libstdc++
stl_map.h
Go to the documentation of this file.
1 // Map implementation -*- C++ -*-
2 
3 // Copyright (C) 2001-2024 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_map.h
52  * This is an internal header file, included by other library headers.
53  * Do not attempt to use it directly. @headername{map}
54  */
55 
56 #ifndef _STL_MAP_H
57 #define _STL_MAP_H 1
58 
59 #include <bits/functexcept.h>
60 #include <bits/concept_check.h>
61 #if __cplusplus >= 201103L
62 #include <initializer_list>
63 #include <tuple>
64 #endif
65 
66 namespace std _GLIBCXX_VISIBILITY(default)
67 {
68 _GLIBCXX_BEGIN_NAMESPACE_VERSION
69 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
70 
71  template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
72  class multimap;
73 
74  /**
75  * @brief A standard container made up of (key,value) pairs, which can be
76  * retrieved based on a key, in logarithmic time.
77  *
78  * @ingroup associative_containers
79  * @headerfile map
80  * @since C++98
81  *
82  * @tparam _Key Type of key objects.
83  * @tparam _Tp Type of mapped objects.
84  * @tparam _Compare Comparison function object type, defaults to less<_Key>.
85  * @tparam _Alloc Allocator type, defaults to
86  * allocator<pair<const _Key, _Tp>.
87  *
88  * Meets the requirements of a <a href="tables.html#65">container</a>, a
89  * <a href="tables.html#66">reversible container</a>, and an
90  * <a href="tables.html#69">associative container</a> (using unique keys).
91  * For a @c map<Key,T> the key_type is Key, the mapped_type is T, and the
92  * value_type is std::pair<const Key,T>.
93  *
94  * Maps support bidirectional iterators.
95  *
96  * The private tree data is declared exactly the same way for map and
97  * multimap; the distinction is made entirely in how the tree functions are
98  * called (*_unique versus *_equal, same as the standard).
99  */
100  template <typename _Key, typename _Tp, typename _Compare = std::less<_Key>,
101  typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
102  class map
103  {
104  public:
105  typedef _Key key_type;
106  typedef _Tp mapped_type;
108  typedef _Compare key_compare;
109  typedef _Alloc allocator_type;
110 
111  private:
112 #ifdef _GLIBCXX_CONCEPT_CHECKS
113  // concept requirements
114  typedef typename _Alloc::value_type _Alloc_value_type;
115 # if __cplusplus < 201103L
116  __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
117 # endif
118  __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
119  _BinaryFunctionConcept)
120  __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
121 #endif
122 
123 #if __cplusplus >= 201103L
124 #if __cplusplus > 201703L || defined __STRICT_ANSI__
126  "std::map must have the same value_type as its allocator");
127 #endif
128 #endif
129 
130  public:
131 #pragma GCC diagnostic push
132 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
133  class value_compare
134  : public std::binary_function<value_type, value_type, bool>
135  {
136  friend class map<_Key, _Tp, _Compare, _Alloc>;
137  protected:
138  _Compare comp;
139 
140  value_compare(_Compare __c)
141  : comp(__c) { }
142 
143  public:
144  bool operator()(const value_type& __x, const value_type& __y) const
145  { return comp(__x.first, __y.first); }
146  };
147 #pragma GCC diagnostic pop
148 
149  private:
150  /// This turns a red-black tree into a [multi]map.
152  rebind<value_type>::other _Pair_alloc_type;
153 
154  typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
155  key_compare, _Pair_alloc_type> _Rep_type;
156 
157  /// The actual tree structure.
158  _Rep_type _M_t;
159 
161 
162 #if __cplusplus >= 201703L
163  template<typename _Up, typename _Vp = remove_reference_t<_Up>>
164  static constexpr bool __usable_key
165  = __or_v<is_same<const _Vp, const _Key>,
166  __and_<is_scalar<_Vp>, is_scalar<_Key>>>;
167 #endif
168 
169  public:
170  // many of these are specified differently in ISO, but the following are
171  // "functionally equivalent"
172  typedef typename _Alloc_traits::pointer pointer;
173  typedef typename _Alloc_traits::const_pointer const_pointer;
174  typedef typename _Alloc_traits::reference reference;
175  typedef typename _Alloc_traits::const_reference const_reference;
176  typedef typename _Rep_type::iterator iterator;
177  typedef typename _Rep_type::const_iterator const_iterator;
178  typedef typename _Rep_type::size_type size_type;
179  typedef typename _Rep_type::difference_type difference_type;
182 
183 #if __cplusplus > 201402L
184  using node_type = typename _Rep_type::node_type;
185  using insert_return_type = typename _Rep_type::insert_return_type;
186 #endif
187 
188  // [23.3.1.1] construct/copy/destroy
189  // (get_allocator() is also listed in this section)
190 
191  /**
192  * @brief Default constructor creates no elements.
193  */
194 #if __cplusplus < 201103L
195  map() : _M_t() { }
196 #else
197  map() = default;
198 #endif
199 
200  /**
201  * @brief Creates a %map with no elements.
202  * @param __comp A comparison object.
203  * @param __a An allocator object.
204  */
205  explicit
206  map(const _Compare& __comp,
207  const allocator_type& __a = allocator_type())
208  : _M_t(__comp, _Pair_alloc_type(__a)) { }
209 
210  /**
211  * @brief %Map copy constructor.
212  *
213  * Whether the allocator is copied depends on the allocator traits.
214  */
215 #if __cplusplus < 201103L
216  map(const map& __x)
217  : _M_t(__x._M_t) { }
218 #else
219  map(const map&) = default;
220 
221  /**
222  * @brief %Map move constructor.
223  *
224  * The newly-created %map contains the exact contents of the moved
225  * instance. The moved instance is a valid, but unspecified, %map.
226  */
227  map(map&&) = default;
228 
229  /**
230  * @brief Builds a %map from an initializer_list.
231  * @param __l An initializer_list.
232  * @param __comp A comparison object.
233  * @param __a An allocator object.
234  *
235  * Create a %map consisting of copies of the elements in the
236  * initializer_list @a __l.
237  * This is linear in N if the range is already sorted, and NlogN
238  * otherwise (where N is @a __l.size()).
239  */
241  const _Compare& __comp = _Compare(),
242  const allocator_type& __a = allocator_type())
243  : _M_t(__comp, _Pair_alloc_type(__a))
244  { _M_t._M_insert_range_unique(__l.begin(), __l.end()); }
245 
246  /// Allocator-extended default constructor.
247  explicit
248  map(const allocator_type& __a)
249  : _M_t(_Pair_alloc_type(__a)) { }
250 
251  /// Allocator-extended copy constructor.
252  map(const map& __m, const __type_identity_t<allocator_type>& __a)
253  : _M_t(__m._M_t, _Pair_alloc_type(__a)) { }
254 
255  /// Allocator-extended move constructor.
256  map(map&& __m, const __type_identity_t<allocator_type>& __a)
258  && _Alloc_traits::_S_always_equal())
259  : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { }
260 
261  /// Allocator-extended initialier-list constructor.
262  map(initializer_list<value_type> __l, const allocator_type& __a)
263  : _M_t(_Pair_alloc_type(__a))
264  { _M_t._M_insert_range_unique(__l.begin(), __l.end()); }
265 
266  /// Allocator-extended range constructor.
267  template<typename _InputIterator>
268  map(_InputIterator __first, _InputIterator __last,
269  const allocator_type& __a)
270  : _M_t(_Pair_alloc_type(__a))
271  { _M_t._M_insert_range_unique(__first, __last); }
272 #endif
273 
274  /**
275  * @brief Builds a %map from a range.
276  * @param __first An input iterator.
277  * @param __last An input iterator.
