libstdc++
stl_map.h
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1 // Map implementation -*- C++ -*-
2 
3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 // Free Software Foundation, Inc.
5 //
6 // This file is part of the GNU ISO C++ Library. This library is free
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25 
26 /*
27  *
28  * Copyright (c) 1994
29  * Hewlett-Packard Company
30  *
31  * Permission to use, copy, modify, distribute and sell this software
32  * and its documentation for any purpose is hereby granted without fee,
33  * provided that the above copyright notice appear in all copies and
34  * that both that copyright notice and this permission notice appear
35  * in supporting documentation. Hewlett-Packard Company makes no
36  * representations about the suitability of this software for any
37  * purpose. It is provided "as is" without express or implied warranty.
38  *
39  *
40  * Copyright (c) 1996,1997
41  * Silicon Graphics Computer Systems, Inc.
42  *
43  * Permission to use, copy, modify, distribute and sell this software
44  * and its documentation for any purpose is hereby granted without fee,
45  * provided that the above copyright notice appear in all copies and
46  * that both that copyright notice and this permission notice appear
47  * in supporting documentation. Silicon Graphics makes no
48  * representations about the suitability of this software for any
49  * purpose. It is provided "as is" without express or implied warranty.
50  */
51 
52 /** @file stl_map.h
53  * This is an internal header file, included by other library headers.
54  * You should not attempt to use it directly.
55  */
56 
57 #ifndef _STL_MAP_H
58 #define _STL_MAP_H 1
59 
60 #include <bits/functexcept.h>
61 #include <bits/concept_check.h>
62 #include <initializer_list>
63 
64 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
65 
66  /**
67  * @brief A standard container made up of (key,value) pairs, which can be
68  * retrieved based on a key, in logarithmic time.
69  *
70  * @ingroup associative_containers
71  *
72  * Meets the requirements of a <a href="tables.html#65">container</a>, a
73  * <a href="tables.html#66">reversible container</a>, and an
74  * <a href="tables.html#69">associative container</a> (using unique keys).
75  * For a @c map<Key,T> the key_type is Key, the mapped_type is T, and the
76  * value_type is std::pair<const Key,T>.
77  *
78  * Maps support bidirectional iterators.
79  *
80  * The private tree data is declared exactly the same way for map and
81  * multimap; the distinction is made entirely in how the tree functions are
82  * called (*_unique versus *_equal, same as the standard).
83  */
84  template <typename _Key, typename _Tp, typename _Compare = std::less<_Key>,
85  typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
86  class map
87  {
88  public:
89  typedef _Key key_type;
90  typedef _Tp mapped_type;
92  typedef _Compare key_compare;
93  typedef _Alloc allocator_type;
94 
95  private:
96  // concept requirements
97  typedef typename _Alloc::value_type _Alloc_value_type;
98  __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
99  __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
100  _BinaryFunctionConcept)
101  __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
102 
103  public:
104  class value_compare
105  : public std::binary_function<value_type, value_type, bool>
106  {
107  friend class map<_Key, _Tp, _Compare, _Alloc>;
108  protected:
109  _Compare comp;
110 
111  value_compare(_Compare __c)
112  : comp(__c) { }
113 
114  public:
115  bool operator()(const value_type& __x, const value_type& __y) const
116  { return comp(__x.first, __y.first); }
117  };
118 
119  private:
120  /// This turns a red-black tree into a [multi]map.
121  typedef typename _Alloc::template rebind<value_type>::other
122  _Pair_alloc_type;
123 
124  typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
125  key_compare, _Pair_alloc_type> _Rep_type;
126 
127  /// The actual tree structure.
