1   // Fig. 12.19: fig12_19.cpp
 2   // Demonstrating downcasting and runtime type information.
 3   // NOTE: You may need to enable RTTI on your compiler
 4   // before you can compile this application.
 5   #include <iostream>
 6   #include <iomanip>
 7   #include <vector>
 8   #include <typeinfo>
 9   #include "Employee.h"
10   #include "SalariedEmployee.h"
11   #include "CommissionEmployee.h"
12   #include "BasePlusCommissionEmployee.h"
13   using namespace std;
14
15   int main()
16   {
17      // set floating-point output formatting
18      cout << fixed << setprecision( 2 );
19
20      // create vector of three base-class pointers
21      vector < Employee * > employees( 3 );
22
23      // initialize vector with various kinds of Employees
24      employees[ 0 ] = new SalariedEmployee(              
25         "John", "Smith", "111-11-1111", 800 );           
26      employees[ 1 ] = new CommissionEmployee(            
27         "Sue", "Jones", "333-33-3333", 10000, .06 );     
28      employees[ 2 ] = new BasePlusCommissionEmployee(    
29         "Bob", "Lewis", "444-44-4444", 5000, .04, 300 ); 
30
31      // polymorphically process each element in vector employees
32      for ( Employee *employeePtr : employees )
33      {
34         employeePtr->print(); // output employee information
35         cout << endl;
36
37         // attempt to downcast pointer                                  
38         BasePlusCommissionEmployee *derivedPtr =                        
39            dynamic_cast < BasePlusCommissionEmployee * >( employeePtr );
40
41         // determine whether element points to a BasePlusCommissionEmployee
42         if ( derivedPtr != nullptr ) // true for "is a" relationship
43         {
44            double oldBaseSalary = derivedPtr->getBaseSalary();
45            cout << "old base salary: $" << oldBaseSalary << endl;
46            derivedPtr->setBaseSalary( 1.10 * oldBaseSalary );
47            cout << "new base salary with 10% increase is: $"
48               << derivedPtr->getBaseSalary() << endl;
49         } // end if
50
51         cout << "earned $" << employeePtr->earnings() << " ";
52      } // end for
53
54      // release objects pointed to by vector's elements
55      for ( const Employee *employeePtr : employees )
56      {
57         // output class name                        
58         cout << "deleting object of "               
59            << typeid( *employeePtr ).name() << endl;
60
61         delete employeePtr;
62      } // end for
63   } // end main