1// Map implementation -*- C++ -*-
2
3// Copyright (C) 2001-2016 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation. Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose. It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1996,1997
40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
45 * that both that copyright notice and this permission notice appear
46 * in supporting documentation. Silicon Graphics makes no
47 * representations about the suitability of this software for any
48 * purpose. It is provided "as is" without express or implied warranty.
49 */
50
51/** @file bits/stl_map.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{map}
54 */
55
56#ifndef _STL_MAP_H
57#define _STL_MAP_H 1
58
59#include <bits/functexcept.h>
60#include <bits/concept_check.h>
61#if __cplusplus >= 201103L
62#include <initializer_list>
63#include <tuple>
64#endif
65
66namespace std _GLIBCXX_VISIBILITY(default)
67{
68_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
69
70 /**
71 * @brief A standard container made up of (key,value) pairs, which can be
72 * retrieved based on a key, in logarithmic time.
73 *
74 * @ingroup associative_containers
75 *
76 * @tparam _Key Type of key objects.
77 * @tparam _Tp Type of mapped objects.
78 * @tparam _Compare Comparison function object type, defaults to less<_Key>.
79 * @tparam _Alloc Allocator type, defaults to
80 * allocator<pair<const _Key, _Tp>.
81 *
82 * Meets the requirements of a <a href="tables.html#65">container</a>, a
83 * <a href="tables.html#66">reversible container</a>, and an
84 * <a href="tables.html#69">associative container</a> (using unique keys).
85 * For a @c map<Key,T> the key_type is Key, the mapped_type is T, and the
86 * value_type is std::pair<const Key,T>.
87 *
88 * Maps support bidirectional iterators.
89 *
90 * The private tree data is declared exactly the same way for map and
91 * multimap; the distinction is made entirely in how the tree functions are
92 * called (*_unique versus *_equal, same as the standard).
93 */
94 template <typename _Key, typename _Tp, typename _Compare = std::less<_Key>,
95 typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
96 class map
97 {
98 public:
99 typedef _Key key_type;
100 typedef _Tp mapped_type;
101 typedef std::pair<const _Key, _Tp> value_type;
102 typedef _Compare key_compare;
103 typedef _Alloc allocator_type;
104
105 private:
106 // concept requirements
107 typedef typename _Alloc::value_type _Alloc_value_type;
108 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
109 __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
110 _BinaryFunctionConcept)
111 __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
112
113 public:
114 class value_compare
115 : public std::binary_function<value_type, value_type, bool>
116 {
117 friend class map<_Key, _Tp, _Compare, _Alloc>;
118 protected:
119 _Compare comp;
120
121 value_compare(_Compare __c)
122 : comp(__c) { }
123
124 public:
125 bool operator()(const value_type& __x, const value_type& __y) const
126 { return comp(__x.first, __y.first); }
127 };
128
129 private:
130 /// This turns a red-black tree into a [multi]map.
131 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
132 rebind<value_type>::other _Pair_alloc_type;
133
134 typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
135 key_compare, _Pair_alloc_type> _Rep_type;
136
137 /// The actual tree structure.
138 _Rep_type _M_t;
139
140 typedef __gnu_cxx::__alloc_traits<_Pair_alloc_type> _Alloc_traits;
141
142 public:
143 // many of these are specified differently in ISO, but the following are
144 // "functionally equivalent"
145 typedef typename _Alloc_traits::pointer pointer;
146 typedef typename _Alloc_traits::const_pointer const_pointer;
147 typedef typename _Alloc_traits::reference reference;
148 typedef typename _Alloc_traits::const_reference const_reference;
149 typedef typename _Rep_type::iterator iterator;
150 typedef typename _Rep_type::const_iterator const_iterator;
151 typedef typename _Rep_type::size_type size_type;
152 typedef typename _Rep_type::difference_type difference_type;
153 typedef typename _Rep_type::reverse_iterator reverse_iterator;
154 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
155
156 // [23.3.1.1] construct/copy/destroy
157 // (get_allocator() is also listed in this section)
158
159 /**
160 * @brief Default constructor creates no elements.
161 */
162 map()
163#if __cplusplus >= 201103L
164 noexcept(is_nothrow_default_constructible<allocator_type>::value)
165#endif
166 : _M_t() { }
167
168 /**
169 * @brief Creates a %map with no elements.
170 * @param __comp A comparison object.
171 * @param __a An allocator object.
172 */
173 explicit
174 map(const _Compare& __comp,
175 const allocator_type& __a = allocator_type())
176 : _M_t(__comp, _Pair_alloc_type(__a)) { }
177
178 /**
179 * @brief %Map copy constructor.
180 * @param __x A %map of identical element and allocator types.
181 *
182 * The newly-created %map uses a copy of the allocation object
183 * used by @a __x.
184 */
185 map(const map& __x)
186 : _M_t(__x._M_t) { }
187
188#if __cplusplus >= 201103L
189 /**
190 * @brief %Map move constructor.
191 * @param __x A %map of identical element and allocator types.
192 *
193 * The newly-created %map contains the exact contents of @a __x.
194 * The contents of @a __x are a valid, but unspecified %map.
195 */
196 map(map&& __x)
197 noexcept(is_nothrow_copy_constructible<_Compare>::value)
198 : _M_t(std::move(__x._M_t)) { }
199
200 /**
201 * @brief Builds a %map from an initializer_list.
202 * @param __l An initializer_list.
203 * @param __comp A comparison object.
204 * @param __a An allocator object.
205 *
206 * Create a %map consisting of copies of the elements in the
207 * initializer_list @a __l.