278  *
279  * Create a %map consisting of copies of the elements from
280  * [__first,__last). This is linear in N if the range is
281  * already sorted, and NlogN otherwise (where N is
282  * distance(__first,__last)).
283  */
284  template<typename _InputIterator>
285  map(_InputIterator __first, _InputIterator __last)
286  : _M_t()
287  { _M_t._M_insert_range_unique(__first, __last); }
288 
289  /**
290  * @brief Builds a %map from a range.
291  * @param __first An input iterator.
292  * @param __last An input iterator.
293  * @param __comp A comparison functor.
294  * @param __a An allocator object.
295  *
296  * Create a %map consisting of copies of the elements from
297  * [__first,__last). This is linear in N if the range is
298  * already sorted, and NlogN otherwise (where N is
299  * distance(__first,__last)).
300  */
301  template<typename _InputIterator>
302  map(_InputIterator __first, _InputIterator __last,
303  const _Compare& __comp,
304  const allocator_type& __a = allocator_type())
305  : _M_t(__comp, _Pair_alloc_type(__a))
306  { _M_t._M_insert_range_unique(__first, __last); }
307 
308 #if __cplusplus >= 201103L
309  /**
310  * The dtor only erases the elements, and note that if the elements
311  * themselves are pointers, the pointed-to memory is not touched in any
312  * way. Managing the pointer is the user's responsibility.
313  */
314  ~map() = default;
315 #endif
316 
317  /**
318  * @brief %Map assignment operator.
319  *
320  * Whether the allocator is copied depends on the allocator traits.
321  */
322 #if __cplusplus < 201103L
323  map&
324  operator=(const map& __x)
325  {
326  _M_t = __x._M_t;
327  return *this;
328  }
329 #else
330  map&
331  operator=(const map&) = default;
332 
333  /// Move assignment operator.
334  map&
335  operator=(map&&) = default;
336 
337  /**
338  * @brief %Map list assignment operator.
339  * @param __l An initializer_list.
340  *
341  * This function fills a %map with copies of the elements in the
342  * initializer list @a __l.
343  *
344  * Note that the assignment completely changes the %map and
345  * that the resulting %map's size is the same as the number
346  * of elements assigned.
347  */
348  map&
350  {
351  _M_t._M_assign_unique(__l.begin(), __l.end());
352  return *this;
353  }
354 #endif
355 
356  /// Get a copy of the memory allocation object.
357  allocator_type
358  get_allocator() const _GLIBCXX_NOEXCEPT
359  { return allocator_type(_M_t.get_allocator()); }
360 
361  // iterators
362  /**
363  * Returns a read/write iterator that points to the first pair in the
364  * %map.
365  * Iteration is done in ascending order according to the keys.
366  */
367  iterator
368  begin() _GLIBCXX_NOEXCEPT
369  { return _M_t.begin(); }
370 
371  /**
372  * Returns a read-only (constant) iterator that points to the first pair
373  * in the %map. Iteration is done in ascending order according to the
374  * keys.
375  */
376  const_iterator
377  begin() const _GLIBCXX_NOEXCEPT
378  { return _M_t.begin(); }
379 
380  /**
381  * Returns a read/write iterator that points one past the last
382  * pair in the %map. Iteration is done in ascending order
383  * according to the keys.
384  */
385  iterator
386  end() _GLIBCXX_NOEXCEPT
387  { return _M_t.end(); }
388 
389  /**
390  * Returns a read-only (constant) iterator that points one past the last
391  * pair in the %map. Iteration is done in ascending order according to
392  * the keys.
393  */
394  const_iterator
395  end() const _GLIBCXX_NOEXCEPT
396  { return _M_t.end(); }
397 
398  /**
399  * Returns a read/write reverse iterator that points to the last pair in
400  * the %map. Iteration is done in descending order according to the
401  * keys.
402  */
404  rbegin() _GLIBCXX_NOEXCEPT
405  { return _M_t.rbegin(); }
406 
407  /**
408  * Returns a read-only (constant) reverse iterator that points to the
409  * last pair in the %map. Iteration is done in descending order
410  * according to the keys.
411  */
412  const_reverse_iterator
413  rbegin() const _GLIBCXX_NOEXCEPT
414  { return _M_t.rbegin(); }
415 
416  /**
417  * Returns a read/write reverse iterator that points to one before the
418  * first pair in the %map. Iteration is done in descending order
419  * according to the keys.
420  */
422  rend() _GLIBCXX_NOEXCEPT
423  { return _M_t.rend(); }
424 
425  /**
426  * Returns a read-only (constant) reverse iterator that points to one
427  * before the first pair in the %map. Iteration is done in descending
428  * order according to the keys.
429  */
430  const_reverse_iterator
431  rend() const _GLIBCXX_NOEXCEPT
432  { return _M_t.rend(); }
433 
434 #if __cplusplus >= 201103L
435  /**
436  * Returns a read-only (constant) iterator that points to the first pair
437  * in the %map. Iteration is done in ascending order according to the
438  * keys.
439  */
440  const_iterator
441  cbegin() const noexcept
442  { return _M_t.begin(); }
443 
444  /**
445  * Returns a read-only (constant) iterator that points one past the last
446  * pair in the %map. Iteration is done in ascending order according to
447  * the keys.
448  */
449  const_iterator
450  cend() const noexcept
451  { return _M_t.end(); }
452 
453  /**
454  * Returns a read-only (constant) reverse iterator that points to the
455  * last pair in the %map. Iteration is done in descending order
456  * according to the keys.
457  */
458  const_reverse_iterator
459  crbegin() const noexcept
460  { return _M_t.rbegin(); }
461 
462  /**
463  * Returns a read-only (constant) reverse iterator that points to one
464  * before the first pair in the %map. Iteration is done in descending
465  * order according to the keys.
466  */
467  const_reverse_iterator
468  crend() const noexcept
469  { return _M_t.rend(); }
470 #endif
471 
472  // capacity
473  /** Returns true if the %map is empty. (Thus begin() would equal
474  * end().)
475  */
476  _GLIBCXX_NODISCARD bool
477  empty() const _GLIBCXX_NOEXCEPT
478  { return _M_t.empty(); }
479 
480  /** Returns the size of the %map. */
481  size_type
482  size() const _GLIBCXX_NOEXCEPT
483  { return _M_t.size(); }
484 
485  /** Returns the maximum size of the %map. */
486  size_type
487  max_size() const _GLIBCXX_NOEXCEPT
488  { return _M_t.max_size(); }
489 
490  // [23.3.1.2] element access
491  /**
492  * @brief Subscript ( @c [] ) access to %map data.
493  * @param __k The key for which data should be retrieved.
494  * @return A reference to the data of the (key,data) %pair.
495  *
496  * Allows for easy lookup with the subscript ( @c [] )
497  * operator. Returns data associated with the key specified in
498  * subscript. If the key does not exist, a pair with that key
499  * is created using default values, which is then returned.
500  *
501  * Lookup requires logarithmic time.
502  */
503  mapped_type&
504  operator[](const key_type& __k)
505  {
506  // concept requirements
507  __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
508 
509  iterator __i = lower_bound(__k);
510  // __i->first is greater than or equivalent to __k.
511  if (__i == end() || key_comp()(__k, (*__i).first))
512 #if __cplusplus >= 201103L
513  __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
515  std::tuple<>());
516 #else
517  __i = insert(__i, value_type(__k, mapped_type()));
518 #endif
519  return (*__i).second;
520  }
521 
522 #if __cplusplus >= 201103L
523  mapped_type&
524  operator[](key_type&& __k)
525  {
526  // concept requirements
527  __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
528 
529  iterator __i = lower_bound(__k);
530  // __i->first is greater than or equivalent to __k.
