1 // RB tree implementation -*- C++ -*-
2
3 // Copyright (C) 2001-2020 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) 1996,1997
28 * Silicon Graphics Computer Systems, Inc.
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. Silicon Graphics 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) 1994
40 * Hewlett-Packard Company
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. Hewlett-Packard Company 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 */
52
53 /** @file bits/stl_tree.h
54 * This is an internal header file, included by other library headers.
55 * Do not attempt to use it directly. @headername{map,set}
56 */
57
58 #ifndef _STL_TREE_H
59 #define _STL_TREE_H 1
60
61 #pragma GCC system_header
62
63 #include <bits/stl_algobase.h>
64 #include <bits/allocator.h>
65 #include <bits/stl_function.h>
66 #include <bits/cpp_type_traits.h>
67 #include <ext/alloc_traits.h>
68 #if __cplusplus >= 201103L
69 # include <ext/aligned_buffer.h>
70 #endif
71 #if __cplusplus > 201402L
72 # include <bits/node_handle.h>
73 #endif
74
_GLIBCXX_VISIBILITY(default)75 namespace std _GLIBCXX_VISIBILITY(default)
76 {
77 _GLIBCXX_BEGIN_NAMESPACE_VERSION
78
79 #if __cplusplus > 201103L
80 # define __cpp_lib_generic_associative_lookup 201304
81 #endif
82
83 // Red-black tree class, designed for use in implementing STL
84 // associative containers (set, multiset, map, and multimap). The
85 // insertion and deletion algorithms are based on those in Cormen,
86 // Leiserson, and Rivest, Introduction to Algorithms (MIT Press,
87 // 1990), except that
88 //
89 // (1) the header cell is maintained with links not only to the root
90 // but also to the leftmost node of the tree, to enable constant
91 // time begin(), and to the rightmost node of the tree, to enable
92 // linear time performance when used with the generic set algorithms
93 // (set_union, etc.)
94 //
95 // (2) when a node being deleted has two children its successor node
96 // is relinked into its place, rather than copied, so that the only
97 // iterators invalidated are those referring to the deleted node.
98
99 enum _Rb_tree_color { _S_red = false, _S_black = true };
100
101 struct _Rb_tree_node_base
102 {
103 typedef _Rb_tree_node_base* _Base_ptr;
104 typedef const _Rb_tree_node_base* _Const_Base_ptr;
105
106 _Rb_tree_color _M_color;
107 _Base_ptr _M_parent;
108 _Base_ptr _M_left;
109 _Base_ptr _M_right;
110
111 static _Base_ptr
112 _S_minimum(_Base_ptr __x) _GLIBCXX_NOEXCEPT
113 {
114 while (__x->_M_left != 0) __x = __x->_M_left;
115 return __x;
116 }
117
118 static _Const_Base_ptr
119 _S_minimum(_Const_Base_ptr __x) _GLIBCXX_NOEXCEPT
120 {
121 while (__x->_M_left != 0) __x = __x->_M_left;
122 return __x;
123 }
124
125 static _Base_ptr
126 _S_maximum(_Base_ptr __x) _GLIBCXX_NOEXCEPT
127 {
128 while (__x->_M_right != 0) __x = __x->_M_right;
129 return __x;
130 }
131
132 static _Const_Base_ptr
133 _S_maximum(_Const_Base_ptr __x) _GLIBCXX_NOEXCEPT
134 {
135 while (__x->_M_right != 0) __x = __x->_M_right;
136 return __x;
137 }
138 };
139
140 // Helper type offering value initialization guarantee on the compare functor.
141 template<typename _Key_compare>
142 struct _Rb_tree_key_compare
143 {
144 _Key_compare _M_key_compare;
145
146 _Rb_tree_key_compare()
147 _GLIBCXX_NOEXCEPT_IF(
148 is_nothrow_default_constructible<_Key_compare>::value)
149 : _M_key_compare()
150 { }
151
152 _Rb_tree_key_compare(const _Key_compare& __comp)
153 : _M_key_compare(__comp)
154 { }
155
156 #if __cplusplus >= 201103L
157 // Copy constructor added for consistency with C++98 mode.
158 _Rb_tree_key_compare(const _Rb_tree_key_compare&) = default;
159
160 _Rb_tree_key_compare(_Rb_tree_key_compare&& __x)
161 noexcept(is_nothrow_copy_constructible<_Key_compare>::value)
162 : _M_key_compare(__x._M_key_compare)
163 { }
164 #endif
165 };
166
167 // Helper type to manage default initialization of node count and header.
168 struct _Rb_tree_header
169 {
170 _Rb_tree_node_base _M_header;
171 size_t _M_node_count; // Keeps track of size of tree.
172
173 _Rb_tree_header() _GLIBCXX_NOEXCEPT
174 {
175 _M_header._M_color = _S_red;
176 _M_reset();
177 }
178
179 #if __cplusplus >= 201103L
180 _Rb_tree_header(_Rb_tree_header&& __x) noexcept
181 {
182 if (__x._M_header._M_parent != nullptr)
183 _M_move_data(__x);
184 else
185 {
186 _M_header._M_color = _S_red;
187 _M_reset();
188 }
189 }
190 #endif
191
192 void
193 _M_move_data(_Rb_tree_header& __from)
194 {
195 _M_header._M_color = __from._M_header._M_color;
196 _M_header._M_parent = __from._M_header._M_parent;
197 _M_header._M_left = __from._M_header._M_left;
198 _M_header._M_right = __from._M_header._M_right;
199 _M_header._M_parent->_M_parent = &_M_header;
200 _M_node_count = __from._M_node_count;
201
202 __from._M_reset();
203 }
204
205 void
206 _M_reset()
207 {
208 _M_header._M_parent = 0;
209 _M_header._M_left = &_M_header;
210 _M_header._M_right = &_M_header;
211 _M_node_count = 0;
212 }
213 };
214
215 template<typename _Val>
216 struct _Rb_tree_node : public _Rb_tree_node_base
217 {
218 typedef _Rb_tree_node<_Val>* _Link_type;
219
220 #if __cplusplus < 201103L
221 _Val _M_value_field;
222
223 _Val*
224 _M_valptr()
225 { return std::__addressof(_M_value_field); }
226
227 const _Val*
228 _M_valptr() const
229 { return std::__addressof(_M_value_field); }
230 #else
231 __gnu_cxx::__aligned_membuf<_Val> _M_storage;
232
233 _Val*
234 _M_valptr()
235 { return _M_storage._M_ptr(); }
236
237 const _Val*
238 _M_valptr() const
239 { return _M_storage._M_ptr(); }
240 #endif
241 };
242
243 _GLIBCXX_PURE _Rb_tree_node_base*
244 _Rb_tree_increment(_Rb_tree_node_base* __x) throw ();
245
246 _GLIBCXX_PURE const _Rb_tree_node_base*
247 _Rb_tree_increment(const _Rb_tree_node_base* __x) throw ();
248
249 _GLIBCXX_PURE _Rb_tree_node_base*
250 _Rb_tree_decrement(_Rb_tree_node_base* __x) throw ();
251
252 _GLIBCXX_PURE const _Rb_tree_node_base*
253 _Rb_tree_decrement(const _Rb_tree_node_base* __x) throw ();
254
255 template<typename _Tp>
256 struct _Rb_tree_iterator
257 {
258 typedef _Tp value_type;
259 typedef _Tp& reference;
260 typedef _Tp* pointer;
261
262 typedef bidirectional_iterator_tag iterator_category;
263 typedef ptrdiff_t difference_type;
264
265 typedef _Rb_tree_iterator<_Tp> _Self;
266 typedef _Rb_tree_node_base::_Base_ptr _Base_ptr;
267 typedef _Rb_tree_node<_Tp>* _Link_type;
268
269 _Rb_tree_iterator() _GLIBCXX_NOEXCEPT
270 : _M_node() { }
271
272 explicit
273 _Rb_tree_iterator(_Base_ptr __x) _GLIBCXX_NOEXCEPT
274 : _M_node(__x) { }
275
276 reference
277 operator*() const _GLIBCXX_NOEXCEPT
278 { return *static_cast<_Link_type>(_M_node)->_M_valptr(); }
279
280 pointer
281 operator->() const _GLIBCXX_NOEXCEPT
282 { return static_cast<_Link_type> (_M_node)->_M_valptr(); }
283
284 _Self&
285 operator++() _GLIBCXX_NOEXCEPT
286 {
287 _M_node = _Rb_tree_increment(_M_node);
288 return *this;
289 }
290
291 _Self
292 operator++(int) _GLIBCXX_NOEXCEPT
293 {
294 _Self __tmp = *this;
295 _M_node = _Rb_tree_increment(_M_node);
296 return __tmp;
297 }
298
299 _Self&
300 operator--() _GLIBCXX_NOEXCEPT
301 {
302 _M_node = _Rb_tree_decrement(_M_node);
303 return *this;
304 }
305
306 _Self
307 operator--(int) _GLIBCXX_NOEXCEPT
308 {
309 _Self __tmp = *this;
310 _M_node = _Rb_tree_decrement(_M_node);
311 return __tmp;
312 }
313
314 friend bool
315 operator==(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT
316 { return __x._M_node == __y._M_node; }
317
318 #if ! __cpp_lib_three_way_comparison
319 friend bool
320 operator!=(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT
321 { return __x._M_node != __y._M_node; }
322 #endif
323
324 _Base_ptr _M_node;
325 };
326
327 template<typename _Tp>
328 struct _Rb_tree_const_iterator
329 {
330 typedef _Tp value_type;
331 typedef const _Tp& reference;
332 typedef const _Tp* pointer;
333
334 typedef _Rb_tree_iterator<_Tp> iterator;
335
336 typedef bidirectional_iterator_tag iterator_category;
337 typedef ptrdiff_t difference_type;
338
339 typedef _Rb_tree_const_iterator<_Tp> _Self;
340 typedef _Rb_tree_node_base::_Const_Base_ptr _Base_ptr;
341 typedef const _Rb_tree_node<_Tp>* _Link_type;
342
343 _Rb_tree_const_iterator() _GLIBCXX_NOEXCEPT
344 : _M_node() { }
345
346 explicit
347 _Rb_tree_const_iterator(_Base_ptr __x) _GLIBCXX_NOEXCEPT
348 : _M_node(__x) { }
349
350 _Rb_tree_const_iterator(const iterator& __it) _GLIBCXX_NOEXCEPT
351 : _M_node(__it._M_node) { }
352
353 iterator
354 _M_const_cast() const _GLIBCXX_NOEXCEPT
355 { return iterator(const_cast<typename iterator::_Base_ptr>(_M_node)); }
356
357 reference
358 operator*() const _GLIBCXX_NOEXCEPT
359 { return *static_cast<_Link_type>(_M_node)->_M_valptr(); }
360
361 pointer
362 operator->() const _GLIBCXX_NOEXCEPT
363 { return static_cast<_Link_type>(_M_node)->_M_valptr(); }
364
365 _Self&
366 operator++() _GLIBCXX_NOEXCEPT
367 {
368 _M_node = _Rb_tree_increment(_M_node);
369 return *this;
370 }
371
372 _Self
373 operator++(int) _GLIBCXX_NOEXCEPT
374 {
375 _Self __tmp = *this;
376 _M_node = _Rb_tree_increment(_M_node);
377 return __tmp;
378 }
379
380 _Self&
381 operator--() _GLIBCXX_NOEXCEPT
382 {
383 _M_node = _Rb_tree_decrement(_M_node);
384 return *this;
385 }
386
387 _Self
388 operator--(int) _GLIBCXX_NOEXCEPT
389 {
390 _Self __tmp = *this;
391 _M_node = _Rb_tree_decrement(_M_node);
392 return __tmp;
393 }
394
395 friend bool
396 operator==(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT
397 { return __x._M_node == __y._M_node; }
398
399 #if ! __cpp_lib_three_way_comparison
400 friend bool
401 operator!=(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT
402 { return __x._M_node != __y._M_node; }
403 #endif
404
405 _Base_ptr _M_node;
406 };
407
408 void
409 _Rb_tree_insert_and_rebalance(const bool __insert_left,
410 _Rb_tree_node_base* __x,
411 _Rb_tree_node_base* __p,
412 _Rb_tree_node_base& __header) throw ();
413
414 _Rb_tree_node_base*
415 _Rb_tree_rebalance_for_erase(_Rb_tree_node_base* const __z,
416 _Rb_tree_node_base& __header) throw ();
417
418 #if __cplusplus >= 201402L
419 template<typename _Cmp, typename _SfinaeType, typename = __void_t<>>
420 struct __has_is_transparent
421 { };
422
423 template<typename _Cmp, typename _SfinaeType>
424 struct __has_is_transparent<_Cmp, _SfinaeType,
425 __void_t<typename _Cmp::is_transparent>>
426 { typedef void type; };
427
428 template<typename _Cmp, typename _SfinaeType>
429 using __has_is_transparent_t
430 = typename __has_is_transparent<_Cmp, _SfinaeType>::type;
431 #endif
432
433 #if __cplusplus > 201402L
434 template<typename _Tree1, typename _Cmp2>
435 struct _Rb_tree_merge_helper { };
436 #endif
437
438 template<typename _Key, typename _Val, typename _KeyOfValue,
439 typename _Compare, typename _Alloc = allocator<_Val> >
440 class _Rb_tree
441 {
442 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
443 rebind<_Rb_tree_node<_Val> >::other _Node_allocator;
444
445 typedef __gnu_cxx::__alloc_traits<_Node_allocator> _Alloc_traits;
446
447 protected:
448 typedef _Rb_tree_node_base* _Base_ptr;
449 typedef const _Rb_tree_node_base* _Const_Base_ptr;
450 typedef _Rb_tree_node<_Val>* _Link_type;
451 typedef const _Rb_tree_node<_Val>* _Const_Link_type;
452
453 private:
454 // Functor recycling a pool of nodes and using allocation once the pool
455 // is empty.
