subsequence matching given key.
854  * @param __x Key to be located.
855  * @return Iterator pointing to the first element
856  * greater than key, or end().
857  */
858  iterator
859  upper_bound(const key_type& __x)
860  { return _M_t.upper_bound(__x); }
861 
863  upper_bound(const key_type& __x) const
864  { return _M_t.upper_bound(__x); }
865 
866 #if __cplusplus > 201103L
867  template<typename _Kt>
868  auto
869  upper_bound(const _Kt& __x)
870  -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
871  { return iterator(_M_t._M_upper_bound_tr(__x)); }
872 
873  template<typename _Kt>
874  auto
875  upper_bound(const _Kt& __x) const
876  -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
877  { return const_iterator(_M_t._M_upper_bound_tr(__x)); }
878 #endif
879  ///@}
880 
881  ///@{
882  /**
883  * @brief Finds a subsequence matching given key.
884  * @param __x Key to be located.
885  * @return Pair of iterators that possibly points to the subsequence
886  * matching given key.
887  *
888  * This function is equivalent to
889  * @code
890  * std::make_pair(c.lower_bound(val),
891  * c.upper_bound(val))
892  * @endcode
893  * (but is faster than making the calls separately).
894  *
895  * This function probably only makes sense for multisets.
896  */
898  equal_range(const key_type& __x)
899  { return _M_t.equal_range(__x); }
900 
902  equal_range(const key_type& __x) const
903  { return _M_t.equal_range(__x); }
904 
905 #if __cplusplus > 201103L
906  template<typename _Kt>
907  auto
908  equal_range(const _Kt& __x)
909  -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
910  { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
911 
912  template<typename _Kt>
913  auto
914  equal_range(const _Kt& __x) const
915  -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
916  { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
917 #endif
918  ///@}
919 
920  template<typename _K1, typename _C1, typename _A1>
921  friend bool
922  operator==(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
923 
924 #if __cpp_lib_three_way_comparison
925  template<typename _K1, typename _C1, typename _A1>
926  friend __detail::__synth3way_t<_K1>
927  operator<=>(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
928 #else
929  template<typename _K1, typename _C1, typename _A1>
930  friend bool
931  operator<(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
932 #endif
933  };
934 
935 #if __cpp_deduction_guides >= 201606
936 
937  template<typename _InputIterator,
938  typename _Compare =
939  less<typename iterator_traits<_InputIterator>::value_type>,
940  typename _Allocator =
941  allocator<typename iterator_traits<_InputIterator>::value_type>,
942  typename = _RequireInputIter<_InputIterator>,
943  typename = _RequireNotAllocator<_Compare>,
944  typename = _RequireAllocator<_Allocator>>
945  set(_InputIterator, _InputIterator,
946  _Compare = _Compare(), _Allocator = _Allocator())
948  _Compare, _Allocator>;
949 
950  template<typename _Key, typename _Compare = less<_Key>,
951  typename _Allocator = allocator<_Key>,
952  typename = _RequireNotAllocator<_Compare>,
953  typename = _RequireAllocator<_Allocator>>
954  set(initializer_list<_Key>,
955  _Compare = _Compare(), _Allocator = _Allocator())
956  -> set<_Key, _Compare, _Allocator>;
957 
958  template<typename _InputIterator, typename _Allocator,
959  typename = _RequireInputIter<_InputIterator>,
960  typename = _RequireAllocator<_Allocator>>
961  set(_InputIterator, _InputIterator, _Allocator)
963  less<typename iterator_traits<_InputIterator>::value_type>,
964  _Allocator>;
965 
966  template<typename _Key, typename _Allocator,
967  typename = _RequireAllocator<_Allocator>>
968  set(initializer_list<_Key>, _Allocator)
969  -> set<_Key, less<_Key>, _Allocator>;
970 
971 #endif // deduction guides
972 
973  /**
974  * @brief Set equality comparison.
975  * @param __x A %set.
976  * @param __y A %set of the same type as @a x.
977  * @return True iff the size and elements of the sets are equal.
978  *
979  * This is an equivalence relation. It is linear in the size of the sets.
980  * Sets are considered equivalent if their sizes are equal, and if
981  * corresponding elements compare equal.
982  */
983  template<typename _Key, typename _Compare, typename _Alloc>
984  inline bool
985  operator==(const set<_Key, _Compare, _Alloc>& __x,
986  const set<_Key, _Compare, _Alloc>& __y)
987  { return __x._M_t == __y._M_t; }
988 
989 #if __cpp_lib_three_way_comparison
990  /**
991  * @brief Set ordering relation.
