Random Access Iterators

• Bidirectional iterator with random access:

// bracket operator
T&        operator [] (unsigned int i) const;      // Return reference to Tval
                                                   // at index i
// "pointer" arithmetic
long      operator -  (const Iterator& I2) const;  // n  = I - I2
Iterator  operator +  (long n) const;              // I2 = I + n
Iterator  operator -  (long n) const;              // I2 = I - n
Iterator& operator += (long n);                    // I += n same as I = I + n
Iterator& operator -= (long n);                    // I -= n same as I = I - n

// similar declarations of last three for all other integral types