libstdc++-v3/include/bits/stl_tree.h

   1 // RB tree implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 /*
  31  *
  32  * Copyright (c) 1996,1997
  33  * Silicon Graphics Computer Systems, Inc.
  34  *
  35  * Permission to use, copy, modify, distribute and sell this software
  36  * and its documentation for any purpose is hereby granted without fee,
  37  * provided that the above copyright notice appear in all copies and
  38  * that both that copyright notice and this permission notice appear
  39  * in supporting documentation.  Silicon Graphics makes no
  40  * representations about the suitability of this software for any
  41  * purpose.  It is provided "as is" without express or implied warranty.
  42  *
  43  *
  44  * Copyright (c) 1994
  45  * Hewlett-Packard Company
  46  *
  47  * Permission to use, copy, modify, distribute and sell this software
  48  * and its documentation for any purpose is hereby granted without fee,
  49  * provided that the above copyright notice appear in all copies and
  50  * that both that copyright notice and this permission notice appear
  51  * in supporting documentation.  Hewlett-Packard Company makes no
  52  * representations about the suitability of this software for any
  53  * purpose.  It is provided "as is" without express or implied warranty.
  54  *
  55  *
  56  */
  57
  58 /** @file stl_tree.h
  59  *  This is an internal header file, included by other library headers.
  60  *  You should not attempt to use it directly.
  61  */
  62
  63 #ifndef _TREE_H
  64 #define _TREE_H 1
  65
  66 #include <bits/stl_algobase.h>
  67 #include <bits/allocator.h>
  68 #include <bits/stl_construct.h>
  69 #include <bits/stl_function.h>
  70 #include <bits/cpp_type_traits.h>
  71
  72 namespace std
  73 {
  74   // Red-black tree class, designed for use in implementing STL
  75   // associative containers (set, multiset, map, and multimap). The
  76   // insertion and deletion algorithms are based on those in Cormen,
  77   // Leiserson, and Rivest, Introduction to Algorithms (MIT Press,
  78   // 1990), except that
  79   //
  80   // (1) the header cell is maintained with links not only to the root
  81   // but also to the leftmost node of the tree, to enable constant
  82   // time begin(), and to the rightmost node of the tree, to enable
  83   // linear time performance when used with the generic set algorithms
  84   // (set_union, etc.)
  85   //
  86   // (2) when a node being deleted has two children its successor node
  87   // is relinked into its place, rather than copied, so that the only
  88   // iterators invalidated are those referring to the deleted node.
  89
  90   enum _Rb_tree_color { _S_red = false, _S_black = true };
  91
  92   struct _Rb_tree_node_base
  93   {
  94     typedef _Rb_tree_node_base* _Base_ptr;
  95     typedef const _Rb_tree_node_base* _Const_Base_ptr;
  96
  97     _Rb_tree_color      _M_color;
  98     _Base_ptr           _M_parent;
  99     _Base_ptr           _M_left;
 100     _Base_ptr           _M_right;
 101
 102     static _Base_ptr
 103     _S_minimum(_Base_ptr __x)
 104     {
 105       while (__x->_M_left != 0) __x = __x->_M_left;
 106       return __x;
 107     }
 108
 109     static _Const_Base_ptr
 110     _S_minimum(_Const_Base_ptr __x)
 111     {
 112       while (__x->_M_left != 0) __x = __x->_M_left;
 113       return __x;
 114     }
 115
 116     static _Base_ptr
 117     _S_maximum(_Base_ptr __x)
 118     {
 119       while (__x->_M_right != 0) __x = __x->_M_right;
 120       return __x;
 121     }
 122
 123     static _Const_Base_ptr
 124     _S_maximum(_Const_Base_ptr __x)
 125     {
 126       while (__x->_M_right != 0) __x = __x->_M_right;
 127       return __x;
 128     }
 129   };
 130
 131   template<typename _Val>
 132     struct _Rb_tree_node : public _Rb_tree_node_base
 133     {
 134       typedef _Rb_tree_node<_Val>* _Link_type;
 135       _Val _M_value_field;
 136     };
 137
 138   _Rb_tree_node_base*
 139   _Rb_tree_increment(_Rb_tree_node_base* __x);
 140
 141   const _Rb_tree_node_base*
 142   _Rb_tree_increment(const _Rb_tree_node_base* __x);
 143
 144   _Rb_tree_node_base*
 145   _Rb_tree_decrement(_Rb_tree_node_base* __x);
 146
 147   const _Rb_tree_node_base*
 148   _Rb_tree_decrement(const _Rb_tree_node_base* __x);
 149
 150   template<typename _Tp>
 151     struct _Rb_tree_iterator
 152     {
 153       typedef _Tp  value_type;
 154       typedef _Tp& reference;
 155       typedef _Tp* pointer;
 156
 157       typedef bidirectional_iterator_tag iterator_category;
 158       typedef ptrdiff_t                  difference_type;
 159
 160       typedef _Rb_tree_iterator<_Tp>        _Self;
 161       typedef _Rb_tree_node_base::_Base_ptr _Base_ptr;
 162       typedef _Rb_tree_node<_Tp>*           _Link_type;
 163
 164       _Rb_tree_iterator()
 165       : _M_node() { }
 166
 167       explicit
 168       _Rb_tree_iterator(_Link_type __x)
 169       : _M_node(__x) { }
 170
 171       reference
 172       operator*() const
 173       { return static_cast<_Link_type>(_M_node)->_M_value_field; }
 174
 175       pointer
 176       operator->() const
 177       { return &static_cast<_Link_type>(_M_node)->_M_value_field; }
 178
 179       _Self&
 180       operator++()
 181       {
 182         _M_node = _Rb_tree_increment(_M_node);
 183         return *this;
 184       }
 185
 186       _Self
 187       operator++(int)
 188       {
 189         _Self __tmp = *this;
 190         _M_node = _Rb_tree_increment(_M_node);
