[multiple changes]

[gcc.git] / libstdc++-v3 / include / bits / stl_tree.h

// RB tree implementation -*- C++ -*-

// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
// 2009, 2010
// Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/*
 *
 * Copyright (c) 1996,1997
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 */

/** @file stl_tree.h
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

#ifndef _STL_TREE_H
#define _STL_TREE_H 1

#include <bits/stl_algobase.h>
#include <bits/allocator.h>
#include <bits/stl_function.h>
#include <bits/cpp_type_traits.h>

_GLIBCXX_BEGIN_NAMESPACE(std)

  // Red-black tree class, designed for use in implementing STL
  // associative containers (set, multiset, map, and multimap). The
  // insertion and deletion algorithms are based on those in Cormen,
  // Leiserson, and Rivest, Introduction to Algorithms (MIT Press,
  // 1990), except that
  //
  // (1) the header cell is maintained with links not only to the root
  // but also to the leftmost node of the tree, to enable constant
  // time begin(), and to the rightmost node of the tree, to enable
  // linear time performance when used with the generic set algorithms
  // (set_union, etc.)
  // 
  // (2) when a node being deleted has two children its successor node
  // is relinked into its place, rather than copied, so that the only
  // iterators invalidated are those referring to the deleted node.

  enum _Rb_tree_color { _S_red = false, _S_black = true };

  struct _Rb_tree_node_base
  {
    typedef _Rb_tree_node_base* _Base_ptr;
    typedef const _Rb_tree_node_base* _Const_Base_ptr;

    _Rb_tree_color      _M_color;
    _Base_ptr           _M_parent;
    _Base_ptr           _M_left;
    _Base_ptr           _M_right;

    static _Base_ptr
    _S_minimum(_Base_ptr __x)
    {
      while (__x->_M_left != 0) __x = __x->_M_left;
      return __x;
    }

    static _Const_Base_ptr
    _S_minimum(_Const_Base_ptr __x)
    {
      while (__x->_M_left != 0) __x = __x->_M_left;
      return __x;
    }

    static _Base_ptr
    _S_maximum(_Base_ptr __x)
    {
      while (__x->_M_right != 0) __x = __x->_M_right;
      return __x;
    }

    static _Const_Base_ptr
    _S_maximum(_Const_Base_ptr __x)
    {
      while (__x->_M_right != 0) __x = __x->_M_right;
      return __x;
    }
  };

  template<typename _Val>
    struct _Rb_tree_node : public _Rb_tree_node_base
    {
      typedef _Rb_tree_node<_Val>* _Link_type;
      _Val _M_value_field;

#ifdef __GXX_EXPERIMENTAL_CXX0X__
      template<typename... _Args>
        _Rb_tree_node(_Args&&... __args)
        : _Rb_tree_node_base(),
          _M_value_field(std::forward<_Args>(__args)...) { }
#endif
    };

  _GLIBCXX_PURE _Rb_tree_node_base*
  _Rb_tree_increment(_Rb_tree_node_base* __x) throw ();

  _GLIBCXX_PURE const _Rb_tree_node_base*
  _Rb_tree_increment(const _Rb_tree_node_base* __x) throw ();

  _GLIBCXX_PURE _Rb_tree_node_base*
  _Rb_tree_decrement(_Rb_tree_node_base* __x) throw ();

  _GLIBCXX_PURE const _Rb_tree_node_base*
  _Rb_tree_decrement(const _Rb_tree_node_base* __x) throw ();

  template<typename _Tp>
    struct _Rb_tree_iterator
    {
      typedef _Tp  value_type;
      typedef _Tp& reference;
      typedef _Tp* pointer;

      typedef bidirectional_iterator_tag iterator_category;
      typedef ptrdiff_t                  difference_type;

      typedef _Rb_tree_iterator<_Tp>        _Self;
      typedef _Rb_tree_node_base::_Base_ptr _Base_ptr;
      typedef _Rb_tree_node<_Tp>*           _Link_type;

      _Rb_tree_iterator()
      : _M_node() { }

      explicit
      _Rb_tree_iterator(_Link_type __x)
      : _M_node(__x) { }

      reference
      operator*() const
      { return static_cast<_Link_type>(_M_node)->_M_value_field; }

      pointer
      operator->() const
      { return std::__addressof(static_cast<_Link_type>
                                (_M_node)->_M_value_field); }

      _Self&
      operator++()
      {
        _M_node = _Rb_tree_increment(_M_node);
        return *this;
      }

      _Self
      operator++(int)
      {
        _Self __tmp = *this;
        _M_node = _Rb_tree_increment(_M_node);
        return __tmp;
      }

      _Self&
      operator--()
      {
        _M_node = _Rb_tree_decrement(_M_node);
        return *this;
      }

      _Self
      operator--(int)
      {
        _Self __tmp = *this;
        _M_node = _Rb_tree_decrement(_M_node);
        return __tmp;
      }

      bool
      operator==(const _Self& __x) const
      { return _M_node == __x._M_node; }

      bool
      operator!=(const _Self& __x) const
      { return _M_node != __x._M_node; }

