1 // Map implementation -*- C++ -*-
3 // Copyright (C) 2001-2015 Free Software Foundation, Inc.
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)
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.
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.
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/>.
28 * Hewlett-Packard Company
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.
39 * Copyright (c) 1996,1997
40 * Silicon Graphics Computer Systems, Inc.
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.
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}
59 #include <bits/functexcept.h>
60 #include <bits/concept_check.h>
61 #if __cplusplus >= 201103L
62 #include <initializer_list>
66 namespace std
_GLIBCXX_VISIBILITY(default)
68 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
71 * @brief A standard container made up of (key,value) pairs, which can be
72 * retrieved based on a key, in logarithmic time.
74 * @ingroup associative_containers
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>.
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>.
88 * Maps support bidirectional iterators.
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).
94 template <typename _Key
, typename _Tp
, typename _Compare
= std::less
<_Key
>,
95 typename _Alloc
= std::allocator
<std::pair
<const _Key
, _Tp
> > >
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
;
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
)
115 : public std::binary_function
<value_type
, value_type
, bool>
117 friend class map
<_Key
, _Tp
, _Compare
, _Alloc
>;
121 value_compare(_Compare __c
)
125 bool operator()(const value_type
& __x
, const value_type
& __y
) const
126 { return comp(__x
.first
, __y
.first
); }
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
;
134 typedef _Rb_tree
<key_type
, value_type
, _Select1st
<value_type
>,
135 key_compare
, _Pair_alloc_type
> _Rep_type
;
137 /// The actual tree structure.
140 typedef __gnu_cxx::__alloc_traits
<_Pair_alloc_type
> _Alloc_traits
;
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
;
156 // [23.3.1.1] construct/copy/destroy
157 // (get_allocator() is also listed in this section)
160 * @brief Default constructor creates no elements.
163 #if __cplusplus >= 201103L
164 noexcept(is_nothrow_default_constructible
<allocator_type
>::value
)
169 * @brief Creates a %map with no elements.
170 * @param __comp A comparison object.
171 * @param __a An allocator object.
174 map(const _Compare
& __comp
,
175 const allocator_type
& __a
= allocator_type())
176 : _M_t(__comp
, _Pair_alloc_type(__a
)) { }
179 * @brief %Map copy constructor.
180 * @param __x A %map of identical element and allocator types.
182 * The newly-created %map uses a copy of the allocation object
188 #if __cplusplus >= 201103L
190 * @brief %Map move constructor.
191 * @param __x A %map of identical element and allocator types.
193 * The newly-created %map contains the exact contents of @a __x.
194 * The contents of @a __x are a valid, but unspecified %map.
197 noexcept(is_nothrow_copy_constructible
<_Compare
>::value
)
198 : _M_t(std::move(__x
._M_t
)) { }
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.
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()).
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()); }
217 /// Allocator-extended default constructor.
219 map(const allocator_type
& __a
)
220 : _M_t(_Compare(), _Pair_alloc_type(__a
)) { }
222 /// Allocator-extended copy constructor.
223 map(const map
& __m
, const allocator_type
& __a
)
224 : _M_t(__m
._M_t
, _Pair_alloc_type(__a
)) { }
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
)) { }
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()); }
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
); }
246 * @brief Builds a %map from a range.
247 * @param __first An input iterator.
248 * @param __last An input iterator.
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)).
255 template<typename _InputIterator
>
256 map(_InputIterator __first
, _InputIterator __last
)
258 { _M_t
._M_insert_unique(__first
, __last
); }
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.
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)).
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
); }
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:
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.
289 * @brief %Map assignment operator.
290 * @param __x A %map of identical element and allocator types.
292 * All the elements of @a __x are copied, but unlike the copy
293 * constructor, the allocator object is not copied.
296 operator=(const map
& __x
)
302 #if __cplusplus >= 201103L
303 /// Move assignment operator.
305 operator=(map
&&) = default;
308 * @brief %Map list assignment operator.
309 * @param __l An initializer_list.
311 * This function fills a %map with copies of the elements in the
312 * initializer list @a __l.
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.
