Sealed classes - would you want them in D?

[KingJoffrey]

On Friday, 11 May 2018 at 10:43:19 UTC, rikki cattermole wrote:
> Classes are expensive, not everybody wants to pay for what it 
> gives in all situations.

Mmm...that claim is so broad is to be meaningless.

Good memory allocation algorithms, intelligent optimising 
compilers/runtimes, prudent use of class inheritance and other 
features, etc..etc.... all this can change performance one way or 
the other.

Programs that do not use classes can (very easily) become poor 
peforming too.

Anyway... nice way for you to sidetrack my argument ;-)
(which is about correcting, the incorrect implementation of class 
enscapsulation in D - so I can start using it).