      _Base_ptr _M_node;
  };

  template<typename _Tp>
    struct _Rb_tree_const_iterator
    {
      typedef _Tp        value_type;
      typedef const _Tp& reference;
      typedef const _Tp* pointer;

      typedef _Rb_tree_iterator<_Tp> iterator;

      typedef bidirectional_iterator_tag iterator_category;
      typedef ptrdiff_t                  difference_type;

      typedef _Rb_tree_const_iterator<_Tp>        _Self;
      typedef _Rb_tree_node_base::_Const_Base_ptr _Base_ptr;
      typedef const _Rb_tree_node<_Tp>*           _Link_type;

      _Rb_tree_const_iterator()
      : _M_node() { }

      explicit
      _Rb_tree_const_iterator(_Link_type __x)
      : _M_node(__x) { }

      _Rb_tree_const_iterator(const iterator& __it)
      : _M_node(__it._M_node) { }

      reference
      operator*() const
      { return static_cast<_Link_type>(_M_node)->_M_value_field; }

      pointer
      operator->() const
      { return std::__addressof(static_cast<_Link_type>
                                (_M_node)->_M_value_field); }

      _Self&
      operator++()
      {
        _M_node = _Rb_tree_increment(_M_node);
        return *this;
      }

      _Self
      operator++(int)
      {
        _Self __tmp = *this;
        _M_node = _Rb_tree_increment(_M_node);
        return __tmp;
      }

      _Self&
      operator--()
      {
        _M_node = _Rb_tree_decrement(_M_node);
        return *this;
      }

      _Self
      operator--(int)
      {
        _Self __tmp = *this;
        _M_node = _Rb_tree_decrement(_M_node);
        return __tmp;
      }

      bool
      operator==(const _Self& __x) const
      { return _M_node == __x._M_node; }

      bool
      operator!=(const _Self& __x) const
      { return _M_node != __x._M_node; }

      _Base_ptr _M_node;
    };

  template<typename _Val>
    inline bool
    operator==(const _Rb_tree_iterator<_Val>& __x,
               const _Rb_tree_const_iterator<_Val>& __y)
    { return __x._M_node == __y._M_node; }

  template<typename _Val>
    inline bool
    operator!=(const _Rb_tree_iterator<_Val>& __x,
               const _Rb_tree_const_iterator<_Val>& __y)
    { return __x._M_node != __y._M_node; }

  void
  _Rb_tree_insert_and_rebalance(const bool __insert_left,
                                _Rb_tree_node_base* __x,
                                _Rb_tree_node_base* __p,
                                _Rb_tree_node_base& __header) throw ();

  _Rb_tree_node_base*
  _Rb_tree_rebalance_for_erase(_Rb_tree_node_base* const __z,
                               _Rb_tree_node_base& __header) throw ();


  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc = allocator<_Val> >
    class _Rb_tree
    {
      typedef typename _Alloc::template rebind<_Rb_tree_node<_Val> >::other
              _Node_allocator;

    protected:
      typedef _Rb_tree_node_base* _Base_ptr;
      typedef const _Rb_tree_node_base* _Const_Base_ptr;

    public:
      typedef _Key key_type;
      typedef _Val value_type;
      typedef value_type* pointer;
      typedef const value_type* const_pointer;
      typedef value_type& reference;
      typedef const value_type& const_reference;
      typedef _Rb_tree_node<_Val>* _Link_type;
      typedef const _Rb_tree_node<_Val>* _Const_Link_type;
      typedef size_t size_type;
      typedef ptrdiff_t difference_type;
      typedef _Alloc allocator_type;

      _Node_allocator&
      _M_get_Node_allocator()
      { return *static_cast<_Node_allocator*>(&this->_M_impl); }
      
      const _Node_allocator&
      _M_get_Node_allocator() const
      { return *static_cast<const _Node_allocator*>(&this->_M_impl); }

      allocator_type
      get_allocator() const
      { return allocator_type(_M_get_Node_allocator()); }

    protected:
      _Link_type
      _M_get_node()
      { return _M_impl._Node_allocator::allocate(1); }

      void
      _M_put_node(_Link_type __p)
      { _M_impl._Node_allocator::deallocate(__p, 1); }

#ifndef __GXX_EXPERIMENTAL_CXX0X__
      _Link_type
      _M_create_node(const value_type& __x)
      {
        _Link_type __tmp = _M_get_node();
        __try
          { get_allocator().construct
              (std::__addressof(__tmp->_M_value_field), __x); }
        __catch(...)
          {
            _M_put_node(__tmp);
            __throw_exception_again;
          }
        return __tmp;
      }

      void
      _M_destroy_node(_Link_type __p)
      {
        get_allocator().destroy(std::__addressof(__p->_M_value_field));
        _M_put_node(__p);
      }
#else
      template<typename... _Args>
        _Link_type
        _M_create_node(_Args&&... __args)
        {
          _Link_type __tmp = _M_get_node();
          __try
            {
              _M_get_Node_allocator().construct(__tmp,
                                             std::forward<_Args>(__args)...);
            }
          __catch(...)
            {
              _M_put_node(__tmp);
              __throw_exception_again;
            }
          return __tmp;
        }

      void
      _M_destroy_node(_Link_type __p)
      {
        _M_get_Node_allocator().destroy(__p);
        _M_put_node(__p);
      }
#endif

      _Link_type
      _M_clone_node(_Const_Link_type __x)
      {
        _Link_type __tmp = _M_create_node(__x->_M_value_field);
        __tmp->_M_color = __x->_M_color;
        __tmp->_M_left = 0;
        __tmp->_M_right = 0;
        return __tmp;
      }

    protected:
      template<typename _Key_compare, 
               bool _Is_pod_comparator = __is_pod(_Key_compare)>
        struct _Rb_tree_impl : public _Node_allocator
        {
          _Key_compare          _M_key_compare;
          _Rb_tree_node_base    _M_header;
          size_type             _M_node_count; // Keeps track of size of tree.

