Sealed classes - would you want them in D?

[Jesse Phillips]

On Tuesday, 15 May 2018 at 10:19:58 UTC, KingJoffrey wrote:
> My own code in D had bugs, cause I didn't realise all my 
> private parts were not just visible, but accessible by all the 
> so called 'friends' around me. They could reach in a do 
> whatever they want! Without my consent!

You've peaked my interest, could you give some details on one or 
more of these bugs?