xref: /freebsd/contrib/llvm-project/libcxx/include/__tree (revision e32fecd0c2c3ee37c47ee100f169e7eb0282a873)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP___TREE
11#define _LIBCPP___TREE
12
13#include <__algorithm/min.h>
14#include <__assert>
15#include <__config>
16#include <__debug>
17#include <__iterator/distance.h>
18#include <__iterator/iterator_traits.h>
19#include <__iterator/next.h>
20#include <__memory/swap_allocator.h>
21#include <__utility/forward.h>
22#include <__utility/swap.h>
23#include <limits>
24#include <memory>
25#include <stdexcept>
26
27#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
28#  pragma GCC system_header
29#endif
30
31_LIBCPP_PUSH_MACROS
32#include <__undef_macros>
33
34
35_LIBCPP_BEGIN_NAMESPACE_STD
36
37template <class, class, class, class> class _LIBCPP_TEMPLATE_VIS map;
38template <class, class, class, class> class _LIBCPP_TEMPLATE_VIS multimap;
39template <class, class, class> class _LIBCPP_TEMPLATE_VIS set;
40template <class, class, class> class _LIBCPP_TEMPLATE_VIS multiset;
41
42template <class _Tp, class _Compare, class _Allocator> class __tree;
43template <class _Tp, class _NodePtr, class _DiffType>
44    class _LIBCPP_TEMPLATE_VIS __tree_iterator;
45template <class _Tp, class _ConstNodePtr, class _DiffType>
46    class _LIBCPP_TEMPLATE_VIS __tree_const_iterator;
47
48template <class _Pointer> class __tree_end_node;
49template <class _VoidPtr> class __tree_node_base;
50template <class _Tp, class _VoidPtr> class __tree_node;
51
52template <class _Key, class _Value>
53struct __value_type;
54
55template <class _Allocator> class __map_node_destructor;
56template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS __map_iterator;
57template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS __map_const_iterator;
58
59/*
60
61_NodePtr algorithms
62
63The algorithms taking _NodePtr are red black tree algorithms.  Those
64algorithms taking a parameter named __root should assume that __root
65points to a proper red black tree (unless otherwise specified).
66
67Each algorithm herein assumes that __root->__parent_ points to a non-null
68structure which has a member __left_ which points back to __root.  No other
69member is read or written to at __root->__parent_.
70
71__root->__parent_ will be referred to below (in comments only) as end_node.
72end_node->__left_ is an externably accessible lvalue for __root, and can be
73changed by node insertion and removal (without explicit reference to end_node).
74
75All nodes (with the exception of end_node), even the node referred to as
76__root, have a non-null __parent_ field.
77
78*/
79
80// Returns:  true if __x is a left child of its parent, else false
81// Precondition:  __x != nullptr.
82template <class _NodePtr>
83inline _LIBCPP_INLINE_VISIBILITY
84bool
85__tree_is_left_child(_NodePtr __x) _NOEXCEPT
86{
87    return __x == __x->__parent_->__left_;
88}
89
90// Determines if the subtree rooted at __x is a proper red black subtree.  If
91//    __x is a proper subtree, returns the black height (null counts as 1).  If
92//    __x is an improper subtree, returns 0.
93template <class _NodePtr>
94unsigned
95__tree_sub_invariant(_NodePtr __x)
96{
97    if (__x == nullptr)
98        return 1;
99    // parent consistency checked by caller
100    // check __x->__left_ consistency
101    if (__x->__left_ != nullptr && __x->__left_->__parent_ != __x)
102        return 0;
103    // check __x->__right_ consistency
104    if (__x->__right_ != nullptr && __x->__right_->__parent_ != __x)
105        return 0;
106    // check __x->__left_ != __x->__right_ unless both are nullptr
107    if (__x->__left_ == __x->__right_ && __x->__left_ != nullptr)
108        return 0;
109    // If this is red, neither child can be red
110    if (!__x->__is_black_)
111    {
112        if (__x->__left_ && !__x->__left_->__is_black_)
113            return 0;
114        if (__x->__right_ && !__x->__right_->__is_black_)
115            return 0;
116    }
117    unsigned __h = _VSTD::__tree_sub_invariant(__x->__left_);
118    if (__h == 0)
119        return 0;  // invalid left subtree
120    if (__h != _VSTD::__tree_sub_invariant(__x->__right_))
121        return 0;  // invalid or different height right subtree
122    return __h + __x->__is_black_;  // return black height of this node
123}
124
125// Determines if the red black tree rooted at __root is a proper red black tree.
126//    __root == nullptr is a proper tree.  Returns true is __root is a proper
127//    red black tree, else returns false.
128template <class _NodePtr>
129bool
130__tree_invariant(_NodePtr __root)
131{
132    if (__root == nullptr)
133        return true;
134    // check __x->__parent_ consistency
135    if (__root->__parent_ == nullptr)
136        return false;
137    if (!_VSTD::__tree_is_left_child(__root))
138        return false;
139    // root must be black
140    if (!__root->__is_black_)
141        return false;
142    // do normal node checks
143    return _VSTD::__tree_sub_invariant(__root) != 0;
144}
145
146// Returns:  pointer to the left-most node under __x.
147template <class _NodePtr>
148inline _LIBCPP_INLINE_VISIBILITY
149_NodePtr
150__tree_min(_NodePtr __x) _NOEXCEPT
151{
152    _LIBCPP_ASSERT(__x != nullptr, "Root node shouldn't be null");
153    while (__x->__left_ != nullptr)
154        __x = __x->__left_;
155    return __x;
156}
157
158// Returns:  pointer to the right-most node under __x.
159template <class _NodePtr>
160inline _LIBCPP_INLINE_VISIBILITY
161_NodePtr
162__tree_max(_NodePtr __x) _NOEXCEPT
163{
164    _LIBCPP_ASSERT(__x != nullptr, "Root node shouldn't be null");
165    while (__x->__right_ != nullptr)
166        __x = __x->__right_;
167    return __x;
168}
169
170// Returns:  pointer to the next in-order node after __x.
171template <class _NodePtr>
172_NodePtr
173__tree_next(_NodePtr __x) _NOEXCEPT
174{
175    _LIBCPP_ASSERT(__x != nullptr, "node shouldn't be null");
176    if (__x->__right_ != nullptr)
177        return _VSTD::__tree_min(__x->__right_);
178    while (!_VSTD::__tree_is_left_child(__x))
179        __x = __x->__parent_unsafe();
180    return __x->__parent_unsafe();
181}
182
183template <class _EndNodePtr, class _NodePtr>
184inline _LIBCPP_INLINE_VISIBILITY
185_EndNodePtr
186__tree_next_iter(_NodePtr __x) _NOEXCEPT
187{
188    _LIBCPP_ASSERT(__x != nullptr, "node shouldn't be null");
189    if (__x->__right_ != nullptr)
190        return static_cast<_EndNodePtr>(_VSTD::__tree_min(__x->__right_));
191    while (!_VSTD::__tree_is_left_child(__x))
192        __x = __x->__parent_unsafe();
193    return static_cast<_EndNodePtr>(__x->__parent_);
194}
195
196// Returns:  pointer to the previous in-order node before __x.
197// Note: __x may be the end node.
198template <class _NodePtr, class _EndNodePtr>
199inline _LIBCPP_INLINE_VISIBILITY
200_NodePtr
201__tree_prev_iter(_EndNodePtr __x) _NOEXCEPT
202{
203    _LIBCPP_ASSERT(__x != nullptr, "node shouldn't be null");
204    if (__x->__left_ != nullptr)
205        return _VSTD::__tree_max(__x->__left_);
206    _NodePtr __xx = static_cast<_NodePtr>(__x);
207    while (_VSTD::__tree_is_left_child(__xx))
208        __xx = __xx->__parent_unsafe();
209    return __xx->__parent_unsafe();
210}
211
212// Returns:  pointer to a node which has no children
213template <class _NodePtr>
214_NodePtr
215__tree_leaf(_NodePtr __x) _NOEXCEPT
216{
217    _LIBCPP_ASSERT(__x != nullptr, "node shouldn't be null");
218    while (true)
219    {
220        if (__x->__left_ != nullptr)
221        {
222            __x = __x->__left_;
223            continue;
224        }
225        if (__x->__right_ != nullptr)
226        {
227            __x = __x->__right_;
228            continue;
229        }
230        break;
231    }
232    return __x;
233}
234
235// Effects:  Makes __x->__right_ the subtree root with __x as its left child
236//           while preserving in-order order.
237template <class _NodePtr>
238void
239__tree_left_rotate(_NodePtr __x) _NOEXCEPT
240{
241    _LIBCPP_ASSERT(__x != nullptr, "node shouldn't be null");
242    _LIBCPP_ASSERT(__x->__right_ != nullptr, "node should have a right child");
243    _NodePtr __y = __x->__right_;
244    __x->__right_ = __y->__left_;
245    if (__x->__right_ != nullptr)
246        __x->__right_->__set_parent(__x);
247    __y->__parent_ = __x->__parent_;
248    if (_VSTD::__tree_is_left_child(__x))
249        __x->__parent_->__left_ = __y;
250    else
251        __x->__parent_unsafe()->__right_ = __y;
252    __y->__left_ = __x;
253    __x->__set_parent(__y);
254}
255
256// Effects:  Makes __x->__left_ the subtree root with __x as its right child
257//           while preserving in-order order.
258template <class _NodePtr>
259void
260__tree_right_rotate(_NodePtr __x) _NOEXCEPT
261{
262    _LIBCPP_ASSERT(__x != nullptr, "node shouldn't be null");
263    _LIBCPP_ASSERT(__x->__left_ != nullptr, "node should have a left child");
264    _NodePtr __y = __x->__left_;
265    __x->__left_ = __y->__right_;
266    if (__x->__left_ != nullptr)
267        __x->__left_->__set_parent(__x);
268    __y->__parent_ = __x->__parent_;
269    if (_VSTD::__tree_is_left_child(__x))
270        __x->__parent_->__left_ = __y;
271    else
272        __x->__parent_unsafe()->__right_ = __y;
273    __y->__right_ = __x;
274    __x->__set_parent(__y);
275}
276
277// Effects:  Rebalances __root after attaching __x to a leaf.
278// Precondition:  __x has no children.
279//                __x == __root or == a direct or indirect child of __root.
280//                If __x were to be unlinked from __root (setting __root to
281//                  nullptr if __root == __x), __tree_invariant(__root) == true.
282// Postcondition: __tree_invariant(end_node->__left_) == true.  end_node->__left_
283//                may be different than the value passed in as __root.
284template <class _NodePtr>
285void
286__tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT
287{
288    _LIBCPP_ASSERT(__root != nullptr, "Root of the tree shouldn't be null");
289    _LIBCPP_ASSERT(__x != nullptr, "Can't attach null node to a leaf");
290    __x->__is_black_ = __x == __root;
291    while (__x != __root && !__x->__parent_unsafe()->__is_black_)
292    {
293        // __x->__parent_ != __root because __x->__parent_->__is_black == false
294        if (_VSTD::__tree_is_left_child(__x->__parent_unsafe()))
295        {
296            _NodePtr __y = __x->__parent_unsafe()->__parent_unsafe()->__right_;
297            if (__y != nullptr && !__y->__is_black_)
298            {
299                __x = __x->__parent_unsafe();
300                __x->__is_black_ = true;
301                __x = __x->__parent_unsafe();
302                __x->__is_black_ = __x == __root;
303                __y->__is_black_ = true;
304            }
305            else
306            {
307                if (!_VSTD::__tree_is_left_child(__x))
308                {
309                    __x = __x->__parent_unsafe();
310                    _VSTD::__tree_left_rotate(__x);
311                }
312                __x = __x->__parent_unsafe();
313                __x->__is_black_ = true;
314                __x = __x->__parent_unsafe();
315                __x->__is_black_ = false;
316                _VSTD::__tree_right_rotate(__x);
317                break;
318            }
319        }
320        else
321        {
322            _NodePtr __y = __x->__parent_unsafe()->__parent_->__left_;
323            if (__y != nullptr && !__y->__is_black_)
324            {
325                __x = __x->__parent_unsafe();
326                __x->__is_black_ = true;
327                __x = __x->__parent_unsafe();
328                __x->__is_black_ = __x == __root;
329                __y->__is_black_ = true;
330            }
331            else
332            {
333                if (_VSTD::__tree_is_left_child(__x))
334                {
335                    __x = __x->__parent_unsafe();
336                    _VSTD::__tree_right_rotate(__x);
337                }
338                __x = __x->__parent_unsafe();
339                __x->__is_black_ = true;
340                __x = __x->__parent_unsafe();
341                __x->__is_black_ = false;
342                _VSTD::__tree_left_rotate(__x);
343                break;
344            }
345        }
346    }
347}
348
349// Precondition:  __z == __root or == a direct or indirect child of __root.
350// Effects:  unlinks __z from the tree rooted at __root, rebalancing as needed.
351// Postcondition: __tree_invariant(end_node->__left_) == true && end_node->__left_
352//                nor any of its children refer to __z.  end_node->__left_
353//                may be different than the value passed in as __root.
354template <class _NodePtr>
355void
356__tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
357{
358    _LIBCPP_ASSERT(__root != nullptr, "Root node should not be null");
359    _LIBCPP_ASSERT(__z != nullptr, "The node to remove should not be null");
360    _LIBCPP_DEBUG_ASSERT(__tree_invariant(__root), "The tree invariants should hold");
361    // __z will be removed from the tree.  Client still needs to destruct/deallocate it
362    // __y is either __z, or if __z has two children, __tree_next(__z).