208 * This is linear in N if the range is already sorted, and NlogN
209 * otherwise (where N is @a __l.size()).
210 */
211 map(initializer_list<value_type> __l,
212 const _Compare& __comp = _Compare(),
213 const allocator_type& __a = allocator_type())
214 : _M_t(__comp, _Pair_alloc_type(__a))
215 { _M_t._M_insert_unique(__l.begin(), __l.end()); }
216
217 /// Allocator-extended default constructor.
218 explicit
219 map(const allocator_type& __a)
220 : _M_t(_Compare(), _Pair_alloc_type(__a)) { }
221
222 /// Allocator-extended copy constructor.
223 map(const map& __m, const allocator_type& __a)
224 : _M_t(__m._M_t, _Pair_alloc_type(__a)) { }
225
226 /// Allocator-extended move constructor.
227 map(map&& __m, const allocator_type& __a)
228 noexcept(is_nothrow_copy_constructible<_Compare>::value
229 && _Alloc_traits::_S_always_equal())
230 : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { }
231
232 /// Allocator-extended initialier-list constructor.
233 map(initializer_list<value_type> __l, const allocator_type& __a)
234 : _M_t(_Compare(), _Pair_alloc_type(__a))
235 { _M_t._M_insert_unique(__l.begin(), __l.end()); }
236
237 /// Allocator-extended range constructor.
238 template<typename _InputIterator>
239 map(_InputIterator __first, _InputIterator __last,
240 const allocator_type& __a)
241 : _M_t(_Compare(), _Pair_alloc_type(__a))
242 { _M_t._M_insert_unique(__first, __last); }
243#endif
244
245 /**
246 * @brief Builds a %map from a range.
247 * @param __first An input iterator.
248 * @param __last An input iterator.
249 *
250 * Create a %map consisting of copies of the elements from
251 * [__first,__last). This is linear in N if the range is
252 * already sorted, and NlogN otherwise (where N is
253 * distance(__first,__last)).
254 */
255 template<typename _InputIterator>
256 map(_InputIterator __first, _InputIterator __last)
257 : _M_t()
258 { _M_t._M_insert_unique(__first, __last); }
259
260 /**
261 * @brief Builds a %map from a range.
262 * @param __first An input iterator.
263 * @param __last An input iterator.
264 * @param __comp A comparison functor.
265 * @param __a An allocator object.
266 *
267 * Create a %map consisting of copies of the elements from
268 * [__first,__last). This is linear in N if the range is
269 * already sorted, and NlogN otherwise (where N is
270 * distance(__first,__last)).
271 */
272 template<typename _InputIterator>
273 map(_InputIterator __first, _InputIterator __last,
274 const _Compare& __comp,
275 const allocator_type& __a = allocator_type())
276 : _M_t(__comp, _Pair_alloc_type(__a))
277 { _M_t._M_insert_unique(__first, __last); }
278
279 // FIXME There is no dtor declared, but we should have something
280 // generated by Doxygen. I don't know what tags to add to this
281 // paragraph to make that happen:
282 /**
283 * The dtor only erases the elements, and note that if the elements
284 * themselves are pointers, the pointed-to memory is not touched in any
285 * way. Managing the pointer is the user's responsibility.
286 */
287
288 /**
289 * @brief %Map assignment operator.
290 * @param __x A %map of identical element and allocator types.
291 *
292 * All the elements of @a __x are copied, but unlike the copy
293 * constructor, the allocator object is not copied.
294 */
295 map&
296 operator=(const map& __x)
297 {
298 _M_t = __x._M_t;
299 return *this;
300 }
301
302#if __cplusplus >= 201103L
303 /// Move assignment operator.
304 map&
305 operator=(map&&) = default;
306
307 /**
308 * @brief %Map list assignment operator.
309 * @param __l An initializer_list.
310 *
311 * This function fills a %map with copies of the elements in the
312 * initializer list @a __l.
313 *
314 * Note that the assignment completely changes the %map and
315 * that the resulting %map's size is the same as the number
316 * of elements assigned. Old data may be lost.
317 */
318 map&
319 operator=(initializer_list<value_type> __l)
320 {
321 _M_t._M_assign_unique(__l.begin(), __l.end());
322 return *this;
323 }
324#endif
325
326 /// Get a copy of the memory allocation object.
327 allocator_type
328 get_allocator() const _GLIBCXX_NOEXCEPT
329 { return allocator_type(_M_t.get_allocator()); }
330
331 // iterators
332 /**
333 * Returns a read/write iterator that points to the first pair in the
334 * %map.
335 * Iteration is done in ascending order according to the keys.
336 */
337 iterator
338 begin() _GLIBCXX_NOEXCEPT
339 { return _M_t.begin(); }
340
341 /**
342 * Returns a read-only (constant) iterator that points to the first pair
343 * in the %map. Iteration is done in ascending order according to the
344 * keys.
345 */
346 const_iterator
347 begin() const _GLIBCXX_NOEXCEPT
348 { return _M_t.begin(); }
349
350 /**
351 * Returns a read/write iterator that points one past the last
352 * pair in the %map. Iteration is done in ascending order
353 * according to the keys.
354 */
355 iterator
356 end() _GLIBCXX_NOEXCEPT
357 { return _M_t.end(); }
358
359 /**
360 * Returns a read-only (constant) iterator that points one past the last
361 * pair in the %map. Iteration is done in ascending order according to
362 * the keys.
363 */
364 const_iterator
365 end() const _GLIBCXX_NOEXCEPT
366 { return _M_t.end(); }
367
368 /**
369 * Returns a read/write reverse iterator that points to the last pair in
370 * the %map. Iteration is done in descending order according to the
371 * keys.