319 operator=(initializer_list
<value_type
> __l
)
321 _M_t
._M_assign_unique(__l
.begin(), __l
.end());
326 /// Get a copy of the memory allocation object.
328 get_allocator() const _GLIBCXX_NOEXCEPT
329 { return allocator_type(_M_t
.get_allocator()); }
333 * Returns a read/write iterator that points to the first pair in the
335 * Iteration is done in ascending order according to the keys.
338 begin() _GLIBCXX_NOEXCEPT
339 { return _M_t
.begin(); }
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
347 begin() const _GLIBCXX_NOEXCEPT
348 { return _M_t
.begin(); }
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.
356 end() _GLIBCXX_NOEXCEPT
357 { return _M_t
.end(); }
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
365 end() const _GLIBCXX_NOEXCEPT
366 { return _M_t
.end(); }
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
374 rbegin() _GLIBCXX_NOEXCEPT
375 { return _M_t
.rbegin(); }
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.
382 const_reverse_iterator
383 rbegin() const _GLIBCXX_NOEXCEPT
384 { return _M_t
.rbegin(); }
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.
392 rend() _GLIBCXX_NOEXCEPT
393 { return _M_t
.rend(); }
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.
400 const_reverse_iterator
401 rend() const _GLIBCXX_NOEXCEPT
402 { return _M_t
.rend(); }
404 #if __cplusplus >= 201103L
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
411 cbegin() const noexcept
412 { return _M_t
.begin(); }
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
420 cend() const noexcept
421 { return _M_t
.end(); }
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.
428 const_reverse_iterator
429 crbegin() const noexcept
430 { return _M_t
.rbegin(); }
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.
437 const_reverse_iterator
438 crend() const noexcept
439 { return _M_t
.rend(); }
443 /** Returns true if the %map is empty. (Thus begin() would equal
447 empty() const _GLIBCXX_NOEXCEPT
448 { return _M_t
.empty(); }
450 /** Returns the size of the %map. */
452 size() const _GLIBCXX_NOEXCEPT
453 { return _M_t
.size(); }
455 /** Returns the maximum size of the %map. */
457 max_size() const _GLIBCXX_NOEXCEPT
458 { return _M_t
.max_size(); }
460 // [23.3.1.2] element access
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.
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.
471 * Lookup requires logarithmic time.
474 operator[](const key_type
& __k
)
476 // concept requirements
477 __glibcxx_function_requires(_DefaultConstructibleConcept
<mapped_type
>)
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
),
487 __i
= insert(__i
, value_type(__k
, mapped_type()));
489 return (*__i
).second
;
492 #if __cplusplus >= 201103L
494 operator[](key_type
&& __k
)
496 // concept requirements
497 __glibcxx_function_requires(_DefaultConstructibleConcept
<mapped_type
>)
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
)),
505 return (*__i
).second
;
509 // _GLIBCXX_RESOLVE_LIB_DEFECTS
510 // DR 464. Suggestion for new member functions in standard containers.
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.
519 at(const key_type
& __k
)
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
;
528 at(const key_type
& __k
) const
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
;
537 #if __cplusplus >= 201103L
539 * @brief Attempts to build and insert a std::pair into the %map.
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).
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.
549 * This function attempts to build and insert a (key, value) %pair into
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.
554 * Insertion requires logarithmic time.
556 template<typename
... _Args
>
557 std::pair
<iterator
, bool>
558 emplace(_Args
&&... __args
)
559 { return _M_t
._M_emplace_unique(std::forward
<_Args
>(__args
)...); }
562 * @brief Attempts to build and insert a std::pair into the %map.
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
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()
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.
581 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
582 * for more on @a hinting.
584 * Insertion requires logarithmic time (if the hint is not taken).
586 template<typename
... _Args
>
588 emplace_hint(const_iterator __pos
, _Args
&&... __args
)
590 return _M_t
._M_emplace_hint_unique(__pos
,
591 std::forward
<_Args
>(__args
)...);
596 * @brief Attempts to insert a std::pair into the %map.
598 * @param __x Pair to be inserted (see std::make_pair for easy
599 * creation of pairs).
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.
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.
609 * Insertion requires logarithmic time.
