Sealed classes - would you want them in D?

[ketmar]

H. S. Teoh wrote:

> On Fri, May 11, 2018 at 05:28:48PM -0600, Jonathan M Davis via 
> Digitalmars-d wrote:
>> [...] what the OP wants is to have the class be publicly available
>> while restricting who's allowed to derive from it, with the idea that
>> a particular class hierarchy would have a well-defined set of classes
>> that the person who wrote them had full control over rather than
>> allowing anyone and everyone to derive from any class in the hierarchy
>> except for any final classes at the leaves of the hierarchy.
> [...]
>
> I would like to hear of a real-world use case for such a restriction. I
> honestly can't think of one that doesn't have a design smell of some
> sort.  Isn't the whole point of OOP that user code can extend your
> classes to implement functionality you have not thought of, rather than
> you needing to implement everything for them?
>
>
> T

besides, in D, there is a little sense in restricting class anyway, as we 
can kinda "extend" it with UFCS at any time.