          _Rb_tree_impl()
          : _Node_allocator(), _M_key_compare(), _M_header(),
            _M_node_count(0)
          { _M_initialize(); }

          _Rb_tree_impl(const _Key_compare& __comp, const _Node_allocator& __a)
          : _Node_allocator(__a), _M_key_compare(__comp), _M_header(),
            _M_node_count(0)
          { _M_initialize(); }

        private:
          void
          _M_initialize()
          {
            this->_M_header._M_color = _S_red;
            this->_M_header._M_parent = 0;
            this->_M_header._M_left = &this->_M_header;
            this->_M_header._M_right = &this->_M_header;
          }         
        };

      _Rb_tree_impl<_Compare> _M_impl;

    protected:
      _Base_ptr&
      _M_root()
      { return this->_M_impl._M_header._M_parent; }

      _Const_Base_ptr
      _M_root() const
      { return this->_M_impl._M_header._M_parent; }

      _Base_ptr&
      _M_leftmost()
      { return this->_M_impl._M_header._M_left; }

      _Const_Base_ptr
      _M_leftmost() const
      { return this->_M_impl._M_header._M_left; }

      _Base_ptr&
      _M_rightmost()
      { return this->_M_impl._M_header._M_right; }

      _Const_Base_ptr
      _M_rightmost() const
      { return this->_M_impl._M_header._M_right; }

      _Link_type
      _M_begin()
      { return static_cast<_Link_type>(this->_M_impl._M_header._M_parent); }

      _Const_Link_type
      _M_begin() const
      {
        return static_cast<_Const_Link_type>
          (this->_M_impl._M_header._M_parent);
      }

      _Link_type
      _M_end()
      { return static_cast<_Link_type>(&this->_M_impl._M_header); }

      _Const_Link_type
      _M_end() const
      { return static_cast<_Const_Link_type>(&this->_M_impl._M_header); }

      static const_reference
      _S_value(_Const_Link_type __x)
      { return __x->_M_value_field; }

      static const _Key&
      _S_key(_Const_Link_type __x)
      { return _KeyOfValue()(_S_value(__x)); }

      static _Link_type
      _S_left(_Base_ptr __x)
      { return static_cast<_Link_type>(__x->_M_left); }

      static _Const_Link_type
      _S_left(_Const_Base_ptr __x)
      { return static_cast<_Const_Link_type>(__x->_M_left); }

      static _Link_type
      _S_right(_Base_ptr __x)
      { return static_cast<_Link_type>(__x->_M_right); }

      static _Const_Link_type
      _S_right(_Const_Base_ptr __x)
      { return static_cast<_Const_Link_type>(__x->_M_right); }

      static const_reference
      _S_value(_Const_Base_ptr __x)
      { return static_cast<_Const_Link_type>(__x)->_M_value_field; }

      static const _Key&
      _S_key(_Const_Base_ptr __x)
      { return _KeyOfValue()(_S_value(__x)); }

      static _Base_ptr
      _S_minimum(_Base_ptr __x)
      { return _Rb_tree_node_base::_S_minimum(__x); }

      static _Const_Base_ptr
      _S_minimum(_Const_Base_ptr __x)
      { return _Rb_tree_node_base::_S_minimum(__x); }

      static _Base_ptr
      _S_maximum(_Base_ptr __x)
      { return _Rb_tree_node_base::_S_maximum(__x); }

      static _Const_Base_ptr
      _S_maximum(_Const_Base_ptr __x)
      { return _Rb_tree_node_base::_S_maximum(__x); }

    public:
      typedef _Rb_tree_iterator<value_type>       iterator;
      typedef _Rb_tree_const_iterator<value_type> const_iterator;

      typedef std::reverse_iterator<iterator>       reverse_iterator;
      typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

    private:
      iterator
      _M_insert_(_Const_Base_ptr __x, _Const_Base_ptr __y,
                 const value_type& __v);

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 233. Insertion hints in associative containers.
      iterator
      _M_insert_lower(_Base_ptr __x, _Base_ptr __y, const value_type& __v);

      iterator
      _M_insert_equal_lower(const value_type& __x);

      _Link_type
      _M_copy(_Const_Link_type __x, _Link_type __p);

      void
      _M_erase(_Link_type __x);

      iterator
      _M_lower_bound(_Link_type __x, _Link_type __y,
                     const _Key& __k);

      const_iterator
      _M_lower_bound(_Const_Link_type __x, _Const_Link_type __y,
                     const _Key& __k) const;

      iterator
      _M_upper_bound(_Link_type __x, _Link_type __y,
                     const _Key& __k);

      const_iterator
      _M_upper_bound(_Const_Link_type __x, _Const_Link_type __y,
                     const _Key& __k) const;

    public:
      // allocation/deallocation
      _Rb_tree() { }

      _Rb_tree(const _Compare& __comp,
               const allocator_type& __a = allocator_type())
      : _M_impl(__comp, __a) { }

