1// Map implementation -*- C++ -*-
2
3// Copyright (C) 2001-2015 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation.  Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose.  It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1996,1997
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
66namespace std _GLIBCXX_VISIBILITY(default)
67{
68_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
69
70  /**
71   *  @brief A standard container made up of (key,value) pairs, which can be
72   *  retrieved based on a key, in logarithmic time.
73   *
74   *  @ingroup associative_containers
75   *
76   *  @tparam _Key  Type of key objects.
77   *  @tparam  _Tp  Type of mapped objects.
78   *  @tparam _Compare  Comparison function object type, defaults to less<_Key>.
79   *  @tparam _Alloc  Allocator type, defaults to
80   *                  allocator<pair<const _Key, _Tp>.
81   *
82   *  Meets the requirements of a <a href="tables.html#65">container</a>, a
83   *  <a href="tables.html#66">reversible container</a>, and an
84   *  <a href="tables.html#69">associative container</a> (using unique keys).
85   *  For a @c map<Key,T> the key_type is Key, the mapped_type is T, and the
86   *  value_type is std::pair<const Key,T>.
87   *
88   *  Maps support bidirectional iterators.
89   *
90   *  The private tree data is declared exactly the same way for map and
91   *  multimap; the distinction is made entirely in how the tree functions are
92   *  called (*_unique versus *_equal, same as the standard).
93  */
94  template <typename _Key, typename _Tp, typename _Compare = std::less<_Key>,
95            typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
96    class map
97    {
98    public:
99      typedef _Key                                          key_type;
100      typedef _Tp                                           mapped_type;
101      typedef std::pair<const _Key, _Tp>                    value_type;
102      typedef _Compare                                      key_compare;
103      typedef _Alloc                                        allocator_type;
104
105    private:
106      // concept requirements
107      typedef typename _Alloc::value_type                   _Alloc_value_type;
108      __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
109      __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
110				_BinaryFunctionConcept)
111      __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
112
113    public:
114      class value_compare
115      : public std::binary_function<value_type, value_type, bool>
116      {
117	friend class map<_Key, _Tp, _Compare, _Alloc>;
118      protected:
119	_Compare comp;
120
121	value_compare(_Compare __c)
122	: comp(__c) { }
123
124      public:
125	bool operator()(const value_type& __x, const value_type& __y) const
126	{ return comp(__x.first, __y.first); }
127      };
128
129    private:
130      /// This turns a red-black tree into a [multi]map.
131      typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
132	rebind<value_type>::other _Pair_alloc_type;
133
134      typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
135		       key_compare, _Pair_alloc_type> _Rep_type;
136
137      /// The actual tree structure.
138      _Rep_type _M_t;
139
140      typedef __gnu_cxx::__alloc_traits<_Pair_alloc_type> _Alloc_traits;
141
142    public:
143      // many of these are specified differently in ISO, but the following are
144      // "functionally equivalent"
145      typedef typename _Alloc_traits::pointer            pointer;
146      typedef typename _Alloc_traits::const_pointer      const_pointer;
147      typedef typename _Alloc_traits::reference          reference;
148      typedef typename _Alloc_traits::const_reference    const_reference;
149      typedef typename _Rep_type::iterator               iterator;
150      typedef typename _Rep_type::const_iterator         const_iterator;
151      typedef typename _Rep_type::size_type              size_type;
152      typedef typename _Rep_type::difference_type        difference_type;
153      typedef typename _Rep_type::reverse_iterator       reverse_iterator;
154      typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
155
156      // [23.3.1.1] construct/copy/destroy
157      // (get_allocator() is also listed in this section)
158
159      /**
160       *  @brief  Default constructor creates no elements.
161       */
162      map()
163#if __cplusplus >= 201103L
164      noexcept(is_nothrow_default_constructible<allocator_type>::value)
165#endif
166      : _M_t() { }
167
168      /**
169       *  @brief  Creates a %map with no elements.
170       *  @param  __comp  A comparison object.
171       *  @param  __a  An allocator object.
172       */
173      explicit
174      map(const _Compare& __comp,
175	  const allocator_type& __a = allocator_type())
176      : _M_t(__comp, _Pair_alloc_type(__a)) { }
177
178      /**
179       *  @brief  %Map copy constructor.
180       *  @param  __x  A %map of identical element and allocator types.
181       *
182       *  The newly-created %map uses a copy of the allocation object
183       *  used by @a __x.
184       */
185      map(const map& __x)
186      : _M_t(__x._M_t) { }
187
188#if __cplusplus >= 201103L
189      /**
190       *  @brief  %Map move constructor.
191       *  @param  __x  A %map of identical element and allocator types.