531  if (__i == end() || key_comp()(__k, (*__i).first))
532  __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
534  std::tuple<>());
535  return (*__i).second;
536  }
537 #endif
538 
539  // _GLIBCXX_RESOLVE_LIB_DEFECTS
540  // DR 464. Suggestion for new member functions in standard containers.
541  /**
542  * @brief Access to %map data.
543  * @param __k The key for which data should be retrieved.
544  * @return A reference to the data whose key is equivalent to @a __k, if
545  * such a data is present in the %map.
546  * @throw std::out_of_range If no such data is present.
547  */
548  mapped_type&
549  at(const key_type& __k)
550  {
551  iterator __i = lower_bound(__k);
552  if (__i == end() || key_comp()(__k, (*__i).first))
553  __throw_out_of_range(__N("map::at"));
554  return (*__i).second;
555  }
556 
557  const mapped_type&
558  at(const key_type& __k) const
559  {
560  const_iterator __i = lower_bound(__k);
561  if (__i == end() || key_comp()(__k, (*__i).first))
562  __throw_out_of_range(__N("map::at"));
563  return (*__i).second;
564  }
565 
566  // modifiers
567 #if __cplusplus >= 201103L
568  /**
569  * @brief Attempts to build and insert a std::pair into the %map.
570  *
571  * @param __args Arguments used to generate a new pair instance (see
572  * std::piecewise_contruct for passing arguments to each
573  * part of the pair constructor).
574  *
575  * @return A pair, of which the first element is an iterator that points
576  * to the possibly inserted pair, and the second is a bool that
577  * is true if the pair was actually inserted.
578  *
579  * This function attempts to build and insert a (key, value) %pair into
580  * the %map.
581  * A %map relies on unique keys and thus a %pair is only inserted if its
582  * first element (the key) is not already present in the %map.
583  *
584  * Insertion requires logarithmic time.
585  */
586  template<typename... _Args>
588  emplace(_Args&&... __args)
589  {
590 #if __cplusplus >= 201703L
591  if constexpr (sizeof...(_Args) == 2)
592  if constexpr (is_same_v<allocator_type, allocator<value_type>>)
593  {
594  auto&& [__a, __v] = pair<_Args&...>(__args...);
595  if constexpr (__usable_key<decltype(__a)>)
596  {
597  const key_type& __k = __a;
598  iterator __i = lower_bound(__k);
599  if (__i == end() || key_comp()(__k, (*__i).first))
600  {
601  __i = emplace_hint(__i, std::forward<_Args>(__args)...);
602  return {__i, true};
603  }
604  return {__i, false};
605  }
606  }
607 #endif
608  return _M_t._M_emplace_unique(std::forward<_Args>(__args)...);
609  }
610 
611  /**
612  * @brief Attempts to build and insert a std::pair into the %map.
613  *
614  * @param __pos An iterator that serves as a hint as to where the pair
615  * should be inserted.
616  * @param __args Arguments used to generate a new pair instance (see
617  * std::piecewise_contruct for passing arguments to each
618  * part of the pair constructor).
619  * @return An iterator that points to the element with key of the
620  * std::pair built from @a __args (may or may not be that
621  * std::pair).
622  *
623  * This function is not concerned about whether the insertion took place,
624  * and thus does not return a boolean like the single-argument emplace()
625  * does.
626  * Note that the first parameter is only a hint and can potentially
627  * improve the performance of the insertion process. A bad hint would
628  * cause no gains in efficiency.
629  *
630  * See
631  * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
632  * for more on @a hinting.
633  *
634  * Insertion requires logarithmic time (if the hint is not taken).
635  */
636  template<typename... _Args>
637  iterator
638  emplace_hint(const_iterator __pos, _Args&&... __args)
639  {
640  return _M_t._M_emplace_hint_unique(__pos,
641  std::forward<_Args>(__args)...);
642  }
643 #endif
644 
645 #if __cplusplus > 201402L
646  /// Extract a node.
647  node_type
648  extract(const_iterator __pos)
649  {
650  __glibcxx_assert(__pos != end());
651  return _M_t.extract(__pos);
652  }
653 
654  /// Extract a node.
655  node_type
656  extract(const key_type& __x)
657  { return _M_t.extract(__x); }
658 
659  /// Re-insert an extracted node.
660  insert_return_type
661  insert(node_type&& __nh)
662  { return _M_t._M_reinsert_node_unique(std::move(__nh)); }
663 
664  /// Re-insert an extracted node.
665  iterator
666  insert(const_iterator __hint, node_type&& __nh)
667  { return _M_t._M_reinsert_node_hint_unique(__hint, std::move(__nh)); }
668 
669  template<typename, typename>
670  friend struct std::_Rb_tree_merge_helper;
671 
672  template<typename _Cmp2>
673  void
674  merge(map<_Key, _Tp, _Cmp2, _Alloc>& __source)
675  {
676  using _Merge_helper = _Rb_tree_merge_helper<map, _Cmp2>;
677  _M_t._M_merge_unique(_Merge_helper::_S_get_tree(__source));
678  }
679 
680  template<typename _Cmp2>
681  void
682  merge(map<_Key, _Tp, _Cmp2, _Alloc>&& __source)
683  { merge(__source); }
684 
685  template<typename _Cmp2>
686  void
687  merge(multimap<_Key, _Tp, _Cmp2, _Alloc>& __source)
688  {
689  using _Merge_helper = _Rb_tree_merge_helper<map, _Cmp2>;
690  _M_t._M_merge_unique(_Merge_helper::_S_get_tree(__source));
691  }
692 
693  template<typename _Cmp2>
694  void
695  merge(multimap<_Key, _Tp, _Cmp2, _Alloc>&& __source)
696  { merge(__source); }
697 #endif // C++17
698 
699 #ifdef __glibcxx_map_try_emplace // C++ >= 17 && HOSTED
700  /**
701  * @brief Attempts to build and insert a std::pair into the %map.
702  *
703  * @param __k Key to use for finding a possibly existing pair in
704  * the map.
705  * @param __args Arguments used to generate the .second for a new pair
706  * instance.
707  *
708  * @return A pair, of which the first element is an iterator that points
709  * to the possibly inserted pair, and the second is a bool that
710  * is true if the pair was actually inserted.
711  *
712  * This function attempts to build and insert a (key, value) %pair into
713  * the %map.
714  * A %map relies on unique keys and thus a %pair is only inserted if its
715  * first element (the key) is not already present in the %map.
716  * If a %pair is not inserted, this function has no effect.
717  *
718  * Insertion requires logarithmic time.
719  */
720  template <typename... _Args>
721  pair<iterator, bool>
722  try_emplace(const key_type& __k, _Args&&... __args)
723  {
724  iterator __i = lower_bound(__k);
725  if (__i == end() || key_comp()(__k, (*__i).first))
726  {
730  std::forward<_Args>(__args)...));
731  return {__i, true};
732  }
733  return {__i, false};
734  }
735 
736  // move-capable overload
737  template <typename... _Args>
739  try_emplace(key_type&& __k, _Args&&... __args)
740  {
741  iterator __i = lower_bound(__k);
742  if (__i == end() || key_comp()(__k, (*__i).first))
743  {
747  std::forward<_Args>(__args)...));
748  return {__i, true};
749  }
750  return {__i, false};
751  }
752 
753  /**
754  * @brief Attempts to build and insert a std::pair into the %map.
755  *
756  * @param __hint An iterator that serves as a hint as to where the
757  * pair should be inserted.
758  * @param __k Key to use for finding a possibly existing pair in
759  * the map.
760  * @param __args Arguments used to generate the .second for a new pair
761  * instance.
762  * @return An iterator that points to the element with key of the
763  * std::pair built from @a __args (may or may not be that
764  * std::pair).
765  *
766  * This function is not concerned about whether the insertion took place,
767  * and thus does not return a boolean like the single-argument
768  * try_emplace() does. However, if insertion did not take place,
769  * this function has no effect.
