1 // Map implementation -*- C++ -*-
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5 // This file is part of the GNU ISO C++ Library. This library is free
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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_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_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_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_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_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
, typename
= typename
812 std::enable_if
<std::is_constructible
<value_type
,
813 _Pair
&&>::value
>::type
>
814 std::pair
<iterator
, bool>
816 { return _M_t
._M_insert_unique(std::forward
<_Pair
>(__x
)); }
820 #if __cplusplus >= 201103L
822 * @brief Attempts to insert a list of std::pairs into the %map.
823 * @param __list A std::initializer_list<value_type> of pairs to be
826 * Complexity similar to that of the range constructor.
829 insert(std::initializer_list
<value_type
> __list
)
830 { insert(__list
.begin(), __list
.end()); }
834 * @brief Attempts to insert a std::pair into the %map.
835 * @param __position An iterator that serves as a hint as to where the
836 * pair should be inserted.
837 * @param __x Pair to be inserted (see std::make_pair for easy creation
839 * @return An iterator that points to the element with key of
840 * @a __x (may or may not be the %pair passed in).
843 * This function is not concerned about whether the insertion
844 * took place, and thus does not return a boolean like the
845 * single-argument insert() does. Note that the first
846 * parameter is only a hint and can potentially improve the
847 * performance of the insertion process. A bad hint would
848 * cause no gains in efficiency.
851 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
852 * for more on @a hinting.
854 * Insertion requires logarithmic time (if the hint is not taken).
858 #if __cplusplus >= 201103L
859 insert(const_iterator __position
, const value_type
& __x
)
861 insert(iterator __position
, const value_type
& __x
)
863 { return _M_t
._M_insert_unique_(__position
, __x
); }
865 #if __cplusplus >= 201103L
866 // _GLIBCXX_RESOLVE_LIB_DEFECTS
867 // 2354. Unnecessary copying when inserting into maps with braced-init
869 insert(const_iterator __position
, value_type
&& __x
)
870 { return _M_t
._M_insert_unique_(__position
, std::move(__x
)); }
872 template<typename _Pair
, typename
= typename
873 std::enable_if
<std::is_constructible
<value_type
,
874 _Pair
&&>::value
>::type
>
876 insert(const_iterator __position
, _Pair
&& __x
)
877 { return _M_t
._M_insert_unique_(__position
,
878 std::forward
<_Pair
>(__x
)); }
883 * @brief Template function that attempts to insert a range of elements.
884 * @param __first Iterator pointing to the start of the range to be
886 * @param __last Iterator pointing to the end of the range.
888 * Complexity similar to that of the range constructor.
890 template<typename _InputIterator
>
892 insert(_InputIterator __first
, _InputIterator __last
)
893 { _M_t
._M_insert_unique(__first
, __last
); }
895 #if __cplusplus > 201402L
896 #define __cpp_lib_map_insertion 201411
898 * @brief Attempts to insert or assign a std::pair into the %map.
899 * @param __k Key to use for finding a possibly existing pair in
901 * @param __obj Argument used to generate the .second for a pair
904 * @return A pair, of which the first element is an iterator that
905 * points to the possibly inserted pair, and the second is
906 * a bool that is true if the pair was actually inserted.
908 * This function attempts to insert a (key, value) %pair into the %map.
909 * A %map relies on unique keys and thus a %pair is only inserted if its
910 * first element (the key) is not already present in the %map.
911 * If the %pair was already in the %map, the .second of the %pair
912 * is assigned from __obj.
914 * Insertion requires logarithmic time.