992  * @param __x A `set`.
993  * @param __y A `set` of the same type as `x`.
994  * @return A value indicating whether `__x` is less than, equal to,
995  * greater than, or incomparable with `__y`.
996  *
997  * This is a total ordering relation. It is linear in the size of the
998  * maps. The elements must be comparable with @c <.
999  *
1000  * See `std::lexicographical_compare_three_way()` for how the determination
1001  * is made. This operator is used to synthesize relational operators like
1002  * `<` and `>=` etc.
1003  */
1004  template<typename _Key, typename _Compare, typename _Alloc>
1005  inline __detail::__synth3way_t<_Key>
1006  operator<=>(const set<_Key, _Compare, _Alloc>& __x,
1007  const set<_Key, _Compare, _Alloc>& __y)
1008  { return __x._M_t <=> __y._M_t; }
1009 #else
1010  /**
1011  * @brief Set ordering relation.
1012  * @param __x A %set.
1013  * @param __y A %set of the same type as @a x.
1014  * @return True iff @a __x is lexicographically less than @a __y.
1015  *
1016  * This is a total ordering relation. It is linear in the size of the
1017  * sets. The elements must be comparable with @c <.
1018  *
1019  * See std::lexicographical_compare() for how the determination is made.
1020  */
1021  template<typename _Key, typename _Compare, typename _Alloc>
1022  inline bool
1023  operator<(const set<_Key, _Compare, _Alloc>& __x,
1024  const set<_Key, _Compare, _Alloc>& __y)
1025  { return __x._M_t < __y._M_t; }
1026 
1027  /// Returns !(x == y).
1028  template<typename _Key, typename _Compare, typename _Alloc>
1029  inline bool
1030  operator!=(const set<_Key, _Compare, _Alloc>& __x,
1031  const set<_Key, _Compare, _Alloc>& __y)
1032  { return !(__x == __y); }
1033 
1034  /// Returns y < x.
1035  template<typename _Key, typename _Compare, typename _Alloc>
1036  inline bool
1037  operator>(const set<_Key, _Compare, _Alloc>& __x,
1038  const set<_Key, _Compare, _Alloc>& __y)
1039  { return __y < __x; }
1040 
1041  /// Returns !(y < x)
1042  template<typename _Key, typename _Compare, typename _Alloc>
1043  inline bool
1044  operator<=(const set<_Key, _Compare, _Alloc>& __x,
1045  const set<_Key, _Compare, _Alloc>& __y)
1046  { return !(__y < __x); }
1047 
1048  /// Returns !(x < y)
1049  template<typename _Key, typename _Compare, typename _Alloc>
1050  inline bool
1051  operator>=(const set<_Key, _Compare, _Alloc>& __x,
1052  const set<_Key, _Compare, _Alloc>& __y)
1053  { return !(__x < __y); }
1054 #endif // three-way comparison
1055 
1056  /// See std::set::swap().
1057  template<typename _Key, typename _Compare, typename _Alloc>
1058  inline void
1060  _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
1061  { __x.swap(__y); }
1062 
1063 _GLIBCXX_END_NAMESPACE_CONTAINER
1064 
1065 #if __cplusplus > 201402L
1066  // Allow std::set access to internals of compatible sets.
1067  template<typename _Val, typename _Cmp1, typename _Alloc, typename _Cmp2>
1068  struct
1069  _Rb_tree_merge_helper<_GLIBCXX_STD_C::set<_Val, _Cmp1, _Alloc>, _Cmp2>
1070  {
1071  private:
1072  friend class _GLIBCXX_STD_C::set<_Val, _Cmp1, _Alloc>;
1073 
1074  static auto&
1075  _S_get_tree(_GLIBCXX_STD_C::set<_Val, _Cmp2, _Alloc>& __set)
1076  { return __set._M_t; }
1077 
1078  static auto&
1079  _S_get_tree(_GLIBCXX_STD_C::multiset<_Val, _Cmp2, _Alloc>& __set)
1080  { return __set._M_t; }
1081  };
1082 #endif // C++17
1083 
1084 _GLIBCXX_END_NAMESPACE_VERSION
1085 } //namespace std
1086 #endif /* _STL_SET_H */
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition: move.h:104
void swap(any &__x, any &__y) noexcept
Exchange the states of two any objects.
Definition: any:422
ISO C++ entities toplevel namespace is std.
initializer_list
is_same
Definition: type_traits:1410
is_nothrow_copy_constructible
Definition: type_traits:1056
Node handle type for maps.
