Silly question

[Ary Borenszweig]

janderson wrote:
> Jarrett Billingsley wrote:
>> "janderson" <askme at me.com> wrote in message 
>> news:fuorvl$2j02$1 at digitalmars.com...
>>
>>> They are however in my book this is plain wrong.  The whole purpose 
>>> of being able to hide abstraction layers is broken.  I should be able 
>>> to protect inherited functions from objects that work on that level.  
>>> Its a fundamental principle in C++.
>>
>> What?
>>
>> Am I the only one who can't understand what this post means?
>>
> 
> 
> I have a interface:
> (I'm using C++ because this won't work in D)
> 
> class OnRenderI
> {
>    public:
>     virtual void OnRender() = 0;
> };
> 
> 
> I have a derived class:
> 
> class A : OnRenderI
> {
>    public:
>     A() {  GetRender().Add(Me); }
>    private:  //Or protected
>     virtual void OnRender(); //This is good private
> }

Are you decreasing the visibility of method OnRender? I don't get it...

void foo(A a) {
   a.OnRender(); // nope, it's private

   OnRenderI r = (OnRenderI) a;
   r.OnRender(); // Now it's public??
}

I'm sure misunderstanding something...