456 struct _Reuse_or_alloc_node
457 {
458 _Reuse_or_alloc_node(_Rb_tree& __t)
459 : _M_root(__t._M_root()), _M_nodes(__t._M_rightmost()), _M_t(__t)
460 {
461 if (_M_root)
462 {
463 _M_root->_M_parent = 0;
464
465 if (_M_nodes->_M_left)
466 _M_nodes = _M_nodes->_M_left;
467 }
468 else
469 _M_nodes = 0;
470 }
471
472 #if __cplusplus >= 201103L
473 _Reuse_or_alloc_node(const _Reuse_or_alloc_node&) = delete;
474 #endif
475
476 ~_Reuse_or_alloc_node()
477 { _M_t._M_erase(static_cast<_Link_type>(_M_root)); }
478
479 template<typename _Arg>
480 _Link_type
481 #if __cplusplus < 201103L
482 operator()(const _Arg& __arg)
483 #else
484 operator()(_Arg&& __arg)
485 #endif
486 {
487 _Link_type __node = static_cast<_Link_type>(_M_extract());
488 if (__node)
489 {
490 _M_t._M_destroy_node(__node);
491 _M_t._M_construct_node(__node, _GLIBCXX_FORWARD(_Arg, __arg));
492 return __node;
493 }
494
495 return _M_t._M_create_node(_GLIBCXX_FORWARD(_Arg, __arg));
496 }
497
498 private:
499 _Base_ptr
500 _M_extract()
501 {
502 if (!_M_nodes)
503 return _M_nodes;
504
505 _Base_ptr __node = _M_nodes;
506 _M_nodes = _M_nodes->_M_parent;
507 if (_M_nodes)
508 {
509 if (_M_nodes->_M_right == __node)
510 {
511 _M_nodes->_M_right = 0;
512
513 if (_M_nodes->_M_left)
514 {
515 _M_nodes = _M_nodes->_M_left;
516
517 while (_M_nodes->_M_right)
518 _M_nodes = _M_nodes->_M_right;
519
520 if (_M_nodes->_M_left)
521 _M_nodes = _M_nodes->_M_left;
522 }
523 }
524 else // __node is on the left.
525 _M_nodes->_M_left = 0;
526 }
527 else
528 _M_root = 0;
529
530 return __node;
531 }
532
533 _Base_ptr _M_root;
534 _Base_ptr _M_nodes;
535 _Rb_tree& _M_t;
536 };
537
538 // Functor similar to the previous one but without any pool of nodes to
539 // recycle.
540 struct _Alloc_node
541 {
542 _Alloc_node(_Rb_tree& __t)
543 : _M_t(__t) { }
544
545 template<typename _Arg>
546 _Link_type
547 #if __cplusplus < 201103L
548 operator()(const _Arg& __arg) const
549 #else
550 operator()(_Arg&& __arg) const
551 #endif
552 { return _M_t._M_create_node(_GLIBCXX_FORWARD(_Arg, __arg)); }
553
554 private:
555 _Rb_tree& _M_t;
556 };
557
558 public:
559 typedef _Key key_type;
560 typedef _Val value_type;
561 typedef value_type* pointer;
562 typedef const value_type* const_pointer;
563 typedef value_type& reference;
564 typedef const value_type& const_reference;
565 typedef size_t size_type;
566 typedef ptrdiff_t difference_type;
567 typedef _Alloc allocator_type;
568
569 _Node_allocator&
570 _M_get_Node_allocator() _GLIBCXX_NOEXCEPT
571 { return this->_M_impl; }
572
573 const _Node_allocator&
574 _M_get_Node_allocator() const _GLIBCXX_NOEXCEPT
575 { return this->_M_impl; }
576
577 allocator_type
578 get_allocator() const _GLIBCXX_NOEXCEPT
579 { return allocator_type(_M_get_Node_allocator()); }
580
581 protected:
582 _Link_type
583 _M_get_node()
584 { return _Alloc_traits::allocate(_M_get_Node_allocator(), 1); }
585
586 void
587 _M_put_node(_Link_type __p) _GLIBCXX_NOEXCEPT
588 { _Alloc_traits::deallocate(_M_get_Node_allocator(), __p, 1); }
589
590 #if __cplusplus < 201103L
591 void
592 _M_construct_node(_Link_type __node, const value_type& __x)
593 {
594 __try
595 { get_allocator().construct(__node->_M_valptr(), __x); }
596 __catch(...)
597 {
598 _M_put_node(__node);
599 __throw_exception_again;
600 }
601 }
602
603 _Link_type
604 _M_create_node(const value_type& __x)
605 {
606 _Link_type __tmp = _M_get_node();
607 _M_construct_node(__tmp, __x);
608 return __tmp;
609 }
610 #else
611 template<typename... _Args>
612 void
613 _M_construct_node(_Link_type __node, _Args&&... __args)
614 {
615 __try
616 {
617 ::new(__node) _Rb_tree_node<_Val>;
618 _Alloc_traits::construct(_M_get_Node_allocator(),
619 __node->_M_valptr(),
620 std::forward<_Args>(__args)...);
621 }
622 __catch(...)
623 {
624 __node->~_Rb_tree_node<_Val>();
625 _M_put_node(__node);
626 __throw_exception_again;
627 }
628 }
629
630 template<typename... _Args>
631 _Link_type
632 _M_create_node(_Args&&... __args)
633 {
634 _Link_type __tmp = _M_get_node();
635 _M_construct_node(__tmp, std::forward<_Args>(__args)...);
636 return __tmp;
637 }
638 #endif
639
640 void
641 _M_destroy_node(_Link_type __p) _GLIBCXX_NOEXCEPT
642 {
643 #if __cplusplus < 201103L
644 get_allocator().destroy(__p->_M_valptr());
645 #else
646 _Alloc_traits::destroy(_M_get_Node_allocator(), __p->_M_valptr());
647 __p->~_Rb_tree_node<_Val>();
648 #endif
649 }
650
651 void
652 _M_drop_node(_Link_type __p) _GLIBCXX_NOEXCEPT
653 {
654 _M_destroy_node(__p);
655 _M_put_node(__p);
656 }
657
658 template<typename _NodeGen>
659 _Link_type
660 _M_clone_node(_Const_Link_type __x, _NodeGen& __node_gen)
661 {
662 _Link_type __tmp = __node_gen(*__x->_M_valptr());
663 __tmp->_M_color = __x->_M_color;
664 __tmp->_M_left = 0;
665 __tmp->_M_right = 0;
666 return __tmp;
667 }
668
669 protected:
670 #if _GLIBCXX_INLINE_VERSION
671 template<typename _Key_compare>
672 #else
673 // Unused _Is_pod_comparator is kept as it is part of mangled name.
674 template<typename _Key_compare,
675 bool /* _Is_pod_comparator */ = __is_pod(_Key_compare)>
676 #endif
677 struct _Rb_tree_impl
678 : public _Node_allocator
679 , public _Rb_tree_key_compare<_Key_compare>
680 , public _Rb_tree_header
681 {
682 typedef _Rb_tree_key_compare<_Key_compare> _Base_key_compare;
683
684 _Rb_tree_impl()
685 _GLIBCXX_NOEXCEPT_IF(
686 is_nothrow_default_constructible<_Node_allocator>::value
687 && is_nothrow_default_constructible<_Base_key_compare>::value )
688 : _Node_allocator()
689 { }
690
691 _Rb_tree_impl(const _Rb_tree_impl& __x)
692 : _Node_allocator(_Alloc_traits::_S_select_on_copy(__x))
693 , _Base_key_compare(__x._M_key_compare)
694 { }
695
696 #if __cplusplus < 201103L
697 _Rb_tree_impl(const _Key_compare& __comp, const _Node_allocator& __a)
698 : _Node_allocator(__a), _Base_key_compare(__comp)
699 { }
700 #else
701 _Rb_tree_impl(_Rb_tree_impl&&)
702 noexcept( is_nothrow_move_constructible<_Base_key_compare>::value )
703 = default;
704
705 explicit
706 _Rb_tree_impl(_Node_allocator&& __a)
707 : _Node_allocator(std::move(__a))
708 { }
709
710 _Rb_tree_impl(_Rb_tree_impl&& __x, _Node_allocator&& __a)
711 : _Node_allocator(std::move(__a)),
712 _Base_key_compare(std::move(__x)),
713 _Rb_tree_header(std::move(__x))
714 { }
715
716 _Rb_tree_impl(const _Key_compare& __comp, _Node_allocator&& __a)
717 : _Node_allocator(std::move(__a)), _Base_key_compare(__comp)
718 { }
719 #endif
720 };
721
722 _Rb_tree_impl<_Compare> _M_impl;
723
724 protected:
725 _Base_ptr&
726 _M_root() _GLIBCXX_NOEXCEPT
727 { return this->_M_impl._M_header._M_parent; }
728
729 _Const_Base_ptr
730 _M_root() const _GLIBCXX_NOEXCEPT
731 { return this->_M_impl._M_header._M_parent; }
732
733 _Base_ptr&
734 _M_leftmost() _GLIBCXX_NOEXCEPT
735 { return this->_M_impl._M_header._M_left; }
736
737 _Const_Base_ptr
738 _M_leftmost() const _GLIBCXX_NOEXCEPT
739 { return this->_M_impl._M_header._M_left; }
740
741 _Base_ptr&
742 _M_rightmost() _GLIBCXX_NOEXCEPT
743 { return this->_M_impl._M_header._M_right; }
744
745 _Const_Base_ptr
746 _M_rightmost() const _GLIBCXX_NOEXCEPT
747 { return this->_M_impl._M_header._M_right; }
748
749 _Link_type
750 _M_begin() _GLIBCXX_NOEXCEPT
751 { return static_cast<_Link_type>(this->_M_impl._M_header._M_parent); }
752
753 _Const_Link_type
754 _M_begin() const _GLIBCXX_NOEXCEPT
755 {
756 return static_cast<_Const_Link_type>
757 (this->_M_impl._M_header._M_parent);
758 }
759
760 _Base_ptr
761 _M_end() _GLIBCXX_NOEXCEPT
762 { return &this->_M_impl._M_header; }
763
764 _Const_Base_ptr
765 _M_end() const _GLIBCXX_NOEXCEPT
766 { return &this->_M_impl._M_header; }
767
768 static const _Key&
769 _S_key(_Const_Link_type __x)
770 {
771 #if __cplusplus >= 201103L
772 // If we're asking for the key we're presumably using the comparison
773 // object, and so this is a good place to sanity check it.
