1 // Map implementation -*- C++ -*-
3 // Copyright (C) 2001-2018 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_VERSION
69 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
71 template <typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
75 * @brief A standard container made up of (key,value) pairs, which can be
76 * retrieved based on a key, in logarithmic time.
78 * @ingroup associative_containers
80 * @tparam _Key Type of key objects.
81 * @tparam _Tp Type of mapped objects.
82 * @tparam _Compare Comparison function object type, defaults to less<_Key>.
83 * @tparam _Alloc Allocator type, defaults to
84 * allocator<pair<const _Key, _Tp>.
86 * Meets the requirements of a <a href="tables.html#65">container</a>, a
87 * <a href="tables.html#66">reversible container</a>, and an
88 * <a href="tables.html#69">associative container</a> (using unique keys).
89 * For a @c map<Key,T> the key_type is Key, the mapped_type is T, and the
90 * value_type is std::pair<const Key,T>.
92 * Maps support bidirectional iterators.
94 * The private tree data is declared exactly the same way for map and
95 * multimap; the distinction is made entirely in how the tree functions are
96 * called (*_unique versus *_equal, same as the standard).
98 template <typename _Key
, typename _Tp
, typename _Compare
= std::less
<_Key
>,
99 typename _Alloc
= std::allocator
<std::pair
<const _Key
, _Tp
> > >
103 typedef _Key key_type
;
104 typedef _Tp mapped_type
;
105 typedef std::pair
<const _Key
, _Tp
> value_type
;
106 typedef _Compare key_compare
;
107 typedef _Alloc allocator_type
;
110 #ifdef _GLIBCXX_CONCEPT_CHECKS
111 // concept requirements
112 typedef typename
_Alloc::value_type _Alloc_value_type
;
113 # if __cplusplus < 201103L
114 __glibcxx_class_requires(_Tp
, _SGIAssignableConcept
)
116 __glibcxx_class_requires4(_Compare
, bool, _Key
, _Key
,
117 _BinaryFunctionConcept
)
118 __glibcxx_class_requires2(value_type
, _Alloc_value_type
, _SameTypeConcept
)
121 #if __cplusplus >= 201103L && defined(__STRICT_ANSI__)
122 static_assert(is_same
<typename
_Alloc::value_type
, value_type
>::value
,
123 "std::map must have the same value_type as its allocator");
128 : public std::binary_function
<value_type
, value_type
, bool>
130 friend class map
<_Key
, _Tp
, _Compare
, _Alloc
>;
134 value_compare(_Compare __c
)
138 bool operator()(const value_type
& __x
, const value_type
& __y
) const
139 { return comp(__x
.first
, __y
.first
); }
143 /// This turns a red-black tree into a [multi]map.
144 typedef typename
__gnu_cxx::__alloc_traits
<_Alloc
>::template
145 rebind
<value_type
>::other _Pair_alloc_type
;
147 typedef _Rb_tree
<key_type
, value_type
, _Select1st
<value_type
>,
148 key_compare
, _Pair_alloc_type
> _Rep_type
;
150 /// The actual tree structure.
153 typedef __gnu_cxx::__alloc_traits
<_Pair_alloc_type
> _Alloc_traits
;
156 // many of these are specified differently in ISO, but the following are
157 // "functionally equivalent"
158 typedef typename
_Alloc_traits::pointer pointer
;
159 typedef typename
_Alloc_traits::const_pointer const_pointer
;
160 typedef typename
_Alloc_traits::reference reference
;
161 typedef typename
_Alloc_traits::const_reference const_reference
;
162 typedef typename
_Rep_type::iterator iterator
;
163 typedef typename
_Rep_type::const_iterator const_iterator
;
164 typedef typename
_Rep_type::size_type size_type
;
165 typedef typename
_Rep_type::difference_type difference_type
;
166 typedef typename
_Rep_type::reverse_iterator reverse_iterator
;
167 typedef typename
_Rep_type::const_reverse_iterator const_reverse_iterator
;
169 #if __cplusplus > 201402L
170 using node_type
= typename
_Rep_type::node_type
;
171 using insert_return_type
= typename
_Rep_type::insert_return_type
;
174 // [23.3.1.1] construct/copy/destroy
175 // (get_allocator() is also listed in this section)
178 * @brief Default constructor creates no elements.
180 #if __cplusplus < 201103L
187 * @brief Creates a %map with no elements.
188 * @param __comp A comparison object.
189 * @param __a An allocator object.
192 map(const _Compare
& __comp
,
193 const allocator_type
& __a
= allocator_type())
194 : _M_t(__comp
, _Pair_alloc_type(__a
)) { }
197 * @brief %Map copy constructor.
199 * Whether the allocator is copied depends on the allocator traits.
201 #if __cplusplus < 201103L
205 map(const map
&) = default;
208 * @brief %Map move constructor.
210 * The newly-created %map contains the exact contents of the moved
211 * instance. The moved instance is a valid, but unspecified, %map.
213 map(map
&&) = default;
216 * @brief Builds a %map from an initializer_list.
217 * @param __l An initializer_list.
218 * @param __comp A comparison object.
219 * @param __a An allocator object.
221 * Create a %map consisting of copies of the elements in the
222 * initializer_list @a __l.
223 * This is linear in N if the range is already sorted, and NlogN
224 * otherwise (where N is @a __l.size()).
226 map(initializer_list
<value_type
> __l
,
227 const _Compare
& __comp
= _Compare(),
228 const allocator_type
& __a
= allocator_type())
229 : _M_t(__comp
, _Pair_alloc_type(__a
))
230 { _M_t
._M_insert_range_unique(__l
.begin(), __l
.end()); }
232 /// Allocator-extended default constructor.
234 map(const allocator_type
& __a
)
235 : _M_t(_Pair_alloc_type(__a
)) { }
237 /// Allocator-extended copy constructor.
