C++ Parent Class with Abstracted Function that Uses Functions in a Child Class - class

Question

I am trying to create a C++ parent class that has two functions, f1 and f2, to be implemented in the child class. This parent class has a function, abstractedFunction that abstracts how f1 and f2 should be used together. Both f1 and f2 are implemented in the child class as shown in the code below.
#include <iostream>
class Parent
{
public:
int f1(); // To be implemented in the derived class
void f2(int i); // To be implemented in the derived class
void abstractedFunction() { // Abstracted in the parant class
auto r = f1();
f2(r);
}
};
class Child : public Parent
{
public:
int f1() {
std::cout << "f1 is implemented in the child class\n";
return 1;
}
void f2(int i) {
std::cout << "f2 is implemented in the child class\n";
std::cout << "Return value for f1 = " << i << "\n";
}
};
int main() {
Child ch;
ch.abstractedFunction();
return 0;
}
Is such a concept implementable in C++?

Answer 1

Yes, You can do something like this. You need to make the functions defined in base class as pure virtual : Follow this link to know more about them and then you can create an object of derived class and assign it to the base pointer to make a required function call
#include <iostream>
using namespace std;
class Parent
{
public:
virtual int f1()=0; // To be implemented in the derived class
virtual void f2(int i)=0; // To be implemented in the derived class
void abstractedFunction() { // Abstracted in the parant class
auto r = f1();
f2(r);
}
};
class Child : public Parent
{
public:
int f1() {
std::cout << "f1 is implemented in the child class\n";
return 1;
}
void f2(int i) {
std::cout << "f2 is implemented in the child class\n";
std::cout << "Return value for f1 = " << i << "\n";
}
};
int main() {
Parent *ptr;
Child c;
ptr=&c;
ptr->abstractedFunction();
return 0;
}