fig13_25.cpp

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// Fig. 13.25: fig13_25.cpp
// Demonstrating downcasting and run-time type information.
// NOTE: For this example to run in Visual C++ .NET, 
// you need to enable RTTI (Run-Time Type Info) for the project.
#include <iostream>
using std::cout;
using std::endl;
using std::fixed;

#include <iomanip>
using std::setprecision;
  
#include <vector>
using std::vector;

#include <typeinfo>

// include definitions of classes in Employee hierarchy
#include "Employee.h"
#include "SalariedEmployee.h" 
#include "HourlyEmployee.h"
#include "CommissionEmployee.h"  
#include "BasePlusCommissionEmployee.h" 

int main()
{
   // set floating-point output formatting
   cout << fixed << setprecision( 2 );   
   
   // create vector of four base-class pointers
   vector < Employee * > employees( 4 );

   // initialize vector with various kinds of Employees
   employees[ 0 ] = new SalariedEmployee( 
      "John", "Smith", "111-11-1111", 800 );
   employees[ 1 ] = new HourlyEmployee( 
      "Karen", "Price", "222-22-2222", 16.75, 40 );
   employees[ 2 ] = new CommissionEmployee( 
      "Sue", "Jones", "333-33-3333", 10000, .06 );
   employees[ 3 ] = new BasePlusCommissionEmployee( 
      "Bob", "Lewis", "444-44-4444", 5000, .04, 300 );

   // polymorphically process each element in vector employees
   for ( size_t i = 0; i < employees.size(); i++ ) 
   {
      employees[ i ]->print(); // output employee information
      cout << endl;

      // downcast pointer
      BasePlusCommissionEmployee *derivedPtr =
         dynamic_cast < BasePlusCommissionEmployee * > 
            ( employees[ i ] );

      // determine whether element points to base-salaried 
      // commission employee
      if ( derivedPtr != 0 ) // 0 if not a BasePlusCommissionEmployee
      {
         double oldBaseSalary = derivedPtr->getBaseSalary();
         cout << "old base salary: $" << oldBaseSalary << endl;
         derivedPtr->setBaseSalary( 1.10 * oldBaseSalary );
         cout << "new base salary with 10% increase is: $" 
            << derivedPtr->getBaseSalary() << endl;
      } // end if
      
      cout << "earned $" << employees[ i ]->earnings() << "\n\n";
   } // end for   
 
   // release objects pointed to by vector抯 elements
   for ( size_t j = 0; j < employees.size(); j++ ) 
   {
      // output class name
      cout << "deleting object of " 
         << typeid( *employees[ j ] ).name() << endl;

      delete employees[ j ];
   } // end for

   return 0;
} // end main


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