238 map(const map
& __m
, const allocator_type
& __a
)
239 : _M_t(__m
._M_t
, _Pair_alloc_type(__a
)) { }
241 /// Allocator-extended move constructor.
242 map(map
&& __m
, const allocator_type
& __a
)
243 noexcept(is_nothrow_copy_constructible
<_Compare
>::value
244 && _Alloc_traits::_S_always_equal())
245 : _M_t(std::move(__m
._M_t
), _Pair_alloc_type(__a
)) { }
247 /// Allocator-extended initialier-list constructor.
248 map(initializer_list
<value_type
> __l
, const allocator_type
& __a
)
249 : _M_t(_Pair_alloc_type(__a
))
250 { _M_t
._M_insert_range_unique(__l
.begin(), __l
.end()); }
252 /// Allocator-extended range constructor.
253 template<typename _InputIterator
>
254 map(_InputIterator __first
, _InputIterator __last
,
255 const allocator_type
& __a
)
256 : _M_t(_Pair_alloc_type(__a
))
257 { _M_t
._M_insert_range_unique(__first
, __last
); }
261 * @brief Builds a %map from a range.
262 * @param __first An input iterator.
263 * @param __last An input iterator.
265 * Create a %map consisting of copies of the elements from
266 * [__first,__last). This is linear in N if the range is
267 * already sorted, and NlogN otherwise (where N is
268 * distance(__first,__last)).
270 template<typename _InputIterator
>
271 map(_InputIterator __first
, _InputIterator __last
)
273 { _M_t
._M_insert_range_unique(__first
, __last
); }
276 * @brief Builds a %map from a range.
277 * @param __first An input iterator.
278 * @param __last An input iterator.
279 * @param __comp A comparison functor.
280 * @param __a An allocator object.
282 * Create a %map consisting of copies of the elements from
283 * [__first,__last). This is linear in N if the range is
284 * already sorted, and NlogN otherwise (where N is
285 * distance(__first,__last)).
287 template<typename _InputIterator
>
288 map(_InputIterator __first
, _InputIterator __last
,
289 const _Compare
& __comp
,
290 const allocator_type
& __a
= allocator_type())
291 : _M_t(__comp
, _Pair_alloc_type(__a
))
292 { _M_t
._M_insert_range_unique(__first
, __last
); }
294 #if __cplusplus >= 201103L
296 * The dtor only erases the elements, and note that if the elements
297 * themselves are pointers, the pointed-to memory is not touched in any
298 * way. Managing the pointer is the user's responsibility.
304 * @brief %Map assignment operator.
306 * Whether the allocator is copied depends on the allocator traits.
308 #if __cplusplus < 201103L
310 operator=(const map
& __x
)
317 operator=(const map
&) = default;
319 /// Move assignment operator.
321 operator=(map
&&) = default;
324 * @brief %Map list assignment operator.
325 * @param __l An initializer_list.
327 * This function fills a %map with copies of the elements in the
328 * initializer list @a __l.
330 * Note that the assignment completely changes the %map and
331 * that the resulting %map's size is the same as the number
332 * of elements assigned.
335 operator=(initializer_list
<value_type
> __l
)
337 _M_t
._M_assign_unique(__l
.begin(), __l
.end());
342 /// Get a copy of the memory allocation object.
344 get_allocator() const _GLIBCXX_NOEXCEPT
345 { return allocator_type(_M_t
.get_allocator()); }
349 * Returns a read/write iterator that points to the first pair in the
351 * Iteration is done in ascending order according to the keys.
354 begin() _GLIBCXX_NOEXCEPT
355 { return _M_t
.begin(); }
358 * Returns a read-only (constant) iterator that points to the first pair
359 * in the %map. Iteration is done in ascending order according to the
363 begin() const _GLIBCXX_NOEXCEPT
364 { return _M_t
.begin(); }
367 * Returns a read/write iterator that points one past the last
368 * pair in the %map. Iteration is done in ascending order
369 * according to the keys.
372 end() _GLIBCXX_NOEXCEPT
373 { return _M_t
.end(); }
376 * Returns a read-only (constant) iterator that points one past the last
377 * pair in the %map. Iteration is done in ascending order according to
381 end() const _GLIBCXX_NOEXCEPT
382 { return _M_t
.end(); }
385 * Returns a read/write reverse iterator that points to the last pair in
386 * the %map. Iteration is done in descending order according to the
390 rbegin() _GLIBCXX_NOEXCEPT
391 { return _M_t
.rbegin(); }
394 * Returns a read-only (constant) reverse iterator that points to the
395 * last pair in the %map. Iteration is done in descending order
396 * according to the keys.
398 const_reverse_iterator
399 rbegin() const _GLIBCXX_NOEXCEPT
400 { return _M_t
.rbegin(); }
403 * Returns a read/write reverse iterator that points to one before the
404 * first pair in the %map. Iteration is done in descending order
405 * according to the keys.
408 rend() _GLIBCXX_NOEXCEPT
409 { return _M_t
.rend(); }
412 * Returns a read-only (constant) reverse iterator that points to one
413 * before the first pair in the %map. Iteration is done in descending
414 * order according to the keys.
416 const_reverse_iterator
417 rend() const _GLIBCXX_NOEXCEPT
418 { return _M_t
.rend(); }
420 #if __cplusplus >= 201103L
422 * Returns a read-only (constant) iterator that points to the first pair
423 * in the %map. Iteration is done in ascending order according to the
427 cbegin() const noexcept
428 { return _M_t
.begin(); }
431 * Returns a read-only (constant) iterator that points one past the last
432 * pair in the %map. Iteration is done in ascending order according to
436 cend() const noexcept
437 { return _M_t
.end(); }
440 * Returns a read-only (constant) reverse iterator that points to the
441 * last pair in the %map. Iteration is done in descending order
442 * according to the keys.
