Sealed classes - would you want them in D? (v2)

[KingJoffrey]

On Thursday, 17 May 2018 at 02:32:07 UTC, KingJoffrey wrote:
> I propose an idea, for discussion (robust discussion even 
> better ;-)  ....

oh, and it would be great, if the D 'elite' could way in to the 
discussion as well, as opposed to only waying in *after* a DIP is 
put forward.

All ideas would be helpful, including how complex it 'might' be 
to implement (compiler people).

Would it, or could it, break compatability - in any 
way..etc.etc...