192       *
193       *  The newly-created %map contains the exact contents of @a __x.
194       *  The contents of @a __x are a valid, but unspecified %map.
195       */
196      map(map&& __x)
197      noexcept(is_nothrow_copy_constructible<_Compare>::value)
198      : _M_t(std::move(__x._M_t)) { }
199
200      /**
201       *  @brief  Builds a %map from an initializer_list.
202       *  @param  __l  An initializer_list.
203       *  @param  __comp  A comparison object.
204       *  @param  __a  An allocator object.
205       *
206       *  Create a %map consisting of copies of the elements in the
207       *  initializer_list @a __l.
208       *  This is linear in N if the range is already sorted, and NlogN
209       *  otherwise (where N is @a __l.size()).
210       */
211      map(initializer_list<value_type> __l,
212	  const _Compare& __comp = _Compare(),
213	  const allocator_type& __a = allocator_type())
214      : _M_t(__comp, _Pair_alloc_type(__a))
215      { _M_t._M_insert_unique(__l.begin(), __l.end()); }
216
217      /// Allocator-extended default constructor.
218      explicit
219      map(const allocator_type& __a)
220      : _M_t(_Compare(), _Pair_alloc_type(__a)) { }
221
222      /// Allocator-extended copy constructor.
223      map(const map& __m, const allocator_type& __a)
224      : _M_t(__m._M_t, _Pair_alloc_type(__a)) { }
225
226      /// Allocator-extended move constructor.
227      map(map&& __m, const allocator_type& __a)
228      noexcept(is_nothrow_copy_constructible<_Compare>::value
229	       && _Alloc_traits::_S_always_equal())
230      : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { }
231
232      /// Allocator-extended initialier-list constructor.
233      map(initializer_list<value_type> __l, const allocator_type& __a)
234      : _M_t(_Compare(), _Pair_alloc_type(__a))
235      { _M_t._M_insert_unique(__l.begin(), __l.end()); }
236
237      /// Allocator-extended range constructor.
238      template<typename _InputIterator>
239        map(_InputIterator __first, _InputIterator __last,
240	    const allocator_type& __a)
241	: _M_t(_Compare(), _Pair_alloc_type(__a))
242        { _M_t._M_insert_unique(__first, __last); }
243#endif
244
245      /**
246       *  @brief  Builds a %map from a range.
247       *  @param  __first  An input iterator.
248       *  @param  __last  An input iterator.
249       *
250       *  Create a %map consisting of copies of the elements from
251       *  [__first,__last).  This is linear in N if the range is
252       *  already sorted, and NlogN otherwise (where N is
253       *  distance(__first,__last)).
254       */
255      template<typename _InputIterator>
256        map(_InputIterator __first, _InputIterator __last)
257	: _M_t()
258        { _M_t._M_insert_unique(__first, __last); }
259
260      /**
261       *  @brief  Builds a %map from a range.
262       *  @param  __first  An input iterator.
263       *  @param  __last  An input iterator.
264       *  @param  __comp  A comparison functor.
265       *  @param  __a  An allocator object.
266       *
267       *  Create a %map consisting of copies of the elements from
268       *  [__first,__last).  This is linear in N if the range is
269       *  already sorted, and NlogN otherwise (where N is
270       *  distance(__first,__last)).
271       */
272      template<typename _InputIterator>
273        map(_InputIterator __first, _InputIterator __last,
274	    const _Compare& __comp,
275	    const allocator_type& __a = allocator_type())
276	: _M_t(__comp, _Pair_alloc_type(__a))
277        { _M_t._M_insert_unique(__first, __last); }
278
279      // FIXME There is no dtor declared, but we should have something
280      // generated by Doxygen.  I don't know what tags to add to this
281      // paragraph to make that happen:
282      /**
283       *  The dtor only erases the elements, and note that if the elements
284       *  themselves are pointers, the pointed-to memory is not touched in any
285       *  way.  Managing the pointer is the user's responsibility.
286       */
287
288      /**
289       *  @brief  %Map assignment operator.
290       *  @param  __x  A %map of identical element and allocator types.
291       *
292       *  All the elements of @a __x are copied, but unlike the copy
293       *  constructor, the allocator object is not copied.
294       */
295      map&
296      operator=(const map& __x)
297      {
298	_M_t = __x._M_t;
299	return *this;
300      }
301
302#if __cplusplus >= 201103L
303      /// Move assignment operator.
304      map&
305      operator=(map&&) = default;
306
307      /**
308       *  @brief  %Map list assignment operator.
309       *  @param  __l  An initializer_list.
310       *
311       *  This function fills a %map with copies of the elements in the
312       *  initializer list @a __l.