 191         return __tmp;
 192       }
 193
 194       _Self&
 195       operator--()
 196       {
 197         _M_node = _Rb_tree_decrement(_M_node);
 198         return *this;
 199       }
 200
 201       _Self
 202       operator--(int)
 203       {
 204         _Self __tmp = *this;
 205         _M_node = _Rb_tree_decrement(_M_node);
 206         return __tmp;
 207       }
 208
 209       bool
 210       operator==(const _Self& __x) const
 211       { return _M_node == __x._M_node; }
 212
 213       bool
 214       operator!=(const _Self& __x) const
 215       { return _M_node != __x._M_node; }
 216
 217       _Base_ptr _M_node;
 218   };
 219
 220   template<typename _Tp>
 221     struct _Rb_tree_const_iterator
 222     {
 223       typedef _Tp        value_type;
 224       typedef const _Tp& reference;
 225       typedef const _Tp* pointer;
 226
 227       typedef _Rb_tree_iterator<_Tp> iterator;
 228
 229       typedef bidirectional_iterator_tag iterator_category;
 230       typedef ptrdiff_t                  difference_type;
 231
 232       typedef _Rb_tree_const_iterator<_Tp>        _Self;
 233       typedef _Rb_tree_node_base::_Const_Base_ptr _Base_ptr;
 234       typedef const _Rb_tree_node<_Tp>*           _Link_type;
 235
 236       _Rb_tree_const_iterator()
 237       : _M_node() { }
 238
 239       explicit
 240       _Rb_tree_const_iterator(_Link_type __x)
 241       : _M_node(__x) { }
 242
 243       _Rb_tree_const_iterator(const iterator& __it)
 244       : _M_node(__it._M_node) { }
 245
 246       reference
 247       operator*() const
 248       { return static_cast<_Link_type>(_M_node)->_M_value_field; }
 249
 250       pointer
 251       operator->() const
 252       { return &static_cast<_Link_type>(_M_node)->_M_value_field; }
 253
 254       _Self&
 255       operator++()
 256       {
 257         _M_node = _Rb_tree_increment(_M_node);
 258         return *this;
 259       }
 260
 261       _Self
 262       operator++(int)
 263       {
 264         _Self __tmp = *this;
 265         _M_node = _Rb_tree_increment(_M_node);
 266         return __tmp;
 267       }
 268
 269       _Self&
 270       operator--()
 271       {
 272         _M_node = _Rb_tree_decrement(_M_node);
 273         return *this;
 274       }
 275
 276       _Self
 277       operator--(int)
 278       {
 279         _Self __tmp = *this;
 280         _M_node = _Rb_tree_decrement(_M_node);
 281         return __tmp;
 282       }
 283
 284       bool
 285       operator==(const _Self& __x) const
 286       { return _M_node == __x._M_node; }
 287
 288       bool
 289       operator!=(const _Self& __x) const
 290       { return _M_node != __x._M_node; }
 291
 292       _Base_ptr _M_node;
 293     };
 294
 295   template<typename _Val>
 296     inline bool
 297     operator==(const _Rb_tree_iterator<_Val>& __x,
 298                const _Rb_tree_const_iterator<_Val>& __y)
 299     { return __x._M_node == __y._M_node; }
 300
 301   template<typename _Val>
 302     inline bool
 303     operator!=(const _Rb_tree_iterator<_Val>& __x,
 304                const _Rb_tree_const_iterator<_Val>& __y)
 305     { return __x._M_node != __y._M_node; }
 306
 307   void
 308   _Rb_tree_rotate_left(_Rb_tree_node_base* const __x,
 309                        _Rb_tree_node_base*& __root);
 310
 311   void
 312   _Rb_tree_rotate_right(_Rb_tree_node_base* const __x,
 313                         _Rb_tree_node_base*& __root);
 314
 315   void
 316   _Rb_tree_insert_and_rebalance(const bool __insert_left,
 317                                 _Rb_tree_node_base* __x,
 318                                 _Rb_tree_node_base* __p,
 319                                 _Rb_tree_node_base& __header);
 320
 321   _Rb_tree_node_base*
 322   _Rb_tree_rebalance_for_erase(_Rb_tree_node_base* const __z,
 323                                _Rb_tree_node_base& __header);
 324
 325
 326   template<typename _Key, typename _Val, typename _KeyOfValue,
 327            typename _Compare, typename _Alloc = allocator<_Val> >
 328     class _Rb_tree
 329     {
 330       typedef typename _Alloc::template rebind<_Rb_tree_node<_Val> >::other
 331               _Node_allocator;
 332
 333     protected:
 334       typedef _Rb_tree_node_base* _Base_ptr;
 335       typedef const _Rb_tree_node_base* _Const_Base_ptr;
 336       typedef _Rb_tree_node<_Val> _Rb_tree_node;
 337
 338     public:
 339       typedef _Key key_type;
 340       typedef _Val value_type;
 341       typedef value_type* pointer;
 342       typedef const value_type* const_pointer;
 343       typedef value_type& reference;
 344       typedef const value_type& const_reference;
 345       typedef _Rb_tree_node* _Link_type;
 346       typedef const _Rb_tree_node* _Const_Link_type;
 347       typedef size_t size_type;
 348       typedef ptrdiff_t difference_type;
 349       typedef _Alloc allocator_type;
 350
 351       allocator_type
 352       get_allocator() const
 353       { return *static_cast<const _Node_allocator*>(&this->_M_impl); }
 354
 355     protected:
 356       _Rb_tree_node*
 357       _M_get_node()
 358       { return _M_impl._Node_allocator::allocate(1); }
 359
 360       void
 361       _M_put_node(_Rb_tree_node* __p)
 362       { _M_impl._Node_allocator::deallocate(__p, 1); }
 363
 364       _Link_type
 365       _M_create_node(const value_type& __x)
 366       {
 367         _Link_type __tmp = _M_get_node();
 368         try
 369           { get_allocator().construct(&__tmp->_M_value_field, __x); }
 370         catch(...)