444 const_reverse_iterator
445 crbegin() const noexcept
446 { return _M_t
.rbegin(); }
449 * Returns a read-only (constant) reverse iterator that points to one
450 * before the first pair in the %map. Iteration is done in descending
451 * order according to the keys.
453 const_reverse_iterator
454 crend() const noexcept
455 { return _M_t
.rend(); }
459 /** Returns true if the %map is empty. (Thus begin() would equal
463 empty() const _GLIBCXX_NOEXCEPT
464 { return _M_t
.empty(); }
466 /** Returns the size of the %map. */
468 size() const _GLIBCXX_NOEXCEPT
469 { return _M_t
.size(); }
471 /** Returns the maximum size of the %map. */
473 max_size() const _GLIBCXX_NOEXCEPT
474 { return _M_t
.max_size(); }
476 // [23.3.1.2] element access
478 * @brief Subscript ( @c [] ) access to %map data.
479 * @param __k The key for which data should be retrieved.
480 * @return A reference to the data of the (key,data) %pair.
482 * Allows for easy lookup with the subscript ( @c [] )
483 * operator. Returns data associated with the key specified in
484 * subscript. If the key does not exist, a pair with that key
485 * is created using default values, which is then returned.
487 * Lookup requires logarithmic time.
490 operator[](const key_type
& __k
)
492 // concept requirements
493 __glibcxx_function_requires(_DefaultConstructibleConcept
<mapped_type
>)
495 iterator __i
= lower_bound(__k
);
496 // __i->first is greater than or equivalent to __k.
497 if (__i
== end() || key_comp()(__k
, (*__i
).first
))
498 #if __cplusplus >= 201103L
499 __i
= _M_t
._M_emplace_hint_unique(__i
, std::piecewise_construct
,
500 std::tuple
<const key_type
&>(__k
),
503 __i
= insert(__i
, value_type(__k
, mapped_type()));
505 return (*__i
).second
;
508 #if __cplusplus >= 201103L
510 operator[](key_type
&& __k
)
512 // concept requirements
513 __glibcxx_function_requires(_DefaultConstructibleConcept
<mapped_type
>)
515 iterator __i
= lower_bound(__k
);
516 // __i->first is greater than or equivalent to __k.
517 if (__i
== end() || key_comp()(__k
, (*__i
).first
))
518 __i
= _M_t
._M_emplace_hint_unique(__i
, std::piecewise_construct
,
519 std::forward_as_tuple(std::move(__k
)),
521 return (*__i
).second
;
525 // _GLIBCXX_RESOLVE_LIB_DEFECTS
526 // DR 464. Suggestion for new member functions in standard containers.
528 * @brief Access to %map data.
529 * @param __k The key for which data should be retrieved.
530 * @return A reference to the data whose key is equivalent to @a __k, if
531 * such a data is present in the %map.
532 * @throw std::out_of_range If no such data is present.
535 at(const key_type
& __k
)
537 iterator __i
= lower_bound(__k
);
538 if (__i
== end() || key_comp()(__k
, (*__i
).first
))
539 __throw_out_of_range(__N("map::at"));
540 return (*__i
).second
;
544 at(const key_type
& __k
) const
546 const_iterator __i
= lower_bound(__k
);
547 if (__i
== end() || key_comp()(__k
, (*__i
).first
))
548 __throw_out_of_range(__N("map::at"));
549 return (*__i
).second
;
553 #if __cplusplus >= 201103L
555 * @brief Attempts to build and insert a std::pair into the %map.
557 * @param __args Arguments used to generate a new pair instance (see
558 * std::piecewise_contruct for passing arguments to each
559 * part of the pair constructor).
561 * @return A pair, of which the first element is an iterator that points
562 * to the possibly inserted pair, and the second is a bool that
563 * is true if the pair was actually inserted.
565 * This function attempts to build and insert a (key, value) %pair into
567 * A %map relies on unique keys and thus a %pair is only inserted if its
568 * first element (the key) is not already present in the %map.
570 * Insertion requires logarithmic time.
572 template<typename
... _Args
>
573 std::pair
<iterator
, bool>
574 emplace(_Args
&&... __args
)
575 { return _M_t
._M_emplace_unique(std::forward
<_Args
>(__args
)...); }
578 * @brief Attempts to build and insert a std::pair into the %map.
580 * @param __pos An iterator that serves as a hint as to where the pair
581 * should be inserted.
582 * @param __args Arguments used to generate a new pair instance (see
583 * std::piecewise_contruct for passing arguments to each
584 * part of the pair constructor).
585 * @return An iterator that points to the element with key of the
586 * std::pair built from @a __args (may or may not be that
589 * This function is not concerned about whether the insertion took place,
590 * and thus does not return a boolean like the single-argument emplace()
592 * Note that the first parameter is only a hint and can potentially
593 * improve the performance of the insertion process. A bad hint would
594 * cause no gains in efficiency.
597 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
598 * for more on @a hinting.
600 * Insertion requires logarithmic time (if the hint is not taken).
602 template<typename
... _Args
>
604 emplace_hint(const_iterator __pos
, _Args
&&... __args
)
606 return _M_t
._M_emplace_hint_unique(__pos
,
607 std::forward
<_Args
>(__args
)...);
611 #if __cplusplus > 201402L
614 extract(const_iterator __pos
)
616 __glibcxx_assert(__pos
!= end());
617 return _M_t
.extract(__pos
);
622 extract(const key_type
& __x
)
623 { return _M_t
.extract(__x
); }
625 /// Re-insert an extracted node.
627 insert(node_type
&& __nh
)
628 { return _M_t
._M_reinsert_node_unique(std::move(__nh
)); }
630 /// Re-insert an extracted node.
