Question

Even though there are so many articles on how virtual functions are handled in c++, i could not clear one basic doubt. Is vptr variable of derived class overrided by base class variable. Is the ptr varible also name mangled?

Class Base
{
public:
    virtual void test();
};

class Derived 
{
public:
     virtual void test();
};

If I call

Base b = new Derived();
b->test();

It transforms to

(*b->vptr[<index>])(b);

Where index points to vtable entry.

My doubt is whether is this vptr also name mangled ?

Answer 1

The C++ standard doesn’t even acknowledge the existence of a vptr in polymorphic classes because it’s an implementation detail and therefore it isn’t even a requirement that compilers implement virtual functions in this way. So no, vptr is not a reserved keyword (which is what I think you’re trying to ask).