 371           {
 372             _M_put_node(__tmp);
 373             __throw_exception_again;
 374           }
 375         return __tmp;
 376       }
 377
 378       _Link_type
 379       _M_clone_node(_Const_Link_type __x)
 380       {
 381         _Link_type __tmp = _M_create_node(__x->_M_value_field);
 382         __tmp->_M_color = __x->_M_color;
 383         __tmp->_M_left = 0;
 384         __tmp->_M_right = 0;
 385         return __tmp;
 386       }
 387
 388       void
 389       destroy_node(_Link_type __p)
 390       {
 391         get_allocator().destroy(&__p->_M_value_field);
 392         _M_put_node(__p);
 393       }
 394
 395     protected:
 396       template<typename _Key_compare,
 397                bool _Is_pod_comparator = std::__is_pod<_Key_compare>::__value>
 398         struct _Rb_tree_impl : public _Node_allocator
 399         {
 400           _Key_compare          _M_key_compare;
 401           _Rb_tree_node_base    _M_header;
 402           size_type             _M_node_count; // Keeps track of size of tree.
 403
 404           _Rb_tree_impl(const _Node_allocator& __a = _Node_allocator(),
 405                         const _Key_compare& __comp = _Key_compare())
 406           : _Node_allocator(__a), _M_key_compare(__comp), _M_node_count(0)
 407           {
 408             this->_M_header._M_color = _S_red;
 409             this->_M_header._M_parent = 0;
 410             this->_M_header._M_left = &this->_M_header;
 411             this->_M_header._M_right = &this->_M_header;
 412           }
 413         };
 414
 415       // Specialization for _Comparison types that are not capable of
 416       // being base classes / super classes.
 417       template<typename _Key_compare>
 418         struct _Rb_tree_impl<_Key_compare, true> : public _Node_allocator
 419         {
 420           _Key_compare          _M_key_compare;
 421           _Rb_tree_node_base    _M_header;
 422           size_type             _M_node_count; // Keeps track of size of tree.
 423
 424           _Rb_tree_impl(const _Node_allocator& __a = _Node_allocator(),
 425                         const _Key_compare& __comp = _Key_compare())
 426           : _Node_allocator(__a), _M_key_compare(__comp), _M_node_count(0)
 427           {
 428             this->_M_header._M_color = _S_red;
 429             this->_M_header._M_parent = 0;
 430             this->_M_header._M_left = &this->_M_header;
 431             this->_M_header._M_right = &this->_M_header;
 432           }
 433         };
 434
 435       _Rb_tree_impl<_Compare> _M_impl;
 436
 437     protected:
 438       _Base_ptr&
 439       _M_root()
 440       { return this->_M_impl._M_header._M_parent; }
 441
 442       _Const_Base_ptr
 443       _M_root() const
 444       { return this->_M_impl._M_header._M_parent; }
 445
 446       _Base_ptr&
 447       _M_leftmost()
 448       { return this->_M_impl._M_header._M_left; }
 449
 450       _Const_Base_ptr
 451       _M_leftmost() const
 452       { return this->_M_impl._M_header._M_left; }
 453
 454       _Base_ptr&
 455       _M_rightmost()
 456       { return this->_M_impl._M_header._M_right; }
 457
 458       _Const_Base_ptr
 459       _M_rightmost() const
 460       { return this->_M_impl._M_header._M_right; }
 461
 462       _Link_type
 463       _M_begin()
 464       { return static_cast<_Link_type>(this->_M_impl._M_header._M_parent); }
 465
 466       _Const_Link_type
 467       _M_begin() const
 468       {
 469         return static_cast<_Const_Link_type>
 470           (this->_M_impl._M_header._M_parent);
 471       }
 472
 473       _Link_type
 474       _M_end()
 475       { return static_cast<_Link_type>(&this->_M_impl._M_header); }
 476
 477       _Const_Link_type
 478       _M_end() const
 479       { return static_cast<_Const_Link_type>(&this->_M_impl._M_header); }
 480
 481       static const_reference
 482       _S_value(_Const_Link_type __x)
 483       { return __x->_M_value_field; }
 484
 485       static const _Key&
 486       _S_key(_Const_Link_type __x)
 487       { return _KeyOfValue()(_S_value(__x)); }
 488
 489       static _Link_type
 490       _S_left(_Base_ptr __x)
 491       { return static_cast<_Link_type>(__x->_M_left); }
 492
 493       static _Const_Link_type
 494       _S_left(_Const_Base_ptr __x)
 495       { return static_cast<_Const_Link_type>(__x->_M_left); }
 496
 497       static _Link_type
 498       _S_right(_Base_ptr __x)
 499       { return static_cast<_Link_type>(__x->_M_right); }
 500
 501       static _Const_Link_type
 502       _S_right(_Const_Base_ptr __x)
 503       { return static_cast<_Const_Link_type>(__x->_M_right); }
 504
 505       static const_reference
 506       _S_value(_Const_Base_ptr __x)
 507       { return static_cast<_Const_Link_type>(__x)->_M_value_field; }
 508
 509       static const _Key&
 510       _S_key(_Const_Base_ptr __x)
 511       { return _KeyOfValue()(_S_value(__x)); }
 512
 513       static _Base_ptr
 514       _S_minimum(_Base_ptr __x)
 515       { return _Rb_tree_node_base::_S_minimum(__x); }
 516
 517       static _Const_Base_ptr
 518       _S_minimum(_Const_Base_ptr __x)
 519       { return _Rb_tree_node_base::_S_minimum(__x); }
 520
 521       static _Base_ptr
 522       _S_maximum(_Base_ptr __x)
 523       { return _Rb_tree_node_base::_S_maximum(__x); }
 524
 525       static _Const_Base_ptr