372 */
373 reverse_iterator
374 rbegin() _GLIBCXX_NOEXCEPT
375 { return _M_t.rbegin(); }
376
377 /**
378 * Returns a read-only (constant) reverse iterator that points to the
379 * last pair in the %map. Iteration is done in descending order
380 * according to the keys.
381 */
382 const_reverse_iterator
383 rbegin() const _GLIBCXX_NOEXCEPT
384 { return _M_t.rbegin(); }
385
386 /**
387 * Returns a read/write reverse iterator that points to one before the
388 * first pair in the %map. Iteration is done in descending order
389 * according to the keys.
390 */
391 reverse_iterator
392 rend() _GLIBCXX_NOEXCEPT
393 { return _M_t.rend(); }
394
395 /**
396 * Returns a read-only (constant) reverse iterator that points to one
397 * before the first pair in the %map. Iteration is done in descending
398 * order according to the keys.
399 */
400 const_reverse_iterator
401 rend() const _GLIBCXX_NOEXCEPT
402 { return _M_t.rend(); }
403
404#if __cplusplus >= 201103L
405 /**
406 * Returns a read-only (constant) iterator that points to the first pair
407 * in the %map. Iteration is done in ascending order according to the
408 * keys.
409 */
410 const_iterator
411 cbegin() const noexcept
412 { return _M_t.begin(); }
413
414 /**
415 * Returns a read-only (constant) iterator that points one past the last
416 * pair in the %map. Iteration is done in ascending order according to
417 * the keys.
418 */
419 const_iterator
420 cend() const noexcept
421 { return _M_t.end(); }
422
423 /**
424 * Returns a read-only (constant) reverse iterator that points to the
425 * last pair in the %map. Iteration is done in descending order
426 * according to the keys.
427 */
428 const_reverse_iterator
429 crbegin() const noexcept
430 { return _M_t.rbegin(); }
431
432 /**
433 * Returns a read-only (constant) reverse iterator that points to one
434 * before the first pair in the %map. Iteration is done in descending
435 * order according to the keys.
436 */
437 const_reverse_iterator
438 crend() const noexcept
439 { return _M_t.rend(); }
440#endif
441
442 // capacity
443 /** Returns true if the %map is empty. (Thus begin() would equal
444 * end().)
445 */
446 bool
447 empty() const _GLIBCXX_NOEXCEPT
448 { return _M_t.empty(); }
449
450 /** Returns the size of the %map. */
451 size_type
452 size() const _GLIBCXX_NOEXCEPT
453 { return _M_t.size(); }
454
455 /** Returns the maximum size of the %map. */
456 size_type
457 max_size() const _GLIBCXX_NOEXCEPT
458 { return _M_t.max_size(); }
459
460 // [23.3.1.2] element access
461 /**
462 * @brief Subscript ( @c [] ) access to %map data.
463 * @param __k The key for which data should be retrieved.
464 * @return A reference to the data of the (key,data) %pair.
465 *
466 * Allows for easy lookup with the subscript ( @c [] )
467 * operator. Returns data associated with the key specified in
468 * subscript. If the key does not exist, a pair with that key
469 * is created using default values, which is then returned.
470 *
471 * Lookup requires logarithmic time.
472 */
473 mapped_type&
474 operator[](const key_type& __k)
475 {
476 // concept requirements
477 __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
478
479 iterator __i = lower_bound(__k);
480 // __i->first is greater than or equivalent to __k.
481 if (__i == end() || key_comp()(__k, (*__i).first))
482#if __cplusplus >= 201103L
483 __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
484 std::tuple<const key_type&>(__k),
485 std::tuple<>());
486#else
487 __i = insert(__i, value_type(__k, mapped_type()));
488#endif
489 return (*__i).second;
490 }
491
492#if __cplusplus >= 201103L
493 mapped_type&
494 operator[](key_type&& __k)
495 {
496 // concept requirements
497 __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
498
499 iterator __i = lower_bound(__k);
500 // __i->first is greater than or equivalent to __k.
501 if (__i == end() || key_comp()(__k, (*__i).first))
502 __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
503 std::forward_as_tuple(std::move(__k)),
504 std::tuple<>());
505 return (*__i).second;
506 }
507#endif
508
509 // _GLIBCXX_RESOLVE_LIB_DEFECTS
510 // DR 464. Suggestion for new member functions in standard containers.
511 /**
512 * @brief Access to %map data.
513 * @param __k The key for which data should be retrieved.
514 * @return A reference to the data whose key is equivalent to @a __k, if
515 * such a data is present in the %map.
516 * @throw std::out_of_range If no such data is present.
517 */
518 mapped_type&
519 at(const key_type& __k)
520 {
521 iterator __i = lower_bound(__k);
522 if (__i == end() || key_comp()(__k, (*__i).first))
523 __throw_out_of_range(__N("map::at"));
524 return (*__i).second;
525 }
526
527 const mapped_type&
528 at(const key_type& __k) const
529 {
530 const_iterator __i = lower_bound(__k);
531 if (__i == end() || key_comp()(__k, (*__i).first))
532 __throw_out_of_range(__N("map::at"));
533 return (*__i).second;
534 }
535
536 // modifiers
537#if __cplusplus >= 201103L
538 /**
539 * @brief Attempts to build and insert a std::pair into the %map.
540 *
541 * @param __args Arguments used to generate a new pair instance (see
542 * std::piecewise_contruct for passing arguments to each
543 * part of the pair constructor).