774 static_assert(__is_invocable<_Compare&, const _Key&, const _Key&>{},
775 "comparison object must be invocable "
776 "with two arguments of key type");
777 # if __cplusplus >= 201703L
778 // _GLIBCXX_RESOLVE_LIB_DEFECTS
779 // 2542. Missing const requirements for associative containers
780 if constexpr (__is_invocable<_Compare&, const _Key&, const _Key&>{})
781 static_assert(
782 is_invocable_v<const _Compare&, const _Key&, const _Key&>,
783 "comparison object must be invocable as const");
784 # endif // C++17
785 #endif // C++11
786
787 return _KeyOfValue()(*__x->_M_valptr());
788 }
789
790 static _Link_type
791 _S_left(_Base_ptr __x) _GLIBCXX_NOEXCEPT
792 { return static_cast<_Link_type>(__x->_M_left); }
793
794 static _Const_Link_type
795 _S_left(_Const_Base_ptr __x) _GLIBCXX_NOEXCEPT
796 { return static_cast<_Const_Link_type>(__x->_M_left); }
797
798 static _Link_type
799 _S_right(_Base_ptr __x) _GLIBCXX_NOEXCEPT
800 { return static_cast<_Link_type>(__x->_M_right); }
801
802 static _Const_Link_type
803 _S_right(_Const_Base_ptr __x) _GLIBCXX_NOEXCEPT
804 { return static_cast<_Const_Link_type>(__x->_M_right); }
805
806 static const _Key&
807 _S_key(_Const_Base_ptr __x)
808 { return _S_key(static_cast<_Const_Link_type>(__x)); }
809
810 static _Base_ptr
811 _S_minimum(_Base_ptr __x) _GLIBCXX_NOEXCEPT
812 { return _Rb_tree_node_base::_S_minimum(__x); }
813
814 static _Const_Base_ptr
815 _S_minimum(_Const_Base_ptr __x) _GLIBCXX_NOEXCEPT
816 { return _Rb_tree_node_base::_S_minimum(__x); }
817
818 static _Base_ptr
819 _S_maximum(_Base_ptr __x) _GLIBCXX_NOEXCEPT
820 { return _Rb_tree_node_base::_S_maximum(__x); }
821
822 static _Const_Base_ptr
823 _S_maximum(_Const_Base_ptr __x) _GLIBCXX_NOEXCEPT
824 { return _Rb_tree_node_base::_S_maximum(__x); }
825
826 public:
827 typedef _Rb_tree_iterator<value_type> iterator;
828 typedef _Rb_tree_const_iterator<value_type> const_iterator;
829
830 typedef std::reverse_iterator<iterator> reverse_iterator;
831 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
832
833 #if __cplusplus > 201402L
834 using node_type = _Node_handle<_Key, _Val, _Node_allocator>;
835 using insert_return_type = _Node_insert_return<
836 conditional_t<is_same_v<_Key, _Val>, const_iterator, iterator>,
837 node_type>;
838 #endif
839
840 pair<_Base_ptr, _Base_ptr>
841 _M_get_insert_unique_pos(const key_type& __k);
842
843 pair<_Base_ptr, _Base_ptr>
844 _M_get_insert_equal_pos(const key_type& __k);
845
846 pair<_Base_ptr, _Base_ptr>
847 _M_get_insert_hint_unique_pos(const_iterator __pos,
848 const key_type& __k);
849
850 pair<_Base_ptr, _Base_ptr>
851 _M_get_insert_hint_equal_pos(const_iterator __pos,
852 const key_type& __k);
853
854 private:
855 #if __cplusplus >= 201103L
856 template<typename _Arg, typename _NodeGen>
857 iterator
858 _M_insert_(_Base_ptr __x, _Base_ptr __y, _Arg&& __v, _NodeGen&);
859
860 iterator
861 _M_insert_node(_Base_ptr __x, _Base_ptr __y, _Link_type __z);
862
863 template<typename _Arg>
864 iterator
865 _M_insert_lower(_Base_ptr __y, _Arg&& __v);
866
867 template<typename _Arg>
868 iterator
869 _M_insert_equal_lower(_Arg&& __x);
870
871 iterator
872 _M_insert_lower_node(_Base_ptr __p, _Link_type __z);
873
874 iterator
875 _M_insert_equal_lower_node(_Link_type __z);
876 #else
877 template<typename _NodeGen>
878 iterator
879 _M_insert_(_Base_ptr __x, _Base_ptr __y,
880 const value_type& __v, _NodeGen&);
881
882 // _GLIBCXX_RESOLVE_LIB_DEFECTS
883 // 233. Insertion hints in associative containers.
884 iterator
885 _M_insert_lower(_Base_ptr __y, const value_type& __v);
886
887 iterator
888 _M_insert_equal_lower(const value_type& __x);
889 #endif
890
891 template<typename _NodeGen>
892 _Link_type
893 _M_copy(_Const_Link_type __x, _Base_ptr __p, _NodeGen&);
894
895 template<typename _NodeGen>
896 _Link_type
897 _M_copy(const _Rb_tree& __x, _NodeGen& __gen)
898 {
899 _Link_type __root = _M_copy(__x._M_begin(), _M_end(), __gen);
900 _M_leftmost() = _S_minimum(__root);
901 _M_rightmost() = _S_maximum(__root);
902 _M_impl._M_node_count = __x._M_impl._M_node_count;
903 return __root;
904 }
905
906 _Link_type
907 _M_copy(const _Rb_tree& __x)
908 {
909 _Alloc_node __an(*this);
910 return _M_copy(__x, __an);
911 }
912
913 void
914 _M_erase(_Link_type __x);
915
916 iterator
917 _M_lower_bound(_Link_type __x, _Base_ptr __y,
918 const _Key& __k);
919
920 const_iterator
921 _M_lower_bound(_Const_Link_type __x, _Const_Base_ptr __y,
922 const _Key& __k) const;
923
924 iterator
925 _M_upper_bound(_Link_type __x, _Base_ptr __y,
926 const _Key& __k);
927
928 const_iterator
929 _M_upper_bound(_Const_Link_type __x, _Const_Base_ptr __y,
930 const _Key& __k) const;
931
932 public:
933 // allocation/deallocation
934 #if __cplusplus < 201103L
935 _Rb_tree() { }
936 #else
937 _Rb_tree() = default;
938 #endif
939
940 _Rb_tree(const _Compare& __comp,
941 const allocator_type& __a = allocator_type())
942 : _M_impl(__comp, _Node_allocator(__a)) { }
943
944 _Rb_tree(const _Rb_tree& __x)
945 : _M_impl(__x._M_impl)
946 {
947 if (__x._M_root() != 0)
948 _M_root() = _M_copy(__x);
949 }
950
951 #if __cplusplus >= 201103L
952 _Rb_tree(const allocator_type& __a)
953 : _M_impl(_Node_allocator(__a))
954 { }
955
956 _Rb_tree(const _Rb_tree& __x, const allocator_type& __a)
957 : _M_impl(__x._M_impl._M_key_compare, _Node_allocator(__a))
958 {
959 if (__x._M_root() != nullptr)
960 _M_root() = _M_copy(__x);
961 }
962
963 _Rb_tree(_Rb_tree&&) = default;
964
965 _Rb_tree(_Rb_tree&& __x, const allocator_type& __a)
966 : _Rb_tree(std::move(__x), _Node_allocator(__a))
967 { }
968
969 private:
970 _Rb_tree(_Rb_tree&& __x, _Node_allocator&& __a, true_type)
971 noexcept(is_nothrow_default_constructible<_Compare>::value)
972 : _M_impl(std::move(__x._M_impl), std::move(__a))
973 { }
974
975 _Rb_tree(_Rb_tree&& __x, _Node_allocator&& __a, false_type)
976 : _M_impl(__x._M_impl._M_key_compare, std::move(__a))
977 {
978 if (__x._M_root() != nullptr)
979 _M_move_data(__x, false_type{});
980 }
981
982 public:
983 _Rb_tree(_Rb_tree&& __x, _Node_allocator&& __a)
984 noexcept( noexcept(
985 _Rb_tree(std::declval<_Rb_tree&&>(), std::declval<_Node_allocator&&>(),
986 std::declval<typename _Alloc_traits::is_always_equal>())) )
987 : _Rb_tree(std::move(__x), std::move(__a),
988 typename _Alloc_traits::is_always_equal{})
989 { }
990 #endif
991
992 ~_Rb_tree() _GLIBCXX_NOEXCEPT
993 { _M_erase(_M_begin()); }
994
995 _Rb_tree&
996 operator=(const _Rb_tree& __x);
997
998 // Accessors.
999 _Compare
1000 key_comp() const
1001 { return _M_impl._M_key_compare; }
1002
1003 iterator
1004 begin() _GLIBCXX_NOEXCEPT
1005 { return iterator(this->_M_impl._M_header._M_left); }
1006
1007 const_iterator
1008 begin() const _GLIBCXX_NOEXCEPT
1009 { return const_iterator(this->_M_impl._M_header._M_left); }
1010
1011 iterator
1012 end() _GLIBCXX_NOEXCEPT
1013 { return iterator(&this->_M_impl._M_header); }
1014
1015 const_iterator
1016 end() const _GLIBCXX_NOEXCEPT
1017 { return const_iterator(&this->_M_impl._M_header); }
1018
1019 reverse_iterator
1020 rbegin() _GLIBCXX_NOEXCEPT
1021 { return reverse_iterator(end()); }
1022
1023 const_reverse_iterator
1024 rbegin() const _GLIBCXX_NOEXCEPT
1025 { return const_reverse_iterator(end()); }
1026
1027 reverse_iterator
1028 rend() _GLIBCXX_NOEXCEPT
1029 { return reverse_iterator(begin()); }
1030
1031 const_reverse_iterator
1032 rend() const _GLIBCXX_NOEXCEPT
1033 { return const_reverse_iterator(begin()); }
1034
1035 _GLIBCXX_NODISCARD bool
1036 empty() const _GLIBCXX_NOEXCEPT
1037 { return _M_impl._M_node_count == 0; }
1038
1039 size_type
1040 size() const _GLIBCXX_NOEXCEPT
1041 { return _M_impl._M_node_count; }
1042
1043 size_type
1044 max_size() const _GLIBCXX_NOEXCEPT
1045 { return _Alloc_traits::max_size(_M_get_Node_allocator()); }
1046
1047 void
1048 swap(_Rb_tree& __t)
1049 _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value);
1050
1051 // Insert/erase.