313       *
314       *  Note that the assignment completely changes the %map and
315       *  that the resulting %map's size is the same as the number
316       *  of elements assigned.  Old data may be lost.
317       */
318      map&
319      operator=(initializer_list<value_type> __l)
320      {
321	_M_t._M_assign_unique(__l.begin(), __l.end());
322	return *this;
323      }
324#endif
325
326      /// Get a copy of the memory allocation object.
327      allocator_type
328      get_allocator() const _GLIBCXX_NOEXCEPT
329      { return allocator_type(_M_t.get_allocator()); }
330
331      // iterators
332      /**
333       *  Returns a read/write iterator that points to the first pair in the
334       *  %map.
335       *  Iteration is done in ascending order according to the keys.
336       */
337      iterator
338      begin() _GLIBCXX_NOEXCEPT
339      { return _M_t.begin(); }
340
341      /**
342       *  Returns a read-only (constant) iterator that points to the first pair
343       *  in the %map.  Iteration is done in ascending order according to the
344       *  keys.
345       */
346      const_iterator
347      begin() const _GLIBCXX_NOEXCEPT
348      { return _M_t.begin(); }
349
350      /**
351       *  Returns a read/write iterator that points one past the last
352       *  pair in the %map.  Iteration is done in ascending order
353       *  according to the keys.
354       */
355      iterator
356      end() _GLIBCXX_NOEXCEPT
357      { return _M_t.end(); }
358
359      /**
360       *  Returns a read-only (constant) iterator that points one past the last
361       *  pair in the %map.  Iteration is done in ascending order according to
362       *  the keys.
363       */
364      const_iterator
365      end() const _GLIBCXX_NOEXCEPT
366      { return _M_t.end(); }
367
368      /**
369       *  Returns a read/write reverse iterator that points to the last pair in
370       *  the %map.  Iteration is done in descending order according to the
371       *  keys.
372       */
373      reverse_iterator
374      rbegin() _GLIBCXX_NOEXCEPT
375      { return _M_t.rbegin(); }
376
377      /**
378       *  Returns a read-only (constant) reverse iterator that points to the
379       *  last pair in the %map.  Iteration is done in descending order
380       *  according to the keys.
381       */
382      const_reverse_iterator
383      rbegin() const _GLIBCXX_NOEXCEPT
384      { return _M_t.rbegin(); }
385
386      /**
387       *  Returns a read/write reverse iterator that points to one before the
388       *  first pair in the %map.  Iteration is done in descending order
389       *  according to the keys.
390       */
391      reverse_iterator
392      rend() _GLIBCXX_NOEXCEPT
393      { return _M_t.rend(); }
394
395      /**
396       *  Returns a read-only (constant) reverse iterator that points to one
397       *  before the first pair in the %map.  Iteration is done in descending
398       *  order according to the keys.
399       */
400      const_reverse_iterator
401      rend() const _GLIBCXX_NOEXCEPT
402      { return _M_t.rend(); }
403
404#if __cplusplus >= 201103L
405      /**
406       *  Returns a read-only (constant) iterator that points to the first pair
407       *  in the %map.  Iteration is done in ascending order according to the
408       *  keys.
409       */
410      const_iterator
411      cbegin() const noexcept
412      { return _M_t.begin(); }
413
414      /**
415       *  Returns a read-only (constant) iterator that points one past the last
416       *  pair in the %map.  Iteration is done in ascending order according to
417       *  the keys.
418       */
419      const_iterator
420      cend() const noexcept
421      { return _M_t.end(); }
422
423      /**
424       *  Returns a read-only (constant) reverse iterator that points to the
425       *  last pair in the %map.  Iteration is done in descending order
426       *  according to the keys.
427       */
428      const_reverse_iterator
429      crbegin() const noexcept
430      { return _M_t.rbegin(); }
431
432      /**
433       *  Returns a read-only (constant) reverse iterator that points to one
434       *  before the first pair in the %map.  Iteration is done in descending
435       *  order according to the keys.
436       */
437      const_reverse_iterator
438      crend() const noexcept
439      { return _M_t.rend(); }
440#endif
441
442      // capacity
443      /** Returns true if the %map is empty.  (Thus begin() would equal
444       *  end().)
445      */
446      bool
447      empty() const _GLIBCXX_NOEXCEPT
448      { return _M_t.empty(); }
449
450      /** Returns the size of the %map.  */
451      size_type
452      size() const _GLIBCXX_NOEXCEPT
453      { return _M_t.size(); }
454
455      /** Returns the maximum size of the %map.  */
456      size_type
457      max_size() const _GLIBCXX_NOEXCEPT
458      { return _M_t.max_size(); }
459
460      // [23.3.1.2] element access
461      /**
462       *  @brief  Subscript ( @c [] ) access to %map data.