128  _Rep_type _M_t;
129 
130  public:
131  // many of these are specified differently in ISO, but the following are
132  // "functionally equivalent"
133  typedef typename _Pair_alloc_type::pointer pointer;
134  typedef typename _Pair_alloc_type::const_pointer const_pointer;
135  typedef typename _Pair_alloc_type::reference reference;
136  typedef typename _Pair_alloc_type::const_reference const_reference;
137  typedef typename _Rep_type::iterator iterator;
138  typedef typename _Rep_type::const_iterator const_iterator;
139  typedef typename _Rep_type::size_type size_type;
140  typedef typename _Rep_type::difference_type difference_type;
143 
144  // [23.3.1.1] construct/copy/destroy
145  // (get_allocator() is normally listed in this section, but seems to have
146  // been accidentally omitted in the printed standard)
147  /**
148  * @brief Default constructor creates no elements.
149  */
150  map()
151  : _M_t() { }
152 
153  /**
154  * @brief Creates a %map with no elements.
155  * @param comp A comparison object.
156  * @param a An allocator object.
157  */
158  explicit
159  map(const _Compare& __comp,
160  const allocator_type& __a = allocator_type())
161  : _M_t(__comp, __a) { }
162 
163  /**
164  * @brief %Map copy constructor.
165  * @param x A %map of identical element and allocator types.
166  *
167  * The newly-created %map uses a copy of the allocation object
168  * used by @a x.
169  */
170  map(const map& __x)
171  : _M_t(__x._M_t) { }
172 
173 #ifdef __GXX_EXPERIMENTAL_CXX0X__
174  /**
175  * @brief %Map move constructor.
176  * @param x A %map of identical element and allocator types.
177  *
178  * The newly-created %map contains the exact contents of @a x.
179  * The contents of @a x are a valid, but unspecified %map.
180  */
181  map(map&& __x)
182  : _M_t(std::forward<_Rep_type>(__x._M_t)) { }
183 
184  /**
185  * @brief Builds a %map from an initializer_list.
186  * @param l An initializer_list.
187  * @param comp A comparison object.
188  * @param a An allocator object.
189  *
190  * Create a %map consisting of copies of the elements in the
191  * initializer_list @a l.
192  * This is linear in N if the range is already sorted, and NlogN
193  * otherwise (where N is @a l.size()).
194  */
196  const _Compare& __c = _Compare(),
197  const allocator_type& __a = allocator_type())
198  : _M_t(__c, __a)
199  { _M_t._M_insert_unique(__l.begin(), __l.end()); }
200 #endif
201 
202  /**
203  * @brief Builds a %map from a range.
204  * @param first An input iterator.
205  * @param last An input iterator.
206  *
207  * Create a %map consisting of copies of the elements from [first,last).
208  * This is linear in N if the range is already sorted, and NlogN
209  * otherwise (where N is distance(first,last)).
210  */
211  template<typename _InputIterator>
212  map(_InputIterator __first, _InputIterator __last)
213  : _M_t()
214  { _M_t._M_insert_unique(__first, __last); }
215 
216  /**
217  * @brief Builds a %map from a range.
218  * @param first An input iterator.
219  * @param last An input iterator.
220  * @param comp A comparison functor.
221  * @param a An allocator object.
222  *
223  * Create a %map consisting of copies of the elements from [first,last).
224  * This is linear in N if the range is already sorted, and NlogN
225  * otherwise (where N is distance(first,last)).
226  */
227  template<typename _InputIterator>
228  map(_InputIterator __first, _InputIterator __last,
229  const _Compare& __comp,
230  const allocator_type& __a = allocator_type())
231  : _M_t(__comp, __a)
232  { _M_t._M_insert_unique(__first, __last); }
233 
234  // FIXME There is no dtor declared, but we should have something
235  // generated by Doxygen. I don't know what tags to add to this
236  // paragraph to make that happen:
237  /**
238  * The dtor only erases the elements, and note that if the elements
239  * themselves are pointers, the pointed-to memory is not touched in any
240  * way. Managing the pointer is the user's responsibility.
241  */
242 
243  /**
244  * @brief %Map assignment operator.
245  * @param x A %map of identical element and allocator types.
246  *
247  * All the elements of @a x are copied, but unlike the copy constructor,
248  * the allocator object is not copied.
249  */
250  map&
251  operator=(const map& __x)
252  {
253  _M_t = __x._M_t;
254  return *this;
255  }
256 
257 #ifdef __GXX_EXPERIMENTAL_CXX0X__
258  /**
259  * @brief %Map move assignment operator.