916 template <typename _Obj
>
918 insert_or_assign(const key_type
& __k
, _Obj
&& __obj
)
920 iterator __i
= lower_bound(__k
);
921 if (__i
== end() || key_comp()(__k
, (*__i
).first
))
923 __i
= emplace_hint(__i
, std::piecewise_construct
,
924 std::forward_as_tuple(__k
),
925 std::forward_as_tuple(
926 std::forward
<_Obj
>(__obj
)));
929 (*__i
).second
= std::forward
<_Obj
>(__obj
);
933 // move-capable overload
934 template <typename _Obj
>
936 insert_or_assign(key_type
&& __k
, _Obj
&& __obj
)
938 iterator __i
= lower_bound(__k
);
939 if (__i
== end() || key_comp()(__k
, (*__i
).first
))
941 __i
= emplace_hint(__i
, std::piecewise_construct
,
942 std::forward_as_tuple(std::move(__k
)),
943 std::forward_as_tuple(
944 std::forward
<_Obj
>(__obj
)));
947 (*__i
).second
= std::forward
<_Obj
>(__obj
);
952 * @brief Attempts to insert or assign a std::pair into the %map.
953 * @param __hint An iterator that serves as a hint as to where the
954 * pair should be inserted.
955 * @param __k Key to use for finding a possibly existing pair in
957 * @param __obj Argument used to generate the .second for a pair
960 * @return An iterator that points to the element with key of
961 * @a __x (may or may not be the %pair passed in).
963 * This function attempts to insert a (key, value) %pair into the %map.
964 * A %map relies on unique keys and thus a %pair is only inserted if its
965 * first element (the key) is not already present in the %map.
966 * If the %pair was already in the %map, the .second of the %pair
967 * is assigned from __obj.
969 * Insertion requires logarithmic time.
971 template <typename _Obj
>
973 insert_or_assign(const_iterator __hint
,
974 const key_type
& __k
, _Obj
&& __obj
)
977 auto __true_hint
= _M_t
._M_get_insert_hint_unique_pos(__hint
, __k
);
978 if (__true_hint
.second
)
980 return emplace_hint(iterator(__true_hint
.second
),
981 std::piecewise_construct
,
982 std::forward_as_tuple(__k
),
983 std::forward_as_tuple(
984 std::forward
<_Obj
>(__obj
)));
986 __i
= iterator(__true_hint
.first
);
987 (*__i
).second
= std::forward
<_Obj
>(__obj
);
991 // move-capable overload
992 template <typename _Obj
>
994 insert_or_assign(const_iterator __hint
, key_type
&& __k
, _Obj
&& __obj
)
997 auto __true_hint
= _M_t
._M_get_insert_hint_unique_pos(__hint
, __k
);
998 if (__true_hint
.second
)
1000 return emplace_hint(iterator(__true_hint
.second
),
1001 std::piecewise_construct
,
1002 std::forward_as_tuple(std::move(__k
)),
1003 std::forward_as_tuple(
1004 std::forward
<_Obj
>(__obj
)));
1006 __i
= iterator(__true_hint
.first
);
1007 (*__i
).second
= std::forward
<_Obj
>(__obj
);
1012 #if __cplusplus >= 201103L
1013 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1014 // DR 130. Associative erase should return an iterator.
1016 * @brief Erases an element from a %map.
1017 * @param __position An iterator pointing to the element to be erased.
1018 * @return An iterator pointing to the element immediately following
1019 * @a position prior to the element being erased. If no such
1020 * element exists, end() is returned.
1022 * This function erases an element, pointed to by the given
1023 * iterator, from a %map. Note that this function only erases
1024 * the element, and that if the element is itself a pointer,
1025 * the pointed-to memory is not touched in any way. Managing
1026 * the pointer is the user's responsibility.
1031 erase(const_iterator __position
)
1032 { return _M_t
.erase(__position
); }
1035 _GLIBCXX_ABI_TAG_CXX11
1037 erase(iterator __position
)
1038 { return _M_t
.erase(__position
); }
1042 * @brief Erases an element from a %map.
1043 * @param __position An iterator pointing to the element to be erased.