463       *  @param  __k  The key for which data should be retrieved.
464       *  @return  A reference to the data of the (key,data) %pair.
465       *
466       *  Allows for easy lookup with the subscript ( @c [] )
467       *  operator.  Returns data associated with the key specified in
468       *  subscript.  If the key does not exist, a pair with that key
469       *  is created using default values, which is then returned.
470       *
471       *  Lookup requires logarithmic time.
472       */
473      mapped_type&
474      operator[](const key_type& __k)
475      {
476	// concept requirements
477	__glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
478
479	iterator __i = lower_bound(__k);
480	// __i->first is greater than or equivalent to __k.
481	if (__i == end() || key_comp()(__k, (*__i).first))
482#if __cplusplus >= 201103L
483	  __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
484					    std::tuple<const key_type&>(__k),
485					    std::tuple<>());
486#else
487          __i = insert(__i, value_type(__k, mapped_type()));
488#endif
489	return (*__i).second;
490      }
491
492#if __cplusplus >= 201103L
493      mapped_type&
494      operator[](key_type&& __k)
495      {
496	// concept requirements
497	__glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
498
499	iterator __i = lower_bound(__k);
500	// __i->first is greater than or equivalent to __k.
501	if (__i == end() || key_comp()(__k, (*__i).first))
502	  __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
503					std::forward_as_tuple(std::move(__k)),
504					std::tuple<>());
505	return (*__i).second;
506      }
507#endif
508
509      // _GLIBCXX_RESOLVE_LIB_DEFECTS
510      // DR 464. Suggestion for new member functions in standard containers.
511      /**
512       *  @brief  Access to %map data.
513       *  @param  __k  The key for which data should be retrieved.
514       *  @return  A reference to the data whose key is equivalent to @a __k, if
515       *           such a data is present in the %map.
516       *  @throw  std::out_of_range  If no such data is present.
517       */
518      mapped_type&
519      at(const key_type& __k)
520      {
521	iterator __i = lower_bound(__k);
522	if (__i == end() || key_comp()(__k, (*__i).first))
523	  __throw_out_of_range(__N("map::at"));
524	return (*__i).second;
525      }
526
527      const mapped_type&
528      at(const key_type& __k) const
529      {
530	const_iterator __i = lower_bound(__k);
531	if (__i == end() || key_comp()(__k, (*__i).first))
532	  __throw_out_of_range(__N("map::at"));
533	return (*__i).second;
534      }
535
536      // modifiers
537#if __cplusplus >= 201103L
538      /**
539       *  @brief Attempts to build and insert a std::pair into the %map.
540       *
541       *  @param __args  Arguments used to generate a new pair instance (see
542       *	        std::piecewise_contruct for passing arguments to each
543       *	        part of the pair constructor).
544       *
545       *  @return  A pair, of which the first element is an iterator that points
546       *           to the possibly inserted pair, and the second is a bool that
547       *           is true if the pair was actually inserted.
548       *
549       *  This function attempts to build and insert a (key, value) %pair into
550       *  the %map.
551       *  A %map relies on unique keys and thus a %pair is only inserted if its
552       *  first element (the key) is not already present in the %map.
553       *
554       *  Insertion requires logarithmic time.
555       */
556      template<typename... _Args>
557	std::pair<iterator, bool>
558	emplace(_Args&&... __args)
559	{ return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); }
560
561      /**
562       *  @brief Attempts to build and insert a std::pair into the %map.
563       *
564       *  @param  __pos  An iterator that serves as a hint as to where the pair
565       *                should be inserted.
566       *  @param  __args  Arguments used to generate a new pair instance (see
567       *	         std::piecewise_contruct for passing arguments to each
568       *	         part of the pair constructor).
569       *  @return An iterator that points to the element with key of the
570       *          std::pair built from @a __args (may or may not be that
571       *          std::pair).
572       *
573       *  This function is not concerned about whether the insertion took place,
574       *  and thus does not return a boolean like the single-argument emplace()
575       *  does.
576       *  Note that the first parameter is only a hint and can potentially
577       *  improve the performance of the insertion process. A bad hint would
578       *  cause no gains in efficiency.
579       *
580       *  See
581       *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
582       *  for more on @a hinting.
583       *
584       *  Insertion requires logarithmic time (if the hint is not taken).
585       */
586      template<typename... _Args>
587	iterator
588	emplace_hint(const_iterator __pos, _Args&&... __args)
589	{
590	  return _M_t._M_emplace_hint_unique(__pos,
591					     std::forward<_Args>(__args)...);
592	}
593#endif
594
595      /**
596       *  @brief Attempts to insert a std::pair into the %map.
