(Payroll System Modification) Modify the payroll system of Figs. 1-9 to include private da...

(Payroll System Modification) Modify the payroll system of Figs. 1-9 to include private data member birthDate in class Employee. Use class Date from Figs. 10-11 to represent an employee’s birthday. Assume that payroll is processed once per month. Create a vector of Employee references to store the various employee objects. In a loop, calculate the payroll for each Employee (polymorphically), and add a $100.00 bonus to the person’s payroll amount if the current month is the month in which the Employee’s birthday occurs.

Fig 1. Employee abstract base class. (Part 1 of 2.)

Fig 1. Employee abstract base class. (Part 2 of 2.)

Fig 2. Employee class implementation file. (Part 1 of 2.)

Fig 2. Employee class implementation file. (Part 2 of 2.)

Fig 3. SalariedEmployee class header.

Fig 4. SalariedEmployee class implementation file. (Part 1 of 2.)

Fig 4. SalariedEmployee class implementation file. (Part 2 of 2.)

Fig 5. CommissionEmployee class header. (Part 1 of 2.)

Fig 5. CommissionEmployee class header. (Part 2 of 2.)

Fig 6. CommissionEmployee class implementation file. (Part 1 of 2.)

Fig 6. CommissionEmployee class implementation file. (Part 2 of 2.)

Fig 7. BasePlusCommissionEmployee class header.

Fig 8. BasePlusCommissionEmployee class implementation file. (Part 1 of 2.)

Fig 8. BasePlusCommissionEmployee class implementation file. (Part 2 of 2.)

Fig 9. Employee class hierarchy driver program. (Part 1 of 4.)

Fig 9. Employee class hierarchy driver program. (Part 2 of 4.)

Fig 9. Employee class hierarchy driver program. (Part 3 of 4.)

Fig 9. Employee class hierarchy driver program. (Part 4 of 4.)

Fig 10. Date class definition with overloaded increment operators. (Part 1 of 2.)

Fig 10. Date class definition with overloaded increment operators. (Part 2 of 2.)

Fig 11. Date class member- and friend-function definitions. (Part 1 of 3.)

Fig 11. Date class member- and friend-function definitions. (Part 2 of 3.)

Fig 11. Date class member- and friend-function definitions. (Part 3 of 3.)