Definition: node_handle.h:222
Return type of insert(node_handle&&) on unique maps/sets.
Definition: node_handle.h:364
Common iterator class.
A standard container made up of unique keys, which can be retrieved in logarithmic time.
Definition: stl_set.h:95
set(const set &__x, const allocator_type &__a)
Allocator-extended copy constructor.
Definition: stl_set.h:255
set(_InputIterator __first, _InputIterator __last, const _Compare &__comp, const allocator_type &__a=allocator_type())
Builds a set from a range.
Definition: stl_set.h:208
size_type count(const key_type &__x) const
Finds the number of elements.
Definition: stl_set.h:748
_Rep_type::difference_type difference_type
Iterator-related typedefs.
Definition: stl_set.h:152
node_type extract(const_iterator __pos)
Extract a node.
Definition: stl_set.h:585
_GLIBCXX_ABI_TAG_CXX11 iterator erase(const_iterator __position)
Erases an element from a set.
Definition: stl_set.h:654
set(set &&)=default
Set move constructor
void swap(set &__x) noexcept(/*conditional */)
Swaps data with another set.
Definition: stl_set.h:441
_Compare value_compare
Public typedefs.
Definition: stl_set.h:123
value_compare value_comp() const
Returns the comparison object with which the set was constructed.
Definition: stl_set.h:331
iterator cbegin() const noexcept
Definition: stl_set.h:381
_Alloc allocator_type
Public typedefs.
Definition: stl_set.h:124
_Rep_type::const_iterator const_iterator
Iterator-related typedefs.
Definition: stl_set.h:148
_Alloc_traits::const_pointer const_pointer
Iterator-related typedefs.
Definition: stl_set.h:141
_Key value_type
Public typedefs.
Definition: stl_set.h:121
auto lower_bound(const _Kt &__x) -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
Finds the beginning of a subsequence matching given key.
Definition: stl_set.h:839
const_iterator upper_bound(const key_type &__x) const
Finds the end of a subsequence matching given key.
Definition: stl_set.h:863
void insert(initializer_list< value_type > __l)
Attempts to insert a list of elements into the set.
Definition: stl_set.h:578
set(_InputIterator __first, _InputIterator __last)
Builds a set from a range.
Definition: stl_set.h:191
iterator cend() const noexcept
Definition: stl_set.h:390
set(set &&__x, const allocator_type &__a) noexcept(is_nothrow_copy_constructible< _Compare >::value &&_Alloc_traits::_S_always_equal())
Allocator-extended move constructor.
Definition: stl_set.h:259
auto count(const _Kt &__x) const -> decltype(_M_t._M_count_tr(__x))
Finds the number of elements.
Definition: stl_set.h:754
insert_return_type insert(node_type &&__nh)
Re-insert an extracted node.
Definition: stl_set.h:598
iterator insert(const_iterator __hint, node_type &&__nh)
Re-insert an extracted node.
Definition: stl_set.h:603
iterator end() const noexcept
Definition: stl_set.h:353
_Compare key_compare
Public typedefs.
Definition: stl_set.h:122
size_type max_size() const noexcept
Returns the maximum size of the set.
Definition: stl_set.h:424
_Key key_type
Public typedefs.
Definition: stl_set.h:109
auto find(const _Kt &__x) -> decltype(iterator{_M_t._M_find_tr(__x)})
Tries to locate an element in a set.
Definition: stl_set.h:804
_Alloc_traits::const_reference const_reference
Iterator-related typedefs.
Definition: stl_set.h:143
set & operator=(initializer_list< value_type > __l)
Set list assignment operator.
Definition: stl_set.h:316
auto find(const _Kt &__x) const -> decltype(const_iterator{_M_t._M_find_tr(__x)})
Tries to locate an element in a set.
Definition: stl_set.h:810
set & operator=(const set &)=default
Set assignment operator.
set()=default
Default constructor creates no elements.
auto lower_bound(const _Kt &__x) const -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
Finds the beginning of a subsequence matching given key.
Definition: stl_set.h:845
set(const allocator_type &__a)
Allocator-extended default constructor.
Definition: stl_set.h:251
key_compare key_comp() const
Returns the comparison object with which the set was constructed.
Definition: stl_set.h:327
reverse_iterator rbegin() const noexcept
Definition: stl_set.h:362
_Alloc_traits::reference reference
Iterator-related typedefs.
Definition: stl_set.h:142
void insert(_InputIterator __first, _InputIterator __last)
A template function that attempts to insert a range of elements.
Definition: stl_set.h:566
_GLIBCXX_ABI_TAG_CXX11 iterator erase(const_iterator __first, const_iterator __last)
Erases a [__first,__last) range of elements from a set.