597
598       *  @param __x Pair to be inserted (see std::make_pair for easy
599       *	     creation of pairs).
600       *
601       *  @return  A pair, of which the first element is an iterator that
602       *           points to the possibly inserted pair, and the second is
603       *           a bool that is true if the pair was actually inserted.
604       *
605       *  This function attempts to insert a (key, value) %pair into the %map.
606       *  A %map relies on unique keys and thus a %pair is only inserted if its
607       *  first element (the key) is not already present in the %map.
608       *
609       *  Insertion requires logarithmic time.
610       */
611      std::pair<iterator, bool>
612      insert(const value_type& __x)
613      { return _M_t._M_insert_unique(__x); }
614
615#if __cplusplus >= 201103L
616      template<typename _Pair, typename = typename
617	       std::enable_if<std::is_constructible<value_type,
618						    _Pair&&>::value>::type>
619        std::pair<iterator, bool>
620        insert(_Pair&& __x)
621        { return _M_t._M_insert_unique(std::forward<_Pair>(__x)); }
622#endif
623
624#if __cplusplus >= 201103L
625      /**
626       *  @brief Attempts to insert a list of std::pairs into the %map.
627       *  @param  __list  A std::initializer_list<value_type> of pairs to be
628       *                  inserted.
629       *
630       *  Complexity similar to that of the range constructor.
631       */
632      void
633      insert(std::initializer_list<value_type> __list)
634      { insert(__list.begin(), __list.end()); }
635#endif
636
637      /**
638       *  @brief Attempts to insert a std::pair into the %map.
639       *  @param  __position  An iterator that serves as a hint as to where the
640       *                    pair should be inserted.
641       *  @param  __x  Pair to be inserted (see std::make_pair for easy creation
642       *               of pairs).
643       *  @return An iterator that points to the element with key of
644       *           @a __x (may or may not be the %pair passed in).
645       *
646
647       *  This function is not concerned about whether the insertion
648       *  took place, and thus does not return a boolean like the
649       *  single-argument insert() does.  Note that the first
650       *  parameter is only a hint and can potentially improve the
651       *  performance of the insertion process.  A bad hint would
652       *  cause no gains in efficiency.
653       *
654       *  See
655       *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
656       *  for more on @a hinting.
657       *
658       *  Insertion requires logarithmic time (if the hint is not taken).
659       */
660      iterator
661#if __cplusplus >= 201103L
662      insert(const_iterator __position, const value_type& __x)
663#else
664      insert(iterator __position, const value_type& __x)
665#endif
666      { return _M_t._M_insert_unique_(__position, __x); }
667
668#if __cplusplus >= 201103L
669      template<typename _Pair, typename = typename
670	       std::enable_if<std::is_constructible<value_type,
671						    _Pair&&>::value>::type>
672        iterator
673        insert(const_iterator __position, _Pair&& __x)
674        { return _M_t._M_insert_unique_(__position,
675					std::forward<_Pair>(__x)); }
676#endif
677
678      /**
679       *  @brief Template function that attempts to insert a range of elements.
680       *  @param  __first  Iterator pointing to the start of the range to be
681       *                   inserted.
682       *  @param  __last  Iterator pointing to the end of the range.
683       *
684       *  Complexity similar to that of the range constructor.
685       */
686      template<typename _InputIterator>
687        void
688        insert(_InputIterator __first, _InputIterator __last)
689        { _M_t._M_insert_unique(__first, __last); }
690
691#if __cplusplus >= 201103L
692      // _GLIBCXX_RESOLVE_LIB_DEFECTS
693      // DR 130. Associative erase should return an iterator.
694      /**
695       *  @brief Erases an element from a %map.
696       *  @param  __position  An iterator pointing to the element to be erased.
697       *  @return An iterator pointing to the element immediately following
698       *          @a position prior to the element being erased. If no such
699       *          element exists, end() is returned.
700       *
701       *  This function erases an element, pointed to by the given
702       *  iterator, from a %map.  Note that this function only erases
703       *  the element, and that if the element is itself a pointer,
704       *  the pointed-to memory is not touched in any way.  Managing
705       *  the pointer is the user's responsibility.
706       */
707      iterator
708      erase(const_iterator __position)
709      { return _M_t.erase(__position); }
710
711      // LWG 2059
712      _GLIBCXX_ABI_TAG_CXX11
713      iterator
714      erase(iterator __position)
715      { return _M_t.erase(__position); }
716#else
717      /**
718       *  @brief Erases an element from a %map.
719       *  @param  __position  An iterator pointing to the element to be erased.
720       *
721       *  This function erases an element, pointed to by the given
722       *  iterator, from a %map.  Note that this function only erases
723       *  the element, and that if the element is itself a pointer,
724       *  the pointed-to memory is not touched in any way.  Managing
725       *  the pointer is the user's responsibility.