770  * Note that the first parameter is only a hint and can potentially
771  * improve the performance of the insertion process. A bad hint would
772  * cause no gains in efficiency.
773  *
774  * See
775  * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
776  * for more on @a hinting.
777  *
778  * Insertion requires logarithmic time (if the hint is not taken).
779  */
780  template <typename... _Args>
781  iterator
782  try_emplace(const_iterator __hint, const key_type& __k,
783  _Args&&... __args)
784  {
785  iterator __i;
786  auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
787  if (__true_hint.second)
788  __i = emplace_hint(iterator(__true_hint.second),
792  std::forward<_Args>(__args)...));
793  else
794  __i = iterator(__true_hint.first);
795  return __i;
796  }
797 
798  // move-capable overload
799  template <typename... _Args>
800  iterator
801  try_emplace(const_iterator __hint, key_type&& __k, _Args&&... __args)
802  {
803  iterator __i;
804  auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
805  if (__true_hint.second)
806  __i = emplace_hint(iterator(__true_hint.second),
810  std::forward<_Args>(__args)...));
811  else
812  __i = iterator(__true_hint.first);
813  return __i;
814  }
815 #endif
816 
817  /**
818  * @brief Attempts to insert a std::pair into the %map.
819  * @param __x Pair to be inserted (see std::make_pair for easy
820  * creation of pairs).
821  *
822  * @return A pair, of which the first element is an iterator that
823  * points to the possibly inserted pair, and the second is
824  * a bool that is true if the pair was actually inserted.
825  *
826  * This function attempts to insert a (key, value) %pair into the %map.
827  * A %map relies on unique keys and thus a %pair is only inserted if its
828  * first element (the key) is not already present in the %map.
829  *
830  * Insertion requires logarithmic time.
831  * @{
832  */
834  insert(const value_type& __x)
835  { return _M_t._M_insert_unique(__x); }
836 
837 #if __cplusplus >= 201103L
838  // _GLIBCXX_RESOLVE_LIB_DEFECTS
839  // 2354. Unnecessary copying when inserting into maps with braced-init
842  { return _M_t._M_insert_unique(std::move(__x)); }
843 
844  template<typename _Pair>
845  __enable_if_t<is_constructible<value_type, _Pair>::value,
847  insert(_Pair&& __x)
848  {
849 #if __cplusplus >= 201703L
850  using _P2 = remove_reference_t<_Pair>;
851  if constexpr (__is_pair<remove_const_t<_P2>>)
852  if constexpr (is_same_v<allocator_type, allocator<value_type>>)
853  if constexpr (__usable_key<typename _P2::first_type>)
854  {
855  const key_type& __k = __x.first;
856  iterator __i = lower_bound(__k);
857  if (__i == end() || key_comp()(__k, (*__i).first))
858  {
859  __i = emplace_hint(__i, std::forward<_Pair>(__x));
860  return {__i, true};
861  }
862  return {__i, false};
863  }
864 #endif
865  return _M_t._M_emplace_unique(std::forward<_Pair>(__x));
866  }
867 #endif
868  /// @}
869 
870 #if __cplusplus >= 201103L
871  /**
872  * @brief Attempts to insert a list of std::pairs into the %map.
873  * @param __list A std::initializer_list<value_type> of pairs to be
874  * inserted.
875  *
876  * Complexity similar to that of the range constructor.
877  */
878  void
880  { insert(__list.begin(), __list.end()); }
881 #endif
882 
883  /**
884  * @brief Attempts to insert a std::pair into the %map.
885  * @param __position An iterator that serves as a hint as to where the
886  * pair should be inserted.
887  * @param __x Pair to be inserted (see std::make_pair for easy creation
888  * of pairs).
889  * @return An iterator that points to the element with key of
890  * @a __x (may or may not be the %pair passed in).
891  *
892 
893  * This function is not concerned about whether the insertion
894  * took place, and thus does not return a boolean like the
895  * single-argument insert() does. Note that the first
896  * parameter is only a hint and can potentially improve the
897  * performance of the insertion process. A bad hint would
898  * cause no gains in efficiency.
899  *
900  * See
901  * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
902  * for more on @a hinting.
903  *
904  * Insertion requires logarithmic time (if the hint is not taken).
905  * @{
906  */
907  iterator
908 #if __cplusplus >= 201103L
909  insert(const_iterator __position, const value_type& __x)
910 #else
911  insert(iterator __position, const value_type& __x)
912 #endif
913  { return _M_t._M_insert_unique_(__position, __x); }
914 
915 #if __cplusplus >= 201103L
916  // _GLIBCXX_RESOLVE_LIB_DEFECTS
917  // 2354. Unnecessary copying when inserting into maps with braced-init
918  iterator
919  insert(const_iterator __position, value_type&& __x)
920  { return _M_t._M_insert_unique_(__position, std::move(__x)); }
921 
922  template<typename _Pair>
923  __enable_if_t<is_constructible<value_type, _Pair>::value, iterator>
924  insert(const_iterator __position, _Pair&& __x)
925  {
926  return _M_t._M_emplace_hint_unique(__position,
927  std::forward<_Pair>(__x));
928  }
929 #endif
930  /// @}
931 
932  /**
933  * @brief Template function that attempts to insert a range of elements.
934  * @param __first Iterator pointing to the start of the range to be
935  * inserted.
936  * @param __last Iterator pointing to the end of the range.
937  *
938  * Complexity similar to that of the range constructor.
939  */
940  template<typename _InputIterator>
941  void
942  insert(_InputIterator __first, _InputIterator __last)
943  { _M_t._M_insert_range_unique(__first, __last); }
944 
945 #if __cplusplus > 201402L
946  /**
947  * @brief Attempts to insert or assign a std::pair into the %map.
948  * @param __k Key to use for finding a possibly existing pair in
949  * the map.
950  * @param __obj Argument used to generate the .second for a pair
951  * instance.
952  *
953  * @return A pair, of which the first element is an iterator that
954  * points to the possibly inserted pair, and the second is
955  * a bool that is true if the pair was actually inserted.
956  *
957  * This function attempts to insert a (key, value) %pair into the %map.
958  * A %map relies on unique keys and thus a %pair is only inserted if its
959  * first element (the key) is not already present in the %map.
960  * If the %pair was already in the %map, the .second of the %pair
961  * is assigned from __obj.
962  *
963  * Insertion requires logarithmic time.
964  */
965  template <typename _Obj>
967  insert_or_assign(const key_type& __k, _Obj&& __obj)
968  {
969  iterator __i = lower_bound(__k);
970  if (__i == end() || key_comp()(__k, (*__i).first))
971  {
975  std::forward<_Obj>(__obj)));
976  return {__i, true};
977  }
978  (*__i).second = std::forward<_Obj>(__obj);
979  return {__i, false};
980  }
981 
982  // move-capable overload
983  template <typename _Obj>
985  insert_or_assign(key_type&& __k, _Obj&& __obj)
986  {
987  iterator __i = lower_bound(__k);
988  if (__i == end() || key_comp()(__k, (*__i).first))
989  {
993  std::forward<_Obj>(__obj)));
994  return {__i, true};
995  }
996  (*__i).second = std::forward<_Obj>(__obj);
997  return {__i, false};
998  }
999 
1000  /**
1001  * @brief Attempts to insert or assign a std::pair into the %map.
1002  * @param __hint An iterator that serves as a hint as to where the
1003  * pair should be inserted.
1004  * @param __k Key to use for finding a possibly existing pair in
1005  * the map.
1006  * @param __obj Argument used to generate the .second for a pair
1007  * instance.
1008  *
1009  * @return An iterator that points to the element with key of
1010  * @a __x (may or may not be the %pair passed in).
1011  *
1012  * This function attempts to insert a (key, value) %pair into the %map.