 526       _S_maximum(_Const_Base_ptr __x)
 527       { return _Rb_tree_node_base::_S_maximum(__x); }
 528
 529     public:
 530       typedef _Rb_tree_iterator<value_type>       iterator;
 531       typedef _Rb_tree_const_iterator<value_type> const_iterator;
 532
 533       typedef std::reverse_iterator<iterator>       reverse_iterator;
 534       typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
 535
 536     private:
 537       iterator
 538       _M_insert(_Base_ptr __x, _Base_ptr __y, const value_type& __v);
 539
 540       _Link_type
 541       _M_copy(_Const_Link_type __x, _Link_type __p);
 542
 543       void
 544       _M_erase(_Link_type __x);
 545
 546     public:
 547       // allocation/deallocation
 548       _Rb_tree()
 549       { }
 550
 551       _Rb_tree(const _Compare& __comp)
 552       : _M_impl(allocator_type(), __comp)
 553       { }
 554
 555       _Rb_tree(const _Compare& __comp, const allocator_type& __a)
 556       : _M_impl(__a, __comp)
 557       { }
 558
 559       _Rb_tree(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x)
 560       : _M_impl(__x.get_allocator(), __x._M_impl._M_key_compare)
 561       {
 562         if (__x._M_root() != 0)
 563           {
 564             _M_root() = _M_copy(__x._M_begin(), _M_end());
 565             _M_leftmost() = _S_minimum(_M_root());
 566             _M_rightmost() = _S_maximum(_M_root());
 567             _M_impl._M_node_count = __x._M_impl._M_node_count;
 568           }
 569       }
 570
 571       ~_Rb_tree()
 572       { _M_erase(_M_begin()); }
 573
 574       _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&
 575       operator=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x);
 576
 577       // Accessors.
 578       _Compare
 579       key_comp() const
 580       { return _M_impl._M_key_compare; }
 581
 582       iterator
 583       begin()
 584       {
 585         return iterator(static_cast<_Link_type>
 586                         (this->_M_impl._M_header._M_left));
 587       }
 588
 589       const_iterator
 590       begin() const
 591       {
 592         return const_iterator(static_cast<_Const_Link_type>
 593                               (this->_M_impl._M_header._M_left));
 594       }
 595
 596       iterator
 597       end()
 598       { return iterator(static_cast<_Link_type>(&this->_M_impl._M_header)); }
 599
 600       const_iterator
 601       end() const
 602       {
 603         return const_iterator(static_cast<_Const_Link_type>
 604                               (&this->_M_impl._M_header));
 605       }
 606
 607       reverse_iterator
 608       rbegin()
 609       { return reverse_iterator(end()); }
 610
 611       const_reverse_iterator
 612       rbegin() const
 613       { return const_reverse_iterator(end()); }
 614
 615       reverse_iterator
 616       rend()
 617       { return reverse_iterator(begin()); }
 618
 619       const_reverse_iterator
 620       rend() const
 621       { return const_reverse_iterator(begin()); }
 622
 623       bool
 624       empty() const
 625       { return _M_impl._M_node_count == 0; }
 626
 627       size_type
 628       size() const
 629       { return _M_impl._M_node_count; }
 630
 631       size_type
 632       max_size() const
 633       { return size_type(-1); }
 634
 635       void
 636       swap(_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __t);
 637
 638       // Insert/erase.
 639       pair<iterator,bool>
 640       insert_unique(const value_type& __x);
 641
 642       iterator
 643       insert_equal(const value_type& __x);
 644
 645       iterator
 646       insert_unique(iterator __position, const value_type& __x);
 647
 648       iterator
 649       insert_equal(iterator __position, const value_type& __x);
 650
 651       template<typename _InputIterator>
 652         void
 653         insert_unique(_InputIterator __first, _InputIterator __last);
 654
 655       template<typename _InputIterator>
 656         void
 657         insert_equal(_InputIterator __first, _InputIterator __last);
 658
 659       void
 660       erase(iterator __position);
 661
 662       size_type
 663       erase(const key_type& __x);
 664
 665       void
 666       erase(iterator __first, iterator __last);
 667
 668       void
 669       erase(const key_type* __first, const key_type* __last);
 670
 671       void
 672       clear()
 673       {
 674         _M_erase(_M_begin());
 675         _M_leftmost() = _M_end();
 676         _M_root() = 0;
 677         _M_rightmost() = _M_end();
 678         _M_impl._M_node_count = 0;
 679       }
 680
 681       // Set operations.
 682       iterator
 683       find(const key_type& __x);
 684
 685       const_iterator
 686       find(const key_type& __x) const;
 687
 688       size_type
 689       count(const key_type& __x) const;
 690
 691       iterator
 692       lower_bound(const key_type& __x);
 693
 694       const_iterator
 695       lower_bound(const key_type& __x) const;
 696
 697       iterator
 698       upper_bound(const key_type& __x);
 699
 700       const_iterator
 701       upper_bound(const key_type& __x) const;
 702
 703       pair<iterator,iterator>
 704       equal_range(const key_type& __x);
 705
 706       pair<const_iterator, const_iterator>
 707       equal_range(const key_type& __x) const;
 708
 709       // Debugging.
