DM560, Introduction to Programming in C++

#include<iostream>

using namespace std;


class B1 {
public:
  virtual void vf() {cout<<__PRETTY_FUNCTION__<<endl;};
  void f() {cout<<"B1:f()"<<endl;};
  //virtual void pvf() = 0;
};


class D1 : public B1 {
public:
  void vf() override {cout<<__PRETTY_FUNCTION__<<endl;};
  //void f() {cout<<"D1:f()"<<endl;}; 
};


class D2 : public D1 {
public:
  //void pvf() override {cout<<__PRETTY_FUNCTION__<<endl;};
};


class B2 {
public:
  virtual void pvf() = 0;
};


class D21 : public B2 {
public:
  void pvf() override {cout<<s<<endl;};
private:
  string s="ciao";
};


class D22 : public B2 {
public:
  void pvf() override {cout<<i<<endl;};
private:
  int i=23;
};


void f(B2 &b) {
  b.pvf();
}
  

int main (int argc, char **argv) {
  /*
  cout << "Task. 1"<<endl;
  B1 b1;
  b1.vf();
  b1.f();

  cout << "Task. 2"<<endl;
  D1 d1;
  d1.vf();
  d1.f();

  cout << "Task. 3"<<endl;
  B1& b2=d1;
  b2.vf();
  b2.f();
  
  cout << "Task. 6"<<endl;
  D2 d2;
  d2.f();
  d2.vf();
  d2.pvf();
  */

  cout << "Task. 7"<<endl;
  D21 d21;
  D22 d22;
  f(d21);
  f(d22);
  exit(EXIT_SUCCESS);
}