CareerCup

I suppose one question would be why you are attempting to extend a class that was not designed for inheritance (or else it would have been given a virtual destructor). I'm sure there may be situations when you might need to do something like that, but are you sure you need to use inheritance here? Is this an interview question?

I think question is incomplete, whether this base class has virtual functions or not ? if not then why we need virtual destructor if no polymorphism.

I hope we need to overload new and delete operator in derived class.

Make a new base class BaseX by inheriting from the third party Base class and Declare destructor of this new BaseX as virtual. Now use new BaseX wherever you need to inherit. This will resolve all your issues.

Why do we need to inherit it even? I will create a wrapper class and make the third party's class a member and forward all the functions to that member. When my class goes out of scope, the destructor of the member will be called and it will be properly cleaned up.

I think when you inherit in derived class, do not create pointer object of base class. Always create pointer object of derived one and it will always call the derived class destructor and not base.