stl_map.h

gcc3.2.1源代码

// Map implementation -*- C++ -*-

// Copyright (C) 2001, 2002 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 2, 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.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/*
 *
 * 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.
 *
 *
 * 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.
 */

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

#ifndef _CPP_BITS_STL_MAP_H
#define _CPP_BITS_STL_MAP_H 1

#include <bits/concept_check.h>

namespace std
{

/**
 *  @brief A standard container made up of pairs (see std::pair in <utility>)
 *         which can be retrieved based on a key.
 *
 *  This is an associative container.  Values contained within it can be
 *  quickly retrieved through a key element.  Example:  MyMap["First"] would
 *  return the data associated with the key "First".
*/
template <class _Key, class _Tp, class _Compare = less<_Key>,
          class _Alloc = allocator<pair<const _Key, _Tp> > >
class map
{
  // concept requirements
  __glibcpp_class_requires(_Tp, _SGIAssignableConcept)
  __glibcpp_class_requires4(_Compare, bool, _Key, _Key, _BinaryFunctionConcept);

public:
  // typedefs:
  typedef _Key                 key_type;
  typedef _Tp                   data_type;
  typedef _Tp                   mapped_type;
  typedef pair<const _Key, _Tp> value_type;
  typedef _Compare             key_compare;

  class value_compare
    : public binary_function<value_type, value_type, bool> {
  friend class map<_Key,_Tp,_Compare,_Alloc>;
  protected :
    _Compare comp;
    value_compare(_Compare __c) : comp(__c) {}
  public:
    bool operator()(const value_type& __x, const value_type& __y) const {
      return comp(__x.first, __y.first);
    }
  };

private:
  typedef _Rb_tree<key_type, value_type,
                   _Select1st<value_type>, key_compare, _Alloc> _Rep_type;
  _Rep_type _M_t;  // red-black tree representing map
public:
  typedef typename _Rep_type::pointer pointer;
  typedef typename _Rep_type::const_pointer const_pointer;
  typedef typename _Rep_type::reference reference;
  typedef typename _Rep_type::const_reference const_reference;
  typedef typename _Rep_type::iterator iterator;
  typedef typename _Rep_type::const_iterator const_iterator;
  typedef typename _Rep_type::reverse_iterator reverse_iterator;
  typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
  typedef typename _Rep_type::size_type size_type;
  typedef typename _Rep_type::difference_type difference_type;
  typedef typename _Rep_type::allocator_type allocator_type;

  // allocation/deallocation

  map() : _M_t(_Compare(), allocator_type()) {}
  explicit map(const _Compare& __comp,
               const allocator_type& __a = allocator_type())
    : _M_t(__comp, __a) {}

  template <class _InputIterator>
  map(_InputIterator __first, _InputIterator __last)
    : _M_t(_Compare(), allocator_type())
    { _M_t.insert_unique(__first, __last); }

  template <class _InputIterator>
  map(_InputIterator __first, _InputIterator __last, const _Compare& __comp,
      const allocator_type& __a = allocator_type())
    : _M_t(__comp, __a) { _M_t.insert_unique(__first, __last); }
  map(const map<_Key,_Tp,_Compare,_Alloc>& __x) : _M_t(__x._M_t) {}

  map<_Key,_Tp,_Compare,_Alloc>&
  operator=(const map<_Key, _Tp, _Compare, _Alloc>& __x)
  {
    _M_t = __x._M_t;
    return *this;
  }

  // accessors:

  key_compare key_comp() const { return _M_t.key_comp(); }
  value_compare value_comp() const { return value_compare(_M_t.key_comp()); }
  allocator_type get_allocator() const { return _M_t.get_allocator(); }

  /**
   *  Returns a read/write iterator that points to the first pair in the map.
   *  Iteration is done in ascending order according to the keys.
  */
  iterator begin() { return _M_t.begin(); }

  /**
   *  Returns a read-only (constant) iterator that points to the first pair
   *  in the map.  Iteration is done in ascending order according to the keys.
  */
  const_iterator begin() const { return _M_t.begin(); }

  /**
   *  Returns a read/write iterator that points one past the last pair in the
   *  map.  Iteration is done in ascending order according to the keys.
  */
  iterator end() { return _M_t.end(); }

  /**
   *  Returns a read-only (constant) iterator that points one past the last
   *  pair in the map.  Iteration is done in ascending order according to the
   *  keys.
  */
  const_iterator end() const { return _M_t.end(); }

  /**
   *  Returns a read/write reverse iterator that points to the last pair in
   *  the map.  Iteration is done in descending order according to the keys.
  */
  reverse_iterator rbegin() { return _M_t.rbegin(); }

  /**
   *  Returns a read-only (constant) reverse iterator that points to the last
   *  pair in the map.  Iteration is done in descending order according to
   *  the keys.
  */
  const_reverse_iterator rbegin() const { return _M_t.rbegin(); }

  /**
   *  Returns a read/write reverse iterator that points to one before the
   *  first pair in the map.  Iteration is done in descending order according
   *  to the keys.
  */
  reverse_iterator rend() { return _M_t.rend(); }

  /**
   *  Returns a read-only (constant) reverse iterator that points to one
   *  before the first pair in the map.  Iteration is done in descending order
   *  according to the keys.
  */
  const_reverse_iterator rend() const { return _M_t.rend(); }

  /** Returns true if the map is empty.  (Thus begin() would equal end().)  */
  bool empty() const { return _M_t.empty(); }
  /** Returns the size of the map.  */
  size_type size() const { return _M_t.size(); }
  /** Returns the maximum size of the map.  */
  size_type max_size() const { return _M_t.max_size(); }

  /**
   *  @brief Subscript ( [] ) access to map data.
   *  @param  k  The key for which data should be retrieved.
   * 
   *  Allows for easy lookup with the subscript ( [] ) operator.  Returns the
   *  data associated with the key specified in subscript.  If the key does
   *  not exist a pair with that key is created with a default value, which
   *  is then returned.
  */
  _Tp& operator[](const key_type& __k) {
    iterator __i = lower_bound(__k);
    // __i->first is greater than or equivalent to __k.
    if (__i == end() || key_comp()(__k, (*__i).first))
      __i = insert(__i, value_type(__k, _Tp()));
    return (*__i).second;
  }

  void swap(map<_Key,_Tp,_Compare,_Alloc>& __x) { _M_t.swap(__x._M_t); }

  // insert/erase
  /**
   *  @brief Attempts to insert a std::pair into the map.
   *  @param  x  Pair to be inserted (see std::make_pair for easy creation of
   *             pairs).
   *  @return  A pair of which the first element is an iterator that points
   *           to the possibly inserted pair, a second element of type bool
   *           to show if the pair was actually inserted.
   *
   *  This function attempts to insert a (key, value) pair into the map.  A
   *  map relies on unique keys and thus a pair is only inserted if its first
   *  element (the key) is not already present in the map.
  */
  pair<iterator,bool> insert(const value_type& __x)
    { return _M_t.insert_unique(__x); }

  /**
   *  @brief Attempts to insert a std::pair into the map.
   *  @param  position  An iterator that serves as a hint as to where the
   *                    pair should be inserted.
   *  @param  x  Pair to be inserted (see std::make_pair for easy creation of
   *             pairs).