544 *
545 * @return A pair, of which the first element is an iterator that points
546 * to the possibly inserted pair, and the second is a bool that
547 * is true if the pair was actually inserted.
548 *
549 * This function attempts to build and insert a (key, value) %pair into
550 * the %map.
551 * A %map relies on unique keys and thus a %pair is only inserted if its
552 * first element (the key) is not already present in the %map.
553 *
554 * Insertion requires logarithmic time.
555 */
556 template<typename... _Args>
557 std::pair<iterator, bool>
558 emplace(_Args&&... __args)
559 { return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); }
560
561 /**
562 * @brief Attempts to build and insert a std::pair into the %map.
563 *
564 * @param __pos An iterator that serves as a hint as to where the pair
565 * should be inserted.
566 * @param __args Arguments used to generate a new pair instance (see
567 * std::piecewise_contruct for passing arguments to each
568 * part of the pair constructor).
569 * @return An iterator that points to the element with key of the
570 * std::pair built from @a __args (may or may not be that
571 * std::pair).
572 *
573 * This function is not concerned about whether the insertion took place,
574 * and thus does not return a boolean like the single-argument emplace()
575 * does.
576 * Note that the first parameter is only a hint and can potentially
577 * improve the performance of the insertion process. A bad hint would
578 * cause no gains in efficiency.
579 *
580 * See
581 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
582 * for more on @a hinting.
583 *
584 * Insertion requires logarithmic time (if the hint is not taken).
585 */
586 template<typename... _Args>
587 iterator
588 emplace_hint(const_iterator __pos, _Args&&... __args)
589 {
590 return _M_t._M_emplace_hint_unique(__pos,
591 std::forward<_Args>(__args)...);
592 }
593#endif
594
595#if __cplusplus > 201402L
596#define __cpp_lib_map_try_emplace 201411
597 /**
598 * @brief Attempts to build and insert a std::pair into the %map.
599 *
600 * @param __k Key to use for finding a possibly existing pair in
601 * the map.
602 * @param __args Arguments used to generate the .second for a new pair
603 * instance.
604 *
605 * @return A pair, of which the first element is an iterator that points
606 * to the possibly inserted pair, and the second is a bool that
607 * is true if the pair was actually inserted.
608 *
609 * This function attempts to build and insert a (key, value) %pair into
610 * the %map.
611 * A %map relies on unique keys and thus a %pair is only inserted if its
612 * first element (the key) is not already present in the %map.
613 * If a %pair is not inserted, this function has no effect.
614 *
615 * Insertion requires logarithmic time.
616 */
617 template <typename... _Args>
618 pair<iterator, bool>
619 try_emplace(const key_type& __k, _Args&&... __args)
620 {
621 iterator __i = lower_bound(__k);
622 if (__i == end() || key_comp()(__k, (*__i).first))
623 {
624 __i = emplace_hint(__i, std::piecewise_construct,
625 std::forward_as_tuple(__k),
626 std::forward_as_tuple(
627 std::forward<_Args>(__args)...));
628 return {__i, true};
629 }
630 return {__i, false};
631 }
632
633 // move-capable overload
634 template <typename... _Args>
635 pair<iterator, bool>
636 try_emplace(key_type&& __k, _Args&&... __args)
637 {
638 iterator __i = lower_bound(__k);
639 if (__i == end() || key_comp()(__k, (*__i).first))
640 {
641 __i = emplace_hint(__i, std::piecewise_construct,
642 std::forward_as_tuple(std::move(__k)),
643 std::forward_as_tuple(
644 std::forward<_Args>(__args)...));
645 return {__i, true};
646 }
647 return {__i, false};
648 }
649
650 /**
651 * @brief Attempts to build and insert a std::pair into the %map.
652 *
653 * @param __hint An iterator that serves as a hint as to where the
654 * pair should be inserted.
655 * @param __k Key to use for finding a possibly existing pair in
656 * the map.
657 * @param __args Arguments used to generate the .second for a new pair
658 * instance.
659 * @return An iterator that points to the element with key of the
660 * std::pair built from @a __args (may or may not be that
661 * std::pair).
662 *
663 * This function is not concerned about whether the insertion took place,
664 * and thus does not return a boolean like the single-argument
665 * try_emplace() does. However, if insertion did not take place,
666 * this function has no effect.
667 * Note that the first parameter is only a hint and can potentially
668 * improve the performance of the insertion process. A bad hint would
669 * cause no gains in efficiency.
670 *
671 * See
672 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
673 * for more on @a hinting.
674 *
675 * Insertion requires logarithmic time (if the hint is not taken).
676 */
677 template <typename... _Args>
678 iterator
679 try_emplace(const_iterator __hint, const key_type& __k,
680 _Args&&... __args)
681 {
682 iterator __i;
683 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
684 if (__true_hint.second)
685 __i = emplace_hint(iterator(__true_hint.second),
686 std::piecewise_construct,
687 std::forward_as_tuple(__k),
688 std::forward_as_tuple(
689 std::forward<_Args>(__args)...));
690 else
691 __i = iterator(__true_hint.first);
692 return __i;
693 }
694
695 // move-capable overload
696 template <typename... _Args>
697 iterator
698 try_emplace(const_iterator __hint, key_type&& __k, _Args&&... __args)
699 {
700 iterator __i;
701 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
702 if (__true_hint.second)
703 __i = emplace_hint(iterator(__true_hint.second),
704 std::piecewise_construct,
705 std::forward_as_tuple(std::move(__k)),
706 std::forward_as_tuple(
707 std::forward<_Args>(__args)...));
708 else
709 __i = iterator(__true_hint.first);
710 return __i;
711 }
712#endif
713
714 /**
715 * @brief Attempts to insert a std::pair into the %map.
