// Ex9_10.cpp
  // Using an abstract class
  include <Box.h>                       // For CBox and CContainer
  include <Can.h>                       // For CCan (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(void)
  {
    // Pointer to abstract base class
    // initialized with address of CBox object
    CContainer* pC1 = new CBox(2.0, 3.0, 4.0);
  
    // Pointer to abstract base class
    // initialized with address of CCan object
    CContainer* pC2 = new CCan(6.5, 3.0);
  
    pC1->ShowVolume();                   // Output the volumes of the two
    pC2->ShowVolume();                   // objects pointed to
    cout << endl;
  
    delete pC1;                          // Now clean up the free store
    delete pC2;                          // ....
  
    return 0;
  }