Class Inheritance

[Demoris]

I have two classes: A and B.

Class B is a child class of A.

In class A I have the friend operator>> overloaded, and want to access a public function from the child class B.

However, when I build, I get the error "class A has no member named function".

Why can't I access the public function in the child class?

code snippets:

//Parent Class A: 
istream& operator>>(istream& ins, A& c)
{
    getline(ins, c.title);
    ins >> c.size;
 
    for (int i = 0; i < c.size; i++)
        ins >> c.people[i];
    c.function(c.people, c.size); //this line produces error
 
    return ins;
}
 
//Child Class B:
void B::function(A people[], int& size)
{
    //....
}
 

[Ganon11]

In general, a superclass (A) knows nothing about its subclasses (B). So how can A call a function defined in B?

B, however, can call a function in A. Subclasses do know about their superclasses.

[Demoris]

In general, a superclass (A) knows nothing about its subclasses (B). So how can A call a function defined in B?

B, however, can call a function in A. Subclasses do know about their superclasses.

How could I call the function from within the parent class?

The function in the child class is public.

[Banfa]

How could I call the function from within the parent class?

The function in the child class is public.

How do you plan to determine if the object in question is of type B or A or some other subclass of A?

[Ganon11]

You could include the same function in A, and either provide a unique definition or make it virtual. That way, any subclass of A can (or, if virtual, must) include a definition of that method, and you can call the method on any A object. At run-time, though, it would be determined that the object is actually a B, and the B function would be used rather than the A.

[Banfa]

(or, if virtual, must)

Could be pure virtual.

[Ganon11]

In which case any subclass must define it or still declare it as pure virtual and be abstract. Since the OP ncluded a definition in B of function, I assumed he would want to define it and, thus, either pure virtual or virtual could work in A.

[Banfa]

In which case any subclass must define it or still declare it as pure virtual and be abstract. Since the OP ncluded a definition in B of function, I assumed he would want to define it and, thus, either pure virtual or virtual could work in A.

Sorry I misread your original post and thought you were refering to class A not a sub-class of class A