716
717 * @param __x Pair to be inserted (see std::make_pair for easy
718 * creation of pairs).
719 *
720 * @return A pair, of which the first element is an iterator that
721 * points to the possibly inserted pair, and the second is
722 * a bool that is true if the pair was actually inserted.
723 *
724 * This function attempts to insert a (key, value) %pair into the %map.
725 * A %map relies on unique keys and thus a %pair is only inserted if its
726 * first element (the key) is not already present in the %map.
727 *
728 * Insertion requires logarithmic time.
729 */
730 std::pair<iterator, bool>
731 insert(const value_type& __x)
732 { return _M_t._M_insert_unique(__x); }
733
734#if __cplusplus >= 201103L
735 template<typename _Pair, typename = typename
736 std::enable_if<std::is_constructible<value_type,
737 _Pair&&>::value>::type>
738 std::pair<iterator, bool>
739 insert(_Pair&& __x)
740 { return _M_t._M_insert_unique(std::forward<_Pair>(__x)); }
741#endif
742
743#if __cplusplus >= 201103L
744 /**
745 * @brief Attempts to insert a list of std::pairs into the %map.
746 * @param __list A std::initializer_list<value_type> of pairs to be
747 * inserted.
748 *
749 * Complexity similar to that of the range constructor.
750 */
751 void
752 insert(std::initializer_list<value_type> __list)
753 { insert(__list.begin(), __list.end()); }
754#endif
755
756 /**
757 * @brief Attempts to insert a std::pair into the %map.
758 * @param __position An iterator that serves as a hint as to where the
759 * pair should be inserted.
760 * @param __x Pair to be inserted (see std::make_pair for easy creation
761 * of pairs).
762 * @return An iterator that points to the element with key of
763 * @a __x (may or may not be the %pair passed in).
764 *
765
766 * This function is not concerned about whether the insertion
767 * took place, and thus does not return a boolean like the
768 * single-argument insert() does. Note that the first
769 * parameter is only a hint and can potentially improve the
770 * performance of the insertion process. A bad hint would
771 * cause no gains in efficiency.
772 *
773 * See
774 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
775 * for more on @a hinting.
776 *
777 * Insertion requires logarithmic time (if the hint is not taken).
778 */
779 iterator
780#if __cplusplus >= 201103L
781 insert(const_iterator __position, const value_type& __x)
782#else
783 insert(iterator __position, const value_type& __x)
784#endif
785 { return _M_t._M_insert_unique_(__position, __x); }
786
787#if __cplusplus >= 201103L
788 template<typename _Pair, typename = typename
789 std::enable_if<std::is_constructible<value_type,
790 _Pair&&>::value>::type>
791 iterator
792 insert(const_iterator __position, _Pair&& __x)
793 { return _M_t._M_insert_unique_(__position,
794 std::forward<_Pair>(__x)); }
795#endif
796
797 /**
798 * @brief Template function that attempts to insert a range of elements.
799 * @param __first Iterator pointing to the start of the range to be
800 * inserted.
801 * @param __last Iterator pointing to the end of the range.
802 *
803 * Complexity similar to that of the range constructor.
804 */
805 template<typename _InputIterator>
806 void
807 insert(_InputIterator __first, _InputIterator __last)
808 { _M_t._M_insert_unique(__first, __last); }
809
810#if __cplusplus > 201402L
811#define __cpp_lib_map_insertion 201411
812 /**
813 * @brief Attempts to insert or assign a std::pair into the %map.
814 * @param __k Key to use for finding a possibly existing pair in
815 * the map.
816 * @param __obj Argument used to generate the .second for a pair
817 * instance.
818 *
819 * @return A pair, of which the first element is an iterator that
820 * points to the possibly inserted pair, and the second is
821 * a bool that is true if the pair was actually inserted.
822 *
823 * This function attempts to insert a (key, value) %pair into the %map.
824 * A %map relies on unique keys and thus a %pair is only inserted if its
825 * first element (the key) is not already present in the %map.
826 * If the %pair was already in the %map, the .second of the %pair
827 * is assigned from __obj.
828 *
829 * Insertion requires logarithmic time.
830 */
831 template <typename _Obj>
832 pair<iterator, bool>
833 insert_or_assign(const key_type& __k, _Obj&& __obj)
834 {
835 iterator __i = lower_bound(__k);
836 if (__i == end() || key_comp()(__k, (*__i).first))
837 {
838 __i = emplace_hint(__i, std::piecewise_construct,
839 std::forward_as_tuple(__k),
840 std::forward_as_tuple(
841 std::forward<_Obj>(__obj)));
842 return {__i, true};
843 }
844 (*__i).second = std::forward<_Obj>(__obj);
845 return {__i, false};
846 }
847
848 // move-capable overload
849 template <typename _Obj>
850 pair<iterator, bool>
851 insert_or_assign(key_type&& __k, _Obj&& __obj)
852 {
853 iterator __i = lower_bound(__k);
854 if (__i == end() || key_comp()(__k, (*__i).first))
855 {
856 __i = emplace_hint(__i, std::piecewise_construct,
857 std::forward_as_tuple(std::move(__k)),
858 std::forward_as_tuple(
859 std::forward<_Obj>(__obj)));
860 return {__i, true};
861 }
862 (*__i).second = std::forward<_Obj>(__obj);
863 return {__i, false};
864 }
865
866 /**
867 * @brief Attempts to insert or assign a std::pair into the %map.