1045 * This function erases an element, pointed to by the given
1046 * iterator, from a %map. Note that this function only erases
1047 * the element, and that if the element is itself a pointer,
1048 * the pointed-to memory is not touched in any way. Managing
1049 * the pointer is the user's responsibility.
1052 erase(iterator __position
)
1053 { _M_t
.erase(__position
); }
1057 * @brief Erases elements according to the provided key.
1058 * @param __x Key of element to be erased.
1059 * @return The number of elements erased.
1061 * This function erases all the elements located by the given key from
1063 * Note that this function only erases the element, and that if
1064 * the element is itself a pointer, the pointed-to memory is not touched
1065 * in any way. Managing the pointer is the user's responsibility.
1068 erase(const key_type
& __x
)
1069 { return _M_t
.erase(__x
); }
1071 #if __cplusplus >= 201103L
1072 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1073 // DR 130. Associative erase should return an iterator.
1075 * @brief Erases a [first,last) range of elements from a %map.
1076 * @param __first Iterator pointing to the start of the range to be
1078 * @param __last Iterator pointing to the end of the range to
1080 * @return The iterator @a __last.
1082 * This function erases a sequence of elements from a %map.
1083 * Note that this function only erases the element, and that if
1084 * the element is itself a pointer, the pointed-to memory is not touched
1085 * in any way. Managing the pointer is the user's responsibility.
1088 erase(const_iterator __first
, const_iterator __last
)
1089 { return _M_t
.erase(__first
, __last
); }
1092 * @brief Erases a [__first,__last) range of elements from a %map.
1093 * @param __first Iterator pointing to the start of the range to be
1095 * @param __last Iterator pointing to the end of the range to
1098 * This function erases a sequence of elements from a %map.
1099 * Note that this function only erases the element, and that if
1100 * the element is itself a pointer, the pointed-to memory is not touched
1101 * in any way. Managing the pointer is the user's responsibility.
1104 erase(iterator __first
, iterator __last
)
1105 { _M_t
.erase(__first
, __last
); }
1109 * @brief Swaps data with another %map.
1110 * @param __x A %map of the same element and allocator types.
1112 * This exchanges the elements between two maps in constant
1113 * time. (It is only swapping a pointer, an integer, and an
1114 * instance of the @c Compare type (which itself is often
1115 * stateless and empty), so it should be quite fast.) Note
1116 * that the global std::swap() function is specialized such
1117 * that std::swap(m1,m2) will feed to this function.
1119 * Whether the allocators are swapped depends on the allocator traits.
1123 _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable
<_Compare
>::value
)
1124 { _M_t
.swap(__x
._M_t
); }
1127 * Erases all elements in a %map. Note that this function only
1128 * erases the elements, and that if the elements themselves are
1129 * pointers, the pointed-to memory is not touched in any way.
1130 * Managing the pointer is the user's responsibility.
1133 clear() _GLIBCXX_NOEXCEPT
1138 * Returns the key comparison object out of which the %map was
1143 { return _M_t
.key_comp(); }
1146 * Returns a value comparison object, built from the key comparison
1147 * object out of which the %map was constructed.
1151 { return value_compare(_M_t
.key_comp()); }
1153 // [23.3.1.3] map operations
1157 * @brief Tries to locate an element in a %map.
1158 * @param __x Key of (key, value) %pair to be located.
1159 * @return Iterator pointing to sought-after element, or end() if not
1162 * This function takes a key and tries to locate the element with which
1163 * the key matches. If successful the function returns an iterator
1164 * pointing to the sought after %pair. If unsuccessful it returns the
1165 * past-the-end ( @c end() ) iterator.
1169 find(const key_type
& __x
)
1170 { return _M_t
.find(__x
); }
1172 #if __cplusplus > 201103L
1173 template<typename _Kt
>
1175 find(const _Kt
& __x
) -> decltype(_M_t
._M_find_tr(__x
))
1176 { return _M_t
._M_find_tr(__x
); }
1182 * @brief Tries to locate an element in a %map.