632 insert(const_iterator __hint
, node_type
&& __nh
)
633 { return _M_t
._M_reinsert_node_hint_unique(__hint
, std::move(__nh
)); }
635 template<typename
, typename
>
636 friend class std::_Rb_tree_merge_helper
;
638 template<typename _C2
>
640 merge(map
<_Key
, _Tp
, _C2
, _Alloc
>& __source
)
642 using _Merge_helper
= _Rb_tree_merge_helper
<map
, _C2
>;
643 _M_t
._M_merge_unique(_Merge_helper::_S_get_tree(__source
));
646 template<typename _C2
>
648 merge(map
<_Key
, _Tp
, _C2
, _Alloc
>&& __source
)
651 template<typename _C2
>
653 merge(multimap
<_Key
, _Tp
, _C2
, _Alloc
>& __source
)
655 using _Merge_helper
= _Rb_tree_merge_helper
<map
, _C2
>;
656 _M_t
._M_merge_unique(_Merge_helper::_S_get_tree(__source
));
659 template<typename _C2
>
661 merge(multimap
<_Key
, _Tp
, _C2
, _Alloc
>&& __source
)
665 #if __cplusplus > 201402L
666 #define __cpp_lib_map_try_emplace 201411
668 * @brief Attempts to build and insert a std::pair into the %map.
670 * @param __k Key to use for finding a possibly existing pair in
672 * @param __args Arguments used to generate the .second for a new pair
675 * @return A pair, of which the first element is an iterator that points
676 * to the possibly inserted pair, and the second is a bool that
677 * is true if the pair was actually inserted.
679 * This function attempts to build and insert a (key, value) %pair into
681 * A %map relies on unique keys and thus a %pair is only inserted if its
682 * first element (the key) is not already present in the %map.
683 * If a %pair is not inserted, this function has no effect.
685 * Insertion requires logarithmic time.
687 template <typename
... _Args
>
689 try_emplace(const key_type
& __k
, _Args
&&... __args
)
691 iterator __i
= lower_bound(__k
);
692 if (__i
== end() || key_comp()(__k
, (*__i
).first
))
694 __i
= emplace_hint(__i
, std::piecewise_construct
,
695 std::forward_as_tuple(__k
),
696 std::forward_as_tuple(
697 std::forward
<_Args
>(__args
)...));
703 // move-capable overload
704 template <typename
... _Args
>
706 try_emplace(key_type
&& __k
, _Args
&&... __args
)
708 iterator __i
= lower_bound(__k
);
709 if (__i
== end() || key_comp()(__k
, (*__i
).first
))
711 __i
= emplace_hint(__i
, std::piecewise_construct
,
712 std::forward_as_tuple(std::move(__k
)),
713 std::forward_as_tuple(
714 std::forward
<_Args
>(__args
)...));
721 * @brief Attempts to build and insert a std::pair into the %map.
723 * @param __hint An iterator that serves as a hint as to where the
724 * pair should be inserted.
725 * @param __k Key to use for finding a possibly existing pair in
727 * @param __args Arguments used to generate the .second for a new pair
729 * @return An iterator that points to the element with key of the
730 * std::pair built from @a __args (may or may not be that
733 * This function is not concerned about whether the insertion took place,
734 * and thus does not return a boolean like the single-argument
735 * try_emplace() does. However, if insertion did not take place,
736 * this function has no effect.
737 * Note that the first parameter is only a hint and can potentially
738 * improve the performance of the insertion process. A bad hint would
739 * cause no gains in efficiency.
742 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
743 * for more on @a hinting.
745 * Insertion requires logarithmic time (if the hint is not taken).
747 template <typename
... _Args
>
749 try_emplace(const_iterator __hint
, const key_type
& __k
,
753 auto __true_hint
= _M_t
._M_get_insert_hint_unique_pos(__hint
, __k
);
754 if (__true_hint
.second
)
755 __i
= emplace_hint(iterator(__true_hint
.second
),
756 std::piecewise_construct
,
757 std::forward_as_tuple(__k
),
758 std::forward_as_tuple(
759 std::forward
<_Args
>(__args
)...));
761 __i
= iterator(__true_hint
.first
);
765 // move-capable overload
766 template <typename
... _Args
>
768 try_emplace(const_iterator __hint
, key_type
&& __k
, _Args
&&... __args
)
771 auto __true_hint
= _M_t
._M_get_insert_hint_unique_pos(__hint
, __k
);
772 if (__true_hint
.second
)
773 __i
= emplace_hint(iterator(__true_hint
.second
),
774 std::piecewise_construct
,
775 std::forward_as_tuple(std::move(__k
)),
776 std::forward_as_tuple(
777 std::forward
<_Args
>(__args
)...));
779 __i
= iterator(__true_hint
.first
);
785 * @brief Attempts to insert a std::pair into the %map.
786 * @param __x Pair to be inserted (see std::make_pair for easy
787 * creation of pairs).
789 * @return A pair, of which the first element is an iterator that
790 * points to the possibly inserted pair, and the second is
791 * a bool that is true if the pair was actually inserted.
793 * This function attempts to insert a (key, value) %pair into the %map.
794 * A %map relies on unique keys and thus a %pair is only inserted if its
795 * first element (the key) is not already present in the %map.
797 * Insertion requires logarithmic time.
800 std::pair
<iterator
, bool>
801 insert(const value_type
& __x
)
802 { return _M_t
._M_insert_unique(__x
); }
804 #if __cplusplus >= 201103L
805 // _GLIBCXX_RESOLVE_LIB_DEFECTS
806 // 2354. Unnecessary copying when inserting into maps with braced-init
807 std::pair
<iterator
, bool>
808 insert(value_type
&& __x
)
809 { return _M_t
._M_insert_unique(std::move(__x
)); }
811 template<typename _Pair
>
812 __enable_if_t
<is_constructible
<value_type
, _Pair
>::value
,
813 pair
<iterator
, bool>>
815 { return _M_t
._M_emplace_unique(std::forward
<_Pair
>(__x
)); }
819 #if __cplusplus >= 201103L
821 * @brief Attempts to insert a list of std::pairs into the %map.