1013  * A %map relies on unique keys and thus a %pair is only inserted if its
1014  * first element (the key) is not already present in the %map.
1015  * If the %pair was already in the %map, the .second of the %pair
1016  * is assigned from __obj.
1017  *
1018  * Insertion requires logarithmic time.
1019  */
1020  template <typename _Obj>
1021  iterator
1022  insert_or_assign(const_iterator __hint,
1023  const key_type& __k, _Obj&& __obj)
1024  {
1025  iterator __i;
1026  auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
1027  if (__true_hint.second)
1028  {
1029  return emplace_hint(iterator(__true_hint.second),
1031  std::forward_as_tuple(__k),
1033  std::forward<_Obj>(__obj)));
1034  }
1035  __i = iterator(__true_hint.first);
1036  (*__i).second = std::forward<_Obj>(__obj);
1037  return __i;
1038  }
1039 
1040  // move-capable overload
1041  template <typename _Obj>
1042  iterator
1043  insert_or_assign(const_iterator __hint, key_type&& __k, _Obj&& __obj)
1044  {
1045  iterator __i;
1046  auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
1047  if (__true_hint.second)
1048  {
1049  return emplace_hint(iterator(__true_hint.second),
1053  std::forward<_Obj>(__obj)));
1054  }
1055  __i = iterator(__true_hint.first);
1056  (*__i).second = std::forward<_Obj>(__obj);
1057  return __i;
1058  }
1059 #endif
1060 
1061 #if __cplusplus >= 201103L
1062  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1063  // DR 130. Associative erase should return an iterator.
1064  /**
1065  * @brief Erases an element from a %map.
1066  * @param __position An iterator pointing to the element to be erased.
1067  * @return An iterator pointing to the element immediately following
1068  * @a position prior to the element being erased. If no such
1069  * element exists, end() is returned.
1070  *
1071  * This function erases an element, pointed to by the given
1072  * iterator, from a %map. Note that this function only erases
1073  * the element, and that if the element is itself a pointer,
1074  * the pointed-to memory is not touched in any way. Managing
1075  * the pointer is the user's responsibility.
1076  *
1077  * @{
1078  */
1079  iterator
1080  erase(const_iterator __position)
1081  { return _M_t.erase(__position); }
1082 
1083  // LWG 2059
1084  _GLIBCXX_ABI_TAG_CXX11
1085  iterator
1086  erase(iterator __position)
1087  { return _M_t.erase(__position); }
1088  /// @}
1089 #else
1090  /**
1091  * @brief Erases an element from a %map.
1092  * @param __position An iterator pointing to the element to be erased.
1093  *
1094  * This function erases an element, pointed to by the given
1095  * iterator, from a %map. Note that this function only erases
1096  * the element, and that if the element is itself a pointer,
1097  * the pointed-to memory is not touched in any way. Managing
1098  * the pointer is the user's responsibility.
1099  */
1100  void
1101  erase(iterator __position)
1102  { _M_t.erase(__position); }
1103 #endif
1104 
1105  /**
1106  * @brief Erases elements according to the provided key.
1107  * @param __x Key of element to be erased.
1108  * @return The number of elements erased.
1109  *
1110  * This function erases all the elements located by the given key from
1111  * a %map.
1112  * Note that this function only erases the element, and that if
1113  * the element is itself a pointer, the pointed-to memory is not touched
1114  * in any way. Managing the pointer is the user's responsibility.
1115  */
1116  size_type
1117  erase(const key_type& __x)
1118  { return _M_t.erase(__x); }
1119 
1120 #if __cplusplus >= 201103L
1121  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1122  // DR 130. Associative erase should return an iterator.
1123  /**
1124  * @brief Erases a [first,last) range of elements from a %map.
1125  * @param __first Iterator pointing to the start of the range to be
1126  * erased.
1127  * @param __last Iterator pointing to the end of the range to
1128  * be erased.
1129  * @return The iterator @a __last.
1130  *
1131  * This function erases a sequence of elements from a %map.
1132  * Note that this function only erases the element, and that if
1133  * the element is itself a pointer, the pointed-to memory is not touched
1134  * in any way. Managing the pointer is the user's responsibility.
1135  */
1136  iterator
1137  erase(const_iterator __first, const_iterator __last)
1138  { return _M_t.erase(__first, __last); }
1139 #else
1140  /**
1141  * @brief Erases a [__first,__last) range of elements from a %map.
1142  * @param __first Iterator pointing to the start of the range to be
1143  * erased.
1144  * @param __last Iterator pointing to the end of the range to
1145  * be erased.
1146  *
1147  * This function erases a sequence of elements from a %map.
1148  * Note that this function only erases the element, and that if
1149  * the element is itself a pointer, the pointed-to memory is not touched
1150  * in any way. Managing the pointer is the user's responsibility.
1151  */
1152  void
1153  erase(iterator __first, iterator __last)
1154  { _M_t.erase(__first, __last); }
1155 #endif
1156 
1157  /**
1158  * @brief Swaps data with another %map.
1159  * @param __x A %map of the same element and allocator types.
1160  *
1161  * This exchanges the elements between two maps in constant
1162  * time. (It is only swapping a pointer, an integer, and an
1163  * instance of the @c Compare type (which itself is often
1164  * stateless and empty), so it should be quite fast.) Note
1165  * that the global std::swap() function is specialized such
1166  * that std::swap(m1,m2) will feed to this function.
1167  *
1168  * Whether the allocators are swapped depends on the allocator traits.
1169  */
1170  void
1171  swap(map& __x)
1172  _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
1173  { _M_t.swap(__x._M_t); }
1174 
1175  /**
1176  * Erases all elements in a %map. Note that this function only
1177  * erases the elements, and that if the elements themselves are
1178  * pointers, the pointed-to memory is not touched in any way.
1179  * Managing the pointer is the user's responsibility.
1180  */
1181  void
1182  clear() _GLIBCXX_NOEXCEPT
1183  { _M_t.clear(); }
1184 
1185  // observers
1186  /**
1187  * Returns the key comparison object out of which the %map was
1188  * constructed.
1189  */
1190  key_compare
1191  key_comp() const
1192  { return _M_t.key_comp(); }
1193 
1194  /**
1195  * Returns a value comparison object, built from the key comparison
1196  * object out of which the %map was constructed.
1197  */
1198  value_compare
1199  value_comp() const
1200  { return value_compare(_M_t.key_comp()); }
1201 
1202  // [23.3.1.3] map operations
1203 
1204  ///@{
1205  /**
1206  * @brief Tries to locate an element in a %map.
1207  * @param __x Key of (key, value) %pair to be located.
1208  * @return Iterator pointing to sought-after element, or end() if not
1209  * found.
1210  *
1211  * This function takes a key and tries to locate the element with which
1212  * the key matches. If successful the function returns an iterator
1213  * pointing to the sought after %pair. If unsuccessful it returns the
1214  * past-the-end ( @c end() ) iterator.
1215  */
1216 
1217  iterator
1218  find(const key_type& __x)
1219  { return _M_t.find(__x); }
1220 
1221 #if __cplusplus > 201103L
1222  template<typename _Kt>
1223  auto
1224  find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
1225  { return _M_t._M_find_tr(__x); }
1226 #endif
1227  ///@}
1228 
1229  ///@{
1230  /**
1231  * @brief Tries to locate an element in a %map.
1232  * @param __x Key of (key, value) %pair to be located.
1233  * @return Read-only (constant) iterator pointing to sought-after
1234  * element, or end() if not found.
1235  *
1236  * This function takes a key and tries to locate the element with which
1237  * the key matches. If successful the function returns a constant
1238  * iterator pointing to the sought after %pair. If unsuccessful it
1239  * returns the past-the-end ( @c end() ) iterator.