1183 * @param __x Key of (key, value) %pair to be located.
1184 * @return Read-only (constant) iterator pointing to sought-after
1185 * element, or end() if not found.
1187 * This function takes a key and tries to locate the element with which
1188 * the key matches. If successful the function returns a constant
1189 * iterator pointing to the sought after %pair. If unsuccessful it
1190 * returns the past-the-end ( @c end() ) iterator.
1194 find(const key_type
& __x
) const
1195 { return _M_t
.find(__x
); }
1197 #if __cplusplus > 201103L
1198 template<typename _Kt
>
1200 find(const _Kt
& __x
) const -> decltype(_M_t
._M_find_tr(__x
))
1201 { return _M_t
._M_find_tr(__x
); }
1207 * @brief Finds the number of elements with given key.
1208 * @param __x Key of (key, value) pairs to be located.
1209 * @return Number of elements with specified key.
1211 * This function only makes sense for multimaps; for map the result will
1212 * either be 0 (not present) or 1 (present).
1215 count(const key_type
& __x
) const
1216 { return _M_t
.find(__x
) == _M_t
.end() ? 0 : 1; }
1218 #if __cplusplus > 201103L
1219 template<typename _Kt
>
1221 count(const _Kt
& __x
) const -> decltype(_M_t
._M_count_tr(__x
))
1222 { return _M_t
._M_count_tr(__x
); }
1228 * @brief Finds the beginning of a subsequence matching given key.
1229 * @param __x Key of (key, value) pair to be located.
1230 * @return Iterator pointing to first element equal to or greater
1231 * than key, or end().
1233 * This function returns the first element of a subsequence of elements
1234 * that matches the given key. If unsuccessful it returns an iterator
1235 * pointing to the first element that has a greater value than given key
1236 * or end() if no such element exists.
1239 lower_bound(const key_type
& __x
)
1240 { return _M_t
.lower_bound(__x
); }
1242 #if __cplusplus > 201103L
1243 template<typename _Kt
>
1245 lower_bound(const _Kt
& __x
)
1246 -> decltype(iterator(_M_t
._M_lower_bound_tr(__x
)))
1247 { return iterator(_M_t
._M_lower_bound_tr(__x
)); }
1253 * @brief Finds the beginning of a subsequence matching given key.
1254 * @param __x Key of (key, value) pair to be located.
1255 * @return Read-only (constant) iterator pointing to first element
1256 * equal to or greater than key, or end().
1258 * This function returns the first element of a subsequence of elements
1259 * that matches the given key. If unsuccessful it returns an iterator
1260 * pointing to the first element that has a greater value than given key
1261 * or end() if no such element exists.
1264 lower_bound(const key_type
& __x
) const
1265 { return _M_t
.lower_bound(__x
); }
1267 #if __cplusplus > 201103L
1268 template<typename _Kt
>
1270 lower_bound(const _Kt
& __x
) const
1271 -> decltype(const_iterator(_M_t
._M_lower_bound_tr(__x
)))
1272 { return const_iterator(_M_t
._M_lower_bound_tr(__x
)); }
1278 * @brief Finds the end of a subsequence matching given key.
1279 * @param __x Key of (key, value) pair to be located.
1280 * @return Iterator pointing to the first element
1281 * greater than key, or end().
1284 upper_bound(const key_type
& __x
)
1285 { return _M_t
.upper_bound(__x
); }
1287 #if __cplusplus > 201103L
1288 template<typename _Kt
>
1290 upper_bound(const _Kt
& __x
)
1291 -> decltype(iterator(_M_t
._M_upper_bound_tr(__x
)))
1292 { return iterator(_M_t
._M_upper_bound_tr(__x
)); }
1298 * @brief Finds the end of a subsequence matching given key.
1299 * @param __x Key of (key, value) pair to be located.
