main.cc

#include <iostream>
#include <vector>

class Shape {
  public:
    virtual void print() = 0;
};

class Square : public Shape {
  virtual void print() {
    std::cout << "Square" << std::endl;
  }
};

class Rectangle : public Shape {
  virtual void print() {
    std::cout << "Rectangle" << std::endl;
  }
};

class CompositeShape : public Shape {
  public:
    virtual void print() {
      for (auto &shape : this->shapes) {
        shape->print();
      }
    }

    void add(Shape *shape) {
      this->shapes.push_back(shape);
    }
  private:
    std::vector<Shape*> shapes;
};

int main() {
  CompositeShape* compShape = new CompositeShape;
  Rectangle* rect = new Rectangle;
  Square* sq = new Square;
  Rectangle* rect2 = new Rectangle;

  compShape->add(rect);
  compShape->add(sq);
  compShape->add(rect2);

  compShape->print();
}