 710       bool
 711       __rb_verify() const;
 712     };
 713
 714   template<typename _Key, typename _Val, typename _KeyOfValue,
 715            typename _Compare, typename _Alloc>
 716     inline bool
 717     operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
 718                const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
 719     {
 720       return __x.size() == __y.size()
 721              && std::equal(__x.begin(), __x.end(), __y.begin());
 722     }
 723
 724   template<typename _Key, typename _Val, typename _KeyOfValue,
 725            typename _Compare, typename _Alloc>
 726     inline bool
 727     operator<(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
 728               const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
 729     {
 730       return std::lexicographical_compare(__x.begin(), __x.end(),
 731                                           __y.begin(), __y.end());
 732     }
 733
 734   template<typename _Key, typename _Val, typename _KeyOfValue,
 735            typename _Compare, typename _Alloc>
 736     inline bool
 737     operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
 738                const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
 739     { return !(__x == __y); }
 740
 741   template<typename _Key, typename _Val, typename _KeyOfValue,
 742            typename _Compare, typename _Alloc>
 743     inline bool
 744     operator>(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
 745               const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
 746     { return __y < __x; }
 747
 748   template<typename _Key, typename _Val, typename _KeyOfValue,
 749            typename _Compare, typename _Alloc>
 750     inline bool
 751     operator<=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
 752                const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
 753     { return !(__y < __x); }
 754
 755   template<typename _Key, typename _Val, typename _KeyOfValue,
 756            typename _Compare, typename _Alloc>
 757     inline bool
 758     operator>=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
 759                const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
 760     { return !(__x < __y); }
 761
 762   template<typename _Key, typename _Val, typename _KeyOfValue,
 763            typename _Compare, typename _Alloc>
 764     inline void
 765     swap(_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
 766          _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
 767     { __x.swap(__y); }
 768
 769   template<typename _Key, typename _Val, typename _KeyOfValue,
 770            typename _Compare, typename _Alloc>
 771     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&
 772     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
 773     operator=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x)
 774     {
 775       if (this != &__x)
 776         {
 777           // Note that _Key may be a constant type.
 778           clear();
 779           _M_impl._M_key_compare = __x._M_impl._M_key_compare;
 780           if (__x._M_root() != 0)
 781             {
 782               _M_root() = _M_copy(__x._M_begin(), _M_end());
 783               _M_leftmost() = _S_minimum(_M_root());
 784               _M_rightmost() = _S_maximum(_M_root());
 785               _M_impl._M_node_count = __x._M_impl._M_node_count;
 786             }
 787         }
 788       return *this;
 789     }
 790
 791   template<typename _Key, typename _Val, typename _KeyOfValue,
 792            typename _Compare, typename _Alloc>
 793     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
 794     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
 795     _M_insert(_Base_ptr __x, _Base_ptr __p, const _Val& __v)
 796     {
 797       bool __insert_left = (__x != 0 || __p == _M_end()
 798                             || _M_impl._M_key_compare(_KeyOfValue()(__v),
 799                                                       _S_key(__p)));
 800
 801       _Link_type __z = _M_create_node(__v);
 802
 803       _Rb_tree_insert_and_rebalance(__insert_left, __z, __p,
 804                                     this->_M_impl._M_header);
 805       ++_M_impl._M_node_count;
 806       return iterator(__z);
 807     }
 808
 809   template<typename _Key, typename _Val, typename _KeyOfValue,
 810            typename _Compare, typename _Alloc>
 811     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
 812     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
 813     insert_equal(const _Val& __v)
 814     {
 815       _Link_type __x = _M_begin();
 816       _Link_type __y = _M_end();
 817       while (__x != 0)
 818         {
 819           __y = __x;
 820           __x = _M_impl._M_key_compare(_KeyOfValue()(__v), _S_key(__x)) ?
 821                 _S_left(__x) : _S_right(__x);
 822         }
 823       return _M_insert(__x, __y, __v);
 824     }
 825
 826   template<typename _Key, typename _Val, typename _KeyOfValue,
 827            typename _Compare, typename _Alloc>
 828     void
 829     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
 830     swap(_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __t)
 831     {
 832       if (_M_root() == 0)
 833       {
 834         if (__t._M_root() != 0)
 835         {
 836           _M_root() = __t._M_root();
 837           _M_leftmost() = __t._M_leftmost();
 838           _M_rightmost() = __t._M_rightmost();
 839           _M_root()->_M_parent = _M_end();
 840
 841           __t._M_root() = 0;
 842           __t._M_leftmost() = __t._M_end();
 843           __t._M_rightmost() = __t._M_end();
 844         }
 845       }
 846       else if (__t._M_root() == 0)
 847       {
 848         __t._M_root() = _M_root();
 849         __t._M_leftmost() = _M_leftmost();
 850         __t._M_rightmost() = _M_rightmost();
 851         __t._M_root()->_M_parent = __t._M_end();
 852
 853         _M_root() = 0;
 854         _M_leftmost() = _M_end();
 855         _M_rightmost() = _M_end();
 856       }
 857       else
 858       {
 859         std::swap(_M_root(),__t._M_root());
 860         std::swap(_M_leftmost(),__t._M_leftmost());
 861         std::swap(_M_rightmost(),__t._M_rightmost());
 862
 863         _M_root()->_M_parent = _M_end();
 864         __t._M_root()->_M_parent = __t._M_end();
 865       }
 866       // No need to swap header's color as it does not change.