1300 * @return Read-only (constant) iterator pointing to first iterator
1301 * greater than key, or end().
1304 upper_bound(const key_type
& __x
) const
1305 { return _M_t
.upper_bound(__x
); }
1307 #if __cplusplus > 201103L
1308 template<typename _Kt
>
1310 upper_bound(const _Kt
& __x
) const
1311 -> decltype(const_iterator(_M_t
._M_upper_bound_tr(__x
)))
1312 { return const_iterator(_M_t
._M_upper_bound_tr(__x
)); }
1318 * @brief Finds a subsequence matching given key.
1319 * @param __x Key of (key, value) pairs to be located.
1320 * @return Pair of iterators that possibly points to the subsequence
1321 * matching given key.
1323 * This function is equivalent to
1325 * std::make_pair(c.lower_bound(val),
1326 * c.upper_bound(val))
1328 * (but is faster than making the calls separately).
1330 * This function probably only makes sense for multimaps.
1332 std::pair
<iterator
, iterator
>
1333 equal_range(const key_type
& __x
)
1334 { return _M_t
.equal_range(__x
); }
1336 #if __cplusplus > 201103L
1337 template<typename _Kt
>
1339 equal_range(const _Kt
& __x
)
1340 -> decltype(pair
<iterator
, iterator
>(_M_t
._M_equal_range_tr(__x
)))
1341 { return pair
<iterator
, iterator
>(_M_t
._M_equal_range_tr(__x
)); }
1347 * @brief Finds a subsequence matching given key.
1348 * @param __x Key of (key, value) pairs to be located.
1349 * @return Pair of read-only (constant) iterators that possibly points
1350 * to the subsequence matching given key.
1352 * This function is equivalent to
1354 * std::make_pair(c.lower_bound(val),
1355 * c.upper_bound(val))
1357 * (but is faster than making the calls separately).
1359 * This function probably only makes sense for multimaps.
1361 std::pair
<const_iterator
, const_iterator
>
1362 equal_range(const key_type
& __x
) const
1363 { return _M_t
.equal_range(__x
); }
1365 #if __cplusplus > 201103L
1366 template<typename _Kt
>
1368 equal_range(const _Kt
& __x
) const
1369 -> decltype(pair
<const_iterator
, const_iterator
>(
1370 _M_t
._M_equal_range_tr(__x
)))
1372 return pair
<const_iterator
, const_iterator
>(
1373 _M_t
._M_equal_range_tr(__x
));
1378 template<typename _K1
, typename _T1
, typename _C1
, typename _A1
>
1380 operator==(const map
<_K1
, _T1
, _C1
, _A1
>&,
1381 const map
<_K1
, _T1
, _C1
, _A1
>&);
1383 template<typename _K1
, typename _T1
, typename _C1
, typename _A1
>
1385 operator<(const map
<_K1
, _T1
, _C1
, _A1
>&,
1386 const map
<_K1
, _T1
, _C1
, _A1
>&);
1390 #if __cpp_deduction_guides >= 201606
1392 template<typename _InputIterator
,
1393 typename _Compare
= less
<__iter_key_t
<_InputIterator
>>,
1394 typename _Allocator
= allocator
<__iter_to_alloc_t
<_InputIterator
>>,
1395 typename
= _RequireInputIter
<_InputIterator
>,
1396 typename
= _RequireAllocator
<_Allocator
>>
1397 map(_InputIterator
, _InputIterator
,
1398 _Compare
= _Compare(), _Allocator
= _Allocator())
1399 -> map
<__iter_key_t
<_InputIterator
>, __iter_val_t
<_InputIterator
>,
1400 _Compare
, _Allocator
>;
1402 template<typename _Key
, typename _Tp
, typename _Compare
= less
<_Key
>,
1403 typename _Allocator
= allocator
<pair
<const _Key
, _Tp
>>,
1404 typename
= _RequireAllocator
<_Allocator
>>
1405 map(initializer_list
<pair
<_Key
, _Tp
>>,
1406 _Compare
= _Compare(), _Allocator
= _Allocator())
1407 -> map
<_Key
, _Tp
, _Compare
, _Allocator
>;
1409 template <typename _InputIterator
, typename _Allocator
,
1410 typename
= _RequireInputIter
<_InputIterator
>,
1411 typename
= _RequireAllocator
<_Allocator
>>
1412 map(_InputIterator
, _InputIterator
, _Allocator
)
1413 -> map
<__iter_key_t
<_InputIterator
>, __iter_val_t
<_InputIterator
>,
1414 less
<__iter_key_t
<_InputIterator
>>, _Allocator
>;
1416 template<typename _Key
, typename _Tp
, typename _Allocator
,
1417 typename
= _RequireAllocator
<_Allocator
>>
1418 map(initializer_list
<pair
<_Key
, _Tp
>>, _Allocator
)
1419 -> map
<_Key
, _Tp
, less
<_Key
>, _Allocator
>;
1424 * @brief Map equality comparison.
