Question About Polymorphism And Function Calls

Question

Can a polymorphed class only call functions that exist/are derived from the base class if the object is a pointer to the base class? And if so, is there a possible work-around to call the derived functions?

class A{
public:
virtual void go() = 0;
};

class B : public A{
public:
void go() {
//stuff
}
void stop() {
//other stuff
}
};

int main() {
A *a = new B;
a->go();
a->stop(); //Doesn't know about 'stop'
}

Answer 1

not that I am aware. Having a stop() in A is how I would go about this.

Answer 2

You can always recast it to call derived functions. This will work:

https://code.sololearn.com/c3auwm2ywMkO/#cpp

Answer 3

I would use a dynamic_cast <> in this case though, just in case. Then check that it's not a nullptr before using it.