 867       std::swap(this->_M_impl._M_node_count, __t._M_impl._M_node_count);
 868       std::swap(this->_M_impl._M_key_compare, __t._M_impl._M_key_compare);
 869     }
 870
 871   template<typename _Key, typename _Val, typename _KeyOfValue,
 872            typename _Compare, typename _Alloc>
 873     pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
 874                            _Compare, _Alloc>::iterator, bool>
 875     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
 876     insert_unique(const _Val& __v)
 877     {
 878       _Link_type __x = _M_begin();
 879       _Link_type __y = _M_end();
 880       bool __comp = true;
 881       while (__x != 0)
 882         {
 883           __y = __x;
 884           __comp = _M_impl._M_key_compare(_KeyOfValue()(__v), _S_key(__x));
 885           __x = __comp ? _S_left(__x) : _S_right(__x);
 886         }
 887       iterator __j = iterator(__y);
 888       if (__comp)
 889         if (__j == begin())
 890           return pair<iterator,bool>(_M_insert(__x, __y, __v), true);
 891         else
 892           --__j;
 893       if (_M_impl._M_key_compare(_S_key(__j._M_node), _KeyOfValue()(__v)))
 894         return pair<iterator, bool>(_M_insert(__x, __y, __v), true);
 895       return pair<iterator, bool>(__j, false);
 896     }
 897
 898   template<typename _Key, typename _Val, typename _KeyOfValue,
 899            typename _Compare, typename _Alloc>
 900     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
 901     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
 902     insert_unique(iterator __position, const _Val& __v)
 903     {
 904       // end()
 905       if (__position._M_node == _M_end())
 906         {
 907           if (size() > 0
 908               && _M_impl._M_key_compare(_S_key(_M_rightmost()),
 909                                         _KeyOfValue()(__v)))
 910             return _M_insert(0, _M_rightmost(), __v);
 911           else
 912             return insert_unique(__v).first;
 913         }
 914       else if (_M_impl._M_key_compare(_KeyOfValue()(__v),
 915                                       _S_key(__position._M_node)))
 916         {
 917           // First, try before...
 918           iterator __before = __position;
 919           if (__position._M_node == _M_leftmost()) // begin()
 920             return _M_insert(_M_leftmost(), _M_leftmost(), __v);
 921           else if (_M_impl._M_key_compare(_S_key((--__before)._M_node),
 922                                           _KeyOfValue()(__v)))
 923             {
 924               if (_S_right(__before._M_node) == 0)
 925                 return _M_insert(0, __before._M_node, __v);
 926               else
 927                 return _M_insert(__position._M_node,
 928                                  __position._M_node, __v);
 929             }
 930           else
 931             return insert_unique(__v).first;
 932         }
 933       else if (_M_impl._M_key_compare(_S_key(__position._M_node),
 934                                       _KeyOfValue()(__v)))
 935         {
 936           // ... then try after.
 937           iterator __after = __position;
 938           if (__position._M_node == _M_rightmost())
 939             return _M_insert(0, _M_rightmost(), __v);
 940           else if (_M_impl._M_key_compare(_KeyOfValue()(__v),
 941                                           _S_key((++__after)._M_node)))
 942             {
 943               if (_S_right(__position._M_node) == 0)
 944                 return _M_insert(0, __position._M_node, __v);
 945               else
 946                 return _M_insert(__after._M_node, __after._M_node, __v);
 947             }
 948           else
 949             return insert_unique(__v).first;
 950         }
 951       else
 952         return __position; // Equivalent keys.
 953     }
 954
 955   template<typename _Key, typename _Val, typename _KeyOfValue,
 956            typename _Compare, typename _Alloc>
 957     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
 958     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
 959     insert_equal(iterator __position, const _Val& __v)
 960     {
 961       // end()
 962       if (__position._M_node == _M_end())
 963         {
 964           if (size() > 0
 965               && !_M_impl._M_key_compare(_KeyOfValue()(__v),
 966                                          _S_key(_M_rightmost())))
 967             return _M_insert(0, _M_rightmost(), __v);
 968           else
 969             return insert_equal(__v);
 970         }
 971       else if (!_M_impl._M_key_compare(_S_key(__position._M_node),
 972                                        _KeyOfValue()(__v)))
 973         {
 974           // First, try before...
 975           iterator __before = __position;
 976           if (__position._M_node == _M_leftmost()) // begin()
 977             return _M_insert(_M_leftmost(), _M_leftmost(), __v);
 978           else if (!_M_impl._M_key_compare(_KeyOfValue()(__v),
 979                                            _S_key((--__before)._M_node)))
 980             {
 981               if (_S_right(__before._M_node) == 0)
 982                 return _M_insert(0, __before._M_node, __v);
 983               else
 984                 return _M_insert(__position._M_node,
 985                                  __position._M_node, __v);
 986             }
 987           else
 988             return insert_equal(__v);
 989         }
 990       else
 991         {
 992           // ... then try after.