868 * @param __hint An iterator that serves as a hint as to where the
869 * pair should be inserted.
870 * @param __k Key to use for finding a possibly existing pair in
871 * the map.
872 * @param __obj Argument used to generate the .second for a pair
873 * instance.
874 *
875 * @return An iterator that points to the element with key of
876 * @a __x (may or may not be the %pair passed in).
877 *
878 * This function attempts to insert a (key, value) %pair into the %map.
879 * A %map relies on unique keys and thus a %pair is only inserted if its
880 * first element (the key) is not already present in the %map.
881 * If the %pair was already in the %map, the .second of the %pair
882 * is assigned from __obj.
883 *
884 * Insertion requires logarithmic time.
885 */
886 template <typename _Obj>
887 iterator
888 insert_or_assign(const_iterator __hint,
889 const key_type& __k, _Obj&& __obj)
890 {
891 iterator __i;
892 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
893 if (__true_hint.second)
894 {
895 return emplace_hint(iterator(__true_hint.second),
896 std::piecewise_construct,
897 std::forward_as_tuple(__k),
898 std::forward_as_tuple(
899 std::forward<_Obj>(__obj)));
900 }
901 __i = iterator(__true_hint.first);
902 (*__i).second = std::forward<_Obj>(__obj);
903 return __i;
904 }
905
906 // move-capable overload
907 template <typename _Obj>
908 iterator
909 insert_or_assign(const_iterator __hint, key_type&& __k, _Obj&& __obj)
910 {
911 iterator __i;
912 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
913 if (__true_hint.second)
914 {
915 return emplace_hint(iterator(__true_hint.second),
916 std::piecewise_construct,
917 std::forward_as_tuple(std::move(__k)),
918 std::forward_as_tuple(
919 std::forward<_Obj>(__obj)));
920 }
921 __i = iterator(__true_hint.first);
922 (*__i).second = std::forward<_Obj>(__obj);
923 return __i;
924 }
925#endif
926
927#if __cplusplus >= 201103L
928 // _GLIBCXX_RESOLVE_LIB_DEFECTS
929 // DR 130. Associative erase should return an iterator.
930 /**
931 * @brief Erases an element from a %map.
932 * @param __position An iterator pointing to the element to be erased.
933 * @return An iterator pointing to the element immediately following
934 * @a position prior to the element being erased. If no such
935 * element exists, end() is returned.
936 *
937 * This function erases an element, pointed to by the given
938 * iterator, from a %map. Note that this function only erases
939 * the element, and that if the element is itself a pointer,
940 * the pointed-to memory is not touched in any way. Managing
941 * the pointer is the user's responsibility.
942 */
943 iterator
944 erase(const_iterator __position)
945 { return _M_t.erase(__position); }
946
947 // LWG 2059
948 _GLIBCXX_ABI_TAG_CXX11
949 iterator
950 erase(iterator __position)
951 { return _M_t.erase(__position); }
952#else
953 /**
954 * @brief Erases an element from a %map.
955 * @param __position An iterator pointing to the element to be erased.
956 *
957 * This function erases an element, pointed to by the given
958 * iterator, from a %map. Note that this function only erases
959 * the element, and that if the element is itself a pointer,
960 * the pointed-to memory is not touched in any way. Managing
961 * the pointer is the user's responsibility.
962 */
963 void
964 erase(iterator __position)
965 { _M_t.erase(__position); }
966#endif
967
968 /**
969 * @brief Erases elements according to the provided key.
970 * @param __x Key of element to be erased.
971 * @return The number of elements erased.
972 *
973 * This function erases all the elements located by the given key from
974 * a %map.
975 * Note that this function only erases the element, and that if
976 * the element is itself a pointer, the pointed-to memory is not touched
977 * in any way. Managing the pointer is the user's responsibility.
978 */
979 size_type
980 erase(const key_type& __x)
981 { return _M_t.erase(__x); }
982
983#if __cplusplus >= 201103L
984 // _GLIBCXX_RESOLVE_LIB_DEFECTS
985 // DR 130. Associative erase should return an iterator.
986 /**
987 * @brief Erases a [first,last) range of elements from a %map.
988 * @param __first Iterator pointing to the start of the range to be
989 * erased.
990 * @param __last Iterator pointing to the end of the range to
991 * be erased.
992 * @return The iterator @a __last.
993 *
994 * This function erases a sequence of elements from a %map.
995 * Note that this function only erases the element, and that if
996 * the element is itself a pointer, the pointed-to memory is not touched
997 * in any way. Managing the pointer is the user's responsibility.
998 */
999 iterator
1000 erase(const_iterator __first, const_iterator __last)
1001 { return _M_t.erase(__first, __last); }
1002#else
1003 /**
1004 * @brief Erases a [__first,__last) range of elements from a %map.
1005 * @param __first Iterator pointing to the start of the range to be
1006 * erased.
1007 * @param __last Iterator pointing to the end of the range to
1008 * be erased.
1009 *
1010 * This function erases a sequence of elements from a %map.
1011 * Note that this function only erases the element, and that if
1012 * the element is itself a pointer, the pointed-to memory is not touched
1013 * in any way. Managing the pointer is the user's responsibility.
1014 */
1015 void
1016 erase(iterator __first, iterator __last)
1017 { _M_t.erase(__first, __last); }
1018#endif
1019
1020 /**
1021 * @brief Swaps data with another %map.
1022 * @param __x A %map of the same element and allocator types.