1052 #if __cplusplus >= 201103L
1053 template<typename _Arg>
1054 pair<iterator, bool>
1055 _M_insert_unique(_Arg&& __x);
1056
1057 template<typename _Arg>
1058 iterator
1059 _M_insert_equal(_Arg&& __x);
1060
1061 template<typename _Arg, typename _NodeGen>
1062 iterator
1063 _M_insert_unique_(const_iterator __pos, _Arg&& __x, _NodeGen&);
1064
1065 template<typename _Arg>
1066 iterator
1067 _M_insert_unique_(const_iterator __pos, _Arg&& __x)
1068 {
1069 _Alloc_node __an(*this);
1070 return _M_insert_unique_(__pos, std::forward<_Arg>(__x), __an);
1071 }
1072
1073 template<typename _Arg, typename _NodeGen>
1074 iterator
1075 _M_insert_equal_(const_iterator __pos, _Arg&& __x, _NodeGen&);
1076
1077 template<typename _Arg>
1078 iterator
1079 _M_insert_equal_(const_iterator __pos, _Arg&& __x)
1080 {
1081 _Alloc_node __an(*this);
1082 return _M_insert_equal_(__pos, std::forward<_Arg>(__x), __an);
1083 }
1084
1085 template<typename... _Args>
1086 pair<iterator, bool>
1087 _M_emplace_unique(_Args&&... __args);
1088
1089 template<typename... _Args>
1090 iterator
1091 _M_emplace_equal(_Args&&... __args);
1092
1093 template<typename... _Args>
1094 iterator
1095 _M_emplace_hint_unique(const_iterator __pos, _Args&&... __args);
1096
1097 template<typename... _Args>
1098 iterator
1099 _M_emplace_hint_equal(const_iterator __pos, _Args&&... __args);
1100
1101 template<typename _Iter>
1102 using __same_value_type
1103 = is_same<value_type, typename iterator_traits<_Iter>::value_type>;
1104
1105 template<typename _InputIterator>
1106 __enable_if_t<__same_value_type<_InputIterator>::value>
1107 _M_insert_range_unique(_InputIterator __first, _InputIterator __last)
1108 {
1109 _Alloc_node __an(*this);
1110 for (; __first != __last; ++__first)
1111 _M_insert_unique_(end(), *__first, __an);
1112 }
1113
1114 template<typename _InputIterator>
1115 __enable_if_t<!__same_value_type<_InputIterator>::value>
1116 _M_insert_range_unique(_InputIterator __first, _InputIterator __last)
1117 {
1118 for (; __first != __last; ++__first)
1119 _M_emplace_unique(*__first);
1120 }
1121
1122 template<typename _InputIterator>
1123 __enable_if_t<__same_value_type<_InputIterator>::value>
1124 _M_insert_range_equal(_InputIterator __first, _InputIterator __last)
1125 {
1126 _Alloc_node __an(*this);
1127 for (; __first != __last; ++__first)
1128 _M_insert_equal_(end(), *__first, __an);
1129 }
1130
1131 template<typename _InputIterator>
1132 __enable_if_t<!__same_value_type<_InputIterator>::value>
1133 _M_insert_range_equal(_InputIterator __first, _InputIterator __last)
1134 {
1135 _Alloc_node __an(*this);
1136 for (; __first != __last; ++__first)
1137 _M_emplace_equal(*__first);
1138 }
1139 #else
1140 pair<iterator, bool>
1141 _M_insert_unique(const value_type& __x);
1142
1143 iterator
1144 _M_insert_equal(const value_type& __x);
1145
1146 template<typename _NodeGen>
1147 iterator
1148 _M_insert_unique_(const_iterator __pos, const value_type& __x,
1149 _NodeGen&);
1150
1151 iterator
1152 _M_insert_unique_(const_iterator __pos, const value_type& __x)
1153 {
1154 _Alloc_node __an(*this);
1155 return _M_insert_unique_(__pos, __x, __an);
1156 }
1157
1158 template<typename _NodeGen>
1159 iterator
1160 _M_insert_equal_(const_iterator __pos, const value_type& __x,
1161 _NodeGen&);
1162 iterator
1163 _M_insert_equal_(const_iterator __pos, const value_type& __x)
1164 {
1165 _Alloc_node __an(*this);
1166 return _M_insert_equal_(__pos, __x, __an);
1167 }
1168
1169 template<typename _InputIterator>
1170 void
1171 _M_insert_range_unique(_InputIterator __first, _InputIterator __last)
1172 {
1173 _Alloc_node __an(*this);
1174 for (; __first != __last; ++__first)
1175 _M_insert_unique_(end(), *__first, __an);
1176 }
1177
1178 template<typename _InputIterator>
1179 void
1180 _M_insert_range_equal(_InputIterator __first, _InputIterator __last)
1181 {
1182 _Alloc_node __an(*this);
1183 for (; __first != __last; ++__first)
1184 _M_insert_equal_(end(), *__first, __an);
1185 }
1186 #endif
1187
1188 private:
1189 void
1190 _M_erase_aux(const_iterator __position);
1191
1192 void
1193 _M_erase_aux(const_iterator __first, const_iterator __last);
1194
1195 public:
1196 #if __cplusplus >= 201103L
1197 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1198 // DR 130. Associative erase should return an iterator.
1199 _GLIBCXX_ABI_TAG_CXX11
1200 iterator
1201 erase(const_iterator __position)
1202 {
1203 __glibcxx_assert(__position != end());
1204 const_iterator __result = __position;
1205 ++__result;
1206 _M_erase_aux(__position);
1207 return __result._M_const_cast();
1208 }
1209
1210 // LWG 2059.
1211 _GLIBCXX_ABI_TAG_CXX11
1212 iterator
1213 erase(iterator __position)
1214 {
1215 __glibcxx_assert(__position != end());
1216 iterator __result = __position;
1217 ++__result;
1218 _M_erase_aux(__position);
1219 return __result;
1220 }
1221 #else
1222 void
1223 erase(iterator __position)
1224 {
1225 __glibcxx_assert(__position != end());
1226 _M_erase_aux(__position);
1227 }
1228
1229 void
1230 erase(const_iterator __position)
1231 {
1232 __glibcxx_assert(__position != end());
1233 _M_erase_aux(__position);
1234 }
1235 #endif
1236
1237 size_type
1238 erase(const key_type& __x);
1239
1240 #if __cplusplus >= 201103L
1241 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1242 // DR 130. Associative erase should return an iterator.
1243 _GLIBCXX_ABI_TAG_CXX11
1244 iterator
1245 erase(const_iterator __first, const_iterator __last)
1246 {
1247 _M_erase_aux(__first, __last);
1248 return __last._M_const_cast();
1249 }
1250 #else
1251 void
1252 erase(iterator __first, iterator __last)
1253 { _M_erase_aux(__first, __last); }
1254
1255 void
1256 erase(const_iterator __first, const_iterator __last)
1257 { _M_erase_aux(__first, __last); }
1258 #endif
1259
1260 void
1261 clear() _GLIBCXX_NOEXCEPT
1262 {
1263 _M_erase(_M_begin());
1264 _M_impl._M_reset();
1265 }
1266
1267 // Set operations.
1268 iterator
1269 find(const key_type& __k);
1270
1271 const_iterator
1272 find(const key_type& __k) const;
1273
1274 size_type
1275 count(const key_type& __k) const;
1276
1277 iterator
1278 lower_bound(const key_type& __k)
1279 { return _M_lower_bound(_M_begin(), _M_end(), __k); }
1280
1281 const_iterator
1282 lower_bound(const key_type& __k) const
1283 { return _M_lower_bound(_M_begin(), _M_end(), __k); }
1284
1285 iterator
1286 upper_bound(const key_type& __k)
1287 { return _M_upper_bound(_M_begin(), _M_end(), __k); }
1288
1289 const_iterator
1290 upper_bound(const key_type& __k) const
1291 { return _M_upper_bound(_M_begin(), _M_end(), __k); }
1292
1293 pair<iterator, iterator>
1294 equal_range(const key_type& __k);
1295
1296 pair<const_iterator, const_iterator>
1297 equal_range(const key_type& __k) const;
1298
1299 #if __cplusplus >= 201402L
1300 template<typename _Kt,
1301 typename _Req = __has_is_transparent_t<_Compare, _Kt>>
1302 iterator
1303 _M_find_tr(const _Kt& __k)
1304 {
1305 const _Rb_tree* __const_this = this;
1306 return __const_this->_M_find_tr(__k)._M_const_cast();
1307 }
1308
1309 template<typename _Kt,
1310 typename _Req = __has_is_transparent_t<_Compare, _Kt>>
1311 const_iterator
1312 _M_find_tr(const _Kt& __k) const
1313 {
1314 auto __j = _M_lower_bound_tr(__k);
1315 if (__j != end() && _M_impl._M_key_compare(__k, _S_key(__j._M_node)))
1316 __j = end();
1317 return __j;
1318 }
1319
1320 template<typename _Kt,
1321 typename _Req = __has_is_transparent_t<_Compare, _Kt>>
1322 size_type
1323 _M_count_tr(const _Kt& __k) const
1324 {
1325 auto __p = _M_equal_range_tr(__k);
1326 return std::distance(__p.first, __p.second);
1327 }
1328
1329 template<typename _Kt,
1330 typename _Req = __has_is_transparent_t<_Compare, _Kt>>
1331 iterator
1332 _M_lower_bound_tr(const _Kt& __k)
1333 {
1334 const _Rb_tree* __const_this = this;
1335 return __const_this->_M_lower_bound_tr(__k)._M_const_cast();
1336 }
1337
1338 template<typename _Kt,
1339 typename _Req = __has_is_transparent_t<_Compare, _Kt>>
1340 const_iterator
1341 _M_lower_bound_tr(const _Kt& __k) const
1342 {
1343 auto __x = _M_begin();
1344 auto __y = _M_end();
1345 while (__x != 0)
1346 if (!_M_impl._M_key_compare(_S_key(__x), __k))
1347 {
1348 __y = __x;
1349 __x = _S_left(__x);
1350 }
1351 else
1352 __x = _S_right(__x);
1353 return const_iterator(__y);
1354 }
1355
1356 template<typename _Kt,
1357 typename _Req = __has_is_transparent_t<_Compare, _Kt>>
1358 iterator
1359 _M_upper_bound_tr(const _Kt& __k)
1360 {
1361 const _Rb_tree* __const_this = this;
1362 return __const_this->_M_upper_bound_tr(__k)._M_const_cast();
1363 }
1364
1365 template<typename _Kt,
1366 typename _Req = __has_is_transparent_t<_Compare, _Kt>>
1367 const_iterator
1368 _M_upper_bound_tr(const _Kt& __k) const
1369 {
1370 auto __x = _M_begin();
1371 auto __y = _M_end();
1372 while (__x != 0)
1373 if (_M_impl._M_key_compare(__k, _S_key(__x)))
1374 {
1375 __y = __x;
1376 __x = _S_left(__x);
1377 }
1378 else
1379 __x = _S_right(__x);
1380 return const_iterator(__y);
1381 }
1382
1383 template<typename _Kt,
1384 typename _Req = __has_is_transparent_t<_Compare, _Kt>>
1385 pair<iterator, iterator>
1386 _M_equal_range_tr(const _Kt& __k)
1387 {
1388 const _Rb_tree* __const_this = this;
1389 auto __ret = __const_this->_M_equal_range_tr(__k);
1390 return { __ret.first._M_const_cast(), __ret.second._M_const_cast() };
1391 }
1392
1393 template<typename _Kt,
1394 typename _Req = __has_is_transparent_t<_Compare, _Kt>>
1395 pair<const_iterator, const_iterator>
1396 _M_equal_range_tr(const _Kt& __k) const
1397 {
1398 auto __low = _M_lower_bound_tr(__k);
1399 auto __high = __low;
1400 auto& __cmp = _M_impl._M_key_compare;
1401 while (__high != end() && !__cmp(__k, _S_key(__high._M_node)))
1402 ++__high;
1403 return { __low, __high };
1404 }
1405 #endif
1406
1407 // Debugging.