363    // __y will have at most one child.
364    // __y will be the initial hole in the tree (make the hole at a leaf)
365    _NodePtr __y = (__z->__left_ == nullptr || __z->__right_ == nullptr) ?
366                    __z : _VSTD::__tree_next(__z);
367    // __x is __y's possibly null single child
368    _NodePtr __x = __y->__left_ != nullptr ? __y->__left_ : __y->__right_;
369    // __w is __x's possibly null uncle (will become __x's sibling)
370    _NodePtr __w = nullptr;
371    // link __x to __y's parent, and find __w
372    if (__x != nullptr)
373        __x->__parent_ = __y->__parent_;
374    if (_VSTD::__tree_is_left_child(__y))
375    {
376        __y->__parent_->__left_ = __x;
377        if (__y != __root)
378            __w = __y->__parent_unsafe()->__right_;
379        else
380            __root = __x;  // __w == nullptr
381    }
382    else
383    {
384        __y->__parent_unsafe()->__right_ = __x;
385        // __y can't be root if it is a right child
386        __w = __y->__parent_->__left_;
387    }
388    bool __removed_black = __y->__is_black_;
389    // If we didn't remove __z, do so now by splicing in __y for __z,
390    //    but copy __z's color.  This does not impact __x or __w.
391    if (__y != __z)
392    {
393        // __z->__left_ != nulptr but __z->__right_ might == __x == nullptr
394        __y->__parent_ = __z->__parent_;
395        if (_VSTD::__tree_is_left_child(__z))
396            __y->__parent_->__left_ = __y;
397        else
398            __y->__parent_unsafe()->__right_ = __y;
399        __y->__left_ = __z->__left_;
400        __y->__left_->__set_parent(__y);
401        __y->__right_ = __z->__right_;
402        if (__y->__right_ != nullptr)
403            __y->__right_->__set_parent(__y);
404        __y->__is_black_ = __z->__is_black_;
405        if (__root == __z)
406            __root = __y;
407    }
408    // There is no need to rebalance if we removed a red, or if we removed
409    //     the last node.
410    if (__removed_black && __root != nullptr)
411    {
412        // Rebalance:
413        // __x has an implicit black color (transferred from the removed __y)
414        //    associated with it, no matter what its color is.
415        // If __x is __root (in which case it can't be null), it is supposed
416        //    to be black anyway, and if it is doubly black, then the double
417        //    can just be ignored.
418        // If __x is red (in which case it can't be null), then it can absorb
419        //    the implicit black just by setting its color to black.
420        // Since __y was black and only had one child (which __x points to), __x
421        //   is either red with no children, else null, otherwise __y would have
422        //   different black heights under left and right pointers.
423        // if (__x == __root || __x != nullptr && !__x->__is_black_)
424        if (__x != nullptr)
425            __x->__is_black_ = true;
426        else
427        {
428            //  Else __x isn't root, and is "doubly black", even though it may
429            //     be null.  __w can not be null here, else the parent would
430            //     see a black height >= 2 on the __x side and a black height
431            //     of 1 on the __w side (__w must be a non-null black or a red
432            //     with a non-null black child).
433            while (true)
434            {
435                if (!_VSTD::__tree_is_left_child(__w))  // if x is left child
436                {
437                    if (!__w->__is_black_)
438                    {
439                        __w->__is_black_ = true;
440                        __w->__parent_unsafe()->__is_black_ = false;
441                        _VSTD::__tree_left_rotate(__w->__parent_unsafe());
442                        // __x is still valid
443                        // reset __root only if necessary
444                        if (__root == __w->__left_)
445                            __root = __w;
446                        // reset sibling, and it still can't be null
447                        __w = __w->__left_->__right_;
448                    }
449                    // __w->__is_black_ is now true, __w may have null children
450                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) &&
451                        (__w->__right_ == nullptr || __w->__right_->__is_black_))
452                    {
453                        __w->__is_black_ = false;
454                        __x = __w->__parent_unsafe();
455                        // __x can no longer be null
456                        if (__x == __root || !__x->__is_black_)
457                        {
458                            __x->__is_black_ = true;
459                            break;
460                        }
461                        // reset sibling, and it still can't be null
462                        __w = _VSTD::__tree_is_left_child(__x) ?
463                                    __x->__parent_unsafe()->__right_ :
464                                    __x->__parent_->__left_;
465                        // continue;
466                    }
467                    else  // __w has a red child
468                    {
469                        if (__w->__right_ == nullptr || __w->__right_->__is_black_)
470                        {
471                            // __w left child is non-null and red
472                            __w->__left_->__is_black_ = true;
473                            __w->__is_black_ = false;
474                            _VSTD::__tree_right_rotate(__w);
475                            // __w is known not to be root, so root hasn't changed
476                            // reset sibling, and it still can't be null
477                            __w = __w->__parent_unsafe();
478                        }
479                        // __w has a right red child, left child may be null
480                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_;
481                        __w->__parent_unsafe()->__is_black_ = true;
482                        __w->__right_->__is_black_ = true;
483                        _VSTD::__tree_left_rotate(__w->__parent_unsafe());
484                        break;
485                    }
486                }
487                else
488                {
489                    if (!__w->__is_black_)
490                    {
491                        __w->__is_black_ = true;
492                        __w->__parent_unsafe()->__is_black_ = false;
493                        _VSTD::__tree_right_rotate(__w->__parent_unsafe());
494                        // __x is still valid
495                        // reset __root only if necessary
496                        if (__root == __w->__right_)
497                            __root = __w;
498                        // reset sibling, and it still can't be null
499                        __w = __w->__right_->__left_;
500                    }
501                    // __w->__is_black_ is now true, __w may have null children
502                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) &&
503                        (__w->__right_ == nullptr || __w->__right_->__is_black_))
504                    {
505                        __w->__is_black_ = false;
506                        __x = __w->__parent_unsafe();
507                        // __x can no longer be null
508                        if (!__x->__is_black_ || __x == __root)
509                        {
510                            __x->__is_black_ = true;
511                            break;
512                        }
513                        // reset sibling, and it still can't be null
514                        __w = _VSTD::__tree_is_left_child(__x) ?
515                                    __x->__parent_unsafe()->__right_ :
516                                    __x->__parent_->__left_;
517                        // continue;
518                    }
519                    else  // __w has a red child
520                    {
521                        if (__w->__left_ == nullptr || __w->__left_->__is_black_)
522                        {
523                            // __w right child is non-null and red
524                            __w->__right_->__is_black_ = true;
525                            __w->__is_black_ = false;
526                            _VSTD::__tree_left_rotate(__w);
527                            // __w is known not to be root, so root hasn't changed
528                            // reset sibling, and it still can't be null
529                            __w = __w->__parent_unsafe();
530                        }
531                        // __w has a left red child, right child may be null
532                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_;
533                        __w->__parent_unsafe()->__is_black_ = true;
534                        __w->__left_->__is_black_ = true;
535                        _VSTD::__tree_right_rotate(__w->__parent_unsafe());
536                        break;
537                    }
538                }
539            }
540        }
541    }
542}
543
544// node traits
545
546
547template <class _Tp>
548struct __is_tree_value_type_imp : false_type {};
549
550template <class _Key, class _Value>
551struct __is_tree_value_type_imp<__value_type<_Key, _Value> > : true_type {};
552
553template <class ..._Args>
554struct __is_tree_value_type : false_type {};
555
556template <class _One>
557struct __is_tree_value_type<_One> : __is_tree_value_type_imp<__uncvref_t<_One> > {};
558
559template <class _Tp>
560struct __tree_key_value_types {
561  typedef _Tp key_type;
562  typedef _Tp __node_value_type;
563  typedef _Tp __container_value_type;
564  static const bool __is_map = false;
565
566  _LIBCPP_INLINE_VISIBILITY
567  static key_type const& __get_key(_Tp const& __v) {
568    return __v;
569  }
570  _LIBCPP_INLINE_VISIBILITY
571  static __container_value_type const& __get_value(__node_value_type const& __v) {
572    return __v;
573  }
574  _LIBCPP_INLINE_VISIBILITY
575  static __container_value_type* __get_ptr(__node_value_type& __n) {
576    return _VSTD::addressof(__n);
577  }
578  _LIBCPP_INLINE_VISIBILITY
579  static __container_value_type&& __move(__node_value_type& __v) {
580    return _VSTD::move(__v);
581  }
582};
583
584template <class _Key, class _Tp>
585struct __tree_key_value_types<__value_type<_Key, _Tp> > {
586  typedef _Key                                         key_type;
587  typedef _Tp                                          mapped_type;
588  typedef __value_type<_Key, _Tp>                      __node_value_type;
589  typedef pair<const _Key, _Tp>                        __container_value_type;
590  typedef __container_value_type                       __map_value_type;
591  static const bool __is_map = true;
592
593  _LIBCPP_INLINE_VISIBILITY
594  static key_type const&
595  __get_key(__node_value_type const& __t) {
596    return __t.__get_value().first;
597  }
598
599  template <class _Up>
600  _LIBCPP_INLINE_VISIBILITY
601  static __enable_if_t<__is_same_uncvref<_Up, __container_value_type>::value, key_type const&>
602  __get_key(_Up& __t) {
603    return __t.first;
604  }
605
606  _LIBCPP_INLINE_VISIBILITY
607  static __container_value_type const&
608  __get_value(__node_value_type const& __t) {
609    return __t.__get_value();
610  }
611
612  template <class _Up>
613  _LIBCPP_INLINE_VISIBILITY
614  static __enable_if_t<__is_same_uncvref<_Up, __container_value_type>::value, __container_value_type const&>
615  __get_value(_Up& __t) {
616    return __t;
617  }
618
619  _LIBCPP_INLINE_VISIBILITY
620  static __container_value_type* __get_ptr(__node_value_type& __n) {
621    return _VSTD::addressof(__n.__get_value());
622  }
623
624  _LIBCPP_INLINE_VISIBILITY
625  static pair<key_type&&, mapped_type&&> __move(__node_value_type& __v) {
626    return __v.__move();
627  }
628};
629
630template <class _VoidPtr>
631struct __tree_node_base_types {
632  typedef _VoidPtr                                               __void_pointer;
633
634  typedef __tree_node_base<__void_pointer>                      __node_base_type;
635  typedef typename __rebind_pointer<_VoidPtr, __node_base_type>::type
636                                                             __node_base_pointer;
637
638  typedef __tree_end_node<__node_base_pointer>                  __end_node_type;
639  typedef typename __rebind_pointer<_VoidPtr, __end_node_type>::type
640                                                             __end_node_pointer;
641#if defined(_LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB)
642  typedef __end_node_pointer __parent_pointer;
643#else
644  typedef typename conditional<
645      is_pointer<__end_node_pointer>::value,
646        __end_node_pointer,
647        __node_base_pointer>::type __parent_pointer;
648#endif
649
650private:
651  static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value),
652                  "_VoidPtr does not point to unqualified void type");
653};
654
655template <class _Tp, class _AllocPtr, class _KVTypes = __tree_key_value_types<_Tp>,
656         bool = _KVTypes::__is_map>
657struct __tree_map_pointer_types {};
658
659template <class _Tp, class _AllocPtr, class _KVTypes>
660struct __tree_map_pointer_types<_Tp, _AllocPtr, _KVTypes, true> {
661  typedef typename _KVTypes::__map_value_type   _Mv;
662  typedef typename __rebind_pointer<_AllocPtr, _Mv>::type
663                                                       __map_value_type_pointer;
664  typedef typename __rebind_pointer<_AllocPtr, const _Mv>::type
665                                                 __const_map_value_type_pointer;
666};
667
668template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type>
669struct __tree_node_types;
670
671template <class _NodePtr, class _Tp, class _VoidPtr>
672struct __tree_node_types<_NodePtr, __tree_node<_Tp, _VoidPtr> >
673    : public __tree_node_base_types<_VoidPtr>,
674             __tree_key_value_types<_Tp>,
675             __tree_map_pointer_types<_Tp, _VoidPtr>
676{
677  typedef __tree_node_base_types<_VoidPtr> __base;
678  typedef __tree_key_value_types<_Tp>      __key_base;
679  typedef __tree_map_pointer_types<_Tp, _VoidPtr> __map_pointer_base;
