stl_map.h

/*
 *
 * 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.
 */

/* NOTE: This is an internal header file, included by other STL headers.
 *   You should not attempt to use it directly.
 */

#ifndef __SGI_STL_INTERNAL_MAP_H
#define __SGI_STL_INTERNAL_MAP_H

#include <concept_checks.h>

__STL_BEGIN_NAMESPACE

#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)
#pragma set woff 1174
#pragma set woff 1375
#endif

// Forward declarations of operators == and <, needed for friend declarations.
template <class _Key, class _Tp, 
          class _Compare __STL_DEPENDENT_DEFAULT_TMPL(less<_Key>),
          class _Alloc = __STL_DEFAULT_ALLOCATOR(_Tp) >
class map;

template <class _Key, class _Tp, class _Compare, class _Alloc>
inline bool operator==(const map<_Key,_Tp,_Compare,_Alloc>& __x, 
                       const map<_Key,_Tp,_Compare,_Alloc>& __y);

template <class _Key, class _Tp, class _Compare, class _Alloc>
inline bool operator<(const map<_Key,_Tp,_Compare,_Alloc>& __x, 
                      const map<_Key,_Tp,_Compare,_Alloc>& __y);

// _Key 为键值类型，_Tp为实值类型。
template <class _Key, class _Tp, class _Compare, class _Alloc>
class map {
public:

// requirements:

  __STL_CLASS_REQUIRES(_Tp, _Assignable);
  __STL_CLASS_BINARY_FUNCTION_CHECK(_Compare, bool, _Key, _Key);

// typedefs:

  typedef _Key                  key_type;  // 键值类型
  typedef _Tp                   data_type; // 数据类型
  typedef _Tp                   mapped_type;
  typedef pair<const _Key, _Tp> value_type;    // 元素类型(键值/实值)
  typedef _Compare              key_compare;   // 键值比较函数
    
  // 下面定义一个functor,其作用就是调用“元素比较函数”
  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:
  // 以下定义表述类型(representation type).以map元素类型(一个pair)的第一类型，
  // 作为RB-tree节点的键值类型
  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;
  // 注意上一行，map并不像set一样将iterator定义为RB-tree的const_iterator.
  // 因为它允许用户通过其迭代器修改元素的实值(value)。
  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
  // 注意，map异地你敢使用底层RB-tree的insert_unique()而非insert_equal()
  // multimap才使用insert_equal()
  // 因为map不允许相同的键值存在，multimap才允许相同键值存在。

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

#ifdef __STL_MEMBER_TEMPLATES
  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); }
#else
  map(const value_type* __first, const value_type* __last)
    : _M_t(_Compare(), allocator_type())
    { _M_t.insert_unique(__first, __last); }

  map(const value_type* __first,
      const value_type* __last, const _Compare& __comp,
      const allocator_type& __a = allocator_type())
    : _M_t(__comp, __a) { _M_t.insert_unique(__first, __last); }

  map(const_iterator __first, const_iterator __last)
    : _M_t(_Compare(), allocator_type()) 
    { _M_t.insert_unique(__first, __last); }

  map(const_iterator __first, const_iterator __last, const _Compare& __comp,
      const allocator_type& __a = allocator_type())
    : _M_t(__comp, __a) { _M_t.insert_unique(__first, __last); }

#endif /* __STL_MEMBER_TEMPLATES */

  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:
  // 以下所有的map操作行为，RG-tree都已提供，map只要转调用即可。

  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(); }

  iterator begin() { return _M_t.begin(); }
  const_iterator begin() const { return _M_t.begin(); }
  iterator end() { return _M_t.end(); }
  const_iterator end() const { return _M_t.end(); }
  reverse_iterator rbegin() { return _M_t.rbegin(); }
  const_reverse_iterator rbegin() const { return _M_t.rbegin(); }
  reverse_iterator rend() { return _M_t.rend(); }
  const_reverse_iterator rend() const { return _M_t.rend(); }
  bool empty() const { return _M_t.empty(); }
  size_type size() const { return _M_t.size(); }
  size_type max_size() const { return _M_t.max_size(); }
  _Tp& operator[](const key_type& __k) {
    iterator __i = lower_bound(__k);
    // __i->first is greater than or equivalent to __k.
    // insert那句，根据键值和实值取出一个元素，由于实值未知，所以产生一个与实值
    // 类型相同的暂时对象替代->value_type(__k,_Tp()),然后将这个元素插入到map里面
    // 此时，__i指向插入之后的新位置的迭代器，然后在返回实值。
    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