611 std::pair
<iterator
, bool>
612 insert(const value_type
& __x
)
613 { return _M_t
._M_insert_unique(__x
); }
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>
621 { return _M_t
._M_insert_unique(std::forward
<_Pair
>(__x
)); }
624 #if __cplusplus >= 201103L
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
630 * Complexity similar to that of the range constructor.
633 insert(std::initializer_list
<value_type
> __list
)
634 { insert(__list
.begin(), __list
.end()); }
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
643 * @return An iterator that points to the element with key of
644 * @a __x (may or may not be the %pair passed in).
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.
655 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
656 * for more on @a hinting.
658 * Insertion requires logarithmic time (if the hint is not taken).
661 #if __cplusplus >= 201103L
662 insert(const_iterator __position
, const value_type
& __x
)
664 insert(iterator __position
, const value_type
& __x
)
666 { return _M_t
._M_insert_unique_(__position
, __x
); }
668 #if __cplusplus >= 201103L
669 template<typename _Pair
, typename
= typename
670 std::enable_if
<std::is_constructible
<value_type
,
671 _Pair
&&>::value
>::type
>
673 insert(const_iterator __position
, _Pair
&& __x
)
674 { return _M_t
._M_insert_unique_(__position
,
675 std::forward
<_Pair
>(__x
)); }
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
682 * @param __last Iterator pointing to the end of the range.
684 * Complexity similar to that of the range constructor.
686 template<typename _InputIterator
>
688 insert(_InputIterator __first
, _InputIterator __last
)
689 { _M_t
._M_insert_unique(__first
, __last
); }
691 #if __cplusplus >= 201103L
692 // _GLIBCXX_RESOLVE_LIB_DEFECTS
693 // DR 130. Associative erase should return an iterator.
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.
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.
708 erase(const_iterator __position
)
709 { return _M_t
.erase(__position
); }
712 _GLIBCXX_ABI_TAG_CXX11
714 erase(iterator __position
)
715 { return _M_t
.erase(__position
); }
718 * @brief Erases an element from a %map.
719 * @param __position An iterator pointing to the element to be erased.
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.
728 erase(iterator __position
)
729 { _M_t
.erase(__position
); }
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.
737 * This function erases all the elements located by the given key from
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.
744 erase(const key_type
& __x
)
745 { return _M_t
.erase(__x
); }
747 #if __cplusplus >= 201103L
748 // _GLIBCXX_RESOLVE_LIB_DEFECTS
749 // DR 130. Associative erase should return an iterator.
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
754 * @param __last Iterator pointing to the end of the range to
756 * @return The iterator @a __last.
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.
764 erase(const_iterator __first
, const_iterator __last
)
765 { return _M_t
.erase(__first
, __last
); }
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
771 * @param __last Iterator pointing to the end of the range to
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.
780 erase(iterator __first
, iterator __last
)
781 { _M_t
.erase(__first
, __last
); }
785 * @brief Swaps data with another %map.
786 * @param __x A %map of the same element and allocator types.
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.
797 #if __cplusplus >= 201103L
798 noexcept(_Alloc_traits::_S_nothrow_swap())
800 { _M_t
.swap(__x
._M_t
); }
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.
809 clear() _GLIBCXX_NOEXCEPT
814 * Returns the key comparison object out of which the %map was
819 { return _M_t
.key_comp(); }
822 * Returns a value comparison object, built from the key comparison
823 * object out of which the %map was constructed.
827 { return value_compare(_M_t
.key_comp()); }
829 // [23.3.1.3] map operations
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
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.
845 find(const key_type
& __x
)
846 { return _M_t
.find(__x
); }
848 #if __cplusplus > 201103L
849 template<typename _Kt
>
851 find(const _Kt
& __x
) -> decltype(_M_t
._M_find_tr(__x
))
852 { return _M_t
._M_find_tr(__x
); }
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.
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.
870 find(const key_type
& __x
) const
871 { return _M_t
.find(__x
); }
873 #if __cplusplus > 201103L
874 template<typename _Kt
>
876 find(const _Kt
& __x
) const -> decltype(_M_t
._M_find_tr(__x
))
877 { return _M_t
._M_find_tr(__x
); }
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.