      _Rb_tree(const _Rb_tree& __x)
      : _M_impl(__x._M_impl._M_key_compare, __x._M_get_Node_allocator())
      {
        if (__x._M_root() != 0)
          {
            _M_root() = _M_copy(__x._M_begin(), _M_end());
            _M_leftmost() = _S_minimum(_M_root());
            _M_rightmost() = _S_maximum(_M_root());
            _M_impl._M_node_count = __x._M_impl._M_node_count;
          }
      }

#ifdef __GXX_EXPERIMENTAL_CXX0X__
      _Rb_tree(_Rb_tree&& __x);
#endif

      ~_Rb_tree()
      { _M_erase(_M_begin()); }

      _Rb_tree&
      operator=(const _Rb_tree& __x);

      // Accessors.
      _Compare
      key_comp() const
      { return _M_impl._M_key_compare; }

      iterator
      begin()
      { 
        return iterator(static_cast<_Link_type>
                        (this->_M_impl._M_header._M_left));
      }

      const_iterator
      begin() const
      { 
        return const_iterator(static_cast<_Const_Link_type>
                              (this->_M_impl._M_header._M_left));
      }

      iterator
      end()
      { return iterator(static_cast<_Link_type>(&this->_M_impl._M_header)); }

      const_iterator
      end() const
      { 
        return const_iterator(static_cast<_Const_Link_type>
                              (&this->_M_impl._M_header));
      }

      reverse_iterator
      rbegin()
      { return reverse_iterator(end()); }

      const_reverse_iterator
      rbegin() const
      { return const_reverse_iterator(end()); }

      reverse_iterator
      rend()
      { return reverse_iterator(begin()); }

      const_reverse_iterator
      rend() const
      { return const_reverse_iterator(begin()); }

      bool
      empty() const
      { return _M_impl._M_node_count == 0; }

      size_type
      size() const
      { return _M_impl._M_node_count; }

      size_type
      max_size() const
      { return _M_get_Node_allocator().max_size(); }

      void
      swap(_Rb_tree& __t);      

      // Insert/erase.
      pair<iterator, bool>
      _M_insert_unique(const value_type& __x);

      iterator
      _M_insert_equal(const value_type& __x);

      iterator
      _M_insert_unique_(const_iterator __position, const value_type& __x);

      iterator
      _M_insert_equal_(const_iterator __position, const value_type& __x);

      template<typename _InputIterator>
        void
        _M_insert_unique(_InputIterator __first, _InputIterator __last);

      template<typename _InputIterator>
        void
        _M_insert_equal(_InputIterator __first, _InputIterator __last);

#ifdef __GXX_EXPERIMENTAL_CXX0X__
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // DR 130. Associative erase should return an iterator.
      iterator
      erase(iterator __position);

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // DR 130. Associative erase should return an iterator.
      const_iterator
      erase(const_iterator __position);
#else
      void
      erase(iterator __position);

      void
      erase(const_iterator __position);
#endif
      size_type
      erase(const key_type& __x);

#ifdef __GXX_EXPERIMENTAL_CXX0X__
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // DR 130. Associative erase should return an iterator.
      iterator
      erase(iterator __first, iterator __last);

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // DR 130. Associative erase should return an iterator.
      const_iterator
      erase(const_iterator __first, const_iterator __last);
#else
      void
      erase(iterator __first, iterator __last);

      void
      erase(const_iterator __first, const_iterator __last);
#endif
      void
      erase(const key_type* __first, const key_type* __last);

      void
      clear()
      {
        _M_erase(_M_begin());
        _M_leftmost() = _M_end();
        _M_root() = 0;
        _M_rightmost() = _M_end();
        _M_impl._M_node_count = 0;
      }

      // Set operations.
      iterator
      find(const key_type& __k);

      const_iterator
      find(const key_type& __k) const;

      size_type
      count(const key_type& __k) const;

      iterator
      lower_bound(const key_type& __k)
      { return _M_lower_bound(_M_begin(), _M_end(), __k); }

      const_iterator
      lower_bound(const key_type& __k) const
      { return _M_lower_bound(_M_begin(), _M_end(), __k); }

      iterator
      upper_bound(const key_type& __k)
      { return _M_upper_bound(_M_begin(), _M_end(), __k); }

      const_iterator
      upper_bound(const key_type& __k) const
      { return _M_upper_bound(_M_begin(), _M_end(), __k); }

      pair<iterator, iterator>
      equal_range(const key_type& __k);

      pair<const_iterator, const_iterator>
      equal_range(const key_type& __k) const;

      // Debugging.
      bool
      __rb_verify() const;
    };

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline bool
    operator==(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
               const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
    {
      return __x.size() == __y.size()
             && std::equal(__x.begin(), __x.end(), __y.begin());
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline bool
    operator<(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
              const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
    {
      return std::lexicographical_compare(__x.begin(), __x.end(), 
                                          __y.begin(), __y.end());
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline bool
    operator!=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
               const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
    { return !(__x == __y); }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline bool
    operator>(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
              const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
    { return __y < __x; }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline bool
    operator<=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
               const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
    { return !(__y < __x); }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline bool
    operator>=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
               const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
    { return !(__x < __y); }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline void
    swap(_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
         _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __y)
    { __x.swap(__y); }

