How can I determine if a C++ object has been deallocated?

Question

I have a previous question that was answered in which I describe difficulties catching an exception when I try to access an object that has been deallocated by a third-party

Answer 1

create a destructor that notifies upon desrtruction. It could even toggle a bool, if you wanted to check it during runtime.

class free
{

public:

    ~free() { cout << "Im being freed " << endl; } //destructor output
};

This will output in console that its being freed. After being freed, any reference to it will be undefined behaviour, even if it appears to exist.