1408 bool
1409 __rb_verify() const;
1410
1411 #if __cplusplus >= 201103L
1412 _Rb_tree&
1413 operator=(_Rb_tree&&)
1414 noexcept(_Alloc_traits::_S_nothrow_move()
1415 && is_nothrow_move_assignable<_Compare>::value);
1416
1417 template<typename _Iterator>
1418 void
1419 _M_assign_unique(_Iterator, _Iterator);
1420
1421 template<typename _Iterator>
1422 void
1423 _M_assign_equal(_Iterator, _Iterator);
1424
1425 private:
1426 // Move elements from container with equal allocator.
1427 void
1428 _M_move_data(_Rb_tree& __x, true_type)
1429 { _M_impl._M_move_data(__x._M_impl); }
1430
1431 // Move elements from container with possibly non-equal allocator,
1432 // which might result in a copy not a move.
1433 void
1434 _M_move_data(_Rb_tree&, false_type);
1435
1436 // Move assignment from container with equal allocator.
1437 void
1438 _M_move_assign(_Rb_tree&, true_type);
1439
1440 // Move assignment from container with possibly non-equal allocator,
1441 // which might result in a copy not a move.
1442 void
1443 _M_move_assign(_Rb_tree&, false_type);
1444 #endif
1445
1446 #if __cplusplus > 201402L
1447 public:
1448 /// Re-insert an extracted node.
1449 insert_return_type
1450 _M_reinsert_node_unique(node_type&& __nh)
1451 {
1452 insert_return_type __ret;
1453 if (__nh.empty())
1454 __ret.position = end();
1455 else
1456 {
1457 __glibcxx_assert(_M_get_Node_allocator() == *__nh._M_alloc);
1458
1459 auto __res = _M_get_insert_unique_pos(__nh._M_key());
1460 if (__res.second)
1461 {
1462 __ret.position
1463 = _M_insert_node(__res.first, __res.second, __nh._M_ptr);
1464 __nh._M_ptr = nullptr;
1465 __ret.inserted = true;
1466 }
1467 else
1468 {
1469 __ret.node = std::move(__nh);
1470 __ret.position = iterator(__res.first);
1471 __ret.inserted = false;
1472 }
1473 }
1474 return __ret;
1475 }
1476
1477 /// Re-insert an extracted node.
1478 iterator
1479 _M_reinsert_node_equal(node_type&& __nh)
1480 {
1481 iterator __ret;
1482 if (__nh.empty())
1483 __ret = end();
1484 else
1485 {
1486 __glibcxx_assert(_M_get_Node_allocator() == *__nh._M_alloc);
1487 auto __res = _M_get_insert_equal_pos(__nh._M_key());
1488 if (__res.second)
1489 __ret = _M_insert_node(__res.first, __res.second, __nh._M_ptr);
1490 else
1491 __ret = _M_insert_equal_lower_node(__nh._M_ptr);
1492 __nh._M_ptr = nullptr;
1493 }
1494 return __ret;
1495 }
1496
1497 /// Re-insert an extracted node.
1498 iterator
1499 _M_reinsert_node_hint_unique(const_iterator __hint, node_type&& __nh)
1500 {
1501 iterator __ret;
1502 if (__nh.empty())
1503 __ret = end();
1504 else
1505 {
1506 __glibcxx_assert(_M_get_Node_allocator() == *__nh._M_alloc);
1507 auto __res = _M_get_insert_hint_unique_pos(__hint, __nh._M_key());
1508 if (__res.second)
1509 {
1510 __ret = _M_insert_node(__res.first, __res.second, __nh._M_ptr);
1511 __nh._M_ptr = nullptr;
1512 }
1513 else
1514 __ret = iterator(__res.first);
1515 }
1516 return __ret;
1517 }
1518
1519 /// Re-insert an extracted node.
1520 iterator
1521 _M_reinsert_node_hint_equal(const_iterator __hint, node_type&& __nh)
1522 {
1523 iterator __ret;
1524 if (__nh.empty())
1525 __ret = end();
1526 else
1527 {
1528 __glibcxx_assert(_M_get_Node_allocator() == *__nh._M_alloc);
1529 auto __res = _M_get_insert_hint_equal_pos(__hint, __nh._M_key());
1530 if (__res.second)
1531 __ret = _M_insert_node(__res.first, __res.second, __nh._M_ptr);
1532 else
1533 __ret = _M_insert_equal_lower_node(__nh._M_ptr);
1534 __nh._M_ptr = nullptr;
1535 }
1536 return __ret;
1537 }
1538
1539 /// Extract a node.
1540 node_type
1541 extract(const_iterator __pos)
1542 {
1543 auto __ptr = _Rb_tree_rebalance_for_erase(
1544 __pos._M_const_cast()._M_node, _M_impl._M_header);
1545 --_M_impl._M_node_count;
1546 return { static_cast<_Link_type>(__ptr), _M_get_Node_allocator() };
1547 }
1548
1549 /// Extract a node.
1550 node_type
1551 extract(const key_type& __k)
1552 {
1553 node_type __nh;
1554 auto __pos = find(__k);
1555 if (__pos != end())
1556 __nh = extract(const_iterator(__pos));
1557 return __nh;
1558 }
1559
1560 template<typename _Compare2>
1561 using _Compatible_tree
1562 = _Rb_tree<_Key, _Val, _KeyOfValue, _Compare2, _Alloc>;
1563
1564 template<typename, typename>
1565 friend class _Rb_tree_merge_helper;
1566
1567 /// Merge from a compatible container into one with unique keys.
1568 template<typename _Compare2>
1569 void
1570 _M_merge_unique(_Compatible_tree<_Compare2>& __src) noexcept
1571 {
1572 using _Merge_helper = _Rb_tree_merge_helper<_Rb_tree, _Compare2>;
1573 for (auto __i = __src.begin(), __end = __src.end(); __i != __end;)
1574 {
1575 auto __pos = __i++;
1576 auto __res = _M_get_insert_unique_pos(_KeyOfValue()(*__pos));
1577 if (__res.second)
1578 {
1579 auto& __src_impl = _Merge_helper::_S_get_impl(__src);
1580 auto __ptr = _Rb_tree_rebalance_for_erase(
1581 __pos._M_node, __src_impl._M_header);
1582 --__src_impl._M_node_count;
1583 _M_insert_node(__res.first, __res.second,
1584 static_cast<_Link_type>(__ptr));
1585 }
1586 }
1587 }
1588
1589 /// Merge from a compatible container into one with equivalent keys.
1590 template<typename _Compare2>
1591 void
1592 _M_merge_equal(_Compatible_tree<_Compare2>& __src) noexcept
1593 {
1594 using _Merge_helper = _Rb_tree_merge_helper<_Rb_tree, _Compare2>;
1595 for (auto __i = __src.begin(), __end = __src.end(); __i != __end;)
1596 {
1597 auto __pos = __i++;
1598 auto __res = _M_get_insert_equal_pos(_KeyOfValue()(*__pos));
1599 if (__res.second)
1600 {
1601 auto& __src_impl = _Merge_helper::_S_get_impl(__src);
1602 auto __ptr = _Rb_tree_rebalance_for_erase(
1603 __pos._M_node, __src_impl._M_header);
1604 --__src_impl._M_node_count;
1605 _M_insert_node(__res.first, __res.second,
1606 static_cast<_Link_type>(__ptr));
1607 }
1608 }
1609 }
1610 #endif // C++17
1611
1612 friend bool
1613 operator==(const _Rb_tree& __x, const _Rb_tree& __y)
1614 {
1615 return __x.size() == __y.size()
1616 && std::equal(__x.begin(), __x.end(), __y.begin());
1617 }
1618
1619 #if __cpp_lib_three_way_comparison
1620 friend auto
1621 operator<=>(const _Rb_tree& __x, const _Rb_tree& __y)
1622 {
1623 if constexpr (requires { typename __detail::__synth3way_t<_Val>; })
1624 return std::lexicographical_compare_three_way(__x.begin(), __x.end(),
1625 __y.begin(), __y.end(),
1626 __detail::__synth3way);
1627 }
1628 #else
1629 friend bool
1630 operator<(const _Rb_tree& __x, const _Rb_tree& __y)
1631 {
1632 return std::lexicographical_compare(__x.begin(), __x.end(),
1633 __y.begin(), __y.end());
1634 }
1635
1636 friend bool _GLIBCXX_DEPRECATED
1637 operator!=(const _Rb_tree& __x, const _Rb_tree& __y)
1638 { return !(__x == __y); }
1639
1640 friend bool _GLIBCXX_DEPRECATED
1641 operator>(const _Rb_tree& __x, const _Rb_tree& __y)
1642 { return __y < __x; }
1643
1644 friend bool _GLIBCXX_DEPRECATED
1645 operator<=(const _Rb_tree& __x, const _Rb_tree& __y)
1646 { return !(__y < __x); }
1647
1648 friend bool _GLIBCXX_DEPRECATED
1649 operator>=(const _Rb_tree& __x, const _Rb_tree& __y)
1650 { return !(__x < __y); }
1651 #endif
1652 };
1653
1654 template<typename _Key, typename _Val, typename _KeyOfValue,
1655 typename _Compare, typename _Alloc>
1656 inline void
1657 swap(_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
1658 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
1659 { __x.swap(__y); }
1660
1661 #if __cplusplus >= 201103L
1662 template<typename _Key, typename _Val, typename _KeyOfValue,
1663 typename _Compare, typename _Alloc>
1664 void
1665 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1666 _M_move_data(_Rb_tree& __x, false_type)
1667 {
1668 if (_M_get_Node_allocator() == __x._M_get_Node_allocator())
1669 _M_move_data(__x, true_type());
1670 else
1671 {
1672 constexpr bool __move = !__move_if_noexcept_cond<value_type>::value;
1673 _Alloc_node __an(*this);
1674 auto __lbd =
1675 [&__an](const value_type& __cval)
1676 {
1677 auto& __val = const_cast<value_type&>(__cval);
1678 return __an(std::move_if_noexcept(__val));
1679 };
1680 _M_root() = _M_copy(__x, __lbd);
1681 if _GLIBCXX17_CONSTEXPR (__move)
1682 __x.clear();
1683 }
1684 }
1685
1686 template<typename _Key, typename _Val, typename _KeyOfValue,
1687 typename _Compare, typename _Alloc>
1688 inline void
1689 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1690 _M_move_assign(_Rb_tree& __x, true_type)
1691 {
1692 clear();
1693 if (__x._M_root() != nullptr)
1694 _M_move_data(__x, true_type());
1695 std::__alloc_on_move(_M_get_Node_allocator(),
1696 __x._M_get_Node_allocator());
1697 }
1698
1699 template<typename _Key, typename _Val, typename _KeyOfValue,
1700 typename _Compare, typename _Alloc>
1701 void
1702 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1703 _M_move_assign(_Rb_tree& __x, false_type)
1704 {
1705 if (_M_get_Node_allocator() == __x._M_get_Node_allocator())
1706 return _M_move_assign(__x, true_type{});
1707
1708 // Try to move each node reusing existing nodes and copying __x nodes
1709 // structure.