260  * @param x A %map of identical element and allocator types.
261  *
262  * The contents of @a x are moved into this map (without copying).
263  * @a x is a valid, but unspecified %map.
264  */
265  map&
266  operator=(map&& __x)
267  {
268  // NB: DR 675.
269  this->clear();
270  this->swap(__x);
271  return *this;
272  }
273 
274  /**
275  * @brief %Map list assignment operator.
276  * @param l An initializer_list.
277  *
278  * This function fills a %map with copies of the elements in the
279  * initializer list @a l.
280  *
281  * Note that the assignment completely changes the %map and
282  * that the resulting %map's size is the same as the number
283  * of elements assigned. Old data may be lost.
284  */
285  map&
287  {
288  this->clear();
289  this->insert(__l.begin(), __l.end());
290  return *this;
291  }
292 #endif
293 
294  /// Get a copy of the memory allocation object.
295  allocator_type
297  { return _M_t.get_allocator(); }
298 
299  // iterators
300  /**
301  * Returns a read/write iterator that points to the first pair in the
302  * %map.
303  * Iteration is done in ascending order according to the keys.
304  */
305  iterator
307  { return _M_t.begin(); }
308 
309  /**
310  * Returns a read-only (constant) iterator that points to the first pair
311  * in the %map. Iteration is done in ascending order according to the
312  * keys.
313  */
314  const_iterator
315  begin() const
316  { return _M_t.begin(); }
317 
318  /**
319  * Returns a read/write iterator that points one past the last
320  * pair in the %map. Iteration is done in ascending order
321  * according to the keys.
322  */
323  iterator
324  end()
325  { return _M_t.end(); }
326 
327  /**
328  * Returns a read-only (constant) iterator that points one past the last
329  * pair in the %map. Iteration is done in ascending order according to
330  * the keys.
331  */
332  const_iterator
333  end() const
334  { return _M_t.end(); }
335 
336  /**
337  * Returns a read/write reverse iterator that points to the last pair in
338  * the %map. Iteration is done in descending order according to the
339  * keys.
340  */
341  reverse_iterator
343  { return _M_t.rbegin(); }
344 
345  /**
346  * Returns a read-only (constant) reverse iterator that points to the
347  * last pair in the %map. Iteration is done in descending order
348  * according to the keys.
349  */
350  const_reverse_iterator
351  rbegin() const
352  { return _M_t.rbegin(); }
353 
354  /**
355  * Returns a read/write reverse iterator that points to one before the
356  * first pair in the %map. Iteration is done in descending order
357  * according to the keys.
358  */
359  reverse_iterator
361  { return _M_t.rend(); }
362 
363  /**
364  * Returns a read-only (constant) reverse iterator that points to one
365  * before the first pair in the %map. Iteration is done in descending
366  * order according to the keys.
367  */
368  const_reverse_iterator
369  rend() const
370  { return _M_t.rend(); }
371 
372 #ifdef __GXX_EXPERIMENTAL_CXX0X__
373  /**
374  * Returns a read-only (constant) iterator that points to the first pair
375  * in the %map. Iteration is done in ascending order according to the
376  * keys.
377  */
378  const_iterator
379  cbegin() const
380  { return _M_t.begin(); }
381 
382  /**
383  * Returns a read-only (constant) iterator that points one past the last
384  * pair in the %map. Iteration is done in ascending order according to
385  * the keys.
386  */
387  const_iterator
388  cend() const
389  { return _M_t.end(); }
390 
391  /**
392  * Returns a read-only (constant) reverse iterator that points to the
393  * last pair in the %map. Iteration is done in descending order
394  * according to the keys.
395  */
396  const_reverse_iterator
397  crbegin() const
398  { return _M_t.rbegin(); }
399 
400  /**
401  * Returns a read-only (constant) reverse iterator that points to one
402  * before the first pair in the %map. Iteration is done in descending
403  * order according to the keys.