680public:
681
682  typedef typename pointer_traits<_NodePtr>::element_type       __node_type;
683  typedef _NodePtr                                              __node_pointer;
684
685  typedef _Tp                                                 __node_value_type;
686  typedef typename __rebind_pointer<_VoidPtr, __node_value_type>::type
687                                                      __node_value_type_pointer;
688  typedef typename __rebind_pointer<_VoidPtr, const __node_value_type>::type
689                                                __const_node_value_type_pointer;
690#if defined(_LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB)
691  typedef typename __base::__end_node_pointer __iter_pointer;
692#else
693  typedef typename conditional<
694      is_pointer<__node_pointer>::value,
695        typename __base::__end_node_pointer,
696        __node_pointer>::type __iter_pointer;
697#endif
698private:
699    static_assert(!is_const<__node_type>::value,
700                "_NodePtr should never be a pointer to const");
701    static_assert((is_same<typename __rebind_pointer<_VoidPtr, __node_type>::type,
702                          _NodePtr>::value), "_VoidPtr does not rebind to _NodePtr.");
703};
704
705template <class _ValueTp, class _VoidPtr>
706struct __make_tree_node_types {
707  typedef typename __rebind_pointer<_VoidPtr, __tree_node<_ValueTp, _VoidPtr> >::type
708                                                                        _NodePtr;
709  typedef __tree_node_types<_NodePtr> type;
710};
711
712// node
713
714template <class _Pointer>
715class __tree_end_node
716{
717public:
718    typedef _Pointer pointer;
719    pointer __left_;
720
721    _LIBCPP_INLINE_VISIBILITY
722    __tree_end_node() _NOEXCEPT : __left_() {}
723};
724
725template <class _VoidPtr>
726class _LIBCPP_STANDALONE_DEBUG __tree_node_base
727    : public __tree_node_base_types<_VoidPtr>::__end_node_type
728{
729    typedef __tree_node_base_types<_VoidPtr> _NodeBaseTypes;
730
731public:
732    typedef typename _NodeBaseTypes::__node_base_pointer pointer;
733    typedef typename _NodeBaseTypes::__parent_pointer __parent_pointer;
734
735    pointer          __right_;
736    __parent_pointer __parent_;
737    bool __is_black_;
738
739    _LIBCPP_INLINE_VISIBILITY
740    pointer __parent_unsafe() const { return static_cast<pointer>(__parent_);}
741
742    _LIBCPP_INLINE_VISIBILITY
743    void __set_parent(pointer __p) {
744        __parent_ = static_cast<__parent_pointer>(__p);
745    }
746
747private:
748  ~__tree_node_base() = delete;
749  __tree_node_base(__tree_node_base const&) = delete;
750  __tree_node_base& operator=(__tree_node_base const&) = delete;
751};
752
753template <class _Tp, class _VoidPtr>
754class _LIBCPP_STANDALONE_DEBUG __tree_node
755    : public __tree_node_base<_VoidPtr>
756{
757public:
758    typedef _Tp __node_value_type;
759
760    __node_value_type __value_;
761
762private:
763  ~__tree_node() = delete;
764  __tree_node(__tree_node const&) = delete;
765  __tree_node& operator=(__tree_node const&) = delete;
766};
767
768
769template <class _Allocator>
770class __tree_node_destructor
771{
772    typedef _Allocator                                      allocator_type;
773    typedef allocator_traits<allocator_type>                __alloc_traits;
774
775public:
776    typedef typename __alloc_traits::pointer                pointer;
777private:
778    typedef __tree_node_types<pointer> _NodeTypes;
779    allocator_type& __na_;
780
781
782public:
783    bool __value_constructed;
784
785
786    __tree_node_destructor(const __tree_node_destructor &) = default;
787    __tree_node_destructor& operator=(const __tree_node_destructor&) = delete;
788
789    _LIBCPP_INLINE_VISIBILITY
790    explicit __tree_node_destructor(allocator_type& __na, bool __val = false) _NOEXCEPT
791        : __na_(__na),
792          __value_constructed(__val)
793        {}
794
795    _LIBCPP_INLINE_VISIBILITY
796    void operator()(pointer __p) _NOEXCEPT
797    {
798        if (__value_constructed)
799            __alloc_traits::destroy(__na_, _NodeTypes::__get_ptr(__p->__value_));
800        if (__p)
801            __alloc_traits::deallocate(__na_, __p, 1);
802    }
803
804    template <class> friend class __map_node_destructor;
805};
806
807#if _LIBCPP_STD_VER > 14
808template <class _NodeType, class _Alloc>
809struct __generic_container_node_destructor;
810template <class _Tp, class _VoidPtr, class _Alloc>
811struct __generic_container_node_destructor<__tree_node<_Tp, _VoidPtr>, _Alloc>
812    : __tree_node_destructor<_Alloc>
813{
814    using __tree_node_destructor<_Alloc>::__tree_node_destructor;
815};
816#endif
817
818template <class _Tp, class _NodePtr, class _DiffType>
819class _LIBCPP_TEMPLATE_VIS __tree_iterator
820{
821    typedef __tree_node_types<_NodePtr>                     _NodeTypes;
822    typedef _NodePtr                                        __node_pointer;
823    typedef typename _NodeTypes::__node_base_pointer        __node_base_pointer;
824    typedef typename _NodeTypes::__end_node_pointer         __end_node_pointer;
825    typedef typename _NodeTypes::__iter_pointer             __iter_pointer;
826    typedef pointer_traits<__node_pointer> __pointer_traits;
827
828    __iter_pointer __ptr_;
829
830public:
831    typedef bidirectional_iterator_tag                     iterator_category;
832    typedef _Tp                                            value_type;
833    typedef _DiffType                                      difference_type;
834    typedef value_type&                                    reference;
835    typedef typename _NodeTypes::__node_value_type_pointer pointer;
836
837    _LIBCPP_INLINE_VISIBILITY __tree_iterator() _NOEXCEPT
838#if _LIBCPP_STD_VER > 11
839    : __ptr_(nullptr)
840#endif
841    {}
842
843    _LIBCPP_INLINE_VISIBILITY reference operator*() const
844        {return __get_np()->__value_;}
845    _LIBCPP_INLINE_VISIBILITY pointer operator->() const
846        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);}
847
848    _LIBCPP_INLINE_VISIBILITY
849    __tree_iterator& operator++() {
850      __ptr_ = static_cast<__iter_pointer>(
851          _VSTD::__tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_)));
852      return *this;
853    }
854    _LIBCPP_INLINE_VISIBILITY
855    __tree_iterator operator++(int)
856        {__tree_iterator __t(*this); ++(*this); return __t;}
857
858    _LIBCPP_INLINE_VISIBILITY
859    __tree_iterator& operator--() {
860      __ptr_ = static_cast<__iter_pointer>(_VSTD::__tree_prev_iter<__node_base_pointer>(
861          static_cast<__end_node_pointer>(__ptr_)));
862      return *this;
863    }
864    _LIBCPP_INLINE_VISIBILITY
865    __tree_iterator operator--(int)
866        {__tree_iterator __t(*this); --(*this); return __t;}
867
868    friend _LIBCPP_INLINE_VISIBILITY
869        bool operator==(const __tree_iterator& __x, const __tree_iterator& __y)
870        {return __x.__ptr_ == __y.__ptr_;}
871    friend _LIBCPP_INLINE_VISIBILITY
872        bool operator!=(const __tree_iterator& __x, const __tree_iterator& __y)
873        {return !(__x == __y);}
874
875private:
876    _LIBCPP_INLINE_VISIBILITY
877    explicit __tree_iterator(__node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
878    _LIBCPP_INLINE_VISIBILITY
879    explicit __tree_iterator(__end_node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
880    _LIBCPP_INLINE_VISIBILITY
881    __node_pointer __get_np() const { return static_cast<__node_pointer>(__ptr_); }
882    template <class, class, class> friend class __tree;
883    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS __tree_const_iterator;
884    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_iterator;
885    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
886    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
887    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS set;
888    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS multiset;
889};
890
891template <class _Tp, class _NodePtr, class _DiffType>
892class _LIBCPP_TEMPLATE_VIS __tree_const_iterator
893{
894    typedef __tree_node_types<_NodePtr>                     _NodeTypes;
895    typedef typename _NodeTypes::__node_pointer             __node_pointer;
896    typedef typename _NodeTypes::__node_base_pointer        __node_base_pointer;
897    typedef typename _NodeTypes::__end_node_pointer         __end_node_pointer;
898    typedef typename _NodeTypes::__iter_pointer             __iter_pointer;
899    typedef pointer_traits<__node_pointer> __pointer_traits;
900
901    __iter_pointer __ptr_;
902
903public:
904    typedef bidirectional_iterator_tag                           iterator_category;
905    typedef _Tp                                                  value_type;
906    typedef _DiffType                                            difference_type;
907    typedef const value_type&                                    reference;
908    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
909
910    _LIBCPP_INLINE_VISIBILITY __tree_const_iterator() _NOEXCEPT
911#if _LIBCPP_STD_VER > 11
912    : __ptr_(nullptr)
913#endif
914    {}
915
916private:
917    typedef __tree_iterator<value_type, __node_pointer, difference_type>
918                                                           __non_const_iterator;
919public:
920    _LIBCPP_INLINE_VISIBILITY
921    __tree_const_iterator(__non_const_iterator __p) _NOEXCEPT
922        : __ptr_(__p.__ptr_) {}
923
924    _LIBCPP_INLINE_VISIBILITY reference operator*() const
925        {return __get_np()->__value_;}
926    _LIBCPP_INLINE_VISIBILITY pointer operator->() const
927        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);}
928
929    _LIBCPP_INLINE_VISIBILITY
930    __tree_const_iterator& operator++() {
931      __ptr_ = static_cast<__iter_pointer>(
932          _VSTD::__tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_)));
933      return *this;
934    }
935
936    _LIBCPP_INLINE_VISIBILITY
937    __tree_const_iterator operator++(int)
938        {__tree_const_iterator __t(*this); ++(*this); return __t;}
939
940    _LIBCPP_INLINE_VISIBILITY
941    __tree_const_iterator& operator--() {
942      __ptr_ = static_cast<__iter_pointer>(_VSTD::__tree_prev_iter<__node_base_pointer>(
943          static_cast<__end_node_pointer>(__ptr_)));
944      return *this;
945    }
946
947    _LIBCPP_INLINE_VISIBILITY
948    __tree_const_iterator operator--(int)
949        {__tree_const_iterator __t(*this); --(*this); return __t;}
950
951    friend _LIBCPP_INLINE_VISIBILITY
952        bool operator==(const __tree_const_iterator& __x, const __tree_const_iterator& __y)
953        {return __x.__ptr_ == __y.__ptr_;}
954    friend _LIBCPP_INLINE_VISIBILITY
955        bool operator!=(const __tree_const_iterator& __x, const __tree_const_iterator& __y)
956        {return !(__x == __y);}
957
958private:
959    _LIBCPP_INLINE_VISIBILITY
960    explicit __tree_const_iterator(__node_pointer __p) _NOEXCEPT
961        : __ptr_(__p) {}
962    _LIBCPP_INLINE_VISIBILITY
963    explicit __tree_const_iterator(__end_node_pointer __p) _NOEXCEPT
964        : __ptr_(__p) {}
965    _LIBCPP_INLINE_VISIBILITY
966    __node_pointer __get_np() const { return static_cast<__node_pointer>(__ptr_); }
967
968    template <class, class, class> friend class __tree;
969    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
970    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
971    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS set;
972    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS multiset;
973    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_const_iterator;
974
975};
976
977template<class _Tp, class _Compare>
978#ifndef _LIBCPP_CXX03_LANG
979    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Compare const&, _Tp const&, _Tp const&>::value,
980        "the specified comparator type does not provide a viable const call operator")
981#endif
982int __diagnose_non_const_comparator();
983
984template <class _Tp, class _Compare, class _Allocator>
985class __tree
986{
987public:
988    typedef _Tp                                      value_type;
989    typedef _Compare                                 value_compare;
990    typedef _Allocator                               allocator_type;
991
992private:
993    typedef allocator_traits<allocator_type>         __alloc_traits;
994    typedef typename __make_tree_node_types<value_type,
995        typename __alloc_traits::void_pointer>::type
996                                                    _NodeTypes;
997    typedef typename _NodeTypes::key_type           key_type;
998public:
999    typedef typename _NodeTypes::__node_value_type      __node_value_type;
1000    typedef typename _NodeTypes::__container_value_type __container_value_type;
1001
1002    typedef typename __alloc_traits::pointer         pointer;
1003    typedef typename __alloc_traits::const_pointer   const_pointer;
1004    typedef typename __alloc_traits::size_type       size_type;
1005    typedef typename __alloc_traits::difference_type difference_type;
1006
1007public:
1008    typedef typename _NodeTypes::__void_pointer        __void_pointer;
1009
1010    typedef typename _NodeTypes::__node_type           __node;
1011    typedef typename _NodeTypes::__node_pointer        __node_pointer;
1012
1013    typedef typename _NodeTypes::__node_base_type      __node_base;
1014    typedef typename _NodeTypes::__node_base_pointer   __node_base_pointer;
1015
1016    typedef typename _NodeTypes::__end_node_type       __end_node_t;
1017    typedef typename _NodeTypes::__end_node_pointer    __end_node_ptr;
1018
1019    typedef typename _NodeTypes::__parent_pointer      __parent_pointer;
1020    typedef typename _NodeTypes::__iter_pointer        __iter_pointer;
1021
1022    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
1023    typedef allocator_traits<__node_allocator>         __node_traits;
1024
1025private:
1026    // check for sane allocator pointer rebinding semantics. Rebinding the
1027    // allocator for a new pointer type should be exactly the same as rebinding
1028    // the pointer using 'pointer_traits'.