1240  */
1241 
1242  const_iterator
1243  find(const key_type& __x) const
1244  { return _M_t.find(__x); }
1245 
1246 #if __cplusplus > 201103L
1247  template<typename _Kt>
1248  auto
1249  find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
1250  { return _M_t._M_find_tr(__x); }
1251 #endif
1252  ///@}
1253 
1254  ///@{
1255  /**
1256  * @brief Finds the number of elements with given key.
1257  * @param __x Key of (key, value) pairs to be located.
1258  * @return Number of elements with specified key.
1259  *
1260  * This function only makes sense for multimaps; for map the result will
1261  * either be 0 (not present) or 1 (present).
1262  */
1263  size_type
1264  count(const key_type& __x) const
1265  { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
1266 
1267 #if __cplusplus > 201103L
1268  template<typename _Kt>
1269  auto
1270  count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
1271  { return _M_t._M_count_tr(__x); }
1272 #endif
1273  ///@}
1274 
1275 #if __cplusplus > 201703L
1276  ///@{
1277  /**
1278  * @brief Finds whether an element with the given key exists.
1279  * @param __x Key of (key, value) pairs to be located.
1280  * @return True if there is an element with the specified key.
1281  */
1282  bool
1283  contains(const key_type& __x) const
1284  { return _M_t.find(__x) != _M_t.end(); }
1285 
1286  template<typename _Kt>
1287  auto
1288  contains(const _Kt& __x) const
1289  -> decltype(_M_t._M_find_tr(__x), void(), true)
1290  { return _M_t._M_find_tr(__x) != _M_t.end(); }
1291  ///@}
1292 #endif
1293 
1294  ///@{
1295  /**
1296  * @brief Finds the beginning of a subsequence matching given key.
1297  * @param __x Key of (key, value) pair to be located.
1298  * @return Iterator pointing to first element equal to or greater
1299  * than key, or end().
1300  *
1301  * This function returns the first element of a subsequence of elements
1302  * that matches the given key. If unsuccessful it returns an iterator
1303  * pointing to the first element that has a greater value than given key
1304  * or end() if no such element exists.
1305  */
1306  iterator
1307  lower_bound(const key_type& __x)
1308  { return _M_t.lower_bound(__x); }
1309 
1310 #if __cplusplus > 201103L
1311  template<typename _Kt>
1312  auto
1313  lower_bound(const _Kt& __x)
1314  -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
1315  { return iterator(_M_t._M_lower_bound_tr(__x)); }
1316 #endif
1317  ///@}
1318 
1319  ///@{
1320  /**
1321  * @brief Finds the beginning of a subsequence matching given key.
1322  * @param __x Key of (key, value) pair to be located.
1323  * @return Read-only (constant) iterator pointing to first element
1324  * equal to or greater than key, or end().
1325  *
1326  * This function returns the first element of a subsequence of elements
1327  * that matches the given key. If unsuccessful it returns an iterator
1328  * pointing to the first element that has a greater value than given key
1329  * or end() if no such element exists.
1330  */
1331  const_iterator
1332  lower_bound(const key_type& __x) const
1333  { return _M_t.lower_bound(__x); }
1334 
1335 #if __cplusplus > 201103L
1336  template<typename _Kt>
1337  auto
1338  lower_bound(const _Kt& __x) const
1339  -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
1340  { return const_iterator(_M_t._M_lower_bound_tr(__x)); }
1341 #endif
1342  ///@}
1343 
1344  ///@{
1345  /**
1346  * @brief Finds the end of a subsequence matching given key.
1347  * @param __x Key of (key, value) pair to be located.
1348  * @return Iterator pointing to the first element
1349  * greater than key, or end().
1350  */
1351  iterator
1352  upper_bound(const key_type& __x)
1353  { return _M_t.upper_bound(__x); }
1354 
1355 #if __cplusplus > 201103L
1356  template<typename _Kt>
1357  auto
1358  upper_bound(const _Kt& __x)
1359  -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
1360  { return iterator(_M_t._M_upper_bound_tr(__x)); }
1361 #endif
1362  ///@}
1363 
1364  ///@{
1365  /**
1366  * @brief Finds the end of a subsequence matching given key.
1367  * @param __x Key of (key, value) pair to be located.
1368  * @return Read-only (constant) iterator pointing to first iterator
1369  * greater than key, or end().
1370  */
1371  const_iterator
1372  upper_bound(const key_type& __x) const
1373  { return _M_t.upper_bound(__x); }
1374 
1375 #if __cplusplus > 201103L
1376  template<typename _Kt>
1377  auto
1378  upper_bound(const _Kt& __x) const
1379  -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
1380  { return const_iterator(_M_t._M_upper_bound_tr(__x)); }
1381 #endif
1382  ///@}
1383 
1384  ///@{
1385  /**
1386  * @brief Finds a subsequence matching given key.
1387  * @param __x Key of (key, value) pairs to be located.
1388  * @return Pair of iterators that possibly points to the subsequence
1389  * matching given key.
1390  *
1391  * This function is equivalent to
1392  * @code
1393  * std::make_pair(c.lower_bound(val),
1394  * c.upper_bound(val))
1395  * @endcode
1396  * (but is faster than making the calls separately).
1397  *
1398  * This function probably only makes sense for multimaps.
1399  */
1401  equal_range(const key_type& __x)
1402  { return _M_t.equal_range(__x); }
1403 
1404 #if __cplusplus > 201103L
1405  template<typename _Kt>
1406  auto
1407  equal_range(const _Kt& __x)
1408  -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
1409  { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
1410 #endif
1411  ///@}
1412 
1413  ///@{
1414  /**
1415  * @brief Finds a subsequence matching given key.
1416  * @param __x Key of (key, value) pairs to be located.
1417  * @return Pair of read-only (constant) iterators that possibly points
1418  * to the subsequence matching given key.
1419  *
1420  * This function is equivalent to
1421  * @code
1422  * std::make_pair(c.lower_bound(val),
1423  * c.upper_bound(val))
1424  * @endcode
1425  * (but is faster than making the calls separately).
1426  *
1427  * This function probably only makes sense for multimaps.
1428  */
1430  equal_range(const key_type& __x) const
1431  { return _M_t.equal_range(__x); }
1432 
1433 #if __cplusplus > 201103L
1434  template<typename _Kt>
1435  auto
1436  equal_range(const _Kt& __x) const
1438  _M_t._M_equal_range_tr(__x)))
1439  {
1441  _M_t._M_equal_range_tr(__x));
1442  }
1443 #endif
1444  ///@}
1445 
1446  template<typename _K1, typename _T1, typename _C1, typename _A1>
1447  friend bool
1448  operator==(const map<_K1, _T1, _C1, _A1>&,
1449  const map<_K1, _T1, _C1, _A1>&);
1450 
1451 #if __cpp_lib_three_way_comparison
1452  template<typename _K1, typename _T1, typename _C1, typename _A1>
1453  friend __detail::__synth3way_t<pair<const _K1, _T1>>
1454  operator<=>(const map<_K1, _T1, _C1, _A1>&,
1455  const map<_K1, _T1, _C1, _A1>&);
1456 #else
1457  template<typename _K1, typename _T1, typename _C1, typename _A1>
1458  friend bool
1459  operator<(const map<_K1, _T1, _C1, _A1>&,
1460  const map<_K1, _T1, _C1, _A1>&);
1461 #endif
1462  };
1463 
1464 
1465 #if __cpp_deduction_guides >= 201606
1466 
1467  template<typename _InputIterator,
1468  typename _Compare = less<__iter_key_t<_InputIterator>>,
1469  typename _Allocator = allocator<__iter_to_alloc_t<_InputIterator>>,
1470  typename = _RequireInputIter<_InputIterator>,
1471  typename = _RequireNotAllocator<_Compare>,
1472  typename = _RequireAllocator<_Allocator>>
1473  map(_InputIterator, _InputIterator,
1474  _Compare = _Compare(), _Allocator = _Allocator())
1475  -> map<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
1476  _Compare, _Allocator>;
1477 
1478  template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
1479  typename _Allocator = allocator<pair<const _Key, _Tp>>,
1480  typename = _RequireNotAllocator<_Compare>,
1481  typename = _RequireAllocator<_Allocator>>
1482  map(initializer_list<pair<_Key, _Tp>>,
1483  _Compare = _Compare(), _Allocator = _Allocator())
1484  -> map<_Key, _Tp, _Compare, _Allocator>;
1485 
1486  template <typename _InputIterator, typename _Allocator,
1487  typename = _RequireInputIter<_InputIterator>,
1488  typename = _RequireAllocator<_Allocator>>
1489  map(_InputIterator, _InputIterator, _Allocator)
1490  -> map<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
1491  less<__iter_key_t<_InputIterator>>, _Allocator>;
1492 
1493  template<typename _Key, typename _Tp, typename _Allocator,
1494  typename = _RequireAllocator<_Allocator>>
1495  map(initializer_list<pair<_Key, _Tp>>, _Allocator)
1496  -> map<_Key, _Tp, less<_Key>, _Allocator>;
1497 
1498 #endif // deduction guides
1499 
1500  /**
1501  * @brief Map equality comparison.