726       */
727      void
728      erase(iterator __position)
729      { _M_t.erase(__position); }
730#endif
731
732      /**
733       *  @brief Erases elements according to the provided key.
734       *  @param  __x  Key of element to be erased.
735       *  @return  The number of elements erased.
736       *
737       *  This function erases all the elements located by the given key from
738       *  a %map.
739       *  Note that this function only erases the element, and that if
740       *  the element is itself a pointer, the pointed-to memory is not touched
741       *  in any way.  Managing the pointer is the user's responsibility.
742       */
743      size_type
744      erase(const key_type& __x)
745      { return _M_t.erase(__x); }
746
747#if __cplusplus >= 201103L
748      // _GLIBCXX_RESOLVE_LIB_DEFECTS
749      // DR 130. Associative erase should return an iterator.
750      /**
751       *  @brief Erases a [first,last) range of elements from a %map.
752       *  @param  __first  Iterator pointing to the start of the range to be
753       *                   erased.
754       *  @param __last Iterator pointing to the end of the range to
755       *                be erased.
756       *  @return The iterator @a __last.
757       *
758       *  This function erases a sequence of elements from a %map.
759       *  Note that this function only erases the element, and that if
760       *  the element is itself a pointer, the pointed-to memory is not touched
761       *  in any way.  Managing the pointer is the user's responsibility.
762       */
763      iterator
764      erase(const_iterator __first, const_iterator __last)
765      { return _M_t.erase(__first, __last); }
766#else
767      /**
768       *  @brief Erases a [__first,__last) range of elements from a %map.
769       *  @param  __first  Iterator pointing to the start of the range to be
770       *                   erased.
771       *  @param __last Iterator pointing to the end of the range to
772       *                be erased.
773       *
774       *  This function erases a sequence of elements from a %map.
775       *  Note that this function only erases the element, and that if
776       *  the element is itself a pointer, the pointed-to memory is not touched
777       *  in any way.  Managing the pointer is the user's responsibility.
778       */
779      void
780      erase(iterator __first, iterator __last)
781      { _M_t.erase(__first, __last); }
782#endif
783
784      /**
785       *  @brief  Swaps data with another %map.
786       *  @param  __x  A %map of the same element and allocator types.
787       *
788       *  This exchanges the elements between two maps in constant
789       *  time.  (It is only swapping a pointer, an integer, and an
790       *  instance of the @c Compare type (which itself is often
791       *  stateless and empty), so it should be quite fast.)  Note
792       *  that the global std::swap() function is specialized such
793       *  that std::swap(m1,m2) will feed to this function.
794       */
795      void
796      swap(map& __x)
797#if __cplusplus >= 201103L
798      noexcept(_Alloc_traits::_S_nothrow_swap())
799#endif
800      { _M_t.swap(__x._M_t); }
801
802      /**
803       *  Erases all elements in a %map.  Note that this function only
804       *  erases the elements, and that if the elements themselves are
805       *  pointers, the pointed-to memory is not touched in any way.
806       *  Managing the pointer is the user's responsibility.
807       */
808      void
809      clear() _GLIBCXX_NOEXCEPT
810      { _M_t.clear(); }
811
812      // observers
813      /**
814       *  Returns the key comparison object out of which the %map was
815       *  constructed.
816       */
817      key_compare
818      key_comp() const
819      { return _M_t.key_comp(); }
820
821      /**
822       *  Returns a value comparison object, built from the key comparison
823       *  object out of which the %map was constructed.
824       */
825      value_compare
826      value_comp() const
827      { return value_compare(_M_t.key_comp()); }
828
829      // [23.3.1.3] map operations
830
831      //@{
832      /**
833       *  @brief Tries to locate an element in a %map.
834       *  @param  __x  Key of (key, value) %pair to be located.
835       *  @return  Iterator pointing to sought-after element, or end() if not
836       *           found.
837       *
838       *  This function takes a key and tries to locate the element with which
839       *  the key matches.  If successful the function returns an iterator
840       *  pointing to the sought after %pair.  If unsuccessful it returns the
841       *  past-the-end ( @c end() ) iterator.
842       */
843
844      iterator
845      find(const key_type& __x)
846      { return _M_t.find(__x); }
847
848#if __cplusplus > 201103L
849      template<typename _Kt>
850	auto
851	find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
852	{ return _M_t._M_find_tr(__x); }
853#endif
854      //@}
855
856      //@{
857      /**
858       *  @brief Tries to locate an element in a %map.
859       *  @param  __x  Key of (key, value) %pair to be located.