1029    static_assert((is_same<__node_pointer, typename __node_traits::pointer>::value),
1030                  "Allocator does not rebind pointers in a sane manner.");
1031    typedef typename __rebind_alloc_helper<__node_traits, __node_base>::type
1032        __node_base_allocator;
1033    typedef allocator_traits<__node_base_allocator> __node_base_traits;
1034    static_assert((is_same<__node_base_pointer, typename __node_base_traits::pointer>::value),
1035                 "Allocator does not rebind pointers in a sane manner.");
1036
1037private:
1038    __iter_pointer                                     __begin_node_;
1039    __compressed_pair<__end_node_t, __node_allocator>  __pair1_;
1040    __compressed_pair<size_type, value_compare>        __pair3_;
1041
1042public:
1043    _LIBCPP_INLINE_VISIBILITY
1044    __iter_pointer __end_node() _NOEXCEPT
1045    {
1046        return static_cast<__iter_pointer>(
1047                pointer_traits<__end_node_ptr>::pointer_to(__pair1_.first())
1048        );
1049    }
1050    _LIBCPP_INLINE_VISIBILITY
1051    __iter_pointer __end_node() const _NOEXCEPT
1052    {
1053        return static_cast<__iter_pointer>(
1054            pointer_traits<__end_node_ptr>::pointer_to(
1055                const_cast<__end_node_t&>(__pair1_.first())
1056            )
1057        );
1058    }
1059    _LIBCPP_INLINE_VISIBILITY
1060          __node_allocator& __node_alloc() _NOEXCEPT {return __pair1_.second();}
1061private:
1062    _LIBCPP_INLINE_VISIBILITY
1063    const __node_allocator& __node_alloc() const _NOEXCEPT
1064        {return __pair1_.second();}
1065    _LIBCPP_INLINE_VISIBILITY
1066          __iter_pointer& __begin_node() _NOEXCEPT {return __begin_node_;}
1067    _LIBCPP_INLINE_VISIBILITY
1068    const __iter_pointer& __begin_node() const _NOEXCEPT {return __begin_node_;}
1069public:
1070    _LIBCPP_INLINE_VISIBILITY
1071    allocator_type __alloc() const _NOEXCEPT
1072        {return allocator_type(__node_alloc());}
1073private:
1074    _LIBCPP_INLINE_VISIBILITY
1075          size_type& size() _NOEXCEPT {return __pair3_.first();}
1076public:
1077    _LIBCPP_INLINE_VISIBILITY
1078    const size_type& size() const _NOEXCEPT {return __pair3_.first();}
1079    _LIBCPP_INLINE_VISIBILITY
1080          value_compare& value_comp() _NOEXCEPT {return __pair3_.second();}
1081    _LIBCPP_INLINE_VISIBILITY
1082    const value_compare& value_comp() const _NOEXCEPT
1083        {return __pair3_.second();}
1084public:
1085
1086    _LIBCPP_INLINE_VISIBILITY
1087    __node_pointer __root() const _NOEXCEPT
1088        {return static_cast<__node_pointer>(__end_node()->__left_);}
1089
1090    __node_base_pointer* __root_ptr() const _NOEXCEPT {
1091        return _VSTD::addressof(__end_node()->__left_);
1092    }
1093
1094    typedef __tree_iterator<value_type, __node_pointer, difference_type>             iterator;
1095    typedef __tree_const_iterator<value_type, __node_pointer, difference_type> const_iterator;
1096
1097    explicit __tree(const value_compare& __comp)
1098        _NOEXCEPT_(
1099            is_nothrow_default_constructible<__node_allocator>::value &&
1100            is_nothrow_copy_constructible<value_compare>::value);
1101    explicit __tree(const allocator_type& __a);
1102    __tree(const value_compare& __comp, const allocator_type& __a);
1103    __tree(const __tree& __t);
1104    __tree& operator=(const __tree& __t);
1105    template <class _ForwardIterator>
1106        void __assign_unique(_ForwardIterator __first, _ForwardIterator __last);
1107    template <class _InputIterator>
1108        void __assign_multi(_InputIterator __first, _InputIterator __last);
1109    __tree(__tree&& __t)
1110        _NOEXCEPT_(
1111            is_nothrow_move_constructible<__node_allocator>::value &&
1112            is_nothrow_move_constructible<value_compare>::value);
1113    __tree(__tree&& __t, const allocator_type& __a);
1114    __tree& operator=(__tree&& __t)
1115        _NOEXCEPT_(
1116            __node_traits::propagate_on_container_move_assignment::value &&
1117            is_nothrow_move_assignable<value_compare>::value &&
1118            is_nothrow_move_assignable<__node_allocator>::value);
1119    ~__tree();
1120
1121    _LIBCPP_INLINE_VISIBILITY
1122          iterator begin()  _NOEXCEPT {return       iterator(__begin_node());}
1123    _LIBCPP_INLINE_VISIBILITY
1124    const_iterator begin() const _NOEXCEPT {return const_iterator(__begin_node());}
1125    _LIBCPP_INLINE_VISIBILITY
1126          iterator end() _NOEXCEPT {return       iterator(__end_node());}
1127    _LIBCPP_INLINE_VISIBILITY
1128    const_iterator end() const _NOEXCEPT {return const_iterator(__end_node());}
1129
1130    _LIBCPP_INLINE_VISIBILITY
1131    size_type max_size() const _NOEXCEPT
1132        {return _VSTD::min<size_type>(
1133                __node_traits::max_size(__node_alloc()),
1134                numeric_limits<difference_type >::max());}
1135
1136    void clear() _NOEXCEPT;
1137
1138    void swap(__tree& __t)
1139#if _LIBCPP_STD_VER <= 11
1140        _NOEXCEPT_(
1141            __is_nothrow_swappable<value_compare>::value
1142            && (!__node_traits::propagate_on_container_swap::value ||
1143                 __is_nothrow_swappable<__node_allocator>::value)
1144            );
1145#else
1146        _NOEXCEPT_(__is_nothrow_swappable<value_compare>::value);
1147#endif
1148
1149    template <class _Key, class ..._Args>
1150    pair<iterator, bool>
1151    __emplace_unique_key_args(_Key const&, _Args&&... __args);
1152    template <class _Key, class ..._Args>
1153    pair<iterator, bool>
1154    __emplace_hint_unique_key_args(const_iterator, _Key const&, _Args&&...);
1155
1156    template <class... _Args>
1157    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args);
1158
1159    template <class... _Args>
1160    iterator __emplace_hint_unique_impl(const_iterator __p, _Args&&... __args);
1161
1162    template <class... _Args>
1163    iterator __emplace_multi(_Args&&... __args);
1164
1165    template <class... _Args>
1166    iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);
1167
1168    template <class _Pp>
1169    _LIBCPP_INLINE_VISIBILITY
1170    pair<iterator, bool> __emplace_unique(_Pp&& __x) {
1171        return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x),
1172                                            __can_extract_key<_Pp, key_type>());
1173    }
1174
1175    template <class _First, class _Second>
1176    _LIBCPP_INLINE_VISIBILITY
1177    __enable_if_t<__can_extract_map_key<_First, key_type, __container_value_type>::value, pair<iterator, bool> >
1178    __emplace_unique(_First&& __f, _Second&& __s) {
1179        return __emplace_unique_key_args(__f, _VSTD::forward<_First>(__f),
1180                                              _VSTD::forward<_Second>(__s));
1181    }
1182
1183    template <class... _Args>
1184    _LIBCPP_INLINE_VISIBILITY
1185    pair<iterator, bool> __emplace_unique(_Args&&... __args) {
1186        return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...);
1187    }
1188
1189    template <class _Pp>
1190    _LIBCPP_INLINE_VISIBILITY
1191    pair<iterator, bool>
1192    __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) {
1193      return __emplace_unique_impl(_VSTD::forward<_Pp>(__x));
1194    }
1195
1196    template <class _Pp>
1197    _LIBCPP_INLINE_VISIBILITY
1198    pair<iterator, bool>
1199    __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) {
1200      return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x));
1201    }
1202
1203    template <class _Pp>
1204    _LIBCPP_INLINE_VISIBILITY
1205    pair<iterator, bool>
1206    __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) {
1207      return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x));
1208    }
1209
1210    template <class _Pp>
1211    _LIBCPP_INLINE_VISIBILITY
1212    iterator __emplace_hint_unique(const_iterator __p, _Pp&& __x) {
1213        return __emplace_hint_unique_extract_key(__p, _VSTD::forward<_Pp>(__x),
1214                                            __can_extract_key<_Pp, key_type>());
1215    }
1216
1217    template <class _First, class _Second>
1218    _LIBCPP_INLINE_VISIBILITY
1219    __enable_if_t<__can_extract_map_key<_First, key_type, __container_value_type>::value, iterator>
1220    __emplace_hint_unique(const_iterator __p, _First&& __f, _Second&& __s) {
1221        return __emplace_hint_unique_key_args(__p, __f,
1222                                              _VSTD::forward<_First>(__f),
1223                                              _VSTD::forward<_Second>(__s)).first;
1224    }
1225
1226    template <class... _Args>
1227    _LIBCPP_INLINE_VISIBILITY
1228    iterator __emplace_hint_unique(const_iterator __p, _Args&&... __args) {
1229        return __emplace_hint_unique_impl(__p, _VSTD::forward<_Args>(__args)...);
1230    }
1231
1232    template <class _Pp>
1233    _LIBCPP_INLINE_VISIBILITY
1234    iterator
1235    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_fail_tag) {
1236      return __emplace_hint_unique_impl(__p, _VSTD::forward<_Pp>(__x));
1237    }
1238
1239    template <class _Pp>
1240    _LIBCPP_INLINE_VISIBILITY
1241    iterator
1242    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_self_tag) {
1243      return __emplace_hint_unique_key_args(__p, __x, _VSTD::forward<_Pp>(__x)).first;
1244    }
1245
1246    template <class _Pp>
1247    _LIBCPP_INLINE_VISIBILITY
1248    iterator
1249    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_first_tag) {
1250      return __emplace_hint_unique_key_args(__p, __x.first, _VSTD::forward<_Pp>(__x)).first;
1251    }
1252
1253    _LIBCPP_INLINE_VISIBILITY
1254    pair<iterator, bool> __insert_unique(const __container_value_type& __v) {
1255        return __emplace_unique_key_args(_NodeTypes::__get_key(__v), __v);
1256    }
1257
1258    _LIBCPP_INLINE_VISIBILITY
1259    iterator __insert_unique(const_iterator __p, const __container_value_type& __v) {
1260        return __emplace_hint_unique_key_args(__p, _NodeTypes::__get_key(__v), __v).first;
1261    }
1262
1263    _LIBCPP_INLINE_VISIBILITY
1264    pair<iterator, bool> __insert_unique(__container_value_type&& __v) {
1265        return __emplace_unique_key_args(_NodeTypes::__get_key(__v), _VSTD::move(__v));
1266    }
1267
1268    _LIBCPP_INLINE_VISIBILITY
1269    iterator __insert_unique(const_iterator __p, __container_value_type&& __v) {
1270        return __emplace_hint_unique_key_args(__p, _NodeTypes::__get_key(__v), _VSTD::move(__v)).first;
1271    }
1272
1273    template <class _Vp,
1274              class = __enable_if_t<!is_same<typename __unconstref<_Vp>::type, __container_value_type>::value> >
1275    _LIBCPP_INLINE_VISIBILITY
1276    pair<iterator, bool> __insert_unique(_Vp&& __v) {
1277        return __emplace_unique(_VSTD::forward<_Vp>(__v));
1278    }
1279
1280    template <class _Vp,
1281              class = __enable_if_t<!is_same<typename __unconstref<_Vp>::type, __container_value_type>::value> >
1282    _LIBCPP_INLINE_VISIBILITY
1283    iterator __insert_unique(const_iterator __p, _Vp&& __v) {
1284        return __emplace_hint_unique(__p, _VSTD::forward<_Vp>(__v));
1285    }
1286
1287    _LIBCPP_INLINE_VISIBILITY
1288    iterator __insert_multi(__container_value_type&& __v) {
1289        return __emplace_multi(_VSTD::move(__v));
1290    }
1291
1292    _LIBCPP_INLINE_VISIBILITY
1293    iterator __insert_multi(const_iterator __p, __container_value_type&& __v) {
1294        return __emplace_hint_multi(__p, _VSTD::move(__v));
1295    }
1296
1297    template <class _Vp>
1298    _LIBCPP_INLINE_VISIBILITY
1299    iterator __insert_multi(_Vp&& __v) {
1300        return __emplace_multi(_VSTD::forward<_Vp>(__v));
1301    }
1302
1303    template <class _Vp>
1304    _LIBCPP_INLINE_VISIBILITY
1305    iterator __insert_multi(const_iterator __p, _Vp&& __v) {
1306        return __emplace_hint_multi(__p, _VSTD::forward<_Vp>(__v));
1307    }
1308
1309    _LIBCPP_INLINE_VISIBILITY
1310    pair<iterator, bool> __node_assign_unique(const __container_value_type& __v, __node_pointer __dest);
1311
1312    _LIBCPP_INLINE_VISIBILITY
1313    iterator __node_insert_multi(__node_pointer __nd);
1314    _LIBCPP_INLINE_VISIBILITY
1315    iterator __node_insert_multi(const_iterator __p, __node_pointer __nd);
1316
1317
1318    _LIBCPP_INLINE_VISIBILITY iterator
1319    __remove_node_pointer(__node_pointer) _NOEXCEPT;
1320
1321#if _LIBCPP_STD_VER > 14
1322    template <class _NodeHandle, class _InsertReturnType>
1323    _LIBCPP_INLINE_VISIBILITY
1324    _InsertReturnType __node_handle_insert_unique(_NodeHandle&&);
1325    template <class _NodeHandle>
1326    _LIBCPP_INLINE_VISIBILITY
1327    iterator __node_handle_insert_unique(const_iterator, _NodeHandle&&);
1328    template <class _Tree>
1329    _LIBCPP_INLINE_VISIBILITY
1330    void __node_handle_merge_unique(_Tree& __source);
1331
1332    template <class _NodeHandle>
1333    _LIBCPP_INLINE_VISIBILITY
1334    iterator __node_handle_insert_multi(_NodeHandle&&);
1335    template <class _NodeHandle>
1336    _LIBCPP_INLINE_VISIBILITY
1337    iterator __node_handle_insert_multi(const_iterator, _NodeHandle&&);
1338    template <class _Tree>
1339    _LIBCPP_INLINE_VISIBILITY