1502  * @param __x A %map.
1503  * @param __y A %map of the same type as @a x.
1504  * @return True iff the size and elements of the maps are equal.
1505  *
1506  * This is an equivalence relation. It is linear in the size of the
1507  * maps. Maps are considered equivalent if their sizes are equal,
1508  * and if corresponding elements compare equal.
1509  */
1510  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1511  inline bool
1512  operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1514  { return __x._M_t == __y._M_t; }
1515 
1516 #if __cpp_lib_three_way_comparison
1517  /**
1518  * @brief Map ordering relation.
1519  * @param __x A `map`.
1520  * @param __y A `map` of the same type as `x`.
1521  * @return A value indicating whether `__x` is less than, equal to,
1522  * greater than, or incomparable with `__y`.
1523  *
1524  * This is a total ordering relation. It is linear in the size of the
1525  * maps. The elements must be comparable with @c <.
1526  *
1527  * See `std::lexicographical_compare_three_way()` for how the determination
1528  * is made. This operator is used to synthesize relational operators like
1529  * `<` and `>=` etc.
1530  */
1531  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1532  inline __detail::__synth3way_t<pair<const _Key, _Tp>>
1533  operator<=>(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1535  { return __x._M_t <=> __y._M_t; }
1536 #else
1537  /**
1538  * @brief Map ordering relation.
1539  * @param __x A %map.
1540  * @param __y A %map of the same type as @a x.
1541  * @return True iff @a x is lexicographically less than @a y.
1542  *
1543  * This is a total ordering relation. It is linear in the size of the
1544  * maps. The elements must be comparable with @c <.
1545  *
1546  * See std::lexicographical_compare() for how the determination is made.
1547  */
1548  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1549  inline bool
1550  operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1551  const map<_Key, _Tp, _Compare, _Alloc>& __y)
1552  { return __x._M_t < __y._M_t; }
1553 
1554  /// Based on operator==
1555  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1556  inline bool
1557  operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1558  const map<_Key, _Tp, _Compare, _Alloc>& __y)
1559  { return !(__x == __y); }
1560 
1561  /// Based on operator<
1562  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1563  inline bool
1564  operator>(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1565  const map<_Key, _Tp, _Compare, _Alloc>& __y)
1566  { return __y < __x; }
1567 
1568  /// Based on operator<
1569  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1570  inline bool
1571  operator<=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1572  const map<_Key, _Tp, _Compare, _Alloc>& __y)
1573  { return !(__y < __x); }
1574 
1575  /// Based on operator<
1576  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1577  inline bool
1578  operator>=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1579  const map<_Key, _Tp, _Compare, _Alloc>& __y)
1580  { return !(__x < __y); }
1581 #endif // three-way comparison
1582 
1583  /// See std::map::swap().
1584  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1585  inline void
1588  _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
1589  { __x.swap(__y); }
1590 
1591 _GLIBCXX_END_NAMESPACE_CONTAINER
1592 
1593 #if __cplusplus > 201402L
1594  // Allow std::map access to internals of compatible maps.
1595  template<typename _Key, typename _Val, typename _Cmp1, typename _Alloc,
1596  typename _Cmp2>
1597  struct
1598  _Rb_tree_merge_helper<_GLIBCXX_STD_C::map<_Key, _Val, _Cmp1, _Alloc>,
1599  _Cmp2>
1600  {
1601  private:
1602  friend class _GLIBCXX_STD_C::map<_Key, _Val, _Cmp1, _Alloc>;
1603 
1604  static auto&
1605  _S_get_tree(_GLIBCXX_STD_C::map<_Key, _Val, _Cmp2, _Alloc>& __map)
1606  { return __map._M_t; }
1607 
1608  static auto&
1609  _S_get_tree(_GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp2, _Alloc>& __map)
1610  { return __map._M_t; }
1611  };
1612 #endif // C++17
1613 
1614 _GLIBCXX_END_NAMESPACE_VERSION
1615 } // namespace std
1616 
1617 #endif /* _STL_MAP_H */
reverse_iterator rbegin() noexcept
Definition: stl_map.h:404
ISO C++ entities toplevel namespace is std.
bool empty() const noexcept
Definition: stl_map.h:477
is_same
Definition: type_traits:780
map(initializer_list< value_type > __l, const allocator_type &__a)
Allocator-extended initialier-list constructor.
Definition: stl_map.h:262
const_reverse_iterator rend() const noexcept
Definition: stl_map.h:431
size_type erase(const key_type &__x)
Erases elements according to the provided key.
Definition: stl_map.h:1117
Primary class template, tuple.
Definition: tuple:66
map(const allocator_type &__a)
Allocator-extended default constructor.
Definition: stl_map.h:248
bool contains(const key_type &__x) const
Finds whether an element with the given key exists.
Definition: stl_map.h:1283
map()=default
Default constructor creates no elements.
std::pair< iterator, bool > insert(value_type &&__x)
Attempts to insert a std::pair into the map.
Definition: stl_map.h:841
const_reverse_iterator crend() const noexcept
Definition: stl_map.h:468
iterator find(const key_type &__x)
Tries to locate an element in a map.
Definition: stl_map.h:1218
mapped_type & at(const key_type &__k)
Access to map data.
Definition: stl_map.h:549
const_reverse_iterator crbegin() const noexcept
Definition: stl_map.h:459
iterator insert(const_iterator __position, const value_type &__x)
Attempts to insert a std::pair into the map.
Definition: stl_map.h:909
iterator end() noexcept
Definition: stl_map.h:386
_GLIBCXX_ABI_TAG_CXX11 iterator erase(iterator __position)
Erases an element from a map.
Definition: stl_map.h:1086
Uniform interface to C++98 and C++11 allocators.
iterator emplace_hint(const_iterator __pos, _Args &&... __args)
Attempts to build and insert a std::pair into the map.
Definition: stl_map.h:638
__enable_if_t< is_constructible< value_type, _Pair >::value, pair< iterator, bool > > insert(_Pair &&__x)
Attempts to insert a std::pair into the map.
Definition: stl_map.h:847
constexpr piecewise_construct_t piecewise_construct
Tag for piecewise construction of std::pair objects.
Definition: stl_pair.h:82
reverse_iterator rend() noexcept
Definition: stl_map.h:422
auto contains(const _Kt &__x) const -> decltype(_M_t._M_find_tr(__x), void(), true)
Finds whether an element with the given key exists.