887 * This function only makes sense for multimaps; for map the result will
888 * either be 0 (not present) or 1 (present).
891 count(const key_type
& __x
) const
892 { return _M_t
.find(__x
) == _M_t
.end() ? 0 : 1; }
894 #if __cplusplus > 201103L
895 template<typename _Kt
>
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; }
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().
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.
915 lower_bound(const key_type
& __x
)
916 { return _M_t
.lower_bound(__x
); }
918 #if __cplusplus > 201103L
919 template<typename _Kt
>
921 lower_bound(const _Kt
& __x
)
922 -> decltype(_M_t
._M_lower_bound_tr(__x
))
923 { return _M_t
._M_lower_bound_tr(__x
); }
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().
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.
940 lower_bound(const key_type
& __x
) const
941 { return _M_t
.lower_bound(__x
); }
943 #if __cplusplus > 201103L
944 template<typename _Kt
>
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
); }
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().
960 upper_bound(const key_type
& __x
)
961 { return _M_t
.upper_bound(__x
); }
963 #if __cplusplus > 201103L
964 template<typename _Kt
>
966 upper_bound(const _Kt
& __x
)
967 -> decltype(_M_t
._M_upper_bound_tr(__x
))
968 { return _M_t
._M_upper_bound_tr(__x
); }
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().
980 upper_bound(const key_type
& __x
) const
981 { return _M_t
.upper_bound(__x
); }
983 #if __cplusplus > 201103L
984 template<typename _Kt
>
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
); }
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.
999 * This function is equivalent to
1001 * std::make_pair(c.lower_bound(val),
1002 * c.upper_bound(val))
1004 * (but is faster than making the calls separately).
1006 * This function probably only makes sense for multimaps.
1008 std::pair
<iterator
, iterator
>
1009 equal_range(const key_type
& __x
)
1010 { return _M_t
.equal_range(__x
); }
1012 #if __cplusplus > 201103L
1013 template<typename _Kt
>
1015 equal_range(const _Kt
& __x
)
1016 -> decltype(_M_t
._M_equal_range_tr(__x
))
1017 { return _M_t
._M_equal_range_tr(__x
); }
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.
1028 * This function is equivalent to
1030 * std::make_pair(c.lower_bound(val),
1031 * c.upper_bound(val))
1033 * (but is faster than making the calls separately).
1035 * This function probably only makes sense for multimaps.
1037 std::pair
<const_iterator
, const_iterator
>
1038 equal_range(const key_type
& __x
) const
1039 { return _M_t
.equal_range(__x
); }
1041 #if __cplusplus > 201103L
1042 template<typename _Kt
>
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
); }
1050 template<typename _K1
, typename _T1
, typename _C1
, typename _A1
>
1052 operator==(const map
<_K1
, _T1
, _C1
, _A1
>&,
1053 const map
<_K1
, _T1
, _C1
, _A1
>&);
1055 template<typename _K1
, typename _T1
, typename _C1
, typename _A1
>
1057 operator<(const map
<_K1
, _T1
, _C1
, _A1
>&,
1058 const map
<_K1
, _T1
, _C1
, _A1
>&);
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.
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.
1071 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
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
; }
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.
1083 * This is a total ordering relation. It is linear in the size of the
1084 * maps. The elements must be comparable with @c <.
1086 * See std::lexicographical_compare() for how the determination is made.
1088 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
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
; }
1094 /// Based on operator==
1095 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1097 operator!=(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1098 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1099 { return !(__x
== __y
); }
1101 /// Based on operator<
1102 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1104 operator>(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1105 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1106 { return __y
< __x
; }
1108 /// Based on operator<
1109 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1111 operator<=(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1112 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1113 { return !(__y
< __x
); }
1115 /// Based on operator<
1116 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1118 operator>=(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1119 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1120 { return !(__x
< __y
); }
1122 /// See std::map::swap().
1123 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1125 swap(map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1126 map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1129 _GLIBCXX_END_NAMESPACE_CONTAINER
1132 #endif /* _STL_MAP_H */