#include <iostream>
using namespace std;

class A {
    public:
    A() {
        cout << "A::A() called.\n";
    }
    virtual ~A() {
        cout << "A::~A() called.\n";
    }
};

class B: public A {
    public:
    B(int i) {
        cout << "B::B() called.\n";
        buf = new char[i];
    }
    virtual ~B() {
        delete [] buf;
        cout << "B::~B() called.\n";
    }

    private:
    char *buf;
};

void fun(A *a) {
    delete a;
}

int main() {
    A *a = new B(15);
    fun(a);
}

/*
A::A() called.
B::B() called.
B::~B() called.
A::~A() called.
*/