Definition: stl_map.h:1288
insert_return_type insert(node_type &&__nh)
Re-insert an extracted node.
Definition: stl_map.h:661
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_map.h:1338
map(_InputIterator __first, _InputIterator __last)
Builds a map from a range.
Definition: stl_map.h:285
auto find(const _Kt &__x) -> decltype(_M_t._M_find_tr(__x))
Tries to locate an element in a map.
Definition: stl_map.h:1224
iterator insert(const_iterator __hint, node_type &&__nh)
Re-insert an extracted node.
Definition: stl_map.h:666
Common iterator class.
map(_InputIterator __first, _InputIterator __last, const allocator_type &__a)
Allocator-extended range constructor.
Definition: stl_map.h:268
constexpr bool operator>=(const duration< _Rep1, _Period1 > &__lhs, const duration< _Rep2, _Period2 > &__rhs)
Definition: chrono.h:869
void insert(_InputIterator __first, _InputIterator __last)
Template function that attempts to insert a range of elements.
Definition: stl_map.h:942
_T1 first
The first member.
Definition: stl_pair.h:290
const_iterator cend() const noexcept
Definition: stl_map.h:450
constexpr bool operator>(const duration< _Rep1, _Period1 > &__lhs, const duration< _Rep2, _Period2 > &__rhs)
Definition: chrono.h:862
allocator_type get_allocator() const noexcept
Get a copy of the memory allocation object.
Definition: stl_map.h:358
Node handle type for maps.
Definition: node_handle.h:253
iterator erase(const_iterator __first, const_iterator __last)
Erases a [first,last) range of elements from a map.
Definition: stl_map.h:1137
iterator insert(const_iterator __position, value_type &&__x)
Attempts to insert a std::pair into the map.
Definition: stl_map.h:919
map & operator=(const map &)=default
Map assignment operator.
iterator lower_bound(const key_type &__x)
Finds the beginning of a subsequence matching given key.
Definition: stl_map.h:1307
pair< iterator, bool > insert_or_assign(const key_type &__k, _Obj &&__obj)
Attempts to insert or assign a std::pair into the map.
Definition: stl_map.h:967
size_type max_size() const noexcept
Definition: stl_map.h:487
A standard container made up of (key,value) pairs, which can be retrieved based on a key...
Definition: stl_map.h:102
Struct holding two objects of arbitrary type.
const_iterator end() const noexcept
Definition: stl_map.h:395
void clear() noexcept
Definition: stl_map.h:1182
const_reverse_iterator rbegin() const noexcept
Definition: stl_map.h:413
map & operator=(initializer_list< value_type > __l)
Map list assignment operator.
Definition: stl_map.h:349
const_iterator upper_bound(const key_type &__x) const
Finds the end of a subsequence matching given key.
Definition: stl_map.h:1372
map(_InputIterator __first, _InputIterator __last, const _Compare &__comp, const allocator_type &__a=allocator_type())
Builds a map from a range.
Definition: stl_map.h:302
value_compare value_comp() const
Definition: stl_map.h:1199
A standard container made up of (key,value) pairs, which can be retrieved based on a key...
Definition: stl_map.h:72
typename remove_reference< _Tp >::type remove_reference_t
Alias template for remove_reference.
Definition: type_traits:1718
void insert(std::initializer_list< value_type > __list)
Attempts to insert a list of std::pairs into the map.
Definition: stl_map.h:879
map(const map &__m, const __type_identity_t< allocator_type > &__a)
Allocator-extended copy constructor.
Definition: stl_map.h:252
auto count(const _Kt &__x) const -> decltype(_M_t._M_count_tr(__x))
Finds the number of elements with given key.
Definition: stl_map.h:1270
iterator try_emplace(const_iterator __hint, const key_type &__k, _Args &&... __args)
Attempts to build and insert a std::pair into the map.
Definition: stl_map.h:782
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition: move.h:126
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_map.h:1407
auto find(const _Kt &__x) const -> decltype(_M_t._M_find_tr(__x))
Tries to locate an element in a map.
Definition: stl_map.h:1249
__enable_if_t< is_constructible< value_type, _Pair >::value, iterator > insert(const_iterator __position, _Pair &&__x)
Attempts to insert a std::pair into the map.
Definition: stl_map.h:924
iterator begin() noexcept
Definition: stl_map.h:368
constexpr tuple< _Elements &&... > forward_as_tuple(_Elements &&... __args) noexcept
Create a tuple of lvalue or rvalue references to the arguments.
Definition: tuple:2650
iterator upper_bound(const key_type &__x)
Finds the end of a subsequence matching given key.
Definition: stl_map.h:1352
auto upper_bound(const _Kt &__x) const -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
Finds the end of a subsequence matching given key.
Definition: stl_map.h:1378
std::pair< iterator, bool > insert(const value_type &__x)
Attempts to insert a std::pair into the map.
Definition: stl_map.h:834
const_iterator find(const key_type &__x) const
Tries to locate an element in a map.
Definition: stl_map.h:1243
~map()=default
iterator insert_or_assign(const_iterator __hint, const key_type &__k, _Obj &&__obj)
Attempts to insert or assign a std::pair into the map.
Definition: stl_map.h:1022
std::pair< iterator, iterator > equal_range(const key_type &__x)
Finds a subsequence matching given key.
Definition: stl_map.h:1401
mapped_type & operator[](const key_type &__k)
Subscript ( [] ) access to map data.
Definition: stl_map.h:504
std::pair< iterator, bool > emplace(_Args &&... __args)
Attempts to build and insert a std::pair into the map.
Definition: stl_map.h:588
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_map.h:1313
node_type extract(const key_type &__x)
Extract a node.
Definition: stl_map.h:656
const_iterator cbegin() const noexcept
Definition: stl_map.h:441
auto equal_range(const _Kt &__x) const -> decltype(pair< const_iterator, const_iterator >(_M_t._M_equal_range_tr(__x)))
Finds a subsequence matching given key.
Definition: stl_map.h:1436
initializer_list
void swap(map &__x) noexcept(/*conditional */)
Swaps data with another map.
Definition: stl_map.h:1171
map(initializer_list< value_type > __l, const _Compare &__comp=_Compare(), const allocator_type &__a=allocator_type())
Builds a map from an initializer_list.
Definition: stl_map.h:240
size_type count(const key_type &__x) const
Finds the number of elements with given key.
Definition: stl_map.h:1264
map(map &&__m, const __type_identity_t< allocator_type > &__a) noexcept(is_nothrow_copy_constructible< _Compare >::value &&_Alloc_traits::_S_always_equal())
Allocator-extended move constructor.
Definition: stl_map.h:256
map(const _Compare &__comp, const allocator_type &__a=allocator_type())
Creates a map with no elements.
Definition: stl_map.h:206
pair< iterator, bool > try_emplace(const key_type &__k, _Args &&... __args)
Attempts to build and insert a std::pair into the map.
Definition: stl_map.h:722
std::pair< const_iterator, const_iterator > equal_range(const key_type &__x) const
Finds a subsequence matching given key.
Definition: stl_map.h:1430
is_nothrow_copy_constructible
Definition: type_traits:1201
const_iterator begin() const noexcept
Definition: stl_map.h:377
is_scalar
Definition: type_traits:746
size_type size() const noexcept
Definition: stl_map.h:482
iterator erase(const_iterator __position)
Erases an element from a map.
Definition: stl_map.h:1080
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_map.h:1358
Return type of insert(node_handle&&) on unique maps/sets.
Definition: node_handle.h:395
key_compare key_comp() const
Definition: stl_map.h:1191
const_iterator lower_bound(const key_type &__x) const
Finds the beginning of a subsequence matching given key.
Definition: stl_map.h:1332
node_type extract(const_iterator __pos)
Extract a node.
Definition: stl_map.h:648