Sorta? shows polymorphism in cc

polymorphism.cc

#include <bits/stdc++.h>

struct Shape {
    virtual double area() {
        std::cout << "I am a Shape\n";
        return 0.0;
    }// non-pure virtual
};


struct Rectangle : public Shape {
    int w, h;
    Rectangle(int _w, int _h) : w(_h), h(_h) {}
    double area() { // override
        std::cout << "I am a Rectangle: \n";
        return this->w * this->h;
    }
};

struct Triangle : public Shape {
    int w, h;
    Triangle(int _w, int _h) : w(_h), h(_h) {}
    double area() { // override
        std::cout << "I am a Triangle: \n";
        return (this->w * this->h) / 2;
    }
};

int main() {
    std::vector<Shape*> shapes; // mro (method resolution order)
    Rectangle* r1 = new Rectangle(3, 4);
    Shape* t1 = new Triangle(5, 11);
    Shape* s1 = new Shape;
    shapes.push_back(r1);
    shapes.push_back(t1);
    shapes.push_back(s1);

    for(Shape* s : shapes) {
            std::cout << "Area = " << s->area() << "\n";
    }

    return 0;
}