1023 *
1024 * This exchanges the elements between two maps in constant
1025 * time. (It is only swapping a pointer, an integer, and an
1026 * instance of the @c Compare type (which itself is often
1027 * stateless and empty), so it should be quite fast.) Note
1028 * that the global std::swap() function is specialized such
1029 * that std::swap(m1,m2) will feed to this function.
1030 */
1031 void
1032 swap(map& __x)
1033 _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
1034 { _M_t.swap(__x._M_t); }
1035
1036 /**
1037 * Erases all elements in a %map. Note that this function only
1038 * erases the elements, and that if the elements themselves are
1039 * pointers, the pointed-to memory is not touched in any way.
1040 * Managing the pointer is the user's responsibility.
1041 */
1042 void
1043 clear() _GLIBCXX_NOEXCEPT
1044 { _M_t.clear(); }
1045
1046 // observers
1047 /**
1048 * Returns the key comparison object out of which the %map was
1049 * constructed.
1050 */
1051 key_compare
1052 key_comp() const
1053 { return _M_t.key_comp(); }
1054
1055 /**
1056 * Returns a value comparison object, built from the key comparison
1057 * object out of which the %map was constructed.
1058 */
1059 value_compare
1060 value_comp() const
1061 { return value_compare(_M_t.key_comp()); }
1062
1063 // [23.3.1.3] map operations
1064
1065 //@{
1066 /**
1067 * @brief Tries to locate an element in a %map.
1068 * @param __x Key of (key, value) %pair to be located.
1069 * @return Iterator pointing to sought-after element, or end() if not
1070 * found.
1071 *
1072 * This function takes a key and tries to locate the element with which
1073 * the key matches. If successful the function returns an iterator
1074 * pointing to the sought after %pair. If unsuccessful it returns the
1075 * past-the-end ( @c end() ) iterator.
1076 */
1077
1078 iterator
1079 find(const key_type& __x)
1080 { return _M_t.find(__x); }
1081
1082#if __cplusplus > 201103L
1083 template<typename _Kt>
1084 auto
1085 find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
1086 { return _M_t._M_find_tr(__x); }
1087#endif
1088 //@}
1089
1090 //@{
1091 /**
1092 * @brief Tries to locate an element in a %map.
1093 * @param __x Key of (key, value) %pair to be located.
1094 * @return Read-only (constant) iterator pointing to sought-after
1095 * element, or end() if not found.
1096 *
1097 * This function takes a key and tries to locate the element with which
1098 * the key matches. If successful the function returns a constant
1099 * iterator pointing to the sought after %pair. If unsuccessful it
1100 * returns the past-the-end ( @c end() ) iterator.
1101 */
1102
1103 const_iterator
1104 find(const key_type& __x) const
1105 { return _M_t.find(__x); }
1106
1107#if __cplusplus > 201103L
1108 template<typename _Kt>
1109 auto
1110 find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
1111 { return _M_t._M_find_tr(__x); }
1112#endif
1113 //@}
1114
1115 //@{
1116 /**
1117 * @brief Finds the number of elements with given key.
1118 * @param __x Key of (key, value) pairs to be located.
1119 * @return Number of elements with specified key.
1120 *
1121 * This function only makes sense for multimaps; for map the result will
1122 * either be 0 (not present) or 1 (present).
1123 */
1124 size_type
1125 count(const key_type& __x) const
1126 { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
1127
1128#if __cplusplus > 201103L
1129 template<typename _Kt>
1130 auto
1131 count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
1132 { return _M_t._M_find_tr(__x) == _M_t.end() ? 0 : 1; }
1133#endif
1134 //@}
1135
1136 //@{
1137 /**
1138 * @brief Finds the beginning of a subsequence matching given key.
1139 * @param __x Key of (key, value) pair to be located.
1140 * @return Iterator pointing to first element equal to or greater
1141 * than key, or end().
1142 *
1143 * This function returns the first element of a subsequence of elements
1144 * that matches the given key. If unsuccessful it returns an iterator
1145 * pointing to the first element that has a greater value than given key
1146 * or end() if no such element exists.
1147 */
1148 iterator
1149 lower_bound(const key_type& __x)
1150 { return _M_t.lower_bound(__x); }
1151
1152#if __cplusplus > 201103L
1153 template<typename _Kt>
1154 auto
1155 lower_bound(const _Kt& __x)
1156 -> decltype(_M_t._M_lower_bound_tr(__x))
1157 { return _M_t._M_lower_bound_tr(__x); }
1158#endif
1159 //@}
1160
1161 //@{
1162 /**
1163 * @brief Finds the beginning of a subsequence matching given key.
1164 * @param __x Key of (key, value) pair to be located.
1165 * @return Read-only (constant) iterator pointing to first element
1166 * equal to or greater than key, or end().
1167 *
1168 * This function returns the first element of a subsequence of elements
1169 * that matches the given key. If unsuccessful it returns an iterator
1170 * pointing to the first element that has a greater value than given key
1171 * or end() if no such element exists.
1172 */
1173 const_iterator
1174 lower_bound(const key_type& __x) const
1175 { return _M_t.lower_bound(__x); }
1176
1177#if __cplusplus > 201103L
1178 template<typename _Kt>
1179 auto
1180 lower_bound(const _Kt& __x) const
1181 -> decltype(_M_t._M_lower_bound_tr(__x))
1182 { return _M_t._M_lower_bound_tr(__x); }
1183#endif
1184 //@}
1185
1186 //@{
1187 /**
1188 * @brief Finds the end of a subsequence matching given key.
1189 * @param __x Key of (key, value) pair to be located.
1190 * @return Iterator pointing to the first element
1191 * greater than key, or end().