Definition: stl_set.h:706
reverse_iterator crbegin() const noexcept
Definition: stl_set.h:399
auto upper_bound(const _Kt &__x) const -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
Finds the end of a subsequence matching given key.
Definition: stl_set.h:875
auto equal_range(const _Kt &__x) -> decltype(pair< iterator, iterator >(_M_t._M_equal_range_tr(__x)))
Finds a subsequence matching given key.
Definition: stl_set.h:908
auto equal_range(const _Kt &__x) const -> decltype(pair< iterator, iterator >(_M_t._M_equal_range_tr(__x)))
Finds a subsequence matching given key.
Definition: stl_set.h:914
set(initializer_list< value_type > __l, const allocator_type &__a)
Allocator-extended initialier-list constructor.
Definition: stl_set.h:265
_Alloc_traits::pointer pointer
Iterator-related typedefs.
Definition: stl_set.h:140
size_type size() const noexcept
Returns the size of the set.
Definition: stl_set.h:419
_Rep_type::const_reverse_iterator const_reverse_iterator
Iterator-related typedefs.
Definition: stl_set.h:150
_Rep_type::const_iterator iterator
Iterator-related typedefs.
Definition: stl_set.h:147
_Rep_type::const_reverse_iterator reverse_iterator
Iterator-related typedefs.
Definition: stl_set.h:149
reverse_iterator crend() const noexcept
Definition: stl_set.h:408
iterator insert(const_iterator __position, const value_type &__x)
Attempts to insert an element into the set.
Definition: stl_set.h:546
const_iterator lower_bound(const key_type &__x) const
Finds the beginning of a subsequence matching given key.
Definition: stl_set.h:833
set(_InputIterator __first, _InputIterator __last, const allocator_type &__a)
Allocator-extended range constructor.
Definition: stl_set.h:271
set(initializer_list< value_type > __l, const _Compare &__comp=_Compare(), const allocator_type &__a=allocator_type())
Builds a set from an initializer_list.
Definition: stl_set.h:243
void clear() noexcept
Definition: stl_set.h:733
allocator_type get_allocator() const noexcept
Returns the allocator object with which the set was constructed.
Definition: stl_set.h:335
_Rep_type::size_type size_type
Iterator-related typedefs.
Definition: stl_set.h:151
set(const set &)=default
Set copy constructor.
iterator upper_bound(const key_type &__x)
Finds the end of a subsequence matching given key.
Definition: stl_set.h:859
iterator lower_bound(const key_type &__x)
Finds the beginning of a subsequence matching given key.
Definition: stl_set.h:829
std::pair< const_iterator, const_iterator > equal_range(const key_type &__x) const
Finds a subsequence matching given key.
Definition: stl_set.h:902
auto upper_bound(const _Kt &__x) -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
Finds the end of a subsequence matching given key.
Definition: stl_set.h:869
iterator emplace_hint(const_iterator __pos, _Args &&... __args)
Attempts to insert an element into the set.
Definition: stl_set.h:488
iterator begin() const noexcept
Definition: stl_set.h:344
node_type extract(const key_type &__x)
Extract a node.
Definition: stl_set.h:593
set(const _Compare &__comp, const allocator_type &__a=allocator_type())
Creates a set with no elements.
Definition: stl_set.h:176
~set()=default
std::pair< iterator, bool > insert(const value_type &__x)
Attempts to insert an element into the set.
Definition: stl_set.h:509
std::pair< iterator, bool > emplace(_Args &&... __args)
Attempts to build and insert an element into the set.
Definition: stl_set.h:462
iterator find(const key_type &__x)
Tries to locate an element in a set.
Definition: stl_set.h:794
bool empty() const noexcept
Returns true if the set is empty.
Definition: stl_set.h:414
size_type erase(const key_type &__x)
Erases elements according to the provided key.
Definition: stl_set.h:684
const_iterator find(const key_type &__x) const
Tries to locate an element in a set.
Definition: stl_set.h:798
std::pair< iterator, iterator > equal_range(const key_type &__x)
Finds a subsequence matching given key.
Definition: stl_set.h:898
reverse_iterator rend() const noexcept
Definition: stl_set.h:371
set & operator=(set &&)=default
Move assignment operator.
Struct holding two objects of arbitrary type.
Definition: stl_pair.h:202
_T1 first
The first member.
Definition: stl_pair.h:206
_T2 second
The second member.
Definition: stl_pair.h:207
Uniform interface to C++98 and C++11 allocators.