822 * @param __list A std::initializer_list<value_type> of pairs to be
825 * Complexity similar to that of the range constructor.
828 insert(std::initializer_list
<value_type
> __list
)
829 { insert(__list
.begin(), __list
.end()); }
833 * @brief Attempts to insert a std::pair into the %map.
834 * @param __position An iterator that serves as a hint as to where the
835 * pair should be inserted.
836 * @param __x Pair to be inserted (see std::make_pair for easy creation
838 * @return An iterator that points to the element with key of
839 * @a __x (may or may not be the %pair passed in).
842 * This function is not concerned about whether the insertion
843 * took place, and thus does not return a boolean like the
844 * single-argument insert() does. Note that the first
845 * parameter is only a hint and can potentially improve the
846 * performance of the insertion process. A bad hint would
847 * cause no gains in efficiency.
850 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
851 * for more on @a hinting.
853 * Insertion requires logarithmic time (if the hint is not taken).
857 #if __cplusplus >= 201103L
858 insert(const_iterator __position
, const value_type
& __x
)
860 insert(iterator __position
, const value_type
& __x
)
862 { return _M_t
._M_insert_unique_(__position
, __x
); }
864 #if __cplusplus >= 201103L
865 // _GLIBCXX_RESOLVE_LIB_DEFECTS
866 // 2354. Unnecessary copying when inserting into maps with braced-init
868 insert(const_iterator __position
, value_type
&& __x
)
869 { return _M_t
._M_insert_unique_(__position
, std::move(__x
)); }
871 template<typename _Pair
>
872 __enable_if_t
<is_constructible
<value_type
, _Pair
>::value
, iterator
>
873 insert(const_iterator __position
, _Pair
&& __x
)
875 return _M_t
._M_emplace_hint_unique(__position
,
876 std::forward
<_Pair
>(__x
));
882 * @brief Template function that attempts to insert a range of elements.
883 * @param __first Iterator pointing to the start of the range to be
885 * @param __last Iterator pointing to the end of the range.
887 * Complexity similar to that of the range constructor.
889 template<typename _InputIterator
>
891 insert(_InputIterator __first
, _InputIterator __last
)
892 { _M_t
._M_insert_range_unique(__first
, __last
); }
894 #if __cplusplus > 201402L
895 #define __cpp_lib_map_insertion 201411
897 * @brief Attempts to insert or assign a std::pair into the %map.
898 * @param __k Key to use for finding a possibly existing pair in
900 * @param __obj Argument used to generate the .second for a pair
903 * @return A pair, of which the first element is an iterator that
904 * points to the possibly inserted pair, and the second is
905 * a bool that is true if the pair was actually inserted.
907 * This function attempts to insert a (key, value) %pair into the %map.
908 * A %map relies on unique keys and thus a %pair is only inserted if its
909 * first element (the key) is not already present in the %map.
910 * If the %pair was already in the %map, the .second of the %pair
911 * is assigned from __obj.
913 * Insertion requires logarithmic time.
915 template <typename _Obj
>
917 insert_or_assign(const key_type
& __k
, _Obj
&& __obj
)
919 iterator __i
= lower_bound(__k
);
920 if (__i
== end() || key_comp()(__k
, (*__i
).first
))
922 __i
= emplace_hint(__i
, std::piecewise_construct
,
923 std::forward_as_tuple(__k
),
924 std::forward_as_tuple(
925 std::forward
<_Obj
>(__obj
)));
928 (*__i
).second
= std::forward
<_Obj
>(__obj
);
932 // move-capable overload
933 template <typename _Obj
>
935 insert_or_assign(key_type
&& __k
, _Obj
&& __obj
)
937 iterator __i
= lower_bound(__k
);
938 if (__i
== end() || key_comp()(__k
, (*__i
).first
))
940 __i
= emplace_hint(__i
, std::piecewise_construct
,
941 std::forward_as_tuple(std::move(__k
)),
942 std::forward_as_tuple(
943 std::forward
<_Obj
>(__obj
)));
946 (*__i
).second
= std::forward
<_Obj
>(__obj
);
951 * @brief Attempts to insert or assign a std::pair into the %map.
952 * @param __hint An iterator that serves as a hint as to where the
953 * pair should be inserted.
954 * @param __k Key to use for finding a possibly existing pair in
956 * @param __obj Argument used to generate the .second for a pair
959 * @return An iterator that points to the element with key of
960 * @a __x (may or may not be the %pair passed in).
962 * This function attempts to insert a (key, value) %pair into the %map.
963 * A %map relies on unique keys and thus a %pair is only inserted if its
964 * first element (the key) is not already present in the %map.
965 * If the %pair was already in the %map, the .second of the %pair
966 * is assigned from __obj.
968 * Insertion requires logarithmic time.
970 template <typename _Obj
>
972 insert_or_assign(const_iterator __hint
,
973 const key_type
& __k
, _Obj
&& __obj
)
976 auto __true_hint
= _M_t
._M_get_insert_hint_unique_pos(__hint
, __k
);
977 if (__true_hint
.second
)
979 return emplace_hint(iterator(__true_hint
.second
),
980 std::piecewise_construct
,
981 std::forward_as_tuple(__k
),
982 std::forward_as_tuple(
983 std::forward
<_Obj
>(__obj
)));
985 __i
= iterator(__true_hint
.first
);
986 (*__i
).second
= std::forward
<_Obj
>(__obj
);
990 // move-capable overload
991 template <typename _Obj
>
993 insert_or_assign(const_iterator __hint
, key_type
&& __k
, _Obj
&& __obj
)
996 auto __true_hint
= _M_t
._M_get_insert_hint_unique_pos(__hint
, __k
);
997 if (__true_hint
.second
)
999 return emplace_hint(iterator(__true_hint
.second
),
1000 std::piecewise_construct
,
1001 std::forward_as_tuple(std::move(__k
)),
1002 std::forward_as_tuple(
1003 std::forward
<_Obj
>(__obj
)));
1005 __i
= iterator(__true_hint
.first
);
1006 (*__i
).second
= std::forward
<_Obj
>(__obj
);
1011 #if __cplusplus >= 201103L
1012 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1013 // DR 130. Associative erase should return an iterator.