#ifdef __GXX_EXPERIMENTAL_CXX0X__
  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _Rb_tree(_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&& __x)
    : _M_impl(__x._M_impl._M_key_compare, __x._M_get_Node_allocator())
    {
      if (__x._M_root() != 0)
        {
          _M_root() = __x._M_root();
          _M_leftmost() = __x._M_leftmost();
          _M_rightmost() = __x._M_rightmost();
          _M_root()->_M_parent = _M_end();

          __x._M_root() = 0;
          __x._M_leftmost() = __x._M_end();
          __x._M_rightmost() = __x._M_end();

          this->_M_impl._M_node_count = __x._M_impl._M_node_count;
          __x._M_impl._M_node_count = 0;
        }
    }
#endif

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    operator=(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x)
    {
      if (this != &__x)
        {
          // Note that _Key may be a constant type.
          clear();
          _M_impl._M_key_compare = __x._M_impl._M_key_compare;
          if (__x._M_root() != 0)
            {
              _M_root() = _M_copy(__x._M_begin(), _M_end());
              _M_leftmost() = _S_minimum(_M_root());
              _M_rightmost() = _S_maximum(_M_root());
              _M_impl._M_node_count = __x._M_impl._M_node_count;
            }
        }
      return *this;
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_insert_(_Const_Base_ptr __x, _Const_Base_ptr __p, const _Val& __v)
    {
      bool __insert_left = (__x != 0 || __p == _M_end()
                            || _M_impl._M_key_compare(_KeyOfValue()(__v), 
                                                      _S_key(__p)));

      _Link_type __z = _M_create_node(__v);

      _Rb_tree_insert_and_rebalance(__insert_left, __z,
                                    const_cast<_Base_ptr>(__p),  
                                    this->_M_impl._M_header);
      ++_M_impl._M_node_count;
      return iterator(__z);
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_insert_lower(_Base_ptr __x, _Base_ptr __p, const _Val& __v)
    {
      bool __insert_left = (__x != 0 || __p == _M_end()
                            || !_M_impl._M_key_compare(_S_key(__p),
                                                       _KeyOfValue()(__v)));

      _Link_type __z = _M_create_node(__v);

      _Rb_tree_insert_and_rebalance(__insert_left, __z, __p,  
                                    this->_M_impl._M_header);
      ++_M_impl._M_node_count;
      return iterator(__z);
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_insert_equal_lower(const _Val& __v)
    {
      _Link_type __x = _M_begin();
      _Link_type __y = _M_end();
      while (__x != 0)
        {
          __y = __x;
          __x = !_M_impl._M_key_compare(_S_key(__x), _KeyOfValue()(__v)) ?
                _S_left(__x) : _S_right(__x);
        }
      return _M_insert_lower(__x, __y, __v);
    }

  template<typename _Key, typename _Val, typename _KoV,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KoV, _Compare, _Alloc>::_Link_type
    _Rb_tree<_Key, _Val, _KoV, _Compare, _Alloc>::
    _M_copy(_Const_Link_type __x, _Link_type __p)
    {
      // Structural copy.  __x and __p must be non-null.
      _Link_type __top = _M_clone_node(__x);
      __top->_M_parent = __p;

      __try
        {
          if (__x->_M_right)
            __top->_M_right = _M_copy(_S_right(__x), __top);
          __p = __top;
          __x = _S_left(__x);