1340    void __node_handle_merge_multi(_Tree& __source);
1341
1342
1343    template <class _NodeHandle>
1344    _LIBCPP_INLINE_VISIBILITY
1345    _NodeHandle __node_handle_extract(key_type const&);
1346    template <class _NodeHandle>
1347    _LIBCPP_INLINE_VISIBILITY
1348    _NodeHandle __node_handle_extract(const_iterator);
1349#endif
1350
1351    iterator erase(const_iterator __p);
1352    iterator erase(const_iterator __f, const_iterator __l);
1353    template <class _Key>
1354        size_type __erase_unique(const _Key& __k);
1355    template <class _Key>
1356        size_type __erase_multi(const _Key& __k);
1357
1358    void __insert_node_at(__parent_pointer     __parent,
1359                          __node_base_pointer& __child,
1360                          __node_base_pointer __new_node) _NOEXCEPT;
1361
1362    template <class _Key>
1363        iterator find(const _Key& __v);
1364    template <class _Key>
1365        const_iterator find(const _Key& __v) const;
1366
1367    template <class _Key>
1368        size_type __count_unique(const _Key& __k) const;
1369    template <class _Key>
1370        size_type __count_multi(const _Key& __k) const;
1371
1372    template <class _Key>
1373        _LIBCPP_INLINE_VISIBILITY
1374        iterator lower_bound(const _Key& __v)
1375            {return __lower_bound(__v, __root(), __end_node());}
1376    template <class _Key>
1377        iterator __lower_bound(const _Key& __v,
1378                               __node_pointer __root,
1379                               __iter_pointer __result);
1380    template <class _Key>
1381        _LIBCPP_INLINE_VISIBILITY
1382        const_iterator lower_bound(const _Key& __v) const
1383            {return __lower_bound(__v, __root(), __end_node());}
1384    template <class _Key>
1385        const_iterator __lower_bound(const _Key& __v,
1386                                     __node_pointer __root,
1387                                     __iter_pointer __result) const;
1388    template <class _Key>
1389        _LIBCPP_INLINE_VISIBILITY
1390        iterator upper_bound(const _Key& __v)
1391            {return __upper_bound(__v, __root(), __end_node());}
1392    template <class _Key>
1393        iterator __upper_bound(const _Key& __v,
1394                               __node_pointer __root,
1395                               __iter_pointer __result);
1396    template <class _Key>
1397        _LIBCPP_INLINE_VISIBILITY
1398        const_iterator upper_bound(const _Key& __v) const
1399            {return __upper_bound(__v, __root(), __end_node());}
1400    template <class _Key>
1401        const_iterator __upper_bound(const _Key& __v,
1402                                     __node_pointer __root,
1403                                     __iter_pointer __result) const;
1404    template <class _Key>
1405        pair<iterator, iterator>
1406        __equal_range_unique(const _Key& __k);
1407    template <class _Key>
1408        pair<const_iterator, const_iterator>
1409        __equal_range_unique(const _Key& __k) const;
1410
1411    template <class _Key>
1412        pair<iterator, iterator>
1413        __equal_range_multi(const _Key& __k);
1414    template <class _Key>
1415        pair<const_iterator, const_iterator>
1416        __equal_range_multi(const _Key& __k) const;
1417
1418    typedef __tree_node_destructor<__node_allocator> _Dp;
1419    typedef unique_ptr<__node, _Dp> __node_holder;
1420
1421    __node_holder remove(const_iterator __p) _NOEXCEPT;
1422private:
1423    __node_base_pointer&
1424        __find_leaf_low(__parent_pointer& __parent, const key_type& __v);
1425    __node_base_pointer&
1426        __find_leaf_high(__parent_pointer& __parent, const key_type& __v);
1427    __node_base_pointer&
1428        __find_leaf(const_iterator __hint,
1429                    __parent_pointer& __parent, const key_type& __v);
1430    // FIXME: Make this function const qualified. Unfortunately doing so
1431    // breaks existing code which uses non-const callable comparators.
1432    template <class _Key>
1433    __node_base_pointer&
1434        __find_equal(__parent_pointer& __parent, const _Key& __v);
1435    template <class _Key>
1436    _LIBCPP_INLINE_VISIBILITY __node_base_pointer&
1437    __find_equal(__parent_pointer& __parent, const _Key& __v) const {
1438      return const_cast<__tree*>(this)->__find_equal(__parent, __v);
1439    }
1440    template <class _Key>
1441    __node_base_pointer&
1442        __find_equal(const_iterator __hint, __parent_pointer& __parent,
1443                     __node_base_pointer& __dummy,
1444                     const _Key& __v);
1445
1446    template <class ..._Args>
1447    __node_holder __construct_node(_Args&& ...__args);
1448
1449    void destroy(__node_pointer __nd) _NOEXCEPT;
1450
1451    _LIBCPP_INLINE_VISIBILITY
1452    void __copy_assign_alloc(const __tree& __t)
1453        {__copy_assign_alloc(__t, integral_constant<bool,
1454             __node_traits::propagate_on_container_copy_assignment::value>());}
1455
1456    _LIBCPP_INLINE_VISIBILITY
1457    void __copy_assign_alloc(const __tree& __t, true_type)
1458        {
1459        if (__node_alloc() != __t.__node_alloc())
1460            clear();
1461        __node_alloc() = __t.__node_alloc();
1462        }
1463    _LIBCPP_INLINE_VISIBILITY
1464    void __copy_assign_alloc(const __tree&, false_type) {}
1465
1466    void __move_assign(__tree& __t, false_type);
1467    void __move_assign(__tree& __t, true_type)
1468        _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value &&
1469                   is_nothrow_move_assignable<__node_allocator>::value);
1470
1471    _LIBCPP_INLINE_VISIBILITY
1472    void __move_assign_alloc(__tree& __t)
1473        _NOEXCEPT_(
1474            !__node_traits::propagate_on_container_move_assignment::value ||
1475            is_nothrow_move_assignable<__node_allocator>::value)
1476        {__move_assign_alloc(__t, integral_constant<bool,
1477             __node_traits::propagate_on_container_move_assignment::value>());}
1478
1479    _LIBCPP_INLINE_VISIBILITY
1480    void __move_assign_alloc(__tree& __t, true_type)
1481        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
1482        {__node_alloc() = _VSTD::move(__t.__node_alloc());}
1483    _LIBCPP_INLINE_VISIBILITY
1484    void __move_assign_alloc(__tree&, false_type) _NOEXCEPT {}
1485
1486    struct _DetachedTreeCache {
1487      _LIBCPP_INLINE_VISIBILITY
1488      explicit _DetachedTreeCache(__tree *__t) _NOEXCEPT : __t_(__t),
1489        __cache_root_(__detach_from_tree(__t)) {
1490          __advance();
1491        }
1492
1493      _LIBCPP_INLINE_VISIBILITY
1494      __node_pointer __get() const _NOEXCEPT {
1495        return __cache_elem_;
1496      }
1497
1498      _LIBCPP_INLINE_VISIBILITY
1499      void __advance() _NOEXCEPT {
1500        __cache_elem_ = __cache_root_;
1501        if (__cache_root_) {
1502          __cache_root_ = __detach_next(__cache_root_);
1503        }
1504      }
1505
1506      _LIBCPP_INLINE_VISIBILITY
1507      ~_DetachedTreeCache() {
1508        __t_->destroy(__cache_elem_);
1509        if (__cache_root_) {
1510          while (__cache_root_->__parent_ != nullptr)
1511            __cache_root_ = static_cast<__node_pointer>(__cache_root_->__parent_);
1512          __t_->destroy(__cache_root_);
1513        }
1514      }
1515
1516       _DetachedTreeCache(_DetachedTreeCache const&) = delete;
1517       _DetachedTreeCache& operator=(_DetachedTreeCache const&) = delete;
1518
1519    private:
1520      _LIBCPP_INLINE_VISIBILITY
1521      static __node_pointer __detach_from_tree(__tree *__t) _NOEXCEPT;
1522      _LIBCPP_INLINE_VISIBILITY
1523      static __node_pointer __detach_next(__node_pointer) _NOEXCEPT;
1524
1525      __tree *__t_;
1526      __node_pointer __cache_root_;
1527      __node_pointer __cache_elem_;
1528    };
1529
1530
1531    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
1532    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
1533};
1534
1535template <class _Tp, class _Compare, class _Allocator>
1536__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp)
1537        _NOEXCEPT_(
1538            is_nothrow_default_constructible<__node_allocator>::value &&
1539            is_nothrow_copy_constructible<value_compare>::value)
1540    : __pair3_(0, __comp)
1541{
1542    __begin_node() = __end_node();
1543}
1544
1545template <class _Tp, class _Compare, class _Allocator>
1546__tree<_Tp, _Compare, _Allocator>::__tree(const allocator_type& __a)
1547    : __begin_node_(__iter_pointer()),
1548      __pair1_(__default_init_tag(), __node_allocator(__a)),
1549      __pair3_(0, __default_init_tag())
1550{
1551    __begin_node() = __end_node();
1552}
1553
1554template <class _Tp, class _Compare, class _Allocator>
1555__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp,
1556                                           const allocator_type& __a)
1557    : __begin_node_(__iter_pointer()),
1558      __pair1_(__default_init_tag(), __node_allocator(__a)),
1559      __pair3_(0, __comp)
1560{
1561    __begin_node() = __end_node();
1562}
1563
1564// Precondition:  size() != 0
1565template <class _Tp, class _Compare, class _Allocator>
1566typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
1567__tree<_Tp, _Compare, _Allocator>::_DetachedTreeCache::__detach_from_tree(__tree *__t) _NOEXCEPT
1568{
1569    __node_pointer __cache = static_cast<__node_pointer>(__t->__begin_node());
1570    __t->__begin_node() = __t->__end_node();
1571    __t->__end_node()->__left_->__parent_ = nullptr;
1572    __t->__end_node()->__left_ = nullptr;
1573    __t->size() = 0;
1574    // __cache->__left_ == nullptr
1575    if (__cache->__right_ != nullptr)
1576        __cache = static_cast<__node_pointer>(__cache->__right_);
1577    // __cache->__left_ == nullptr
1578    // __cache->__right_ == nullptr
1579    return __cache;
1580}
1581
1582// Precondition:  __cache != nullptr
1583//    __cache->left_ == nullptr
1584//    __cache->right_ == nullptr
1585//    This is no longer a red-black tree
1586template <class _Tp, class _Compare, class _Allocator>
1587typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
1588__tree<_Tp, _Compare, _Allocator>::_DetachedTreeCache::__detach_next(__node_pointer __cache) _NOEXCEPT
1589{
1590    if (__cache->__parent_ == nullptr)
1591        return nullptr;
1592    if (_VSTD::__tree_is_left_child(static_cast<__node_base_pointer>(__cache)))
1593    {
1594        __cache->__parent_->__left_ = nullptr;
1595        __cache = static_cast<__node_pointer>(__cache->__parent_);
1596        if (__cache->__right_ == nullptr)
1597            return __cache;
1598        return static_cast<__node_pointer>(_VSTD::__tree_leaf(__cache->__right_));
1599    }
1600    // __cache is right child
1601    __cache->__parent_unsafe()->__right_ = nullptr;
1602    __cache = static_cast<__node_pointer>(__cache->__parent_);
1603    if (__cache->__left_ == nullptr)
1604        return __cache;
1605    return static_cast<__node_pointer>(_VSTD::__tree_leaf(__cache->__left_));
1606}
1607
1608template <class _Tp, class _Compare, class _Allocator>
1609__tree<_Tp, _Compare, _Allocator>&
1610__tree<_Tp, _Compare, _Allocator>::operator=(const __tree& __t)
1611{
1612    if (this != _VSTD::addressof(__t))
1613    {
1614        value_comp() = __t.value_comp();
1615        __copy_assign_alloc(__t);
1616        __assign_multi(__t.begin(), __t.end());
1617    }
1618    return *this;
1619}
1620
1621template <class _Tp, class _Compare, class _Allocator>
1622template <class _ForwardIterator>
1623void
1624__tree<_Tp, _Compare, _Allocator>::__assign_unique(_ForwardIterator __first, _ForwardIterator __last)
1625{
1626    typedef iterator_traits<_ForwardIterator> _ITraits;
1627    typedef typename _ITraits::value_type _ItValueType;
1628    static_assert((is_same<_ItValueType, __container_value_type>::value),
1629                  "__assign_unique may only be called with the containers value type");
1630    static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
1631                  "__assign_unique requires a forward iterator");
1632    if (size() != 0)
1633    {
1634        _DetachedTreeCache __cache(this);
1635          for (; __cache.__get() != nullptr && __first != __last; ++__first) {
1636              if (__node_assign_unique(*__first, __cache.__get()).second)
1637                  __cache.__advance();
1638            }
1639    }
1640    for (; __first != __last; ++__first)
1641        __insert_unique(*__first);
1642}
1643
1644template <class _Tp, class _Compare, class _Allocator>
1645template <class _InputIterator>
1646void
1647__tree<_Tp, _Compare, _Allocator>::__assign_multi(_InputIterator __first, _InputIterator __last)
1648{
1649    typedef iterator_traits<_InputIterator> _ITraits;
1650    typedef typename _ITraits::value_type _ItValueType;
1651    static_assert((is_same<_ItValueType, __container_value_type>::value ||
1652                  is_same<_ItValueType, __node_value_type>::value),
1653                  "__assign_multi may only be called with the containers value type"
1654                  " or the nodes value type");
1655    if (size() != 0)
1656    {
1657        _DetachedTreeCache __cache(this);