1710 _Reuse_or_alloc_node __roan(*this);
1711 _M_impl._M_reset();
1712 if (__x._M_root() != nullptr)
1713 {
1714 auto __lbd =
1715 [&__roan](const value_type& __cval)
1716 {
1717 auto& __val = const_cast<value_type&>(__cval);
1718 return __roan(std::move(__val));
1719 };
1720 _M_root() = _M_copy(__x, __lbd);
1721 __x.clear();
1722 }
1723 }
1724
1725 template<typename _Key, typename _Val, typename _KeyOfValue,
1726 typename _Compare, typename _Alloc>
1727 inline _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&
1728 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1729 operator=(_Rb_tree&& __x)
1730 noexcept(_Alloc_traits::_S_nothrow_move()
1731 && is_nothrow_move_assignable<_Compare>::value)
1732 {
1733 _M_impl._M_key_compare = std::move(__x._M_impl._M_key_compare);
1734 _M_move_assign(__x, __bool_constant<_Alloc_traits::_S_nothrow_move()>());
1735 return *this;
1736 }
1737
1738 template<typename _Key, typename _Val, typename _KeyOfValue,
1739 typename _Compare, typename _Alloc>
1740 template<typename _Iterator>
1741 void
1742 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1743 _M_assign_unique(_Iterator __first, _Iterator __last)
1744 {
1745 _Reuse_or_alloc_node __roan(*this);
1746 _M_impl._M_reset();
1747 for (; __first != __last; ++__first)
1748 _M_insert_unique_(end(), *__first, __roan);
1749 }
1750
1751 template<typename _Key, typename _Val, typename _KeyOfValue,
1752 typename _Compare, typename _Alloc>
1753 template<typename _Iterator>
1754 void
1755 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1756 _M_assign_equal(_Iterator __first, _Iterator __last)
1757 {
1758 _Reuse_or_alloc_node __roan(*this);
1759 _M_impl._M_reset();
1760 for (; __first != __last; ++__first)
1761 _M_insert_equal_(end(), *__first, __roan);
1762 }
1763 #endif
1764
1765 template<typename _Key, typename _Val, typename _KeyOfValue,
1766 typename _Compare, typename _Alloc>
1767 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&
1768 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1769 operator=(const _Rb_tree& __x)
1770 {
1771 if (this != &__x)
1772 {
1773 // Note that _Key may be a constant type.
1774 #if __cplusplus >= 201103L
1775 if (_Alloc_traits::_S_propagate_on_copy_assign())
1776 {
1777 auto& __this_alloc = this->_M_get_Node_allocator();
1778 auto& __that_alloc = __x._M_get_Node_allocator();
1779 if (!_Alloc_traits::_S_always_equal()
1780 && __this_alloc != __that_alloc)
1781 {
1782 // Replacement allocator cannot free existing storage, we need
1783 // to erase nodes first.
1784 clear();
1785 std::__alloc_on_copy(__this_alloc, __that_alloc);
1786 }
1787 }
1788 #endif
1789
1790 _Reuse_or_alloc_node __roan(*this);
1791 _M_impl._M_reset();
1792 _M_impl._M_key_compare = __x._M_impl._M_key_compare;
1793 if (__x._M_root() != 0)
1794 _M_root() = _M_copy(__x, __roan);
1795 }
1796
1797 return *this;
1798 }
1799
1800 template<typename _Key, typename _Val, typename _KeyOfValue,
1801 typename _Compare, typename _Alloc>
1802 #if __cplusplus >= 201103L
1803 template<typename _Arg, typename _NodeGen>
1804 #else
1805 template<typename _NodeGen>
1806 #endif
1807 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
1808 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1809 _M_insert_(_Base_ptr __x, _Base_ptr __p,
1810 #if __cplusplus >= 201103L
1811 _Arg&& __v,
1812 #else
1813 const _Val& __v,
1814 #endif
1815 _NodeGen& __node_gen)
1816 {
1817 bool __insert_left = (__x != 0 || __p == _M_end()
1818 || _M_impl._M_key_compare(_KeyOfValue()(__v),
1819 _S_key(__p)));
1820
1821 _Link_type __z = __node_gen(_GLIBCXX_FORWARD(_Arg, __v));
1822
1823 _Rb_tree_insert_and_rebalance(__insert_left, __z, __p,
1824 this->_M_impl._M_header);
1825 ++_M_impl._M_node_count;
1826 return iterator(__z);
1827 }
1828
1829 template<typename _Key, typename _Val, typename _KeyOfValue,
1830 typename _Compare, typename _Alloc>
1831 #if __cplusplus >= 201103L
1832 template<typename _Arg>
1833 #endif
1834 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
1835 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1836 #if __cplusplus >= 201103L
1837 _M_insert_lower(_Base_ptr __p, _Arg&& __v)
1838 #else
1839 _M_insert_lower(_Base_ptr __p, const _Val& __v)
1840 #endif
1841 {
1842 bool __insert_left = (__p == _M_end()
1843 || !_M_impl._M_key_compare(_S_key(__p),
1844 _KeyOfValue()(__v)));
1845
1846 _Link_type __z = _M_create_node(_GLIBCXX_FORWARD(_Arg, __v));
1847
1848 _Rb_tree_insert_and_rebalance(__insert_left, __z, __p,
1849 this->_M_impl._M_header);
1850 ++_M_impl._M_node_count;
1851 return iterator(__z);
1852 }
1853
1854 template<typename _Key, typename _Val, typename _KeyOfValue,
1855 typename _Compare, typename _Alloc>
1856 #if __cplusplus >= 201103L
1857 template<typename _Arg>
1858 #endif
1859 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
1860 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1861 #if __cplusplus >= 201103L
1862 _M_insert_equal_lower(_Arg&& __v)
1863 #else
1864 _M_insert_equal_lower(const _Val& __v)
1865 #endif
1866 {
1867 _Link_type __x = _M_begin();
1868 _Base_ptr __y = _M_end();
1869 while (__x != 0)
1870 {
1871 __y = __x;
1872 __x = !_M_impl._M_key_compare(_S_key(__x), _KeyOfValue()(__v)) ?
1873 _S_left(__x) : _S_right(__x);
1874 }
1875 return _M_insert_lower(__y, _GLIBCXX_FORWARD(_Arg, __v));
1876 }
1877
1878 template<typename _Key, typename _Val, typename _KoV,
1879 typename _Compare, typename _Alloc>
1880 template<typename _NodeGen>
1881 typename _Rb_tree<_Key, _Val, _KoV, _Compare, _Alloc>::_Link_type
1882 _Rb_tree<_Key, _Val, _KoV, _Compare, _Alloc>::
1883 _M_copy(_Const_Link_type __x, _Base_ptr __p, _NodeGen& __node_gen)
1884 {
1885 // Structural copy. __x and __p must be non-null.
1886 _Link_type __top = _M_clone_node(__x, __node_gen);
1887 __top->_M_parent = __p;
1888
1889 __try
1890 {
1891 if (__x->_M_right)
1892 __top->_M_right = _M_copy(_S_right(__x), __top, __node_gen);
1893 __p = __top;
1894 __x = _S_left(__x);
1895
1896 while (__x != 0)
1897 {
1898 _Link_type __y = _M_clone_node(__x, __node_gen);
1899 __p->_M_left = __y;
1900 __y->_M_parent = __p;
1901 if (__x->_M_right)
1902 __y->_M_right = _M_copy(_S_right(__x), __y, __node_gen);
1903 __p = __y;
1904 __x = _S_left(__x);
1905 }
1906 }
1907 __catch(...)
1908 {
1909 _M_erase(__top);
1910 __throw_exception_again;
1911 }
1912 return __top;
1913 }
1914
1915 template<typename _Key, typename _Val, typename _KeyOfValue,
1916 typename _Compare, typename _Alloc>
1917 void
1918 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1919 _M_erase(_Link_type __x)
1920 {
1921 // Erase without rebalancing.
1922 while (__x != 0)
1923 {
1924 _M_erase(_S_right(__x));
1925 _Link_type __y = _S_left(__x);
1926 _M_drop_node(__x);
1927 __x = __y;
1928 }
1929 }
1930
1931 template<typename _Key, typename _Val, typename _KeyOfValue,
1932 typename _Compare, typename _Alloc>
1933 typename _Rb_tree<_Key, _Val, _KeyOfValue,
1934 _Compare, _Alloc>::iterator
1935 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1936 _M_lower_bound(_Link_type __x, _Base_ptr __y,
1937 const _Key& __k)
1938 {
1939 while (__x != 0)
1940 if (!_M_impl._M_key_compare(_S_key(__x), __k))
1941 __y = __x, __x = _S_left(__x);
1942 else
1943 __x = _S_right(__x);
1944 return iterator(__y);
1945 }
1946
1947 template<typename _Key, typename _Val, typename _KeyOfValue,
1948 typename _Compare, typename _Alloc>
1949 typename _Rb_tree<_Key, _Val, _KeyOfValue,
1950 _Compare, _Alloc>::const_iterator
1951 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1952 _M_lower_bound(_Const_Link_type __x, _Const_Base_ptr __y,
1953 const _Key& __k) const
1954 {
1955 while (__x != 0)
1956 if (!_M_impl._M_key_compare(_S_key(__x), __k))
1957 __y = __x, __x = _S_left(__x);
1958 else
1959 __x = _S_right(__x);
1960 return const_iterator(__y);
1961 }
1962
1963 template<typename _Key, typename _Val, typename _KeyOfValue,
1964 typename _Compare, typename _Alloc>
1965 typename _Rb_tree<_Key, _Val, _KeyOfValue,
1966 _Compare, _Alloc>::iterator
1967 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1968 _M_upper_bound(_Link_type __x, _Base_ptr __y,
1969 const _Key& __k)
1970 {
1971 while (__x != 0)
1972 if (_M_impl._M_key_compare(__k, _S_key(__x)))
1973 __y = __x, __x = _S_left(__x);
1974 else
1975 __x = _S_right(__x);
1976 return iterator(__y);
1977 }
1978
1979 template<typename _Key, typename _Val, typename _KeyOfValue,
1980 typename _Compare, typename _Alloc>
1981 typename _Rb_tree<_Key, _Val, _KeyOfValue,
1982 _Compare, _Alloc>::const_iterator
1983 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1984 _M_upper_bound(_Const_Link_type __x, _Const_Base_ptr __y,
1985 const _Key& __k) const
1986 {
1987 while (__x != 0)
1988 if (_M_impl._M_key_compare(__k, _S_key(__x)))
1989 __y = __x, __x = _S_left(__x);
1990 else
1991 __x = _S_right(__x);
1992 return const_iterator(__y);
1993 }
1994
1995 template<typename _Key, typename _Val, typename _KeyOfValue,
1996 typename _Compare, typename _Alloc>
1997 pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
1998 _Compare, _Alloc>::iterator,
1999 typename _Rb_tree<_Key, _Val, _KeyOfValue,
2000 _Compare, _Alloc>::iterator>
2001 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2002 equal_range(const _Key& __k)
2003 {
2004 _Link_type __x = _M_begin();
2005 _Base_ptr __y = _M_end();
2006 while (__x != 0)
2007 {
2008 if (_M_impl._M_key_compare(_S_key(__x), __k))
2009 __x = _S_right(__x);
2010 else if (_M_impl._M_key_compare(__k, _S_key(__x)))
2011 __y = __x, __x = _S_left(__x);
2012 else
2013 {
2014 _Link_type __xu(__x);
2015 _Base_ptr __yu(__y);
2016 __y = __x, __x = _S_left(__x);
2017 __xu = _S_right(__xu);
2018 return pair<iterator,
2019 iterator>(_M_lower_bound(__x, __y, __k),
2020 _M_upper_bound(__xu, __yu, __k));
2021 }
2022 }
2023 return pair<iterator, iterator>(iterator(__y),
2024 iterator(__y));
2025 }
2026
2027 template<typename _Key, typename _Val, typename _KeyOfValue,
2028 typename _Compare, typename _Alloc>
2029 pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
2030 _Compare, _Alloc>::const_iterator,
2031 typename _Rb_tree<_Key, _Val, _KeyOfValue,
2032 _Compare, _Alloc>::const_iterator>
2033 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2034 equal_range(const _Key& __k) const
2035 {
2036 _Const_Link_type __x = _M_begin();
2037 _Const_Base_ptr __y = _M_end();
2038 while (__x != 0)
2039 {
2040 if (_M_impl._M_key_compare(_S_key(__x), __k))
2041 __x = _S_right(__x);
2042 else if (_M_impl._M_key_compare(__k, _S_key(__x)))
2043 __y = __x, __x = _S_left(__x);
2044 else
2045 {
2046 _Const_Link_type __xu(__x);
2047 _Const_Base_ptr __yu(__y);
2048 __y = __x, __x = _S_left(__x);
2049 __xu = _S_right(__xu);
2050 return pair<const_iterator,
2051 const_iterator>(_M_lower_bound(__x, __y, __k),
2052 _M_upper_bound(__xu, __yu, __k));
2053 }
2054 }
2055 return pair<const_iterator, const_iterator>(const_iterator(__y),
2056 const_iterator(__y));
2057 }
2058
2059 template<typename _Key, typename _Val, typename _KeyOfValue,
2060 typename _Compare, typename _Alloc>
2061 void
2062 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2063 swap(_Rb_tree& __t)
2064 _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
2065 {
2066 if (_M_root() == 0)
2067 {
2068 if (__t._M_root() != 0)
2069 _M_impl._M_move_data(__t._M_impl);
2070 }
2071 else if (__t._M_root() == 0)
2072 __t._M_impl._M_move_data(_M_impl);
2073 else
2074 {
2075 std::swap(_M_root(),__t._M_root());
2076 std::swap(_M_leftmost(),__t._M_leftmost());
2077 std::swap(_M_rightmost(),__t._M_rightmost());
2078
2079 _M_root()->_M_parent = _M_end();
2080 __t._M_root()->_M_parent = __t._M_end();
2081 std::swap(this->_M_impl._M_node_count, __t._M_impl._M_node_count);
2082 }
2083 // No need to swap header's color as it does not change.