404  */
405  const_reverse_iterator
406  crend() const
407  { return _M_t.rend(); }
408 #endif
409 
410  // capacity
411  /** Returns true if the %map is empty. (Thus begin() would equal
412  * end().)
413  */
414  bool
415  empty() const
416  { return _M_t.empty(); }
417 
418  /** Returns the size of the %map. */
419  size_type
420  size() const
421  { return _M_t.size(); }
422 
423  /** Returns the maximum size of the %map. */
424  size_type
425  max_size() const
426  { return _M_t.max_size(); }
427 
428  // [23.3.1.2] element access
429  /**
430  * @brief Subscript ( @c [] ) access to %map data.
431  * @param k The key for which data should be retrieved.
432  * @return A reference to the data of the (key,data) %pair.
433  *
434  * Allows for easy lookup with the subscript ( @c [] )
435  * operator. Returns data associated with the key specified in
436  * subscript. If the key does not exist, a pair with that key
437  * is created using default values, which is then returned.
438  *
439  * Lookup requires logarithmic time.
440  */
441  mapped_type&
442  operator[](const key_type& __k)
443  {
444  // concept requirements
445  __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
446 
447  iterator __i = lower_bound(__k);
448  // __i->first is greater than or equivalent to __k.
449  if (__i == end() || key_comp()(__k, (*__i).first))
450  __i = insert(__i, value_type(__k, mapped_type()));
451  return (*__i).second;
452  }
453 
454  // _GLIBCXX_RESOLVE_LIB_DEFECTS
455  // DR 464. Suggestion for new member functions in standard containers.
456  /**
457  * @brief Access to %map data.
458  * @param k The key for which data should be retrieved.
459  * @return A reference to the data whose key is equivalent to @a k, if
460  * such a data is present in the %map.
461  * @throw std::out_of_range If no such data is present.
462  */
463  mapped_type&
464  at(const key_type& __k)
465  {
466  iterator __i = lower_bound(__k);
467  if (__i == end() || key_comp()(__k, (*__i).first))
468  __throw_out_of_range(__N("map::at"));
469  return (*__i).second;
470  }
471 
472  const mapped_type&
473  at(const key_type& __k) const
474  {
475  const_iterator __i = lower_bound(__k);
476  if (__i == end() || key_comp()(__k, (*__i).first))
477  __throw_out_of_range(__N("map::at"));
478  return (*__i).second;
479  }
480 
481  // modifiers
482  /**
483  * @brief Attempts to insert a std::pair into the %map.
484 
485  * @param x Pair to be inserted (see std::make_pair for easy creation
486  * of pairs).
487 
488  * @return A pair, of which the first element is an iterator that
489  * points to the possibly inserted pair, and the second is
490  * a bool that is true if the pair was actually inserted.
491  *
492  * This function attempts to insert a (key, value) %pair into the %map.
493  * A %map relies on unique keys and thus a %pair is only inserted if its
494  * first element (the key) is not already present in the %map.
495  *
496  * Insertion requires logarithmic time.
497  */
499  insert(const value_type& __x)
500  { return _M_t._M_insert_unique(__x); }
501 
502 #ifdef __GXX_EXPERIMENTAL_CXX0X__
503  /**
504  * @brief Attempts to insert a list of std::pairs into the %map.
505  * @param list A std::initializer_list<value_type> of pairs to be
506  * inserted.
507  *
508  * Complexity similar to that of the range constructor.
509  */
510  void
512  { insert (__list.begin(), __list.end()); }
513 #endif
514 
515  /**
516  * @brief Attempts to insert a std::pair into the %map.
517  * @param position An iterator that serves as a hint as to where the
518  * pair should be inserted.
519  * @param x Pair to be inserted (see std::make_pair for easy creation
520  * of pairs).
521  * @return An iterator that points to the element with key of @a x (may
522  * or may not be the %pair passed in).
523  *
524 
525  * This function is not concerned about whether the insertion
526  * took place, and thus does not return a boolean like the
527  * single-argument insert() does. Note that the first
528  * parameter is only a hint and can potentially improve the
529  * performance of the insertion process. A bad hint would
530  * cause no gains in efficiency.