1658        for (; __cache.__get() && __first != __last; ++__first) {
1659            __cache.__get()->__value_ = *__first;
1660            __node_insert_multi(__cache.__get());
1661            __cache.__advance();
1662        }
1663    }
1664    for (; __first != __last; ++__first)
1665        __insert_multi(_NodeTypes::__get_value(*__first));
1666}
1667
1668template <class _Tp, class _Compare, class _Allocator>
1669__tree<_Tp, _Compare, _Allocator>::__tree(const __tree& __t)
1670    : __begin_node_(__iter_pointer()),
1671      __pair1_(__default_init_tag(), __node_traits::select_on_container_copy_construction(__t.__node_alloc())),
1672      __pair3_(0, __t.value_comp())
1673{
1674    __begin_node() = __end_node();
1675}
1676
1677template <class _Tp, class _Compare, class _Allocator>
1678__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t)
1679    _NOEXCEPT_(
1680        is_nothrow_move_constructible<__node_allocator>::value &&
1681        is_nothrow_move_constructible<value_compare>::value)
1682    : __begin_node_(_VSTD::move(__t.__begin_node_)),
1683      __pair1_(_VSTD::move(__t.__pair1_)),
1684      __pair3_(_VSTD::move(__t.__pair3_))
1685{
1686    if (size() == 0)
1687        __begin_node() = __end_node();
1688    else
1689    {
1690        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
1691        __t.__begin_node() = __t.__end_node();
1692        __t.__end_node()->__left_ = nullptr;
1693        __t.size() = 0;
1694    }
1695}
1696
1697template <class _Tp, class _Compare, class _Allocator>
1698__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t, const allocator_type& __a)
1699    : __pair1_(__default_init_tag(), __node_allocator(__a)),
1700      __pair3_(0, _VSTD::move(__t.value_comp()))
1701{
1702    if (__a == __t.__alloc())
1703    {
1704        if (__t.size() == 0)
1705            __begin_node() = __end_node();
1706        else
1707        {
1708            __begin_node() = __t.__begin_node();
1709            __end_node()->__left_ = __t.__end_node()->__left_;
1710            __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
1711            size() = __t.size();
1712            __t.__begin_node() = __t.__end_node();
1713            __t.__end_node()->__left_ = nullptr;
1714            __t.size() = 0;
1715        }
1716    }
1717    else
1718    {
1719        __begin_node() = __end_node();
1720    }
1721}
1722
1723template <class _Tp, class _Compare, class _Allocator>
1724void
1725__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, true_type)
1726    _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value &&
1727               is_nothrow_move_assignable<__node_allocator>::value)
1728{
1729    destroy(static_cast<__node_pointer>(__end_node()->__left_));
1730    __begin_node_ = __t.__begin_node_;
1731    __pair1_.first() = __t.__pair1_.first();
1732    __move_assign_alloc(__t);
1733    __pair3_ = _VSTD::move(__t.__pair3_);
1734    if (size() == 0)
1735        __begin_node() = __end_node();
1736    else
1737    {
1738        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
1739        __t.__begin_node() = __t.__end_node();
1740        __t.__end_node()->__left_ = nullptr;
1741        __t.size() = 0;
1742    }
1743}
1744
1745template <class _Tp, class _Compare, class _Allocator>
1746void
1747__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, false_type)
1748{
1749    if (__node_alloc() == __t.__node_alloc())
1750        __move_assign(__t, true_type());
1751    else
1752    {
1753        value_comp() = _VSTD::move(__t.value_comp());
1754        const_iterator __e = end();
1755        if (size() != 0)
1756        {
1757            _DetachedTreeCache __cache(this);
1758            while (__cache.__get() != nullptr && __t.size() != 0) {
1759              __cache.__get()->__value_ = _VSTD::move(__t.remove(__t.begin())->__value_);
1760              __node_insert_multi(__cache.__get());
1761              __cache.__advance();
1762            }
1763        }
1764        while (__t.size() != 0)
1765            __insert_multi(__e, _NodeTypes::__move(__t.remove(__t.begin())->__value_));
1766    }
1767}
1768
1769template <class _Tp, class _Compare, class _Allocator>
1770__tree<_Tp, _Compare, _Allocator>&
1771__tree<_Tp, _Compare, _Allocator>::operator=(__tree&& __t)
1772    _NOEXCEPT_(
1773        __node_traits::propagate_on_container_move_assignment::value &&
1774        is_nothrow_move_assignable<value_compare>::value &&
1775        is_nothrow_move_assignable<__node_allocator>::value)
1776
1777{
1778    __move_assign(__t, integral_constant<bool,
1779                  __node_traits::propagate_on_container_move_assignment::value>());
1780    return *this;
1781}
1782
1783template <class _Tp, class _Compare, class _Allocator>
1784__tree<_Tp, _Compare, _Allocator>::~__tree()
1785{
1786    static_assert((is_copy_constructible<value_compare>::value),
1787                 "Comparator must be copy-constructible.");
1788  destroy(__root());
1789}
1790
1791template <class _Tp, class _Compare, class _Allocator>
1792void
1793__tree<_Tp, _Compare, _Allocator>::destroy(__node_pointer __nd) _NOEXCEPT
1794{
1795    if (__nd != nullptr)
1796    {
1797        destroy(static_cast<__node_pointer>(__nd->__left_));
1798        destroy(static_cast<__node_pointer>(__nd->__right_));
1799        __node_allocator& __na = __node_alloc();
1800        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__nd->__value_));
1801        __node_traits::deallocate(__na, __nd, 1);
1802    }
1803}
1804
1805template <class _Tp, class _Compare, class _Allocator>
1806void
1807__tree<_Tp, _Compare, _Allocator>::swap(__tree& __t)
1808#if _LIBCPP_STD_VER <= 11
1809        _NOEXCEPT_(
1810            __is_nothrow_swappable<value_compare>::value
1811            && (!__node_traits::propagate_on_container_swap::value ||
1812                 __is_nothrow_swappable<__node_allocator>::value)
1813            )
1814#else
1815        _NOEXCEPT_(__is_nothrow_swappable<value_compare>::value)
1816#endif
1817{
1818    using _VSTD::swap;
1819    swap(__begin_node_, __t.__begin_node_);
1820    swap(__pair1_.first(), __t.__pair1_.first());
1821    _VSTD::__swap_allocator(__node_alloc(), __t.__node_alloc());
1822    __pair3_.swap(__t.__pair3_);
1823    if (size() == 0)
1824        __begin_node() = __end_node();
1825    else
1826        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
1827    if (__t.size() == 0)
1828        __t.__begin_node() = __t.__end_node();
1829    else
1830        __t.__end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__t.__end_node());
1831}
1832
1833template <class _Tp, class _Compare, class _Allocator>
1834void
1835__tree<_Tp, _Compare, _Allocator>::clear() _NOEXCEPT
1836{
1837    destroy(__root());
1838    size() = 0;
1839    __begin_node() = __end_node();
1840    __end_node()->__left_ = nullptr;
1841}
1842
1843// Find lower_bound place to insert
1844// Set __parent to parent of null leaf
1845// Return reference to null leaf
1846template <class _Tp, class _Compare, class _Allocator>
1847typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
1848__tree<_Tp, _Compare, _Allocator>::__find_leaf_low(__parent_pointer& __parent,
1849                                                   const key_type& __v)
1850{
1851    __node_pointer __nd = __root();
1852    if (__nd != nullptr)
1853    {
1854        while (true)
1855        {
1856            if (value_comp()(__nd->__value_, __v))
1857            {
1858                if (__nd->__right_ != nullptr)
1859                    __nd = static_cast<__node_pointer>(__nd->__right_);
1860                else
1861                {
1862                    __parent = static_cast<__parent_pointer>(__nd);
1863                    return __nd->__right_;
1864                }
1865            }
1866            else
1867            {
1868                if (__nd->__left_ != nullptr)
1869                    __nd = static_cast<__node_pointer>(__nd->__left_);
1870                else
1871                {
1872                    __parent = static_cast<__parent_pointer>(__nd);
1873                    return __parent->__left_;
1874                }
1875            }
1876        }
1877    }
1878    __parent = static_cast<__parent_pointer>(__end_node());
1879    return __parent->__left_;
1880}
1881
1882// Find upper_bound place to insert
1883// Set __parent to parent of null leaf
1884// Return reference to null leaf
1885template <class _Tp, class _Compare, class _Allocator>
1886typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
1887__tree<_Tp, _Compare, _Allocator>::__find_leaf_high(__parent_pointer& __parent,
1888                                                    const key_type& __v)
1889{
1890    __node_pointer __nd = __root();
1891    if (__nd != nullptr)
1892    {
1893        while (true)
1894        {
1895            if (value_comp()(__v, __nd->__value_))
1896            {
1897                if (__nd->__left_ != nullptr)
1898                    __nd = static_cast<__node_pointer>(__nd->__left_);
1899                else
1900                {
1901                    __parent = static_cast<__parent_pointer>(__nd);
1902                    return __parent->__left_;
1903                }
1904            }
1905            else
1906            {
1907                if (__nd->__right_ != nullptr)
1908                    __nd = static_cast<__node_pointer>(__nd->__right_);
1909                else
1910                {
1911                    __parent = static_cast<__parent_pointer>(__nd);
1912                    return __nd->__right_;
1913                }
1914            }
1915        }
1916    }
1917    __parent = static_cast<__parent_pointer>(__end_node());
1918    return __parent->__left_;
1919}
1920
1921// Find leaf place to insert closest to __hint
1922// First check prior to __hint.
1923// Next check after __hint.
1924// Next do O(log N) search.
1925// Set __parent to parent of null leaf
1926// Return reference to null leaf
1927template <class _Tp, class _Compare, class _Allocator>
1928typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
1929__tree<_Tp, _Compare, _Allocator>::__find_leaf(const_iterator __hint,
1930                                               __parent_pointer& __parent,
1931                                               const key_type& __v)
1932{
1933    if (__hint == end() || !value_comp()(*__hint, __v))  // check before
1934    {
1935        // __v <= *__hint
1936        const_iterator __prior = __hint;
1937        if (__prior == begin() || !value_comp()(__v, *--__prior))
1938        {
1939            // *prev(__hint) <= __v <= *__hint
1940            if (__hint.__ptr_->__left_ == nullptr)
1941            {
1942                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
1943                return __parent->__left_;
1944            }
1945            else
1946            {
1947                __parent = static_cast<__parent_pointer>(__prior.__ptr_);
1948                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_;
1949            }
1950        }
1951        // __v < *prev(__hint)
1952        return __find_leaf_high(__parent, __v);
1953    }
1954    // else __v > *__hint
1955    return __find_leaf_low(__parent, __v);
1956}
1957
1958// Find place to insert if __v doesn't exist
1959// Set __parent to parent of null leaf
1960// Return reference to null leaf
1961// If __v exists, set parent to node of __v and return reference to node of __v
1962template <class _Tp, class _Compare, class _Allocator>
1963template <class _Key>
1964typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
1965__tree<_Tp, _Compare, _Allocator>::__find_equal(__parent_pointer& __parent,
1966                                                const _Key& __v)
1967{
1968    __node_pointer __nd = __root();
1969    __node_base_pointer* __nd_ptr = __root_ptr();
1970    if (__nd != nullptr)
1971    {
1972        while (true)
1973        {
1974            if (value_comp()(__v, __nd->__value_))
1975            {
1976                if (__nd->__left_ != nullptr) {
1977                    __nd_ptr = _VSTD::addressof(__nd->__left_);
1978                    __nd = static_cast<__node_pointer>(__nd->__left_);
1979                } else {
1980                    __parent = static_cast<__parent_pointer>(__nd);
1981                    return __parent->__left_;
1982                }
1983            }
1984            else if (value_comp()(__nd->__value_, __v))
1985            {
1986                if (__nd->__right_ != nullptr) {
1987                    __nd_ptr = _VSTD::addressof(__nd->__right_);
1988                    __nd = static_cast<__node_pointer>(__nd->__right_);
1989                } else {
1990                    __parent = static_cast<__parent_pointer>(__nd);
1991                    return __nd->__right_;
1992                }
1993            }
1994            else
1995            {
1996                __parent = static_cast<__parent_pointer>(__nd);
1997                return *__nd_ptr;
1998            }
1999        }
2000    }
2001    __parent = static_cast<__parent_pointer>(__end_node());
2002    return __parent->__left_;
2003}
2004
2005// Find place to insert if __v doesn't exist
2006// First check prior to __hint.
2007// Next check after __hint.
2008// Next do O(log N) search.
