In c++ vtables ptrs are attached to object instances (although all instances of the same type vtable), while AFAIK in Haskell "vtables ptrs" (better known as function dictionaries) are attached to object pointers (also known as fat pointers). I believe that rust impl traits behave similarly to Haskell. I think go interfaces also use fat pointers.

The advantage is that "interfaces" can be attached to objects non intrusively (and outside of that object declaration, which is a huge win for interoperability), the disadvantage is that pointers are larger and there is no easy way to cross cast between interfaces.

In c++ "fat pointers" (also sometimes known are virtual concepts) are often implemented manually, the most well known example is std::function. We are all waiting for compile time reflection to be able to implement virtual concepts generically (you can only approximate it up to a point currently).