1015 * @brief Erases an element from a %map.
1016 * @param __position An iterator pointing to the element to be erased.
1017 * @return An iterator pointing to the element immediately following
1018 * @a position prior to the element being erased. If no such
1019 * element exists, end() is returned.
1021 * This function erases an element, pointed to by the given
1022 * iterator, from a %map. Note that this function only erases
1023 * the element, and that if the element is itself a pointer,
1024 * the pointed-to memory is not touched in any way. Managing
1025 * the pointer is the user's responsibility.
1030 erase(const_iterator __position
)
1031 { return _M_t
.erase(__position
); }
1034 _GLIBCXX_ABI_TAG_CXX11
1036 erase(iterator __position
)
1037 { return _M_t
.erase(__position
); }
1041 * @brief Erases an element from a %map.
1042 * @param __position An iterator pointing to the element to be erased.
1044 * This function erases an element, pointed to by the given
1045 * iterator, from a %map. Note that this function only erases
1046 * the element, and that if the element is itself a pointer,
1047 * the pointed-to memory is not touched in any way. Managing
1048 * the pointer is the user's responsibility.
1051 erase(iterator __position
)
1052 { _M_t
.erase(__position
); }
1056 * @brief Erases elements according to the provided key.
1057 * @param __x Key of element to be erased.
1058 * @return The number of elements erased.
1060 * This function erases all the elements located by the given key from
1062 * Note that this function only erases the element, and that if
1063 * the element is itself a pointer, the pointed-to memory is not touched
1064 * in any way. Managing the pointer is the user's responsibility.
1067 erase(const key_type
& __x
)
1068 { return _M_t
.erase(__x
); }
1070 #if __cplusplus >= 201103L
1071 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1072 // DR 130. Associative erase should return an iterator.
1074 * @brief Erases a [first,last) range of elements from a %map.
1075 * @param __first Iterator pointing to the start of the range to be
1077 * @param __last Iterator pointing to the end of the range to
1079 * @return The iterator @a __last.
1081 * This function erases a sequence of elements from a %map.
1082 * Note that this function only erases the element, and that if
1083 * the element is itself a pointer, the pointed-to memory is not touched
1084 * in any way. Managing the pointer is the user's responsibility.
1087 erase(const_iterator __first
, const_iterator __last
)
1088 { return _M_t
.erase(__first
, __last
); }
1091 * @brief Erases a [__first,__last) range of elements from a %map.
1092 * @param __first Iterator pointing to the start of the range to be
1094 * @param __last Iterator pointing to the end of the range to
1097 * This function erases a sequence of elements from a %map.
1098 * Note that this function only erases the element, and that if
1099 * the element is itself a pointer, the pointed-to memory is not touched
1100 * in any way. Managing the pointer is the user's responsibility.
1103 erase(iterator __first
, iterator __last
)
1104 { _M_t
.erase(__first
, __last
); }
1108 * @brief Swaps data with another %map.
1109 * @param __x A %map of the same element and allocator types.
1111 * This exchanges the elements between two maps in constant
1112 * time. (It is only swapping a pointer, an integer, and an
1113 * instance of the @c Compare type (which itself is often
1114 * stateless and empty), so it should be quite fast.) Note
1115 * that the global std::swap() function is specialized such
1116 * that std::swap(m1,m2) will feed to this function.
1118 * Whether the allocators are swapped depends on the allocator traits.
1122 _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable
<_Compare
>::value
)
1123 { _M_t
.swap(__x
._M_t
); }
1126 * Erases all elements in a %map. Note that this function only
1127 * erases the elements, and that if the elements themselves are
1128 * pointers, the pointed-to memory is not touched in any way.
1129 * Managing the pointer is the user's responsibility.
1132 clear() _GLIBCXX_NOEXCEPT
1137 * Returns the key comparison object out of which the %map was
1142 { return _M_t
.key_comp(); }
1145 * Returns a value comparison object, built from the key comparison
1146 * object out of which the %map was constructed.
1150 { return value_compare(_M_t
.key_comp()); }
1152 // [23.3.1.3] map operations
1156 * @brief Tries to locate an element in a %map.
1157 * @param __x Key of (key, value) %pair to be located.
1158 * @return Iterator pointing to sought-after element, or end() if not
1161 * This function takes a key and tries to locate the element with which
1162 * the key matches. If successful the function returns an iterator
1163 * pointing to the sought after %pair. If unsuccessful it returns the
1164 * past-the-end ( @c end() ) iterator.
1168 find(const key_type
& __x
)
1169 { return _M_t
.find(__x
); }
1171 #if __cplusplus > 201103L
1172 template<typename _Kt
>
1174 find(const _Kt
& __x
) -> decltype(_M_t
._M_find_tr(__x
))
1175 { return _M_t
._M_find_tr(__x
); }
1181 * @brief Tries to locate an element in a %map.
1182 * @param __x Key of (key, value) %pair to be located.
1183 * @return Read-only (constant) iterator pointing to sought-after
1184 * element, or end() if not found.