2009// Set __parent to parent of null leaf
2010// Return reference to null leaf
2011// If __v exists, set parent to node of __v and return reference to node of __v
2012template <class _Tp, class _Compare, class _Allocator>
2013template <class _Key>
2014typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
2015__tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint,
2016                                                __parent_pointer& __parent,
2017                                                __node_base_pointer& __dummy,
2018                                                const _Key& __v)
2019{
2020    if (__hint == end() || value_comp()(__v, *__hint))  // check before
2021    {
2022        // __v < *__hint
2023        const_iterator __prior = __hint;
2024        if (__prior == begin() || value_comp()(*--__prior, __v))
2025        {
2026            // *prev(__hint) < __v < *__hint
2027            if (__hint.__ptr_->__left_ == nullptr)
2028            {
2029                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
2030                return __parent->__left_;
2031            }
2032            else
2033            {
2034                __parent = static_cast<__parent_pointer>(__prior.__ptr_);
2035                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_;
2036            }
2037        }
2038        // __v <= *prev(__hint)
2039        return __find_equal(__parent, __v);
2040    }
2041    else if (value_comp()(*__hint, __v))  // check after
2042    {
2043        // *__hint < __v
2044        const_iterator __next = _VSTD::next(__hint);
2045        if (__next == end() || value_comp()(__v, *__next))
2046        {
2047            // *__hint < __v < *_VSTD::next(__hint)
2048            if (__hint.__get_np()->__right_ == nullptr)
2049            {
2050                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
2051                return static_cast<__node_base_pointer>(__hint.__ptr_)->__right_;
2052            }
2053            else
2054            {
2055                __parent = static_cast<__parent_pointer>(__next.__ptr_);
2056                return __parent->__left_;
2057            }
2058        }
2059        // *next(__hint) <= __v
2060        return __find_equal(__parent, __v);
2061    }
2062    // else __v == *__hint
2063    __parent = static_cast<__parent_pointer>(__hint.__ptr_);
2064    __dummy = static_cast<__node_base_pointer>(__hint.__ptr_);
2065    return __dummy;
2066}
2067
2068template <class _Tp, class _Compare, class _Allocator>
2069void __tree<_Tp, _Compare, _Allocator>::__insert_node_at(
2070    __parent_pointer __parent, __node_base_pointer& __child,
2071    __node_base_pointer __new_node) _NOEXCEPT
2072{
2073    __new_node->__left_   = nullptr;
2074    __new_node->__right_  = nullptr;
2075    __new_node->__parent_ = __parent;
2076    // __new_node->__is_black_ is initialized in __tree_balance_after_insert
2077    __child = __new_node;
2078    if (__begin_node()->__left_ != nullptr)
2079        __begin_node() = static_cast<__iter_pointer>(__begin_node()->__left_);
2080    _VSTD::__tree_balance_after_insert(__end_node()->__left_, __child);
2081    ++size();
2082}
2083
2084template <class _Tp, class _Compare, class _Allocator>
2085template <class _Key, class... _Args>
2086pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
2087__tree<_Tp, _Compare, _Allocator>::__emplace_unique_key_args(_Key const& __k, _Args&&... __args)
2088{
2089    __parent_pointer __parent;
2090    __node_base_pointer& __child = __find_equal(__parent, __k);
2091    __node_pointer __r = static_cast<__node_pointer>(__child);
2092    bool __inserted = false;
2093    if (__child == nullptr)
2094    {
2095        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2096        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
2097        __r = __h.release();
2098        __inserted = true;
2099    }
2100    return pair<iterator, bool>(iterator(__r), __inserted);
2101}
2102
2103template <class _Tp, class _Compare, class _Allocator>
2104template <class _Key, class... _Args>
2105pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
2106__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_key_args(
2107    const_iterator __p, _Key const& __k, _Args&&... __args)
2108{
2109    __parent_pointer __parent;
2110    __node_base_pointer __dummy;
2111    __node_base_pointer& __child = __find_equal(__p, __parent, __dummy, __k);
2112    __node_pointer __r = static_cast<__node_pointer>(__child);
2113    bool __inserted = false;
2114    if (__child == nullptr)
2115    {
2116        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2117        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
2118        __r = __h.release();
2119        __inserted = true;
2120    }
2121    return pair<iterator, bool>(iterator(__r), __inserted);
2122}
2123
2124template <class _Tp, class _Compare, class _Allocator>
2125template <class ..._Args>
2126typename __tree<_Tp, _Compare, _Allocator>::__node_holder
2127__tree<_Tp, _Compare, _Allocator>::__construct_node(_Args&& ...__args)
2128{
2129    static_assert(!__is_tree_value_type<_Args...>::value,
2130                  "Cannot construct from __value_type");
2131    __node_allocator& __na = __node_alloc();
2132    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
2133    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), _VSTD::forward<_Args>(__args)...);
2134    __h.get_deleter().__value_constructed = true;
2135    return __h;
2136}
2137
2138
2139template <class _Tp, class _Compare, class _Allocator>
2140template <class... _Args>
2141pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
2142__tree<_Tp, _Compare, _Allocator>::__emplace_unique_impl(_Args&&... __args)
2143{
2144    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2145    __parent_pointer __parent;
2146    __node_base_pointer& __child = __find_equal(__parent, __h->__value_);
2147    __node_pointer __r = static_cast<__node_pointer>(__child);
2148    bool __inserted = false;
2149    if (__child == nullptr)
2150    {
2151        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
2152        __r = __h.release();
2153        __inserted = true;
2154    }
2155    return pair<iterator, bool>(iterator(__r), __inserted);
2156}
2157
2158template <class _Tp, class _Compare, class _Allocator>
2159template <class... _Args>
2160typename __tree<_Tp, _Compare, _Allocator>::iterator
2161__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_impl(const_iterator __p, _Args&&... __args)
2162{
2163    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2164    __parent_pointer __parent;
2165    __node_base_pointer __dummy;
2166    __node_base_pointer& __child = __find_equal(__p, __parent, __dummy, __h->__value_);
2167    __node_pointer __r = static_cast<__node_pointer>(__child);
2168    if (__child == nullptr)
2169    {
2170        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
2171        __r = __h.release();
2172    }
2173    return iterator(__r);
2174}
2175
2176template <class _Tp, class _Compare, class _Allocator>
2177template <class... _Args>
2178typename __tree<_Tp, _Compare, _Allocator>::iterator
2179__tree<_Tp, _Compare, _Allocator>::__emplace_multi(_Args&&... __args)
2180{
2181    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2182    __parent_pointer __parent;
2183    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__h->__value_));
2184    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
2185    return iterator(static_cast<__node_pointer>(__h.release()));
2186}
2187
2188template <class _Tp, class _Compare, class _Allocator>
2189template <class... _Args>
2190typename __tree<_Tp, _Compare, _Allocator>::iterator
2191__tree<_Tp, _Compare, _Allocator>::__emplace_hint_multi(const_iterator __p,
2192                                                        _Args&&... __args)
2193{
2194    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2195    __parent_pointer __parent;
2196    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__h->__value_));
2197    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
2198    return iterator(static_cast<__node_pointer>(__h.release()));
2199}
2200
2201template <class _Tp, class _Compare, class _Allocator>
2202pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
2203__tree<_Tp, _Compare, _Allocator>::__node_assign_unique(const __container_value_type& __v, __node_pointer __nd)
2204{
2205    __parent_pointer __parent;
2206    __node_base_pointer& __child = __find_equal(__parent, _NodeTypes::__get_key(__v));
2207    __node_pointer __r = static_cast<__node_pointer>(__child);
2208    bool __inserted = false;
2209    if (__child == nullptr)
2210    {
2211        __nd->__value_ = __v;
2212        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
2213        __r = __nd;
2214        __inserted = true;
2215    }
2216    return pair<iterator, bool>(iterator(__r), __inserted);
2217}
2218
2219
2220template <class _Tp, class _Compare, class _Allocator>
2221typename __tree<_Tp, _Compare, _Allocator>::iterator
2222__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(__node_pointer __nd)
2223{
2224    __parent_pointer __parent;
2225    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__nd->__value_));
2226    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
2227    return iterator(__nd);
2228}
2229
2230template <class _Tp, class _Compare, class _Allocator>
2231typename __tree<_Tp, _Compare, _Allocator>::iterator
2232__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(const_iterator __p,
2233                                                       __node_pointer __nd)
2234{
2235    __parent_pointer __parent;
2236    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__nd->__value_));
2237    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
2238    return iterator(__nd);
2239}
2240
2241template <class _Tp, class _Compare, class _Allocator>
2242typename __tree<_Tp, _Compare, _Allocator>::iterator
2243__tree<_Tp, _Compare, _Allocator>::__remove_node_pointer(__node_pointer __ptr) _NOEXCEPT
2244{
2245    iterator __r(__ptr);
2246    ++__r;
2247    if (__begin_node() == __ptr)
2248        __begin_node() = __r.__ptr_;
2249    --size();
2250    _VSTD::__tree_remove(__end_node()->__left_,
2251                         static_cast<__node_base_pointer>(__ptr));
2252    return __r;
2253}
2254
2255#if _LIBCPP_STD_VER > 14
2256template <class _Tp, class _Compare, class _Allocator>
2257template <class _NodeHandle, class _InsertReturnType>
2258_LIBCPP_INLINE_VISIBILITY
2259_InsertReturnType
2260__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(
2261    _NodeHandle&& __nh)
2262{
2263    if (__nh.empty())
2264        return _InsertReturnType{end(), false, _NodeHandle()};
2265
2266    __node_pointer __ptr = __nh.__ptr_;
2267    __parent_pointer __parent;
2268    __node_base_pointer& __child = __find_equal(__parent,
2269                                                __ptr->__value_);
2270    if (__child != nullptr)
2271        return _InsertReturnType{
2272            iterator(static_cast<__node_pointer>(__child)),
2273            false, _VSTD::move(__nh)};
2274
2275    __insert_node_at(__parent, __child,
2276                     static_cast<__node_base_pointer>(__ptr));
2277    __nh.__release_ptr();
2278    return _InsertReturnType{iterator(__ptr), true, _NodeHandle()};
2279}
2280
2281template <class _Tp, class _Compare, class _Allocator>
2282template <class _NodeHandle>
2283_LIBCPP_INLINE_VISIBILITY
2284typename __tree<_Tp, _Compare, _Allocator>::iterator
2285__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(
2286    const_iterator __hint, _NodeHandle&& __nh)
2287{
2288    if (__nh.empty())
2289        return end();
2290
2291    __node_pointer __ptr = __nh.__ptr_;
2292    __parent_pointer __parent;
2293    __node_base_pointer __dummy;
2294    __node_base_pointer& __child = __find_equal(__hint, __parent, __dummy,
2295                                                __ptr->__value_);
2296    __node_pointer __r = static_cast<__node_pointer>(__child);
2297    if (__child == nullptr)
2298    {
2299        __insert_node_at(__parent, __child,
2300                         static_cast<__node_base_pointer>(__ptr));
2301        __r = __ptr;
2302        __nh.__release_ptr();
2303    }
2304    return iterator(__r);
2305}
2306
2307template <class _Tp, class _Compare, class _Allocator>
2308template <class _NodeHandle>
2309_LIBCPP_INLINE_VISIBILITY
2310_NodeHandle
2311__tree<_Tp, _Compare, _Allocator>::__node_handle_extract(key_type const& __key)
2312{
2313    iterator __it = find(__key);
2314    if (__it == end())
2315        return _NodeHandle();
2316    return __node_handle_extract<_NodeHandle>(__it);
2317}
2318
2319template <class _Tp, class _Compare, class _Allocator>
2320template <class _NodeHandle>
2321_LIBCPP_INLINE_VISIBILITY
2322_NodeHandle
2323__tree<_Tp, _Compare, _Allocator>::__node_handle_extract(const_iterator __p)
2324{
2325    __node_pointer __np = __p.__get_np();
2326    __remove_node_pointer(__np);
2327    return _NodeHandle(__np, __alloc());
2328}
2329
2330template <class _Tp, class _Compare, class _Allocator>
2331template <class _Tree>
2332_LIBCPP_INLINE_VISIBILITY
2333void
2334__tree<_Tp, _Compare, _Allocator>::__node_handle_merge_unique(_Tree& __source)
2335{
2336    static_assert(is_same<typename _Tree::__node_pointer, __node_pointer>::value, "");
2337
2338    for (typename _Tree::iterator __i = __source.begin();
2339         __i != __source.end();)
2340    {
2341        __node_pointer __src_ptr = __i.__get_np();
2342        __parent_pointer __parent;
2343        __node_base_pointer& __child =
2344            __find_equal(__parent, _NodeTypes::__get_key(__src_ptr->__value_));
2345        ++__i;
2346        if (__child != nullptr)
2347            continue;
2348        __source.__remove_node_pointer(__src_ptr);
2349        __insert_node_at(__parent, __child,
2350                         static_cast<__node_base_pointer>(__src_ptr));
2351    }
2352}
2353
2354template <class _Tp, class _Compare, class _Allocator>
2355template <class _NodeHandle>
2356_LIBCPP_INLINE_VISIBILITY
2357typename __tree<_Tp, _Compare, _Allocator>::iterator
2358__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(_NodeHandle&& __nh)
2359{
2360    if (__nh.empty())
2361        return end();
2362    __node_pointer __ptr = __nh.__ptr_;
2363    __parent_pointer __parent;
2364    __node_base_pointer& __child = __find_leaf_high(
2365        __parent, _NodeTypes::__get_key(__ptr->__value_));