1425 * @param __x A %map.
1426 * @param __y A %map of the same type as @a x.
1427 * @return True iff the size and elements of the maps are equal.
1429 * This is an equivalence relation. It is linear in the size of the
1430 * maps. Maps are considered equivalent if their sizes are equal,
1431 * and if corresponding elements compare equal.
1433 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1435 operator==(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1436 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1437 { return __x
._M_t
== __y
._M_t
; }
1440 * @brief Map ordering relation.
1441 * @param __x A %map.
1442 * @param __y A %map of the same type as @a x.
1443 * @return True iff @a x is lexicographically less than @a y.
1445 * This is a total ordering relation. It is linear in the size of the
1446 * maps. The elements must be comparable with @c <.
1448 * See std::lexicographical_compare() for how the determination is made.
1450 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1452 operator<(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1453 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1454 { return __x
._M_t
< __y
._M_t
; }
1456 /// Based on operator==
1457 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1459 operator!=(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1460 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1461 { return !(__x
== __y
); }
1463 /// Based on operator<
1464 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1466 operator>(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1467 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1468 { return __y
< __x
; }
1470 /// Based on operator<
1471 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1473 operator<=(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1474 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1475 { return !(__y
< __x
); }
1477 /// Based on operator<
1478 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1480 operator>=(const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1481 const map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1482 { return !(__x
< __y
); }
1484 /// See std::map::swap().
1485 template<typename _Key
, typename _Tp
, typename _Compare
, typename _Alloc
>
1487 swap(map
<_Key
, _Tp
, _Compare
, _Alloc
>& __x
,
1488 map
<_Key
, _Tp
, _Compare
, _Alloc
>& __y
)
1489 _GLIBCXX_NOEXCEPT_IF(noexcept(__x
.swap(__y
)))
1492 _GLIBCXX_END_NAMESPACE_CONTAINER
1494 #if __cplusplus > 201402L
1495 // Allow std::map access to internals of compatible maps.
1496 template<typename _Key
, typename _Val
, typename _Cmp1
, typename _Alloc
,
1499 _Rb_tree_merge_helper
<_GLIBCXX_STD_C::map
<_Key
, _Val
, _Cmp1
, _Alloc
>,
1503 friend class _GLIBCXX_STD_C::map
<_Key
, _Val
, _Cmp1
, _Alloc
>;
1506 _S_get_tree(_GLIBCXX_STD_C::map
<_Key
, _Val
, _Cmp2
, _Alloc
>& __map
)
1507 { return __map
._M_t
; }
1510 _S_get_tree(_GLIBCXX_STD_C::multimap
<_Key
, _Val
, _Cmp2
, _Alloc
>& __map
)
1511 { return __map
._M_t
; }
1515 _GLIBCXX_END_NAMESPACE_VERSION
1518 #endif /* _STL_MAP_H */