1192 */
1193 iterator
1194 upper_bound(const key_type& __x)
1195 { return _M_t.upper_bound(__x); }
1196
1197#if __cplusplus > 201103L
1198 template<typename _Kt>
1199 auto
1200 upper_bound(const _Kt& __x)
1201 -> decltype(_M_t._M_upper_bound_tr(__x))
1202 { return _M_t._M_upper_bound_tr(__x); }
1203#endif
1204 //@}
1205
1206 //@{
1207 /**
1208 * @brief Finds the end of a subsequence matching given key.
1209 * @param __x Key of (key, value) pair to be located.
1210 * @return Read-only (constant) iterator pointing to first iterator
1211 * greater than key, or end().
1212 */
1213 const_iterator
1214 upper_bound(const key_type& __x) const
1215 { return _M_t.upper_bound(__x); }
1216
1217#if __cplusplus > 201103L
1218 template<typename _Kt>
1219 auto
1220 upper_bound(const _Kt& __x) const
1221 -> decltype(_M_t._M_upper_bound_tr(__x))
1222 { return _M_t._M_upper_bound_tr(__x); }
1223#endif
1224 //@}
1225
1226 //@{
1227 /**
1228 * @brief Finds a subsequence matching given key.
1229 * @param __x Key of (key, value) pairs to be located.
1230 * @return Pair of iterators that possibly points to the subsequence
1231 * matching given key.
1232 *
1233 * This function is equivalent to
1234 * @code
1235 * std::make_pair(c.lower_bound(val),
1236 * c.upper_bound(val))
1237 * @endcode
1238 * (but is faster than making the calls separately).
1239 *
1240 * This function probably only makes sense for multimaps.
1241 */
1242 std::pair<iterator, iterator>
1243 equal_range(const key_type& __x)
1244 { return _M_t.equal_range(__x); }
1245
1246#if __cplusplus > 201103L
1247 template<typename _Kt>
1248 auto
1249 equal_range(const _Kt& __x)
1250 -> decltype(_M_t._M_equal_range_tr(__x))
1251 { return _M_t._M_equal_range_tr(__x); }
1252#endif
1253 //@}
1254
1255 //@{
1256 /**
1257 * @brief Finds a subsequence matching given key.
1258 * @param __x Key of (key, value) pairs to be located.
1259 * @return Pair of read-only (constant) iterators that possibly points
1260 * to the subsequence matching given key.
1261 *
1262 * This function is equivalent to
1263 * @code
1264 * std::make_pair(c.lower_bound(val),
1265 * c.upper_bound(val))
1266 * @endcode
1267 * (but is faster than making the calls separately).
1268 *
1269 * This function probably only makes sense for multimaps.
1270 */
1271 std::pair<const_iterator, const_iterator>
1272 equal_range(const key_type& __x) const
1273 { return _M_t.equal_range(__x); }
1274
1275#if __cplusplus > 201103L
1276 template<typename _Kt>
1277 auto
1278 equal_range(const _Kt& __x) const
1279 -> decltype(_M_t._M_equal_range_tr(__x))
1280 { return _M_t._M_equal_range_tr(__x); }
1281#endif
1282 //@}
1283
1284 template<typename _K1, typename _T1, typename _C1, typename _A1>
1285 friend bool
1286 operator==(const map<_K1, _T1, _C1, _A1>&,
1287 const map<_K1, _T1, _C1, _A1>&);
1288
1289 template<typename _K1, typename _T1, typename _C1, typename _A1>
1290 friend bool
1291 operator<(const map<_K1, _T1, _C1, _A1>&,
1292 const map<_K1, _T1, _C1, _A1>&);
1293 };
1294
1295 /**
1296 * @brief Map equality comparison.
1297 * @param __x A %map.
1298 * @param __y A %map of the same type as @a x.
1299 * @return True iff the size and elements of the maps are equal.
1300 *
1301 * This is an equivalence relation. It is linear in the size of the
1302 * maps. Maps are considered equivalent if their sizes are equal,
1303 * and if corresponding elements compare equal.
1304 */
1305 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1306 inline bool
1307 operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1308 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1309 { return __x._M_t == __y._M_t; }
1310
1311 /**
1312 * @brief Map ordering relation.
1313 * @param __x A %map.
1314 * @param __y A %map of the same type as @a x.
1315 * @return True iff @a x is lexicographically less than @a y.
1316 *
1317 * This is a total ordering relation. It is linear in the size of the
1318 * maps. The elements must be comparable with @c <.
1319 *
1320 * See std::lexicographical_compare() for how the determination is made.
1321 */
1322 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1323 inline bool
1324 operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1325 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1326 { return __x._M_t < __y._M_t; }
1327
1328 /// Based on operator==
1329 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1330 inline bool
1331 operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1332 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1333 { return !(__x == __y); }
1334
1335 /// Based on operator<
1336 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1337 inline bool
1338 operator>(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1339 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1340 { return __y < __x; }
1341
1342 /// Based on operator<
1343 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1344 inline bool
1345 operator<=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1346 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1347 { return !(__y < __x); }
1348
1349 /// Based on operator<
1350 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1351 inline bool
1352 operator>=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1353 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1354 { return !(__x < __y); }
1355
1356 /// See std::map::swap().
1357 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1358 inline void
1359 swap(map<_Key, _Tp, _Compare, _Alloc>& __x,
1360 map<_Key, _Tp, _Compare, _Alloc>& __y)
1361 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
1362 { __x.swap(__y); }
1363
1364_GLIBCXX_END_NAMESPACE_CONTAINER
1365} // namespace std
1366
1367#endif /* _STL_MAP_H */
1368