531  *
532  * See
533  * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
534  * for more on "hinting".
535  *
536  * Insertion requires logarithmic time (if the hint is not taken).
537  */
538  iterator
539  insert(iterator __position, const value_type& __x)
540  { return _M_t._M_insert_unique_(__position, __x); }
541 
542  /**
543  * @brief Template function that attempts to insert a range of elements.
544  * @param first Iterator pointing to the start of the range to be
545  * inserted.
546  * @param last Iterator pointing to the end of the range.
547  *
548  * Complexity similar to that of the range constructor.
549  */
550  template<typename _InputIterator>
551  void
552  insert(_InputIterator __first, _InputIterator __last)
553  { _M_t._M_insert_unique(__first, __last); }
554 
555  /**
556  * @brief Erases an element from a %map.
557  * @param position An iterator pointing to the element to be erased.
558  *
559  * This function erases an element, pointed to by the given
560  * iterator, from a %map. Note that this function only erases
561  * the element, and that if the element is itself a pointer,
562  * the pointed-to memory is not touched in any way. Managing
563  * the pointer is the user's responsibility.
564  */
565  void
566  erase(iterator __position)
567  { _M_t.erase(__position); }
568 
569  /**
570  * @brief Erases elements according to the provided key.
571  * @param x Key of element to be erased.
572  * @return The number of elements erased.
573  *
574  * This function erases all the elements located by the given key from
575  * a %map.
576  * Note that this function only erases the element, and that if
577  * the element is itself a pointer, the pointed-to memory is not touched
578  * in any way. Managing the pointer is the user's responsibility.
579  */
580  size_type
581  erase(const key_type& __x)
582  { return _M_t.erase(__x); }
583 
584  /**
585  * @brief Erases a [first,last) range of elements from a %map.
586  * @param first Iterator pointing to the start of the range to be
587  * erased.
588  * @param last Iterator pointing to the end of the range to be erased.
589  *
590  * This function erases a sequence of elements from a %map.
591  * Note that this function only erases the element, and that if
592  * the element is itself a pointer, the pointed-to memory is not touched
593  * in any way. Managing the pointer is the user's responsibility.
594  */
595  void
596  erase(iterator __first, iterator __last)
597  { _M_t.erase(__first, __last); }
598 
599  /**
600  * @brief Swaps data with another %map.
601  * @param x A %map of the same element and allocator types.
602  *
603  * This exchanges the elements between two maps in constant
604  * time. (It is only swapping a pointer, an integer, and an
605  * instance of the @c Compare type (which itself is often
606  * stateless and empty), so it should be quite fast.) Note
607  * that the global std::swap() function is specialized such
608  * that std::swap(m1,m2) will feed to this function.
609  */
610  void
611 #ifdef __GXX_EXPERIMENTAL_CXX0X__
612  swap(map&& __x)
613 #else
614  swap(map& __x)
615 #endif
616  { _M_t.swap(__x._M_t); }
617 
618  /**
619  * Erases all elements in a %map. Note that this function only
620  * erases the elements, and that if the elements themselves are
621  * pointers, the pointed-to memory is not touched in any way.
622  * Managing the pointer is the user's responsibility.
623  */
624  void
626  { _M_t.clear(); }
627 
628  // observers
629  /**
630  * Returns the key comparison object out of which the %map was
631  * constructed.
632  */
633  key_compare
634  key_comp() const
635  { return _M_t.key_comp(); }
636 
637  /**
638  * Returns a value comparison object, built from the key comparison
639  * object out of which the %map was constructed.
640  */
641  value_compare
642  value_comp() const
643  { return value_compare(_M_t.key_comp()); }
644 
645  // [23.3.1.3] map operations
646  /**
647  * @brief Tries to locate an element in a %map.
648  * @param x Key of (key, value) %pair to be located.
649  * @return Iterator pointing to sought-after element, or end() if not
650  * found.
651  *
652  * This function takes a key and tries to locate the element with which
653  * the key matches. If successful the function returns an iterator
654  * pointing to the sought after %pair. If unsuccessful it returns the
655  * past-the-end ( @c end() ) iterator.