860       *  @return  Read-only (constant) iterator pointing to sought-after
861       *           element, or end() if not found.
862       *
863       *  This function takes a key and tries to locate the element with which
864       *  the key matches.  If successful the function returns a constant
865       *  iterator pointing to the sought after %pair. If unsuccessful it
866       *  returns the past-the-end ( @c end() ) iterator.
867       */
868
869      const_iterator
870      find(const key_type& __x) const
871      { return _M_t.find(__x); }
872
873#if __cplusplus > 201103L
874      template<typename _Kt>
875	auto
876	find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
877	{ return _M_t._M_find_tr(__x); }
878#endif
879      //@}
880
881      //@{
882      /**
883       *  @brief  Finds the number of elements with given key.
884       *  @param  __x  Key of (key, value) pairs to be located.
885       *  @return  Number of elements with specified key.
886       *
887       *  This function only makes sense for multimaps; for map the result will
888       *  either be 0 (not present) or 1 (present).
889       */
890      size_type
891      count(const key_type& __x) const
892      { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
893
894#if __cplusplus > 201103L
895      template<typename _Kt>
896	auto
897	count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
898	{ return _M_t._M_find_tr(__x) == _M_t.end() ? 0 : 1; }
899#endif
900      //@}
901
902      //@{
903      /**
904       *  @brief Finds the beginning of a subsequence matching given key.
905       *  @param  __x  Key of (key, value) pair to be located.
906       *  @return  Iterator pointing to first element equal to or greater
907       *           than key, or end().
908       *
909       *  This function returns the first element of a subsequence of elements
910       *  that matches the given key.  If unsuccessful it returns an iterator
911       *  pointing to the first element that has a greater value than given key
912       *  or end() if no such element exists.
913       */
914      iterator
915      lower_bound(const key_type& __x)
916      { return _M_t.lower_bound(__x); }
917
918#if __cplusplus > 201103L
919      template<typename _Kt>
920	auto
921	lower_bound(const _Kt& __x)
922	-> decltype(_M_t._M_lower_bound_tr(__x))
923	{ return _M_t._M_lower_bound_tr(__x); }
924#endif
925      //@}
926
927      //@{
928      /**
929       *  @brief Finds the beginning of a subsequence matching given key.
930       *  @param  __x  Key of (key, value) pair to be located.
931       *  @return  Read-only (constant) iterator pointing to first element
932       *           equal to or greater than key, or end().
933       *
934       *  This function returns the first element of a subsequence of elements
935       *  that matches the given key.  If unsuccessful it returns an iterator
936       *  pointing to the first element that has a greater value than given key
937       *  or end() if no such element exists.
938       */
939      const_iterator
940      lower_bound(const key_type& __x) const
941      { return _M_t.lower_bound(__x); }
942
943#if __cplusplus > 201103L
944      template<typename _Kt>
945	auto
946	lower_bound(const _Kt& __x) const
947	-> decltype(_M_t._M_lower_bound_tr(__x))
948	{ return _M_t._M_lower_bound_tr(__x); }
949#endif
950      //@}
951
952      //@{
953      /**
954       *  @brief Finds the end of a subsequence matching given key.
955       *  @param  __x  Key of (key, value) pair to be located.
956       *  @return Iterator pointing to the first element
957       *          greater than key, or end().
958       */
959      iterator
960      upper_bound(const key_type& __x)
961      { return _M_t.upper_bound(__x); }
962
963#if __cplusplus > 201103L
964      template<typename _Kt>
965	auto
966	upper_bound(const _Kt& __x)
967	-> decltype(_M_t._M_upper_bound_tr(__x))
968	{ return _M_t._M_upper_bound_tr(__x); }
969#endif
970      //@}
971
972      //@{
973      /**
974       *  @brief Finds the end of a subsequence matching given key.
975       *  @param  __x  Key of (key, value) pair to be located.
976       *  @return  Read-only (constant) iterator pointing to first iterator
977       *           greater than key, or end().
978       */
979      const_iterator
980      upper_bound(const key_type& __x) const
981      { return _M_t.upper_bound(__x); }
982
983#if __cplusplus > 201103L
984      template<typename _Kt>
985	auto
986	upper_bound(const _Kt& __x) const
987	-> decltype(_M_t._M_upper_bound_tr(__x))
988	{ return _M_t._M_upper_bound_tr(__x); }
989#endif
990      //@}
991
992      //@{
993      /**
994       *  @brief Finds a subsequence matching given key.
995       *  @param  __x  Key of (key, value) pairs to be located.
996       *  @return  Pair of iterators that possibly points to the subsequence
997       *           matching given key.
