How to declare a list with different classes that all have the same function?

Question

I'm currently learning c++ and got stuck on the following problem:

I have unknown number of different classes that all have the same function:

class A {
    doStuff();
}
class B {
    doStuff();
}
class C {
    doStuff();
}

There is a function that creates a single one of these classes with the help of templates:

template<class T>
auto createClass(T classToCreate) {
    return make_shared<classToCreate>();
}

And I have a second function that's supposed to start the function "doStuff" within every object.

Is there a way to create a list or something else that I can iterate through so that I can keep the process dynamic?

I'm not sure what I have to search for to find a solution.

Answer 1

This appears a useful place for an abstract (pure virtual) base class. It defines an interface the derived class must implement, but not any of the implementation details.

class I {
public:
    virtual void doStuff() = 0;
};

class A : public I {
public:
    void doStuff() override {
        std::cout << "A\n";
    }
};

class B : public I {
public:
    void doStuff() override {
        std::cout << "Class B\n";
    }
};

class C : public I {
    int x;
public:
    C(int x) : x(x) { }
 
    void doStuff() override {
        std::cout << x << "\n";
    }
};

You can now ensure that the object received by a function implements this functionality.

void foo(I *obj) {
    if (obj) obj->doStuff();
}