656  */
657  iterator
658  find(const key_type& __x)
659  { return _M_t.find(__x); }
660 
661  /**
662  * @brief Tries to locate an element in a %map.
663  * @param x Key of (key, value) %pair to be located.
664  * @return Read-only (constant) iterator pointing to sought-after
665  * element, or end() if not found.
666  *
667  * This function takes a key and tries to locate the element with which
668  * the key matches. If successful the function returns a constant
669  * iterator pointing to the sought after %pair. If unsuccessful it
670  * returns the past-the-end ( @c end() ) iterator.
671  */
672  const_iterator
673  find(const key_type& __x) const
674  { return _M_t.find(__x); }
675 
676  /**
677  * @brief Finds the number of elements with given key.
678  * @param x Key of (key, value) pairs to be located.
679  * @return Number of elements with specified key.
680  *
681  * This function only makes sense for multimaps; for map the result will
682  * either be 0 (not present) or 1 (present).
683  */
684  size_type
685  count(const key_type& __x) const
686  { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
687 
688  /**
689  * @brief Finds the beginning of a subsequence matching given key.
690  * @param x Key of (key, value) pair to be located.
691  * @return Iterator pointing to first element equal to or greater
692  * than key, or end().
693  *
694  * This function returns the first element of a subsequence of elements
695  * that matches the given key. If unsuccessful it returns an iterator
696  * pointing to the first element that has a greater value than given key
697  * or end() if no such element exists.
698  */
699  iterator
700  lower_bound(const key_type& __x)
701  { return _M_t.lower_bound(__x); }
702 
703  /**
704  * @brief Finds the beginning of a subsequence matching given key.
705  * @param x Key of (key, value) pair to be located.
706  * @return Read-only (constant) iterator pointing to first element
707  * equal to or greater than key, or end().
708  *
709  * This function returns the first element of a subsequence of elements
710  * that matches the given key. If unsuccessful it returns an iterator
711  * pointing to the first element that has a greater value than given key
712  * or end() if no such element exists.
713  */
714  const_iterator
715  lower_bound(const key_type& __x) const
716  { return _M_t.lower_bound(__x); }
717 
718  /**
719  * @brief Finds the end of a subsequence matching given key.
720  * @param x Key of (key, value) pair to be located.
721  * @return Iterator pointing to the first element
722  * greater than key, or end().
723  */
724  iterator
725  upper_bound(const key_type& __x)
726  { return _M_t.upper_bound(__x); }
727 
728  /**
729  * @brief Finds the end of a subsequence matching given key.
730  * @param x Key of (key, value) pair to be located.
731  * @return Read-only (constant) iterator pointing to first iterator
732  * greater than key, or end().
733  */
734  const_iterator
735  upper_bound(const key_type& __x) const
736  { return _M_t.upper_bound(__x); }
737 
738  /**
739  * @brief Finds a subsequence matching given key.
740  * @param x Key of (key, value) pairs to be located.
741  * @return Pair of iterators that possibly points to the subsequence
742  * matching given key.
743  *
744  * This function is equivalent to
745  * @code
746  * std::make_pair(c.lower_bound(val),
747  * c.upper_bound(val))
748  * @endcode
749  * (but is faster than making the calls separately).
750  *
751  * This function probably only makes sense for multimaps.
752  */
754  equal_range(const key_type& __x)
755  { return _M_t.equal_range(__x); }
756 
757  /**
758  * @brief Finds a subsequence matching given key.
759  * @param x Key of (key, value) pairs to be located.
760  * @return Pair of read-only (constant) iterators that possibly points
761  * to the subsequence matching given key.
762  *
763  * This function is equivalent to
764  * @code
765  * std::make_pair(c.lower_bound(val),
766  * c.upper_bound(val))
767  * @endcode
768  * (but is faster than making the calls separately).
769  *
770  * This function probably only makes sense for multimaps.