2084 std::swap(this->_M_impl._M_key_compare, __t._M_impl._M_key_compare);
2085
2086 _Alloc_traits::_S_on_swap(_M_get_Node_allocator(),
2087 __t._M_get_Node_allocator());
2088 }
2089
2090 template<typename _Key, typename _Val, typename _KeyOfValue,
2091 typename _Compare, typename _Alloc>
2092 pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
2093 _Compare, _Alloc>::_Base_ptr,
2094 typename _Rb_tree<_Key, _Val, _KeyOfValue,
2095 _Compare, _Alloc>::_Base_ptr>
2096 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2097 _M_get_insert_unique_pos(const key_type& __k)
2098 {
2099 typedef pair<_Base_ptr, _Base_ptr> _Res;
2100 _Link_type __x = _M_begin();
2101 _Base_ptr __y = _M_end();
2102 bool __comp = true;
2103 while (__x != 0)
2104 {
2105 __y = __x;
2106 __comp = _M_impl._M_key_compare(__k, _S_key(__x));
2107 __x = __comp ? _S_left(__x) : _S_right(__x);
2108 }
2109 iterator __j = iterator(__y);
2110 if (__comp)
2111 {
2112 if (__j == begin())
2113 return _Res(__x, __y);
2114 else
2115 --__j;
2116 }
2117 if (_M_impl._M_key_compare(_S_key(__j._M_node), __k))
2118 return _Res(__x, __y);
2119 return _Res(__j._M_node, 0);
2120 }
2121
2122 template<typename _Key, typename _Val, typename _KeyOfValue,
2123 typename _Compare, typename _Alloc>
2124 pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
2125 _Compare, _Alloc>::_Base_ptr,
2126 typename _Rb_tree<_Key, _Val, _KeyOfValue,
2127 _Compare, _Alloc>::_Base_ptr>
2128 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2129 _M_get_insert_equal_pos(const key_type& __k)
2130 {
2131 typedef pair<_Base_ptr, _Base_ptr> _Res;
2132 _Link_type __x = _M_begin();
2133 _Base_ptr __y = _M_end();
2134 while (__x != 0)
2135 {
2136 __y = __x;
2137 __x = _M_impl._M_key_compare(__k, _S_key(__x)) ?
2138 _S_left(__x) : _S_right(__x);
2139 }
2140 return _Res(__x, __y);
2141 }
2142
2143 template<typename _Key, typename _Val, typename _KeyOfValue,
2144 typename _Compare, typename _Alloc>
2145 #if __cplusplus >= 201103L
2146 template<typename _Arg>
2147 #endif
2148 pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
2149 _Compare, _Alloc>::iterator, bool>
2150 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2151 #if __cplusplus >= 201103L
2152 _M_insert_unique(_Arg&& __v)
2153 #else
2154 _M_insert_unique(const _Val& __v)
2155 #endif
2156 {
2157 typedef pair<iterator, bool> _Res;
2158 pair<_Base_ptr, _Base_ptr> __res
2159 = _M_get_insert_unique_pos(_KeyOfValue()(__v));
2160
2161 if (__res.second)
2162 {
2163 _Alloc_node __an(*this);
2164 return _Res(_M_insert_(__res.first, __res.second,
2165 _GLIBCXX_FORWARD(_Arg, __v), __an),
2166 true);
2167 }
2168
2169 return _Res(iterator(__res.first), false);
2170 }
2171
2172 template<typename _Key, typename _Val, typename _KeyOfValue,
2173 typename _Compare, typename _Alloc>
2174 #if __cplusplus >= 201103L
2175 template<typename _Arg>
2176 #endif
2177 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
2178 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2179 #if __cplusplus >= 201103L
2180 _M_insert_equal(_Arg&& __v)
2181 #else
2182 _M_insert_equal(const _Val& __v)
2183 #endif
2184 {
2185 pair<_Base_ptr, _Base_ptr> __res
2186 = _M_get_insert_equal_pos(_KeyOfValue()(__v));
2187 _Alloc_node __an(*this);
2188 return _M_insert_(__res.first, __res.second,
2189 _GLIBCXX_FORWARD(_Arg, __v), __an);
2190 }
2191
2192 template<typename _Key, typename _Val, typename _KeyOfValue,
2193 typename _Compare, typename _Alloc>
2194 pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
2195 _Compare, _Alloc>::_Base_ptr,
2196 typename _Rb_tree<_Key, _Val, _KeyOfValue,
2197 _Compare, _Alloc>::_Base_ptr>
2198 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2199 _M_get_insert_hint_unique_pos(const_iterator __position,
2200 const key_type& __k)
2201 {
2202 iterator __pos = __position._M_const_cast();
2203 typedef pair<_Base_ptr, _Base_ptr> _Res;
2204
2205 // end()
2206 if (__pos._M_node == _M_end())
2207 {
2208 if (size() > 0
2209 && _M_impl._M_key_compare(_S_key(_M_rightmost()), __k))
2210 return _Res(0, _M_rightmost());
2211 else
2212 return _M_get_insert_unique_pos(__k);
2213 }
2214 else if (_M_impl._M_key_compare(__k, _S_key(__pos._M_node)))
2215 {
2216 // First, try before...
2217 iterator __before = __pos;
2218 if (__pos._M_node == _M_leftmost()) // begin()
2219 return _Res(_M_leftmost(), _M_leftmost());
2220 else if (_M_impl._M_key_compare(_S_key((--__before)._M_node), __k))
2221 {
2222 if (_S_right(__before._M_node) == 0)
2223 return _Res(0, __before._M_node);
2224 else
2225 return _Res(__pos._M_node, __pos._M_node);
2226 }
2227 else
2228 return _M_get_insert_unique_pos(__k);
2229 }
2230 else if (_M_impl._M_key_compare(_S_key(__pos._M_node), __k))
2231 {
2232 // ... then try after.
2233 iterator __after = __pos;
2234 if (__pos._M_node == _M_rightmost())
2235 return _Res(0, _M_rightmost());
2236 else if (_M_impl._M_key_compare(__k, _S_key((++__after)._M_node)))
2237 {
2238 if (_S_right(__pos._M_node) == 0)
2239 return _Res(0, __pos._M_node);
2240 else
2241 return _Res(__after._M_node, __after._M_node);
2242 }
2243 else
2244 return _M_get_insert_unique_pos(__k);
2245 }
2246 else
2247 // Equivalent keys.
2248 return _Res(__pos._M_node, 0);
2249 }
2250
2251 template<typename _Key, typename _Val, typename _KeyOfValue,
2252 typename _Compare, typename _Alloc>
2253 #if __cplusplus >= 201103L
2254 template<typename _Arg, typename _NodeGen>
2255 #else
2256 template<typename _NodeGen>
2257 #endif
2258 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
2259 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2260 _M_insert_unique_(const_iterator __position,
2261 #if __cplusplus >= 201103L
2262 _Arg&& __v,
2263 #else
2264 const _Val& __v,
2265 #endif
2266 _NodeGen& __node_gen)
2267 {
2268 pair<_Base_ptr, _Base_ptr> __res
2269 = _M_get_insert_hint_unique_pos(__position, _KeyOfValue()(__v));
2270
2271 if (__res.second)
2272 return _M_insert_(__res.first, __res.second,
2273 _GLIBCXX_FORWARD(_Arg, __v),
2274 __node_gen);
2275 return iterator(__res.first);
2276 }
2277
2278 template<typename _Key, typename _Val, typename _KeyOfValue,
2279 typename _Compare, typename _Alloc>
2280 pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
2281 _Compare, _Alloc>::_Base_ptr,
2282 typename _Rb_tree<_Key, _Val, _KeyOfValue,
2283 _Compare, _Alloc>::_Base_ptr>
2284 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2285 _M_get_insert_hint_equal_pos(const_iterator __position, const key_type& __k)
2286 {
2287 iterator __pos = __position._M_const_cast();
2288 typedef pair<_Base_ptr, _Base_ptr> _Res;
2289
2290 // end()
2291 if (__pos._M_node == _M_end())
2292 {
2293 if (size() > 0
2294 && !_M_impl._M_key_compare(__k, _S_key(_M_rightmost())))
2295 return _Res(0, _M_rightmost());
2296 else
2297 return _M_get_insert_equal_pos(__k);
2298 }
2299 else if (!_M_impl._M_key_compare(_S_key(__pos._M_node), __k))
2300 {
2301 // First, try before...
2302 iterator __before = __pos;
2303 if (__pos._M_node == _M_leftmost()) // begin()
2304 return _Res(_M_leftmost(), _M_leftmost());
2305 else if (!_M_impl._M_key_compare(__k, _S_key((--__before)._M_node)))
2306 {
2307 if (_S_right(__before._M_node) == 0)
2308 return _Res(0, __before._M_node);
2309 else
2310 return _Res(__pos._M_node, __pos._M_node);
2311 }
2312 else
2313 return _M_get_insert_equal_pos(__k);
2314 }
2315 else
2316 {
2317 // ... then try after.