          while (__x != 0)
            {
              _Link_type __y = _M_clone_node(__x);
              __p->_M_left = __y;
              __y->_M_parent = __p;
              if (__x->_M_right)
                __y->_M_right = _M_copy(_S_right(__x), __y);
              __p = __y;
              __x = _S_left(__x);
            }
        }
      __catch(...)
        {
          _M_erase(__top);
          __throw_exception_again;
        }
      return __top;
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    void
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_erase(_Link_type __x)
    {
      // Erase without rebalancing.
      while (__x != 0)
        {
          _M_erase(_S_right(__x));
          _Link_type __y = _S_left(__x);
          _M_destroy_node(__x);
          __x = __y;
        }
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue,
                      _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_lower_bound(_Link_type __x, _Link_type __y,
                   const _Key& __k)
    {
      while (__x != 0)
        if (!_M_impl._M_key_compare(_S_key(__x), __k))
          __y = __x, __x = _S_left(__x);
        else
          __x = _S_right(__x);
      return iterator(__y);
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue,
                      _Compare, _Alloc>::const_iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_lower_bound(_Const_Link_type __x, _Const_Link_type __y,
                   const _Key& __k) const
    {
      while (__x != 0)
        if (!_M_impl._M_key_compare(_S_key(__x), __k))
          __y = __x, __x = _S_left(__x);
        else
          __x = _S_right(__x);
      return const_iterator(__y);
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue,
                      _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_upper_bound(_Link_type __x, _Link_type __y,
                   const _Key& __k)
    {
      while (__x != 0)
        if (_M_impl._M_key_compare(__k, _S_key(__x)))
          __y = __x, __x = _S_left(__x);
        else
          __x = _S_right(__x);
      return iterator(__y);
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue,
                      _Compare, _Alloc>::const_iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_upper_bound(_Const_Link_type __x, _Const_Link_type __y,
                   const _Key& __k) const
    {
      while (__x != 0)
        if (_M_impl._M_key_compare(__k, _S_key(__x)))
          __y = __x, __x = _S_left(__x);
        else
          __x = _S_right(__x);
      return const_iterator(__y);
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
                           _Compare, _Alloc>::iterator,
         typename _Rb_tree<_Key, _Val, _KeyOfValue,
                           _Compare, _Alloc>::iterator>
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    equal_range(const _Key& __k)
    {
      _Link_type __x = _M_begin();
      _Link_type __y = _M_end();
      while (__x != 0)
        {
          if (_M_impl._M_key_compare(_S_key(__x), __k))
            __x = _S_right(__x);
          else if (_M_impl._M_key_compare(__k, _S_key(__x)))
            __y = __x, __x = _S_left(__x);
          else
            {
              _Link_type __xu(__x), __yu(__y);
              __y = __x, __x = _S_left(__x);
              __xu = _S_right(__xu);
              return pair<iterator,
                          iterator>(_M_lower_bound(__x, __y, __k),
                                    _M_upper_bound(__xu, __yu, __k));
            }
        }
      return pair<iterator, iterator>(iterator(__y),
                                      iterator(__y));
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
                           _Compare, _Alloc>::const_iterator,
         typename _Rb_tree<_Key, _Val, _KeyOfValue,
                           _Compare, _Alloc>::const_iterator>
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    equal_range(const _Key& __k) const
    {
      _Const_Link_type __x = _M_begin();
      _Const_Link_type __y = _M_end();
      while (__x != 0)
        {
          if (_M_impl._M_key_compare(_S_key(__x), __k))
            __x = _S_right(__x);
          else if (_M_impl._M_key_compare(__k, _S_key(__x)))
            __y = __x, __x = _S_left(__x);
          else
            {
              _Const_Link_type __xu(__x), __yu(__y);
              __y = __x, __x = _S_left(__x);
              __xu = _S_right(__xu);
              return pair<const_iterator,
                          const_iterator>(_M_lower_bound(__x, __y, __k),
                                          _M_upper_bound(__xu, __yu, __k));
            }
        }
      return pair<const_iterator, const_iterator>(const_iterator(__y),
                                                  const_iterator(__y));
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    void
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    swap(_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __t)
    {
      if (_M_root() == 0)
        {
          if (__t._M_root() != 0)
            {
              _M_root() = __t._M_root();
              _M_leftmost() = __t._M_leftmost();
              _M_rightmost() = __t._M_rightmost();
              _M_root()->_M_parent = _M_end();
              
              __t._M_root() = 0;
              __t._M_leftmost() = __t._M_end();
              __t._M_rightmost() = __t._M_end();
            }
        }
      else if (__t._M_root() == 0)
        {
          __t._M_root() = _M_root();
          __t._M_leftmost() = _M_leftmost();
          __t._M_rightmost() = _M_rightmost();
          __t._M_root()->_M_parent = __t._M_end();
          
          _M_root() = 0;
          _M_leftmost() = _M_end();
          _M_rightmost() = _M_end();
        }
      else
        {
          std::swap(_M_root(),__t._M_root());
          std::swap(_M_leftmost(),__t._M_leftmost());
          std::swap(_M_rightmost(),__t._M_rightmost());
          
          _M_root()->_M_parent = _M_end();
          __t._M_root()->_M_parent = __t._M_end();
        }
      // No need to swap header's color as it does not change.
      std::swap(this->_M_impl._M_node_count, __t._M_impl._M_node_count);
      std::swap(this->_M_impl._M_key_compare, __t._M_impl._M_key_compare);
      