771  */
773  equal_range(const key_type& __x) const
774  { return _M_t.equal_range(__x); }
775 
776  template<typename _K1, typename _T1, typename _C1, typename _A1>
777  friend bool
779  const map<_K1, _T1, _C1, _A1>&);
780 
781  template<typename _K1, typename _T1, typename _C1, typename _A1>
782  friend bool
783  operator<(const map<_K1, _T1, _C1, _A1>&,
784  const map<_K1, _T1, _C1, _A1>&);
785  };
786 
787  /**
788  * @brief Map equality comparison.
789  * @param x A %map.
790  * @param y A %map of the same type as @a x.
791  * @return True iff the size and elements of the maps are equal.
792  *
793  * This is an equivalence relation. It is linear in the size of the
794  * maps. Maps are considered equivalent if their sizes are equal,
795  * and if corresponding elements compare equal.
796  */
797  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
798  inline bool
801  { return __x._M_t == __y._M_t; }
802 
803  /**
804  * @brief Map ordering relation.
805  * @param x A %map.
806  * @param y A %map of the same type as @a x.
807  * @return True iff @a x is lexicographically less than @a y.
808  *
809  * This is a total ordering relation. It is linear in the size of the
810  * maps. The elements must be comparable with @c <.
811  *
812  * See std::lexicographical_compare() for how the determination is made.
813  */
814  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
815  inline bool
816  operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x,
818  { return __x._M_t < __y._M_t; }
819 
820  /// Based on operator==
821  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
822  inline bool
825  { return !(__x == __y); }
826 
827  /// Based on operator<
828  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
829  inline bool
832  { return __y < __x; }
833 
834  /// Based on operator<
835  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
836  inline bool
837  operator<=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
839  { return !(__y < __x); }
840 
841  /// Based on operator<
842  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
843  inline bool
846  { return !(__x < __y); }
847 
848  /// See std::map::swap().
849  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
850  inline void
853  { __x.swap(__y); }
854 
855 #ifdef __GXX_EXPERIMENTAL_CXX0X__
856  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
857  inline void
858  swap(map<_Key, _Tp, _Compare, _Alloc>&& __x,
859  map<_Key, _Tp, _Compare, _Alloc>& __y)
860  { __x.swap(__y); }
861 
862  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
863  inline void
864  swap(map<_Key, _Tp, _Compare, _Alloc>& __x,
865  map<_Key, _Tp, _Compare, _Alloc>&& __y)
866  { __x.swap(__y); }
867 #endif
868 
869 _GLIBCXX_END_NESTED_NAMESPACE
870 
871 #endif /* _STL_MAP_H */
reverse_iterator rbegin()
Definition: stl_map.h:342
mapped_type & operator[](const key_type &__k)
Subscript ( [] ) access to map data.
Definition: stl_map.h:442
pair holds two objects of arbitrary type.
Definition: stl_pair.h:67
map()
Default constructor creates no elements.
Definition: stl_map.h:150
iterator find(const key_type &__x)
Tries to locate an element in a map.
Definition: stl_map.h:658
std::pair< iterator, iterator > equal_range(const key_type &__x)
Finds a subsequence matching given key.
Definition: stl_map.h:754
map & operator=(initializer_list< value_type > __l)
Map list assignment operator.
Definition: stl_map.h:286
size_type erase(const key_type &__x)
Erases elements according to the provided key.
Definition: stl_map.h:581
std::pair< const_iterator, const_iterator > equal_range(const key_type &__x) const
Finds a subsequence matching given key.
Definition: stl_map.h:773
std::pair< iterator, bool > insert(const value_type &__x)
Attempts to insert a std::pair into the map.
Definition: stl_map.h:499
bool empty() const
Definition: stl_map.h:415
const_iterator begin() const
Definition: stl_map.h:315
bool operator>=(const map< _Key, _Tp, _Compare, _Alloc > &__x, const map< _Key, _Tp, _Compare, _Alloc > &__y)
Based on operator<.
Definition: stl_map.h:844
bool operator==(const map< _Key, _Tp, _Compare, _Alloc > &__x, const map< _Key, _Tp, _Compare, _Alloc > &__y)
Map equality comparison.
