// Ex7_13.cpp
  // Exercising the indirect member access operator
  include <iostream>
  using std::cout;
  using std::endl;
  
  class CBox                             // Class definition at global scope
  {
    public:
      // Constructor definition
      CBox(double lv = 1.0, double bv = 1.0, double hv = 1.0)
      {
        cout << endl << "Constructor called.";
        m_Length = lv;                   // Set values of
        m_Width = bv;                    // data members
        m_Height = hv;
      }
  
      // Function to calculate the volume of a box
      double Volume() const
      {
        return m_Length*m_Width*m_Height;
      }
  
      // Function to compare two boxes which returns true (1)
      // if the first is greater that the second, and false (0) otherwise
      int Compare(CBox* pBox) const
      {
        return this->Volume() > pBox->Volume();
      }
  
    private:
      double m_Length;                   // Length of a box in inches
      double m_Width;                    // Width of a box in inches
      double m_Height;                   // Height of a box in inches
  };
  
  int main()
  {
    CBox boxes[5];                       // Array of CBox objects declared
    CBox match(2.2, 1.1, 0.5);           // Declare match box
    CBox cigar(8.0, 5.0, 1.0);           // Declare cigar Box
    CBox* pB1 = &cigar;             // Initialize pointer to cigar object address
    CBox* pB2 = 0;                       // Pointer to CBox initialized to null
  
    cout << endl 
         << "Address of cigar is " << pB1     // Display address
         << endl
         << "Volume of cigar is "
         << pB1->Volume();                    // Volume of object pointed to
  
    pB2 = &match;
    if(pB2->Compare(pB1))                     // Compare via pointers
      cout << endl
           << "match is greater than cigar";
    else
      cout << endl
           << "match is less than or equal to cigar";
  
    pB1 = boxes;                              // Set to address of array
    boxes[2] = match;                         // Set 3rd element to match
    cout << endl                              // Now access thru pointer
         << "Volume of boxes[2] is " << (pB1 + 2)->Volume();
  
    cout << endl;
    return 0;
  }