2366    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
2367    __nh.__release_ptr();
2368    return iterator(__ptr);
2369}
2370
2371template <class _Tp, class _Compare, class _Allocator>
2372template <class _NodeHandle>
2373_LIBCPP_INLINE_VISIBILITY
2374typename __tree<_Tp, _Compare, _Allocator>::iterator
2375__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(
2376    const_iterator __hint, _NodeHandle&& __nh)
2377{
2378    if (__nh.empty())
2379        return end();
2380
2381    __node_pointer __ptr = __nh.__ptr_;
2382    __parent_pointer __parent;
2383    __node_base_pointer& __child = __find_leaf(__hint, __parent,
2384                                               _NodeTypes::__get_key(__ptr->__value_));
2385    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
2386    __nh.__release_ptr();
2387    return iterator(__ptr);
2388}
2389
2390template <class _Tp, class _Compare, class _Allocator>
2391template <class _Tree>
2392_LIBCPP_INLINE_VISIBILITY
2393void
2394__tree<_Tp, _Compare, _Allocator>::__node_handle_merge_multi(_Tree& __source)
2395{
2396    static_assert(is_same<typename _Tree::__node_pointer, __node_pointer>::value, "");
2397
2398    for (typename _Tree::iterator __i = __source.begin();
2399         __i != __source.end();)
2400    {
2401        __node_pointer __src_ptr = __i.__get_np();
2402        __parent_pointer __parent;
2403        __node_base_pointer& __child = __find_leaf_high(
2404            __parent, _NodeTypes::__get_key(__src_ptr->__value_));
2405        ++__i;
2406        __source.__remove_node_pointer(__src_ptr);
2407        __insert_node_at(__parent, __child,
2408                         static_cast<__node_base_pointer>(__src_ptr));
2409    }
2410}
2411
2412#endif // _LIBCPP_STD_VER > 14
2413
2414template <class _Tp, class _Compare, class _Allocator>
2415typename __tree<_Tp, _Compare, _Allocator>::iterator
2416__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __p)
2417{
2418    __node_pointer __np = __p.__get_np();
2419    iterator __r = __remove_node_pointer(__np);
2420    __node_allocator& __na = __node_alloc();
2421    __node_traits::destroy(__na, _NodeTypes::__get_ptr(
2422        const_cast<__node_value_type&>(*__p)));
2423    __node_traits::deallocate(__na, __np, 1);
2424    return __r;
2425}
2426
2427template <class _Tp, class _Compare, class _Allocator>
2428typename __tree<_Tp, _Compare, _Allocator>::iterator
2429__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __f, const_iterator __l)
2430{
2431    while (__f != __l)
2432        __f = erase(__f);
2433    return iterator(__l.__ptr_);
2434}
2435
2436template <class _Tp, class _Compare, class _Allocator>
2437template <class _Key>
2438typename __tree<_Tp, _Compare, _Allocator>::size_type
2439__tree<_Tp, _Compare, _Allocator>::__erase_unique(const _Key& __k)
2440{
2441    iterator __i = find(__k);
2442    if (__i == end())
2443        return 0;
2444    erase(__i);
2445    return 1;
2446}
2447
2448template <class _Tp, class _Compare, class _Allocator>
2449template <class _Key>
2450typename __tree<_Tp, _Compare, _Allocator>::size_type
2451__tree<_Tp, _Compare, _Allocator>::__erase_multi(const _Key& __k)
2452{
2453    pair<iterator, iterator> __p = __equal_range_multi(__k);
2454    size_type __r = 0;
2455    for (; __p.first != __p.second; ++__r)
2456        __p.first = erase(__p.first);
2457    return __r;
2458}
2459
2460template <class _Tp, class _Compare, class _Allocator>
2461template <class _Key>
2462typename __tree<_Tp, _Compare, _Allocator>::iterator
2463__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v)
2464{
2465    iterator __p = __lower_bound(__v, __root(), __end_node());
2466    if (__p != end() && !value_comp()(__v, *__p))
2467        return __p;
2468    return end();
2469}
2470
2471template <class _Tp, class _Compare, class _Allocator>
2472template <class _Key>
2473typename __tree<_Tp, _Compare, _Allocator>::const_iterator
2474__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v) const
2475{
2476    const_iterator __p = __lower_bound(__v, __root(), __end_node());
2477    if (__p != end() && !value_comp()(__v, *__p))
2478        return __p;
2479    return end();
2480}
2481
2482template <class _Tp, class _Compare, class _Allocator>
2483template <class _Key>
2484typename __tree<_Tp, _Compare, _Allocator>::size_type
2485__tree<_Tp, _Compare, _Allocator>::__count_unique(const _Key& __k) const
2486{
2487    __node_pointer __rt = __root();
2488    while (__rt != nullptr)
2489    {
2490        if (value_comp()(__k, __rt->__value_))
2491        {
2492            __rt = static_cast<__node_pointer>(__rt->__left_);
2493        }
2494        else if (value_comp()(__rt->__value_, __k))
2495            __rt = static_cast<__node_pointer>(__rt->__right_);
2496        else
2497            return 1;
2498    }
2499    return 0;
2500}
2501
2502template <class _Tp, class _Compare, class _Allocator>
2503template <class _Key>
2504typename __tree<_Tp, _Compare, _Allocator>::size_type
2505__tree<_Tp, _Compare, _Allocator>::__count_multi(const _Key& __k) const
2506{
2507    __iter_pointer __result = __end_node();
2508    __node_pointer __rt = __root();
2509    while (__rt != nullptr)
2510    {
2511        if (value_comp()(__k, __rt->__value_))
2512        {
2513            __result = static_cast<__iter_pointer>(__rt);
2514            __rt = static_cast<__node_pointer>(__rt->__left_);
2515        }
2516        else if (value_comp()(__rt->__value_, __k))
2517            __rt = static_cast<__node_pointer>(__rt->__right_);
2518        else
2519            return _VSTD::distance(
2520                __lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)),
2521                __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result)
2522            );
2523    }
2524    return 0;
2525}
2526
2527template <class _Tp, class _Compare, class _Allocator>
2528template <class _Key>
2529typename __tree<_Tp, _Compare, _Allocator>::iterator
2530__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v,
2531                                                 __node_pointer __root,
2532                                                 __iter_pointer __result)
2533{
2534    while (__root != nullptr)
2535    {
2536        if (!value_comp()(__root->__value_, __v))
2537        {
2538            __result = static_cast<__iter_pointer>(__root);
2539            __root = static_cast<__node_pointer>(__root->__left_);
2540        }
2541        else
2542            __root = static_cast<__node_pointer>(__root->__right_);
2543    }
2544    return iterator(__result);
2545}
2546
2547template <class _Tp, class _Compare, class _Allocator>
2548template <class _Key>
2549typename __tree<_Tp, _Compare, _Allocator>::const_iterator
2550__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v,
2551                                                 __node_pointer __root,
2552                                                 __iter_pointer __result) const
2553{
2554    while (__root != nullptr)
2555    {
2556        if (!value_comp()(__root->__value_, __v))
2557        {
2558            __result = static_cast<__iter_pointer>(__root);
2559            __root = static_cast<__node_pointer>(__root->__left_);
2560        }
2561        else
2562            __root = static_cast<__node_pointer>(__root->__right_);
2563    }
2564    return const_iterator(__result);
2565}
2566
2567template <class _Tp, class _Compare, class _Allocator>
2568template <class _Key>
2569typename __tree<_Tp, _Compare, _Allocator>::iterator
2570__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v,
2571                                                 __node_pointer __root,
2572                                                 __iter_pointer __result)
2573{
2574    while (__root != nullptr)
2575    {
2576        if (value_comp()(__v, __root->__value_))
2577        {
2578            __result = static_cast<__iter_pointer>(__root);
2579            __root = static_cast<__node_pointer>(__root->__left_);
2580        }
2581        else
2582            __root = static_cast<__node_pointer>(__root->__right_);
2583    }
2584    return iterator(__result);
2585}
2586
2587template <class _Tp, class _Compare, class _Allocator>
2588template <class _Key>
2589typename __tree<_Tp, _Compare, _Allocator>::const_iterator
2590__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v,
2591                                                 __node_pointer __root,
2592                                                 __iter_pointer __result) const
2593{
2594    while (__root != nullptr)
2595    {
2596        if (value_comp()(__v, __root->__value_))
2597        {
2598            __result = static_cast<__iter_pointer>(__root);
2599            __root = static_cast<__node_pointer>(__root->__left_);
2600        }
2601        else
2602            __root = static_cast<__node_pointer>(__root->__right_);
2603    }
2604    return const_iterator(__result);
2605}
2606
2607template <class _Tp, class _Compare, class _Allocator>
2608template <class _Key>
2609pair<typename __tree<_Tp, _Compare, _Allocator>::iterator,
2610     typename __tree<_Tp, _Compare, _Allocator>::iterator>
2611__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k)
2612{
2613    typedef pair<iterator, iterator> _Pp;
2614    __iter_pointer __result = __end_node();
2615    __node_pointer __rt = __root();
2616    while (__rt != nullptr)
2617    {
2618        if (value_comp()(__k, __rt->__value_))
2619        {
2620            __result = static_cast<__iter_pointer>(__rt);
2621            __rt = static_cast<__node_pointer>(__rt->__left_);
2622        }
2623        else if (value_comp()(__rt->__value_, __k))
2624            __rt = static_cast<__node_pointer>(__rt->__right_);
2625        else
2626            return _Pp(iterator(__rt),
2627                      iterator(
2628                          __rt->__right_ != nullptr ?
2629                              static_cast<__iter_pointer>(_VSTD::__tree_min(__rt->__right_))
2630                            : __result));
2631    }
2632    return _Pp(iterator(__result), iterator(__result));
2633}
2634
2635template <class _Tp, class _Compare, class _Allocator>
2636template <class _Key>
2637pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator,
2638     typename __tree<_Tp, _Compare, _Allocator>::const_iterator>
2639__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k) const
2640{
2641    typedef pair<const_iterator, const_iterator> _Pp;
2642    __iter_pointer __result = __end_node();
2643    __node_pointer __rt = __root();
2644    while (__rt != nullptr)
2645    {
2646        if (value_comp()(__k, __rt->__value_))
2647        {
2648            __result = static_cast<__iter_pointer>(__rt);
2649            __rt = static_cast<__node_pointer>(__rt->__left_);
2650        }
2651        else if (value_comp()(__rt->__value_, __k))
2652            __rt = static_cast<__node_pointer>(__rt->__right_);
2653        else
2654            return _Pp(const_iterator(__rt),
2655                      const_iterator(
2656                          __rt->__right_ != nullptr ?
2657                              static_cast<__iter_pointer>(_VSTD::__tree_min(__rt->__right_))
2658                            : __result));
2659    }
2660    return _Pp(const_iterator(__result), const_iterator(__result));
2661}
2662
2663template <class _Tp, class _Compare, class _Allocator>
2664template <class _Key>
2665pair<typename __tree<_Tp, _Compare, _Allocator>::iterator,
2666     typename __tree<_Tp, _Compare, _Allocator>::iterator>
2667__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k)
2668{
2669    typedef pair<iterator, iterator> _Pp;
2670    __iter_pointer __result = __end_node();
2671    __node_pointer __rt = __root();
2672    while (__rt != nullptr)
2673    {
2674        if (value_comp()(__k, __rt->__value_))
2675        {
2676            __result = static_cast<__iter_pointer>(__rt);
2677            __rt = static_cast<__node_pointer>(__rt->__left_);
2678        }
2679        else if (value_comp()(__rt->__value_, __k))
2680            __rt = static_cast<__node_pointer>(__rt->__right_);
2681        else
2682            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)),
2683                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result));
2684    }
2685    return _Pp(iterator(__result), iterator(__result));
2686}
2687
2688template <class _Tp, class _Compare, class _Allocator>
2689template <class _Key>
2690pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator,
2691     typename __tree<_Tp, _Compare, _Allocator>::const_iterator>
2692__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) const
2693{
2694    typedef pair<const_iterator, const_iterator> _Pp;
2695    __iter_pointer __result = __end_node();
2696    __node_pointer __rt = __root();
2697    while (__rt != nullptr)
2698    {
2699        if (value_comp()(__k, __rt->__value_))
2700        {
2701            __result = static_cast<__iter_pointer>(__rt);
2702            __rt = static_cast<__node_pointer>(__rt->__left_);
2703        }
2704        else if (value_comp()(__rt->__value_, __k))
2705            __rt = static_cast<__node_pointer>(__rt->__right_);
2706        else
2707            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)),
2708                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result));
2709    }
2710    return _Pp(const_iterator(__result), const_iterator(__result));
2711}
2712
2713template <class _Tp, class _Compare, class _Allocator>
2714typename __tree<_Tp, _Compare, _Allocator>::__node_holder
2715__tree<_Tp, _Compare, _Allocator>::remove(const_iterator __p) _NOEXCEPT
2716{
2717    __node_pointer __np = __p.__get_np();
2718    if (__begin_node() == __p.__ptr_)
2719    {
2720        if (__np->__right_ != nullptr)
2721            __begin_node() = static_cast<__iter_pointer>(__np->__right_);
2722        else
2723            __begin_node() = static_cast<__iter_pointer>(__np->__parent_);
2724    }
2725    --size();
2726    _VSTD::__tree_remove(__end_node()->__left_,
2727                         static_cast<__node_base_pointer>(__np));
2728    return __node_holder(__np, _Dp(__node_alloc(), true));
2729}
2730
2731template <class _Tp, class _Compare, class _Allocator>
2732inline _LIBCPP_INLINE_VISIBILITY
2733void
2734swap(__tree<_Tp, _Compare, _Allocator>& __x,
2735     __tree<_Tp, _Compare, _Allocator>& __y)
2736    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
2737{
2738    __x.swap(__y);
2739}
2740
2741_LIBCPP_END_NAMESPACE_STD
2742
2743_LIBCPP_POP_MACROS
2744
2745#endif // _LIBCPP___TREE
2746