1186 * This function takes a key and tries to locate the element with which
1187 * the key matches. If successful the function returns a constant
1188 * iterator pointing to the sought after %pair. If unsuccessful it
1189 * returns the past-the-end ( @c end() ) iterator.
1193 find(const key_type
& __x
) const
1194 { return _M_t
.find(__x
); }
1196 #if __cplusplus > 201103L
1197 template<typename _Kt
>
1199 find(const _Kt
& __x
) const -> decltype(_M_t
._M_find_tr(__x
))
1200 { return _M_t
._M_find_tr(__x
); }
1206 * @brief Finds the number of elements with given key.
1207 * @param __x Key of (key, value) pairs to be located.
1208 * @return Number of elements with specified key.
1210 * This function only makes sense for multimaps; for map the result will
1211 * either be 0 (not present) or 1 (present).
1214 count(const key_type
& __x
) const
1215 { return _M_t
.find(__x
) == _M_t
.end() ? 0 : 1; }
1217 #if __cplusplus > 201103L
1218 template<typename _Kt
>
1220 count(const _Kt
& __x
) const -> decltype(_M_t
._M_count_tr(__x
))
1221 { return _M_t
._M_count_tr(__x
); }
1225 #if __cplusplus > 201703L
1228 * @brief Finds whether an element with the given key exists.
1229 * @param __x Key of (key, value) pairs to be located.
1230 * @return True if there is an element with the specified key.
1233 contains(const key_type
& __x
) const
1234 { return _M_t
.find(__x
) != _M_t
.end(); }
1236 template<typename _Kt
>
1238 contains(const _Kt
& __x
) const
1239 -> decltype(_M_t
._M_find_tr(__x
), void(), true)
1240 { return _M_t
._M_find_tr(__x
) != _M_t
.end(); }
1246 * @brief Finds the beginning of a subsequence matching given key.
1247 * @param __x Key of (key, value) pair to be located.
1248 * @return Iterator pointing to first element equal to or greater
1249 * than key, or end().
1251 * This function returns the first element of a subsequence of elements
1252 * that matches the given key. If unsuccessful it returns an iterator
1253 * pointing to the first element that has a greater value than given key
1254 * or end() if no such element exists.
1257 lower_bound(const key_type
& __x
)
1258 { return _M_t
.lower_bound(__x
); }
1260 #if __cplusplus > 201103L
1261 template<typename _Kt
>
1263 lower_bound(const _Kt
& __x
)
1264 -> decltype(iterator(_M_t
._M_lower_bound_tr(__x
)))
1265 { return iterator(_M_t
._M_lower_bound_tr(__x
)); }
1271 * @brief Finds the beginning of a subsequence matching given key.
1272 * @param __x Key of (key, value) pair to be located.
1273 * @return Read-only (constant) iterator pointing to first element
1274 * equal to or greater than key, or end().
1276 * This function returns the first element of a subsequence of elements
1277 * that matches the given key. If unsuccessful it returns an iterator
1278 * pointing to the first element that has a greater value than given key
1279 * or end() if no such element exists.
1282 lower_bound(const key_type
& __x
) const
1283 { return _M_t
.lower_bound(__x
); }
1285 #if __cplusplus > 201103L
1286 template<typename _Kt
>
1288 lower_bound(const _Kt
& __x
) const
1289 -> decltype(const_iterator(_M_t
._M_lower_bound_tr(__x
)))
1290 { return const_iterator(_M_t
._M_lower_bound_tr(__x
)); }
1296 * @brief Finds the end of a subsequence matching given key.
1297 * @param __x Key of (key, value) pair to be located.
1298 * @return Iterator pointing to the first element
1299 * greater than key, or end().
1302 upper_bound(const key_type
& __x
)
1303 { return _M_t
.upper_bound(__x
); }
1305 #if __cplusplus > 201103L
1306 template<typename _Kt
>
1308 upper_bound(const _Kt
& __x
)
1309 -> decltype(iterator(_M_t
._M_upper_bound_tr(__x
)))
1310 { return iterator(_M_t
._M_upper_bound_tr(__x
)); }
1316 * @brief Finds the end of a subsequence matching given key.
1317 * @param __x Key of (key, value) pair to be located.
1318 * @return Read-only (constant) iterator pointing to first iterator
1319 * greater than key, or end().
1322 upper_bound(const key_type
& __x
) const
1323 { return _M_t
.upper_bound(__x
); }
1325 #if __cplusplus > 201103L
1326 template<typename _Kt
>
1328 upper_bound(const _Kt
& __x
) const
1329 -> decltype(const_iterator(_M_t
._M_upper_bound_tr(__x
)))
1330 { return const_iterator(_M_t
._M_upper_bound_tr(__x
)); }
1336 * @brief Finds a subsequence matching given key.
1337 * @param __x Key of (key, value) pairs to be located.
1338 * @return Pair of iterators that possibly points to the subsequence
1339 * matching given key.
1341 * This function is equivalent to
1343 * std::make_pair(c.lower_bound(val),
1344 * c.upper_bound(val))
1346 * (but is faster than making the calls separately).
1348 * This function probably only makes sense for multimaps.
1350 std::pair
<iterator
, iterator
>
1351 equal_range(const key_type
& __x
)
1352 { return _M_t
.equal_range(__x
); }
1354 #if __cplusplus > 201103L
1355 template<typename _Kt
>
1357 equal_range(const _Kt
& __x
)
1358 -> decltype(pair
<iterator
, iterator
>(_M_t
._M_equal_range_tr(__x
)))
1359 { return pair
<iterator
, iterator
>(_M_t
._M_equal_range_tr(__x
)); }
1365 * @brief Finds a subsequence matching given key.
1366 * @param __x Key of (key, value) pairs to be located.
1367 * @return Pair of read-only (constant) iterators that possibly points
1368 * to the subsequence matching given key.