  // 返回值pair中，bool表示插入成功与否，如果插入成功，iterator就指向
  // 被插入的那个元素。
  pair<iterator,bool> insert(const value_type& __x) 
    { return _M_t.insert_unique(__x); }
  iterator insert(iterator position, const value_type& __x)
    { return _M_t.insert_unique(position, __x); }
#ifdef __STL_MEMBER_TEMPLATES
  template <class _InputIterator>
  void insert(_InputIterator __first, _InputIterator __last) {
    _M_t.insert_unique(__first, __last);
  }
#else
  void insert(const value_type* __first, const value_type* __last) {
    _M_t.insert_unique(__first, __last);
  }
  void insert(const_iterator __first, const_iterator __last) {
    _M_t.insert_unique(__first, __last);
  }
#endif /* __STL_MEMBER_TEMPLATES */

  void erase(iterator __position) { _M_t.erase(__position); }
  size_type erase(const key_type& __x) { return _M_t.erase(__x); }
  void erase(iterator __first, iterator __last)
    { _M_t.erase(__first, __last); }
  void clear() { _M_t.clear(); }

  // map operations:

  iterator find(const key_type& __x) { return _M_t.find(__x); }
  const_iterator find(const key_type& __x) const { return _M_t.find(__x); }
  size_type count(const key_type& __x) const {
    return _M_t.find(__x) == _M_t.end() ? 0 : 1; 
  }
  iterator lower_bound(const key_type& __x) {return _M_t.lower_bound(__x); }
  const_iterator lower_bound(const key_type& __x) const {
    return _M_t.lower_bound(__x); 
  }
  iterator upper_bound(const key_type& __x) {return _M_t.upper_bound(__x); }
  const_iterator upper_bound(const key_type& __x) const {
    return _M_t.upper_bound(__x); 
  }
  
  pair<iterator,iterator> equal_range(const key_type& __x) {
    return _M_t.equal_range(__x);
  }
  pair<const_iterator,const_iterator> equal_range(const key_type& __x) const {
    return _M_t.equal_range(__x);
  }

#ifdef __STL_TEMPLATE_FRIENDS 
  template <class _K1, class _T1, class _C1, class _A1>
  friend bool operator== (const map<_K1, _T1, _C1, _A1>&,
                          const map<_K1, _T1, _C1, _A1>&);
  template <class _K1, class _T1, class _C1, class _A1>
  friend bool operator< (const map<_K1, _T1, _C1, _A1>&,
                         const map<_K1, _T1, _C1, _A1>&);
#else /* __STL_TEMPLATE_FRIENDS */
  friend bool __STD_QUALIFIER
  operator== __STL_NULL_TMPL_ARGS (const map&, const map&);
  friend bool __STD_QUALIFIER
  operator< __STL_NULL_TMPL_ARGS (const map&, const map&);
#endif /* __STL_TEMPLATE_FRIENDS */
};

template <class _Key, class _Tp, class _Compare, class _Alloc>
inline bool operator==(const map<_Key,_Tp,_Compare,_Alloc>& __x, 
                       const map<_Key,_Tp,_Compare,_Alloc>& __y) {
  return __x._M_t == __y._M_t;
}

template <class _Key, class _Tp, class _Compare, class _Alloc>
inline bool operator<(const map<_Key,_Tp,_Compare,_Alloc>& __x, 
                      const map<_Key,_Tp,_Compare,_Alloc>& __y) {
  return __x._M_t < __y._M_t;
}

#ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDER

template <class _Key, class _Tp, class _Compare, class _Alloc>
inline bool operator!=(const map<_Key,_Tp,_Compare,_Alloc>& __x, 
                       const map<_Key,_Tp,_Compare,_Alloc>& __y) {
  return !(__x == __y);
}

template <class _Key, class _Tp, class _Compare, class _Alloc>
inline bool operator>(const map<_Key,_Tp,_Compare,_Alloc>& __x, 
                      const map<_Key,_Tp,_Compare,_Alloc>& __y) {
  return __y < __x;
}

template <class _Key, class _Tp, class _Compare, class _Alloc>
inline bool operator<=(const map<_Key,_Tp,_Compare,_Alloc>& __x, 
                       const map<_Key,_Tp,_Compare,_Alloc>& __y) {
  return !(__y < __x);
}

template <class _Key, class _Tp, class _Compare, class _Alloc>
inline bool operator>=(const map<_Key,_Tp,_Compare,_Alloc>& __x, 
                       const map<_Key,_Tp,_Compare,_Alloc>& __y) {
  return !(__x < __y);
}

template <class _Key, class _Tp, class _Compare, class _Alloc>
inline void swap(map<_Key,_Tp,_Compare,_Alloc>& __x, 
                 map<_Key,_Tp,_Compare,_Alloc>& __y) {
  __x.swap(__y);
}

#endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */

#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)
#pragma reset woff 1174
#pragma reset woff 1375
#endif

__STL_END_NAMESPACE

#endif /* __SGI_STL_INTERNAL_MAP_H */

// Local Variables:
// mode:C++
// End: