Question

I have a base class A and a derived class B.

class A
{
    A();
    virtual ~A();
    void func1();
    virtual void func2();
};

class B : public A
{
    B();
    ~B();
    void func2();
};

int main()
{
    A* lBaseobj = new A ( );

    lBaseobj->func1( );
    lBaseobj = new B( );
    lBaseobj->func2( );

    delete lBaseobj;
return;
}

My question is: does delete lBaseobj frees the memory allocated to the lBaseobj object by new A( ) as well or not?

Answer 1

If you use smart pointers, memory will not be leaked:

std::unique_ptr<A> lBaseobj(new A());
// or: auto lBaseobj = std::make_unique<A>();
lBaseobj->func1();
lBaseobj.reset(new B()); // will delete resources allocated by new A()
lBaseobj->func2();
return 1; // destructor of lBaseobj will delete resources allocated by new B()