Definition: stl_map.h:799
iterator insert(iterator __position, const value_type &__x)
Attempts to insert a std::pair into the map.
Definition: stl_map.h:539
void insert(std::initializer_list< value_type > __list)
Attempts to insert a list of std::pairs into the map.
Definition: stl_map.h:511
iterator lower_bound(const key_type &__x)
Finds the beginning of a subsequence matching given key.
Definition: stl_map.h:700
map & operator=(map &&__x)
Map move assignment operator.
Definition: stl_map.h:266
const_iterator lower_bound(const key_type &__x) const
Finds the beginning of a subsequence matching given key.
Definition: stl_map.h:715
size_type size() const
Definition: stl_map.h:420
iterator upper_bound(const key_type &__x)
Finds the end of a subsequence matching given key.
Definition: stl_map.h:725
map & operator=(const map &__x)
Map assignment operator.
Definition: stl_map.h:251
_T1 first
first is a copy of the first object
Definition: stl_pair.h:72
initializer_list
const_reverse_iterator crend() const
Definition: stl_map.h:406
key_compare key_comp() const
Definition: stl_map.h:634
map(_InputIterator __first, _InputIterator __last)
Builds a map from a range.
Definition: stl_map.h:212
const_iterator find(const key_type &__x) const
Tries to locate an element in a map.
Definition: stl_map.h:673
reverse_iterator rend()
Definition: stl_map.h:360
const_reverse_iterator crbegin() const
Definition: stl_map.h:397
bool operator>(const map< _Key, _Tp, _Compare, _Alloc > &__x, const map< _Key, _Tp, _Compare, _Alloc > &__y)
Based on operator<.
Definition: stl_map.h:830
const_iterator cend() const
Definition: stl_map.h:388
value_compare value_comp() const
Definition: stl_map.h:642
size_type count(const key_type &__x) const
Finds the number of elements with given key.
Definition: stl_map.h:685
map(map &&__x)
Map move constructor.
Definition: stl_map.h:181
A standard container made up of (key,value) pairs, which can be retrieved based on a key...
Definition: stl_map.h:86
void insert(_InputIterator __first, _InputIterator __last)
Template function that attempts to insert a range of elements.
Definition: stl_map.h:552
mapped_type & at(const key_type &__k)
Access to map data.
Definition: stl_map.h:464
void erase(iterator __position)
Erases an element from a map.
Definition: stl_map.h:566
const_reverse_iterator rbegin() const
Definition: stl_map.h:351
map(initializer_list< value_type > __l, const _Compare &__c=_Compare(), const allocator_type &__a=allocator_type())
Builds a map from an initializer_list.
Definition: stl_map.h:195
map(const map &__x)
Map copy constructor.
Definition: stl_map.h:170
allocator_type get_allocator() const
Get a copy of the memory allocation object.
Definition: stl_map.h:296
const_reverse_iterator rend() const
Definition: stl_map.h:369
const_iterator end() const
Definition: stl_map.h:333
bool operator!=(const map< _Key, _Tp, _Compare, _Alloc > &__x, const map< _Key, _Tp, _Compare, _Alloc > &__y)
Based on operator==.
Definition: stl_map.h:823
map(const _Compare &__comp, const allocator_type &__a=allocator_type())
Creates a map with no elements.
Definition: stl_map.h:159
iterator begin()
Definition: stl_map.h:306
size_type max_size() const
Definition: stl_map.h:425
void erase(iterator __first, iterator __last)
Erases a [first,last) range of elements from a map.
Definition: stl_map.h:596
iterator end()
Definition: stl_map.h:324
map(_InputIterator __first, _InputIterator __last, const _Compare &__comp, const allocator_type &__a=allocator_type())
Builds a map from a range.
Definition: stl_map.h:228
const_iterator upper_bound(const key_type &__x) const
Finds the end of a subsequence matching given key.
Definition: stl_map.h:735
void clear()
Definition: stl_map.h:625
const_iterator cbegin() const
Definition: stl_map.h:379
void swap(map &&__x)
Swaps data with another map.
Definition: stl_map.h:612