 993           iterator __after = __position;
 994           if (__position._M_node == _M_rightmost())
 995             return _M_insert(0, _M_rightmost(), __v);
 996           else if (!_M_impl._M_key_compare(_S_key((++__after)._M_node),
 997                                            _KeyOfValue()(__v)))
 998             {
 999               if (_S_right(__position._M_node) == 0)
1000                 return _M_insert(0, __position._M_node, __v);
1001               else
1002                 return _M_insert(__after._M_node, __after._M_node, __v);
1003             }
1004           else
1005             return insert_equal(__v);
1006         }
1007     }
1008
1009   template<typename _Key, typename _Val, typename _KoV,
1010            typename _Cmp, typename _Alloc>
1011     template<class _II>
1012       void
1013       _Rb_tree<_Key, _Val, _KoV, _Cmp, _Alloc>::
1014       insert_equal(_II __first, _II __last)
1015       {
1016         for (; __first != __last; ++__first)
1017           insert_equal(end(), *__first);
1018       }
1019
1020   template<typename _Key, typename _Val, typename _KoV,
1021            typename _Cmp, typename _Alloc>
1022     template<class _II>
1023     void
1024     _Rb_tree<_Key, _Val, _KoV, _Cmp, _Alloc>::
1025     insert_unique(_II __first, _II __last)
1026     {
1027       for (; __first != __last; ++__first)
1028         insert_unique(end(), *__first);
1029     }
1030
1031   template<typename _Key, typename _Val, typename _KeyOfValue,
1032            typename _Compare, typename _Alloc>
1033     inline void
1034     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1035     erase(iterator __position)
1036     {
1037       _Link_type __y =
1038         static_cast<_Link_type>(_Rb_tree_rebalance_for_erase
1039                                 (__position._M_node,
1040                                  this->_M_impl._M_header));
1041       destroy_node(__y);
1042       --_M_impl._M_node_count;
1043     }
1044
1045   template<typename _Key, typename _Val, typename _KeyOfValue,
1046            typename _Compare, typename _Alloc>
1047     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::size_type
1048     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1049     erase(const _Key& __x)
1050     {
1051       pair<iterator,iterator> __p = equal_range(__x);
1052       size_type __n = std::distance(__p.first, __p.second);
1053       erase(__p.first, __p.second);
1054       return __n;
1055     }
1056
1057   template<typename _Key, typename _Val, typename _KoV,
1058            typename _Compare, typename _Alloc>
1059     typename _Rb_tree<_Key, _Val, _KoV, _Compare, _Alloc>::_Link_type
1060     _Rb_tree<_Key, _Val, _KoV, _Compare, _Alloc>::
1061     _M_copy(_Const_Link_type __x, _Link_type __p)
1062     {
1063       // Structural copy.  __x and __p must be non-null.
1064       _Link_type __top = _M_clone_node(__x);
1065       __top->_M_parent = __p;
1066
1067       try
1068         {
1069           if (__x->_M_right)
1070             __top->_M_right = _M_copy(_S_right(__x), __top);
1071           __p = __top;
1072           __x = _S_left(__x);
1073
1074           while (__x != 0)
1075             {
1076               _Link_type __y = _M_clone_node(__x);
1077               __p->_M_left = __y;
1078               __y->_M_parent = __p;
1079               if (__x->_M_right)
1080                 __y->_M_right = _M_copy(_S_right(__x), __y);
1081               __p = __y;
1082               __x = _S_left(__x);
1083             }
1084         }
1085       catch(...)
1086         {
1087           _M_erase(__top);
1088           __throw_exception_again;
1089         }
1090       return __top;
1091     }
1092
1093   template<typename _Key, typename _Val, typename _KeyOfValue,
1094            typename _Compare, typename _Alloc>
1095     void
1096     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1097     _M_erase(_Link_type __x)
1098     {
1099       // Erase without rebalancing.
1100       while (__x != 0)
1101         {
1102           _M_erase(_S_right(__x));
1103           _Link_type __y = _S_left(__x);
1104           destroy_node(__x);
1105           __x = __y;
1106         }
1107     }
1108
1109   template<typename _Key, typename _Val, typename _KeyOfValue,
1110            typename _Compare, typename _Alloc>
1111     void
1112     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1113     erase(iterator __first, iterator __last)
1114     {
1115       if (__first == begin() && __last == end())
1116         clear();
1117       else
1118         while (__first != __last)
1119           erase(__first++);
1120     }
1121
1122   template<typename _Key, typename _Val, typename _KeyOfValue,
1123            typename _Compare, typename _Alloc>
1124     void
1125     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1126     erase(const _Key* __first, const _Key* __last)
1127     {
1128       while (__first != __last)
1129         erase(*__first++);
1130     }
1131
1132   template<typename _Key, typename _Val, typename _KeyOfValue,
1133            typename _Compare, typename _Alloc>
1134     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
1135     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1136     find(const _Key& __k)
1137     {
1138       _Link_type __x = _M_begin(); // Current node.
1139       _Link_type __y = _M_end(); // Last node which is not less than __k.
1140
1141       while (__x != 0)
1142         if (!_M_impl._M_key_compare(_S_key(__x), __k))
1143           __y = __x, __x = _S_left(__x);
1144         else
1145           __x = _S_right(__x);
1146
1147       iterator __j = iterator(__y);
1148       return (__j == end()
1149               || _M_impl._M_key_compare(__k,
1150                                         _S_key(__j._M_node))) ? end() : __j;
1151     }
1152
1153   template<typename _Key, typename _Val, typename _KeyOfValue,
1154            typename _Compare, typename _Alloc>
1155     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::const_iterator
1156     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1157     find(const _Key& __k) const
1158     {
1159       _Const_Link_type __x = _M_begin(); // Current node.
1160       _Const_Link_type __y = _M_end(); // Last node which is not less than __k.
1161
1162      while (__x != 0)
1163        {
1164          if (!_M_impl._M_key_compare(_S_key(__x), __k))
1165            __y = __x, __x = _S_left(__x);
1166          else
1167            __x = _S_right(__x);
1168        }
1169      const_iterator __j = const_iterator(__y);
1170      return (__j == end()
1171              || _M_impl._M_key_compare(__k,
1172                                        _S_key(__j._M_node))) ? end() : __j;
1173     }
1174
1175   template<typename _Key, typename _Val, typename _KeyOfValue,
1176            typename _Compare, typename _Alloc>
1177     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::size_type
1178     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1179     count(const _Key& __k) const
1180     {
1181       pair<const_iterator, const_iterator> __p = equal_range(__k);
1182       const size_type __n = std::distance(__p.first, __p.second);
1183       return __n;
1184     }
1185
1186   template<typename _Key, typename _Val, typename _KeyOfValue,
1187            typename _Compare, typename _Alloc>
1188     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
1189     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1190     lower_bound(const _Key& __k)
1191     {
1192       _Link_type __x = _M_begin(); // Current node.