998       *
999       *  This function is equivalent to
1000       *  @code
1001       *    std::make_pair(c.lower_bound(val),
1002       *                   c.upper_bound(val))
1003       *  @endcode
1004       *  (but is faster than making the calls separately).
1005       *
1006       *  This function probably only makes sense for multimaps.
1007       */
1008      std::pair<iterator, iterator>
1009      equal_range(const key_type& __x)
1010      { return _M_t.equal_range(__x); }
1011
1012#if __cplusplus > 201103L
1013      template<typename _Kt>
1014	auto
1015	equal_range(const _Kt& __x)
1016	-> decltype(_M_t._M_equal_range_tr(__x))
1017	{ return _M_t._M_equal_range_tr(__x); }
1018#endif
1019      //@}
1020
1021      //@{
1022      /**
1023       *  @brief Finds a subsequence matching given key.
1024       *  @param  __x  Key of (key, value) pairs to be located.
1025       *  @return  Pair of read-only (constant) iterators that possibly points
1026       *           to the subsequence matching given key.
1027       *
1028       *  This function is equivalent to
1029       *  @code
1030       *    std::make_pair(c.lower_bound(val),
1031       *                   c.upper_bound(val))
1032       *  @endcode
1033       *  (but is faster than making the calls separately).
1034       *
1035       *  This function probably only makes sense for multimaps.
1036       */
1037      std::pair<const_iterator, const_iterator>
1038      equal_range(const key_type& __x) const
1039      { return _M_t.equal_range(__x); }
1040
1041#if __cplusplus > 201103L
1042      template<typename _Kt>
1043	auto
1044	equal_range(const _Kt& __x) const
1045	-> decltype(_M_t._M_equal_range_tr(__x))
1046	{ return _M_t._M_equal_range_tr(__x); }
1047#endif
1048      //@}
1049
1050      template<typename _K1, typename _T1, typename _C1, typename _A1>
1051        friend bool
1052        operator==(const map<_K1, _T1, _C1, _A1>&,
1053		   const map<_K1, _T1, _C1, _A1>&);
1054
1055      template<typename _K1, typename _T1, typename _C1, typename _A1>
1056        friend bool
1057        operator<(const map<_K1, _T1, _C1, _A1>&,
1058		  const map<_K1, _T1, _C1, _A1>&);
1059    };
1060
1061  /**
1062   *  @brief  Map equality comparison.
1063   *  @param  __x  A %map.
1064   *  @param  __y  A %map of the same type as @a x.
1065   *  @return  True iff the size and elements of the maps are equal.
1066   *
1067   *  This is an equivalence relation.  It is linear in the size of the
1068   *  maps.  Maps are considered equivalent if their sizes are equal,
1069   *  and if corresponding elements compare equal.
1070  */
1071  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1072    inline bool
1073    operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1074               const map<_Key, _Tp, _Compare, _Alloc>& __y)
1075    { return __x._M_t == __y._M_t; }
1076
1077  /**
1078   *  @brief  Map ordering relation.
1079   *  @param  __x  A %map.
1080   *  @param  __y  A %map of the same type as @a x.
1081   *  @return  True iff @a x is lexicographically less than @a y.
1082   *
1083   *  This is a total ordering relation.  It is linear in the size of the
1084   *  maps.  The elements must be comparable with @c <.
1085   *
1086   *  See std::lexicographical_compare() for how the determination is made.
1087  */
1088  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1089    inline bool
1090    operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1091              const map<_Key, _Tp, _Compare, _Alloc>& __y)
1092    { return __x._M_t < __y._M_t; }
1093
1094  /// Based on operator==
1095  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1096    inline bool
1097    operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1098               const map<_Key, _Tp, _Compare, _Alloc>& __y)
1099    { return !(__x == __y); }
1100
1101  /// Based on operator<
1102  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1103    inline bool
1104    operator>(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1105              const map<_Key, _Tp, _Compare, _Alloc>& __y)
1106    { return __y < __x; }
1107
1108  /// Based on operator<
1109  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1110    inline bool
1111    operator<=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1112               const map<_Key, _Tp, _Compare, _Alloc>& __y)
1113    { return !(__y < __x); }
1114
1115  /// Based on operator<
1116  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1117    inline bool
1118    operator>=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1119               const map<_Key, _Tp, _Compare, _Alloc>& __y)
1120    { return !(__x < __y); }
1121
1122  /// See std::map::swap().
1123  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1124    inline void
1125    swap(map<_Key, _Tp, _Compare, _Alloc>& __x,
1126	 map<_Key, _Tp, _Compare, _Alloc>& __y)
1127    { __x.swap(__y); }
1128
1129_GLIBCXX_END_NAMESPACE_CONTAINER
1130} // namespace std
1131
1132#endif /* _STL_MAP_H */
1133