Python Learning

[Bill]

Christian Gollwitzer wrote:
>
> You don't need to explain a vtable to explain dynamic_cast. Only if 
> you want to become a compiler writer. It is not even required, vtables 
> are just the most common implementation.
>
> dynamic_cast simply checks if the actual object that the pointer 
> points to is an instance of a derived class, and then casts it into 
> that. You could "explain" it with the following pseudo-code
>
> template <T*, base*>
> T* dynamic_cast<T*>(base *input) {
>     if (isinstanceof(base, *input)) { return (T*)input; }
>     else { return nullptr; }
> }
>
> How that works (particularly the "isinstanceof") is not the business 
> of the programmer - it is sufficient to know that the compiler 
> somewhere stores this information for every object.
>
>     Christian

With that, the students would "boo you off the stage!"... and maybe 
accuse you of being a "know it all".  ; )    The point of college is 
more about teaching students to think rather than in being efficient.  I 
have little doubt that a tech school could "get through everything" much 
faster.

Bill