1370 * This function is equivalent to
1372 * std::make_pair(c.lower_bound(val),
1373 * c.upper_bound(val))
1375 * (but is faster than making the calls separately).
1377 * This function probably only makes sense for multimaps.
1379 std::pair
<const_iterator
, const_iterator
>
1380 equal_range(const key_type
& __x
) const
1381 { return _M_t
.equal_range(__x
); }
1383 #if __cplusplus > 201103L
1384 template<typename _Kt
>
1386 equal_range(const _Kt
& __x
) const
1387 -> decltype(pair
<const_iterator
, const_iterator
>(
1388 _M_t
._M_equal_range_tr(__x
)))
1390 return pair
<const_iterator
, const_iterator
>(
1391 _M_t
._M_equal_range_tr(__x
));
1396 template<typename _K1
, typename _T1
, typename _C1
, typename _A1
>
1398 operator==(const map
<_K1
, _T1
, _C1
, _A1
>&,
1399 const map
<_K1
, _T1
, _C1
, _A1
>&);
1401 template<typename _K1
, typename _T1
, typename _C1
, typename _A1
>
1403 operator<(const map
<_K1
, _T1
, _C1
, _A1
>&,
1404 const map
<_K1
, _T1
, _C1
, _A1
>&);
1408 #if __cpp_deduction_guides >= 201606
1410 template<typename _InputIterator
,
1411 typename _Compare
= less
<__iter_key_t
<_InputIterator
>>,
1412 typename _Allocator
= allocator
<__iter_to_alloc_t
<_InputIterator
>>,
1413 typename
= _RequireInputIter
<_InputIterator
>,
1414 typename
= _RequireAllocator
<_Allocator
>>
1415 map(_InputIterator
, _InputIterator
,
1416 _Compare
= _Compare(), _Allocator
= _Allocator())
1417 -> map
<__iter_key_t
<_InputIterator
>, __iter_val_t
<_InputIterator
>,
1418 _Compare
, _Allocator
>;
1420 template<typename _Key
, typename _Tp
, typename _Compare
= less
<_Key
>,
1421 typename _Allocator
= allocator
<pair
<const _Key
, _Tp
>>,
1422 typename
= _RequireAllocator
<_Allocator
>>
1423 map(initializer_list
<pair
<_Key
, _Tp
>>,
1424 _Compare
= _Compare(), _Allocator
= _Allocator())
1425 -> map
<_Key
, _Tp
, _Compare
, _Allocator
>;
1427 template <typename _InputIterator
, typename _Allocator
,
1428 typename
= _RequireInputIter
<_InputIterator
>,
1429 typename
= _RequireAllocator
<_Allocator
>>
1430 map(_InputIterator
, _InputIterator
, _Allocator
)
1431 -> map
<__iter_key_t
<_InputIterator
>, __iter_val_t
<_InputIterator
>,
1432 less
<__iter_key_t
<_InputIterator
>>, _Allocator
>;
1434 template<typename _Key
, typename _Tp
, typename _Allocator
,
1435 typename
= _RequireAllocator
<_Allocator
>>
1436 map(initializer_list
<pair
<_Key
, _Tp
>>, _Allocator
)
1437 -> map
<_Key
, _Tp
, less
<_Key
>, _Allocator
>;
1442 * @brief Map equality comparison.
1443 * @param __x A %map.
1444 * @param __y A %map of the same type as @a x.
1445 * @return True iff the size and elements of the maps are equal.
1447 * This is an equivalence relation. It is linear in the size of the
1448 * maps. Maps are considered equivalent if their sizes are equal,
1449 * and if corresponding elements compare equal.
1451 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1453 operator==(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1454 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1455 { return __x
._M_t
== __y
._M_t
; }
1458 * @brief Map ordering relation.
1459 * @param __x A %map.
1460 * @param __y A %map of the same type as @a x.
1461 * @return True iff @a x is lexicographically less than @a y.
1463 * This is a total ordering relation. It is linear in the size of the
1464 * maps. The elements must be comparable with @c <.
1466 * See std::lexicographical_compare() for how the determination is made.
1468 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1470 operator<(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1471 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1472 { return __x
._M_t
< __y
._M_t
; }
1474 /// Based on operator==
1475 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1477 operator!=(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1478 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1479 { return !(__x
== __y
); }
1481 /// Based on operator<
1482 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1484 operator>(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1485 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1486 { return __y
< __x
; }
1488 /// Based on operator<
1489 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1491 operator<=(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1492 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1493 { return !(__y
< __x
); }
1495 /// Based on operator<
1496 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1498 operator>=(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1499 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1500 { return !(__x
< __y
); }
1502 /// See std::map::swap().
1503 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1505 swap(map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1506 map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1507 _GLIBCXX_NOEXCEPT_IF(noexcept(__x
.swap(__y
)))
1510 _GLIBCXX_END_NAMESPACE_CONTAINER
1512 #if __cplusplus > 201402L
1513 // Allow std::map access to internals of compatible maps.
1514 template<typename _Key
, typename _Val
, typename _Cmp1
, typename _Alloc
,
1517 _Rb_tree_merge_helper
<_GLIBCXX_STD_C::map
<_Key
, _Val
, _Cmp1
, _Alloc
>,
1521 friend class _GLIBCXX_STD_C::map
<_Key
, _Val
, _Cmp1
, _Alloc
>;
1524 _S_get_tree(_GLIBCXX_STD_C::map
<_Key
, _Val
, _Cmp2
, _Alloc
>& __map
)
1525 { return __map
._M_t
; }
1528 _S_get_tree(_GLIBCXX_STD_C::multimap
<_Key
, _Val
, _Cmp2
, _Alloc
>& __map
)
1529 { return __map
._M_t
; }
1533 _GLIBCXX_END_NAMESPACE_VERSION
1536 #endif /* _STL_MAP_H */