Create an Employee subclass called PieceWorker. A PieceWorker represents an employee whose pay is based on the number of pieces of merchandise produced.

Class PieceWorker should contain private data member wage (to store the employee’s wage per piece) and pieces (to store the number of pieces produced). provide a concrete implementation of:

The Constructor
Member function earnings that calculates the employee’s earnings by multiplying the number of pieces produced by the wage per piece.
The implementation of the above methods should be done outside the PieceWorker class.

Note: the implementation of the Employee class is provided here:

class Employee {

public:

Employee(const string& first, const string& last, const string& ssn)

: firstName(first), lastName(last), socialSecurityNumber(ssn) {}

virtual ~Employee() = default;

virtual double earnings() const = 0;

private:

std::string firstName;

std::string lastName;

std::string socialSecurityNumber;

};