Forward Iterators

// comparison logic
bool    operator == (const Iterator& ) const;  // equality operator
bool    operator != (const Iterator& ) const;  // non-equality operator

// element access
value_type&       operator*  ();               // dereference operator
const value_type& operator*  () const;         // const version

// motion
Iterator&   operator ++ ();                    // prefix increment
Iterator    operator ++ (int);                 // postfix increment

// proper type
            Iterator    ()                     // constructor
            ~Iterator   ()                     // destructor
            Iterator    (const Iterator& );    // copy constructor
Iterator&   operator =  (const Iterator& );    // assignment