Classes, derived classes, and non-member functions

[dirtydit27]

I have a questions about classes in C++. I'm working on a homework assignment where I have a class called Person and a derived class called Doctor. I also have two other classes that are called Date and Bill. I'm suppose to create a class drived from Person and call it Patient.The only thing thats tripping me up is that the Patient class should hold information from the Bill class and the Date class. I was thinking that I should create nonmember functions in Bill and Date that would allow a Patient object to access the members in both class, but I'm not sure if that's legal.

[tinstaafl]

You can declare objects of type Bill and Date and use the public members in your class. For instance:

class Date
{
public:
    int year;
    string month;
    int day;
    int hour;
    int minute;
    Date()
        :year(1900),
        month("Jan."),
        day(1),
        hour(0),
        minute(0)
    {
    }
};
class Bill
{
public:
    Date lastPayment;
    Date nextPayment;
    double amountOwing;
    Bill()
        :amountOwing(0.00)
    {
    }

};
class Person
{
public:
    string firstName;
    string lastName;
    Address address;
    Person()
        :firstName(""),
        lastName("")
    {
    }
};
class Doctor : Person
{
};
class Patient : Person
{
    Bill bill;
    Date lastAppointment;
    Date nextAppointment;
};

When you declare an object of type Bill,Bill bill;, you can access the public members of the Date class through the objects lastPayment and nextPayment(bill.lastPayment.year).