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 431. Swapping containers with unequal allocators.
      std::__alloc_swap<_Node_allocator>::
        _S_do_it(_M_get_Node_allocator(), __t._M_get_Node_allocator());
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    pair<typename _Rb_tree<_Key, _Val, _KeyOfValue,
                           _Compare, _Alloc>::iterator, bool>
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_insert_unique(const _Val& __v)
    {
      _Link_type __x = _M_begin();
      _Link_type __y = _M_end();
      bool __comp = true;
      while (__x != 0)
        {
          __y = __x;
          __comp = _M_impl._M_key_compare(_KeyOfValue()(__v), _S_key(__x));
          __x = __comp ? _S_left(__x) : _S_right(__x);
        }
      iterator __j = iterator(__y);
      if (__comp)
        {
          if (__j == begin())
            return pair<iterator, bool>(_M_insert_(__x, __y, __v), true);
          else
            --__j;
        }
      if (_M_impl._M_key_compare(_S_key(__j._M_node), _KeyOfValue()(__v)))
        return pair<iterator, bool>(_M_insert_(__x, __y, __v), true);
      return pair<iterator, bool>(__j, false);
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_insert_equal(const _Val& __v)
    {
      _Link_type __x = _M_begin();
      _Link_type __y = _M_end();
      while (__x != 0)
        {
          __y = __x;
          __x = _M_impl._M_key_compare(_KeyOfValue()(__v), _S_key(__x)) ?
                _S_left(__x) : _S_right(__x);
        }
      return _M_insert_(__x, __y, __v);
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_insert_unique_(const_iterator __position, const _Val& __v)
    {
      // end()
      if (__position._M_node == _M_end())
        {
          if (size() > 0
              && _M_impl._M_key_compare(_S_key(_M_rightmost()), 
                                        _KeyOfValue()(__v)))
            return _M_insert_(0, _M_rightmost(), __v);
          else
            return _M_insert_unique(__v).first;
        }
      else if (_M_impl._M_key_compare(_KeyOfValue()(__v),
                                      _S_key(__position._M_node)))
        {
          // First, try before...
          const_iterator __before = __position;
          if (__position._M_node == _M_leftmost()) // begin()
            return _M_insert_(_M_leftmost(), _M_leftmost(), __v);
          else if (_M_impl._M_key_compare(_S_key((--__before)._M_node), 
                                          _KeyOfValue()(__v)))
            {
              if (_S_right(__before._M_node) == 0)
                return _M_insert_(0, __before._M_node, __v);
              else
                return _M_insert_(__position._M_node,
                                  __position._M_node, __v);
            }
          else
            return _M_insert_unique(__v).first;
        }
      else if (_M_impl._M_key_compare(_S_key(__position._M_node),
                                      _KeyOfValue()(__v)))
        {
          // ... then try after.
          const_iterator __after = __position;
          if (__position._M_node == _M_rightmost())
            return _M_insert_(0, _M_rightmost(), __v);
          else if (_M_impl._M_key_compare(_KeyOfValue()(__v),
                                          _S_key((++__after)._M_node)))
            {
              if (_S_right(__position._M_node) == 0)
                return _M_insert_(0, __position._M_node, __v);
              else
                return _M_insert_(__after._M_node, __after._M_node, __v);
            }
          else
            return _M_insert_unique(__v).first;
        }
      else
        // Equivalent keys.
        return iterator(static_cast<_Link_type>
                        (const_cast<_Base_ptr>(__position._M_node)));
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    _M_insert_equal_(const_iterator __position, const _Val& __v)
    {
      // end()
      if (__position._M_node == _M_end())
        {
          if (size() > 0
              && !_M_impl._M_key_compare(_KeyOfValue()(__v),
                                         _S_key(_M_rightmost())))
            return _M_insert_(0, _M_rightmost(), __v);
          else
            return _M_insert_equal(__v);
        }
      else if (!_M_impl._M_key_compare(_S_key(__position._M_node),
                                       _KeyOfValue()(__v)))
        {
          // First, try before...
          const_iterator __before = __position;
          if (__position._M_node == _M_leftmost()) // begin()
            return _M_insert_(_M_leftmost(), _M_leftmost(), __v);
          else if (!_M_impl._M_key_compare(_KeyOfValue()(__v),
                                           _S_key((--__before)._M_node)))
            {
              if (_S_right(__before._M_node) == 0)
                return _M_insert_(0, __before._M_node, __v);
              else
                return _M_insert_(__position._M_node,
                                  __position._M_node, __v);
            }
          else
            return _M_insert_equal(__v);
        }
      else
        {
          // ... then try after.  
          const_iterator __after = __position;
          if (__position._M_node == _M_rightmost())
            return _M_insert_(0, _M_rightmost(), __v);
          else if (!_M_impl._M_key_compare(_S_key((++__after)._M_node),
                                           _KeyOfValue()(__v)))
            {
              if (_S_right(__position._M_node) == 0)
                return _M_insert_(0, __position._M_node, __v);
              else
                return _M_insert_(__after._M_node, __after._M_node, __v);
            }
          else
            return _M_insert_equal_lower(__v);
        }
    }

  template<typename _Key, typename _Val, typename _KoV,
           typename _Cmp, typename _Alloc>
    template<class _II>
      void
      _Rb_tree<_Key, _Val, _KoV, _Cmp, _Alloc>::
      _M_insert_unique(_II __first, _II __last)
      {
        for (; __first != __last; ++__first)
          _M_insert_unique_(end(), *__first);
      }

  template<typename _Key, typename _Val, typename _KoV,
           typename _Cmp, typename _Alloc>
    template<class _II>
      void
      _Rb_tree<_Key, _Val, _KoV, _Cmp, _Alloc>::
      _M_insert_equal(_II __first, _II __last)
      {
        for (; __first != __last; ++__first)
          _M_insert_equal_(end(), *__first);
      }

#ifdef __GXX_EXPERIMENTAL_CXX0X__
  // _GLIBCXX_RESOLVE_LIB_DEFECTS
  // DR 130. Associative erase should return an iterator.
  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    erase(iterator __position)
    {
      iterator __result = __position;
      ++__result;
      _Link_type __y =
        static_cast<_Link_type>(_Rb_tree_rebalance_for_erase
                                (__position._M_node,
                                 this->_M_impl._M_header));
      _M_destroy_node(__y);
      --_M_impl._M_node_count;
      return __result;
    }