2318 iterator __after = __pos;
2319 if (__pos._M_node == _M_rightmost())
2320 return _Res(0, _M_rightmost());
2321 else if (!_M_impl._M_key_compare(_S_key((++__after)._M_node), __k))
2322 {
2323 if (_S_right(__pos._M_node) == 0)
2324 return _Res(0, __pos._M_node);
2325 else
2326 return _Res(__after._M_node, __after._M_node);
2327 }
2328 else
2329 return _Res(0, 0);
2330 }
2331 }
2332
2333 template<typename _Key, typename _Val, typename _KeyOfValue,
2334 typename _Compare, typename _Alloc>
2335 #if __cplusplus >= 201103L
2336 template<typename _Arg, typename _NodeGen>
2337 #else
2338 template<typename _NodeGen>
2339 #endif
2340 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
2341 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2342 _M_insert_equal_(const_iterator __position,
2343 #if __cplusplus >= 201103L
2344 _Arg&& __v,
2345 #else
2346 const _Val& __v,
2347 #endif
2348 _NodeGen& __node_gen)
2349 {
2350 pair<_Base_ptr, _Base_ptr> __res
2351 = _M_get_insert_hint_equal_pos(__position, _KeyOfValue()(__v));
2352
2353 if (__res.second)
2354 return _M_insert_(__res.first, __res.second,
2355 _GLIBCXX_FORWARD(_Arg, __v),
2356 __node_gen);
2357
2358 return _M_insert_equal_lower(_GLIBCXX_FORWARD(_Arg, __v));
2359 }
2360
2361 #if __cplusplus >= 201103L
2362 template<typename _Key, typename _Val, typename _KeyOfValue,
2363 typename _Compare, typename _Alloc>
2364 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
2365 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2366 _M_insert_node(_Base_ptr __x, _Base_ptr __p, _Link_type __z)
2367 {
2368 bool __insert_left = (__x != 0 || __p == _M_end()
2369 || _M_impl._M_key_compare(_S_key(__z),
2370 _S_key(__p)));
2371
2372 _Rb_tree_insert_and_rebalance(__insert_left, __z, __p,
2373 this->_M_impl._M_header);
2374 ++_M_impl._M_node_count;
2375 return iterator(__z);
2376 }
2377
2378 template<typename _Key, typename _Val, typename _KeyOfValue,
2379 typename _Compare, typename _Alloc>
2380 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
2381 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2382 _M_insert_lower_node(_Base_ptr __p, _Link_type __z)
2383 {
2384 bool __insert_left = (__p == _M_end()
2385 || !_M_impl._M_key_compare(_S_key(__p),
2386 _S_key(__z)));
2387
2388 _Rb_tree_insert_and_rebalance(__insert_left, __z, __p,
2389 this->_M_impl._M_header);
2390 ++_M_impl._M_node_count;
2391 return iterator(__z);
2392 }
2393
2394 template<typename _Key, typename _Val, typename _KeyOfValue,
2395 typename _Compare, typename _Alloc>
2396 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
2397 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2398 _M_insert_equal_lower_node(_Link_type __z)
2399 {
2400 _Link_type __x = _M_begin();
2401 _Base_ptr __y = _M_end();
2402 while (__x != 0)
2403 {
2404 __y = __x;
2405 __x = !_M_impl._M_key_compare(_S_key(__x), _S_key(__z)) ?
2406 _S_left(__x) : _S_right(__x);
2407 }
2408 return _M_insert_lower_node(__y, __z);
2409 }
2410
2411 template<typename _Key, typename _Val, typename _KeyOfValue,
2412 typename _Compare, typename _Alloc>
2413 template<typename... _Args>
2414 pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
2415 _Compare, _Alloc>::iterator, bool>
2416 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2417 _M_emplace_unique(_Args&&... __args)
2418 {
2419 _Link_type __z = _M_create_node(std::forward<_Args>(__args)...);
2420
2421 __try
2422 {
2423 typedef pair<iterator, bool> _Res;
2424 auto __res = _M_get_insert_unique_pos(_S_key(__z));
2425 if (__res.second)
2426 return _Res(_M_insert_node(__res.first, __res.second, __z), true);
2427
2428 _M_drop_node(__z);
2429 return _Res(iterator(__res.first), false);
2430 }
2431 __catch(...)
2432 {
2433 _M_drop_node(__z);
2434 __throw_exception_again;
2435 }
2436 }
2437
2438 template<typename _Key, typename _Val, typename _KeyOfValue,
2439 typename _Compare, typename _Alloc>
2440 template<typename... _Args>
2441 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
2442 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2443 _M_emplace_equal(_Args&&... __args)
2444 {
2445 _Link_type __z = _M_create_node(std::forward<_Args>(__args)...);
2446
2447 __try
2448 {
2449 auto __res = _M_get_insert_equal_pos(_S_key(__z));
2450 return _M_insert_node(__res.first, __res.second, __z);
2451 }
2452 __catch(...)
2453 {
2454 _M_drop_node(__z);
2455 __throw_exception_again;
2456 }
2457 }
2458
2459 template<typename _Key, typename _Val, typename _KeyOfValue,
2460 typename _Compare, typename _Alloc>
2461 template<typename... _Args>
2462 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
2463 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2464 _M_emplace_hint_unique(const_iterator __pos, _Args&&... __args)
2465 {
2466 _Link_type __z = _M_create_node(std::forward<_Args>(__args)...);
2467
2468 __try
2469 {
2470 auto __res = _M_get_insert_hint_unique_pos(__pos, _S_key(__z));
2471
2472 if (__res.second)
2473 return _M_insert_node(__res.first, __res.second, __z);
2474
2475 _M_drop_node(__z);
2476 return iterator(__res.first);
2477 }
2478 __catch(...)
2479 {
2480 _M_drop_node(__z);
2481 __throw_exception_again;
2482 }
2483 }
2484
2485 template<typename _Key, typename _Val, typename _KeyOfValue,
2486 typename _Compare, typename _Alloc>
2487 template<typename... _Args>
2488 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
2489 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2490 _M_emplace_hint_equal(const_iterator __pos, _Args&&... __args)
2491 {
2492 _Link_type __z = _M_create_node(std::forward<_Args>(__args)...);
2493
2494 __try
2495 {
2496 auto __res = _M_get_insert_hint_equal_pos(__pos, _S_key(__z));
2497
2498 if (__res.second)
2499 return _M_insert_node(__res.first, __res.second, __z);
2500
2501 return _M_insert_equal_lower_node(__z);
2502 }
2503 __catch(...)
2504 {
2505 _M_drop_node(__z);
2506 __throw_exception_again;
2507 }
2508 }
2509 #endif
2510
2511
2512 template<typename _Key, typename _Val, typename _KeyOfValue,
2513 typename _Compare, typename _Alloc>
2514 void
2515 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2516 _M_erase_aux(const_iterator __position)
2517 {
2518 _Link_type __y =
2519 static_cast<_Link_type>(_Rb_tree_rebalance_for_erase
2520 (const_cast<_Base_ptr>(__position._M_node),
2521 this->_M_impl._M_header));
2522 _M_drop_node(__y);
2523 --_M_impl._M_node_count;
2524 }
2525
2526 template<typename _Key, typename _Val, typename _KeyOfValue,
2527 typename _Compare, typename _Alloc>
2528 void
2529 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2530 _M_erase_aux(const_iterator __first, const_iterator __last)
2531 {
2532 if (__first == begin() && __last == end())
2533 clear();
2534 else
2535 while (__first != __last)
2536 _M_erase_aux(__first++);
2537 }
2538
2539 template<typename _Key, typename _Val, typename _KeyOfValue,
2540 typename _Compare, typename _Alloc>
2541 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::size_type
2542 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2543 erase(const _Key& __x)
2544 {
2545 pair<iterator, iterator> __p = equal_range(__x);
2546 const size_type __old_size = size();
2547 _M_erase_aux(__p.first, __p.second);
2548 return __old_size - size();
2549 }
2550
2551 template<typename _Key, typename _Val, typename _KeyOfValue,
2552 typename _Compare, typename _Alloc>
2553 typename _Rb_tree<_Key, _Val, _KeyOfValue,
2554 _Compare, _Alloc>::iterator
2555 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2556 find(const _Key& __k)
2557 {
2558 iterator __j = _M_lower_bound(_M_begin(), _M_end(), __k);
2559 return (__j == end()
2560 || _M_impl._M_key_compare(__k,
2561 _S_key(__j._M_node))) ? end() : __j;
2562 }
2563
2564 template<typename _Key, typename _Val, typename _KeyOfValue,
2565 typename _Compare, typename _Alloc>
2566 typename _Rb_tree<_Key, _Val, _KeyOfValue,
2567 _Compare, _Alloc>::const_iterator
2568 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2569 find(const _Key& __k) const
2570 {
2571 const_iterator __j = _M_lower_bound(_M_begin(), _M_end(), __k);
2572 return (__j == end()
2573 || _M_impl._M_key_compare(__k,
2574 _S_key(__j._M_node))) ? end() : __j;
2575 }
2576
2577 template<typename _Key, typename _Val, typename _KeyOfValue,
2578 typename _Compare, typename _Alloc>
2579 typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::size_type
2580 _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
2581 count(const _Key& __k) const
2582 {
2583 pair<const_iterator, const_iterator> __p = equal_range(__k);
2584 const size_type __n = std::distance(__p.first, __p.second);
2585 return __n;
2586 }
2587
2588 _GLIBCXX_PURE unsigned int
2589 _Rb_tree_black_count(const _Rb_tree_node_base* __node,
2590 const _Rb_tree_node_base* __root) throw ();
2591
2592 template<typename _Key, typename _Val, typename _KeyOfValue,
2593 typename _Compare, typename _Alloc>
2594 bool
2595 _Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::__rb_verify() const
2596 {
2597 if (_M_impl._M_node_count == 0 || begin() == end())
2598 return _M_impl._M_node_count == 0 && begin() == end()
2599 && this->_M_impl._M_header._M_left == _M_end()
2600 && this->_M_impl._M_header._M_right == _M_end();
2601
2602 unsigned int __len = _Rb_tree_black_count(_M_leftmost(), _M_root());
2603 for (const_iterator __it = begin(); __it != end(); ++__it)
2604 {
2605 _Const_Link_type __x = static_cast<_Const_Link_type>(__it._M_node);
2606 _Const_Link_type __L = _S_left(__x);
2607 _Const_Link_type __R = _S_right(__x);
2608
2609 if (__x->_M_color == _S_red)
2610 if ((__L && __L->_M_color == _S_red)
2611 || (__R && __R->_M_color == _S_red))
2612 return false;
2613
2614 if (__L && _M_impl._M_key_compare(_S_key(__x), _S_key(__L)))
2615 return false;
2616 if (__R && _M_impl._M_key_compare(_S_key(__R), _S_key(__x)))
2617 return false;
2618
2619 if (!__L && !__R && _Rb_tree_black_count(__x, _M_root()) != __len)
2620 return false;
2621 }
2622
2623 if (_M_leftmost() != _Rb_tree_node_base::_S_minimum(_M_root()))
2624 return false;
2625 if (_M_rightmost() != _Rb_tree_node_base::_S_maximum(_M_root()))
2626 return false;
2627 return true;
2628 }
2629
2630 #if __cplusplus > 201402L
2631 // Allow access to internals of compatible _Rb_tree specializations.
2632 template<typename _Key, typename _Val, typename _Sel, typename _Cmp1,
2633 typename _Alloc, typename _Cmp2>
2634 struct _Rb_tree_merge_helper<_Rb_tree<_Key, _Val, _Sel, _Cmp1, _Alloc>,
2635 _Cmp2>
2636 {
2637 private:
2638 friend class _Rb_tree<_Key, _Val, _Sel, _Cmp1, _Alloc>;
2639
2640 static auto&
2641 _S_get_impl(_Rb_tree<_Key, _Val, _Sel, _Cmp2, _Alloc>& __tree)
2642 { return __tree._M_impl; }
2643 };
2644 #endif // C++17
2645
2646 _GLIBCXX_END_NAMESPACE_VERSION
2647 } // namespace
2648
2649 #endif
2650