OT: WWDC 2021, ARC in Swift: Basics and beyond

[Paulo Pinto]

This year's WWDC 2021 session on ARC optimization was focused on 
handling lifetime bugs caused by misuse of weak and owned 
references, alongside compiler optimizations that ellide 
retain/release calls.

https://developer.apple.com/videos/play/wwdc2021/10216/

Maybe consider if this is the future the anti-GC folks want to 
have in D.

It is nice to throw ARC around when unaware of the details how it 
actually works, possible bugs or crashes.