  // _GLIBCXX_RESOLVE_LIB_DEFECTS
  // DR 130. Associative erase should return an iterator.
  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::const_iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    erase(const_iterator __position)
    {
      const_iterator __result = __position;
      ++__result;
      _Link_type __y =
        static_cast<_Link_type>(_Rb_tree_rebalance_for_erase
                                (const_cast<_Base_ptr>(__position._M_node),
                                 this->_M_impl._M_header));
      _M_destroy_node(__y);
      --_M_impl._M_node_count;
      return __result;
    }
#else
  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline void
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    erase(iterator __position)
    {
      _Link_type __y =
        static_cast<_Link_type>(_Rb_tree_rebalance_for_erase
                                (__position._M_node,
                                 this->_M_impl._M_header));
      _M_destroy_node(__y);
      --_M_impl._M_node_count;
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    inline void
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    erase(const_iterator __position)
    {
      _Link_type __y =
        static_cast<_Link_type>(_Rb_tree_rebalance_for_erase
                                (const_cast<_Base_ptr>(__position._M_node),
                                 this->_M_impl._M_header));
      _M_destroy_node(__y);
      --_M_impl._M_node_count;
    }
#endif

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::size_type
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    erase(const _Key& __x)
    {
      pair<iterator, iterator> __p = equal_range(__x);
      const size_type __old_size = size();
      erase(__p.first, __p.second);
      return __old_size - size();
    }

#ifdef __GXX_EXPERIMENTAL_CXX0X__
  // _GLIBCXX_RESOLVE_LIB_DEFECTS
  // DR 130. Associative erase should return an iterator.
  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    erase(iterator __first, iterator __last)
    {
      if (__first == begin() && __last == end())
        {
          clear();
          return end();
        }
      else
        {
          while (__first != __last)
            erase(__first++);
          return __last;
        }
    }

  // _GLIBCXX_RESOLVE_LIB_DEFECTS
  // DR 130. Associative erase should return an iterator.
  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::const_iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    erase(const_iterator __first, const_iterator __last)
    {
      if (__first == begin() && __last == end())
        {
          clear();
          return end();
        }
      else
        {
          while (__first != __last)
            erase(__first++);
          return __last;
        }
    }
#else
  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    void
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    erase(iterator __first, iterator __last)
    {
      if (__first == begin() && __last == end())
        clear();
      else
        while (__first != __last)
          erase(__first++);
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    void
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    erase(const_iterator __first, const_iterator __last)
    {
      if (__first == begin() && __last == end())
        clear();
      else
        while (__first != __last)
          erase(__first++);
    }
#endif

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    void
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    erase(const _Key* __first, const _Key* __last)
    {
      while (__first != __last)
        erase(*__first++);
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue,
                      _Compare, _Alloc>::iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    find(const _Key& __k)
    {
      iterator __j = _M_lower_bound(_M_begin(), _M_end(), __k);
      return (__j == end()
              || _M_impl._M_key_compare(__k,
                                        _S_key(__j._M_node))) ? end() : __j;
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue,
                      _Compare, _Alloc>::const_iterator
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    find(const _Key& __k) const
    {
      const_iterator __j = _M_lower_bound(_M_begin(), _M_end(), __k);
      return (__j == end()
              || _M_impl._M_key_compare(__k, 
                                        _S_key(__j._M_node))) ? end() : __j;
    }

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    typename _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::size_type
    _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
    count(const _Key& __k) const
    {
      pair<const_iterator, const_iterator> __p = equal_range(__k);
      const size_type __n = std::distance(__p.first, __p.second);
      return __n;
    }

  _GLIBCXX_PURE unsigned int
  _Rb_tree_black_count(const _Rb_tree_node_base* __node,
                       const _Rb_tree_node_base* __root) throw ();

  template<typename _Key, typename _Val, typename _KeyOfValue,
           typename _Compare, typename _Alloc>
    bool
    _Rb_tree<_Key,_Val,_KeyOfValue,_Compare,_Alloc>::__rb_verify() const
    {
      if (_M_impl._M_node_count == 0 || begin() == end())
        return _M_impl._M_node_count == 0 && begin() == end()
               && this->_M_impl._M_header._M_left == _M_end()
               && this->_M_impl._M_header._M_right == _M_end();

      unsigned int __len = _Rb_tree_black_count(_M_leftmost(), _M_root());
      for (const_iterator __it = begin(); __it != end(); ++__it)
        {
          _Const_Link_type __x = static_cast<_Const_Link_type>(__it._M_node);
          _Const_Link_type __L = _S_left(__x);
          _Const_Link_type __R = _S_right(__x);

          if (__x->_M_color == _S_red)
            if ((__L && __L->_M_color == _S_red)
                || (__R && __R->_M_color == _S_red))
              return false;

          if (__L && _M_impl._M_key_compare(_S_key(__x), _S_key(__L)))
            return false;
          if (__R && _M_impl._M_key_compare(_S_key(__R), _S_key(__x)))
            return false;

          if (!__L && !__R && _Rb_tree_black_count(__x, _M_root()) != __len)
            return false;
        }

      if (_M_leftmost() != _Rb_tree_node_base::_S_minimum(_M_root()))
        return false;
      if (_M_rightmost() != _Rb_tree_node_base::_S_maximum(_M_root()))
        return false;
      return true;
    }

_GLIBCXX_END_NAMESPACE

#endif