1193       _Link_type __y = _M_end(); // Last node which is not less than __k.
1194
1195       while (__x != 0)
1196         if (!_M_impl._M_key_compare(_S_key(__x), __k))
1197           __y = __x, __x = _S_left(__x);
1198         else
1199           __x = _S_right(__x);
1200
1201       return iterator(__y);
1202     }
1203
1204   template<typename _Key, typename _Val, typename _KeyOfValue,
1205            typename _Compare, typename _Alloc>
1206     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::const_iterator
1207     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1208     lower_bound(const _Key& __k) const
1209     {
1210       _Const_Link_type __x = _M_begin(); // Current node.
1211       _Const_Link_type __y = _M_end(); // Last node which is not less than __k.
1212
1213       while (__x != 0)
1214         if (!_M_impl._M_key_compare(_S_key(__x), __k))
1215           __y = __x, __x = _S_left(__x);
1216         else
1217           __x = _S_right(__x);
1218
1219       return const_iterator(__y);
1220     }
1221
1222   template<typename _Key, typename _Val, typename _KeyOfValue,
1223            typename _Compare, typename _Alloc>
1224     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
1225     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1226     upper_bound(const _Key& __k)
1227     {
1228       _Link_type __x = _M_begin(); // Current node.
1229       _Link_type __y = _M_end(); // Last node which is greater than __k.
1230
1231       while (__x != 0)
1232         if (_M_impl._M_key_compare(__k, _S_key(__x)))
1233           __y = __x, __x = _S_left(__x);
1234         else
1235           __x = _S_right(__x);
1236
1237       return iterator(__y);
1238     }
1239
1240   template<typename _Key, typename _Val, typename _KeyOfValue,
1241            typename _Compare, typename _Alloc>
1242     typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::const_iterator
1243     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1244     upper_bound(const _Key& __k) const
1245     {
1246       _Const_Link_type __x = _M_begin(); // Current node.
1247       _Const_Link_type __y = _M_end(); // Last node which is greater than __k.
1248
1249       while (__x != 0)
1250         if (_M_impl._M_key_compare(__k, _S_key(__x)))
1251           __y = __x, __x = _S_left(__x);
1252         else
1253           __x = _S_right(__x);
1254
1255       return const_iterator(__y);
1256     }
1257
1258   template<typename _Key, typename _Val, typename _KeyOfValue,
1259            typename _Compare, typename _Alloc>
1260     inline
1261     pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
1262                            _Compare, _Alloc>::iterator,
1263          typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator>
1264     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
1265     equal_range(const _Key& __k)
1266     { return pair<iterator, iterator>(lower_bound(__k), upper_bound(__k)); }
1267
1268   template<typename _Key, typename _Val, typename _KoV,
1269            typename _Compare, typename _Alloc>
1270     inline
1271     pair<typename _Rb_tree<_Key, _Val, _KoV,
1272                            _Compare, _Alloc>::const_iterator,
1273          typename _Rb_tree<_Key, _Val, _KoV, _Compare, _Alloc>::const_iterator>
1274     _Rb_tree<_Key, _Val, _KoV, _Compare, _Alloc>::
1275     equal_range(const _Key& __k) const
1276     { return pair<const_iterator, const_iterator>(lower_bound(__k),
1277                                                   upper_bound(__k)); }
1278
1279   unsigned int
1280   _Rb_tree_black_count(const _Rb_tree_node_base* __node,
1281                        const _Rb_tree_node_base* __root);
1282
1283   template<typename _Key, typename _Val, typename _KeyOfValue,
1284            typename _Compare, typename _Alloc>
1285     bool
1286     _Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::__rb_verify() const
1287     {
1288       if (_M_impl._M_node_count == 0 || begin() == end())
1289         return _M_impl._M_node_count == 0 && begin() == end()
1290                && this->_M_impl._M_header._M_left == _M_end()
1291                && this->_M_impl._M_header._M_right == _M_end();
1292
1293       unsigned int __len = _Rb_tree_black_count(_M_leftmost(), _M_root());
1294       for (const_iterator __it = begin(); __it != end(); ++__it)
1295         {
1296           _Const_Link_type __x = static_cast<_Const_Link_type>(__it._M_node);
1297           _Const_Link_type __L = _S_left(__x);
1298           _Const_Link_type __R = _S_right(__x);
1299
1300           if (__x->_M_color == _S_red)
1301             if ((__L && __L->_M_color == _S_red)
1302                 || (__R && __R->_M_color == _S_red))
1303               return false;
1304
1305           if (__L && _M_impl._M_key_compare(_S_key(__x), _S_key(__L)))
1306             return false;
1307           if (__R && _M_impl._M_key_compare(_S_key(__R), _S_key(__x)))
1308             return false;
1309
1310           if (!__L && !__R && _Rb_tree_black_count(__x, _M_root()) != __len)
1311             return false;
1312         }
1313
1314       if (_M_leftmost() != _Rb_tree_node_base::_S_minimum(_M_root()))
1315         return false;
1316       if (_M_rightmost() != _Rb_tree_node_base::_S_maximum(_M_root()))
1317         return false;
1318       return true;
1319     }
1320 } // namespace std
1321
1322 #endif