// Ex9_12.cpp
  // Destructor calls with derived classes
  // using objects via a base class pointer
  
  // You need to uncomment the virtual keyword in Container.h for proper operation...
  
  include <Box.h>                       // For CBox and CContainer
  include <Can.h>                       // For CCan (and CContainer)
  include <GlassBox.h>                  // For CGlassBox (and CBox and CContainer)
  include <iostream>                    // For stream I/O
  using std::cout;
  using std::endl;
  
  const double PI = 3.14159265;          // Global definition for PI
  
  int main()
  {
    // Pointer to abstract base class initialized with CBox object address
    CContainer* pC1 = new CBox(2.0, 3.0, 4.0);
  
    CCan myCan(6.5, 3.0);                // Define CCan object
    CGlassBox myGlassBox(2.0, 3.0, 4.0); // Define CGlassBox object
  
    pC1->ShowVolume();                   // Output the volume of CBox
    cout << endl << "Delete CBox" << endl;
    delete pC1;                          // Now clean up the free store
  
    pC1 = new CGlassBox(4.0, 5.0, 6.0);  // Create CGlassBox dynamically
    pC1->ShowVolume();                   // ...output its volume...
    cout << endl << "Delete CGlassBox" << endl;
    delete pC1;                          // ...and delete it
  
    pC1 = &myCan;                        // Get myCan address in pointer
    pC1->ShowVolume();                   // Output the volume of CCan
  
    pC1 = &myGlassBox;                   // Get myGlassBox address in pointer
    pC1->ShowVolume();                   // Output the volume of CGlassBox
  
    cout << endl;
    return 0;
  }