I only want one feature from Swift: faster type-checking. If you write a few lines of math, or a moderately complex SwiftUI expression, suddenly the typechecker starts timing out. Swift is the only language I've ever used with this problem.

https://hachyderm.io/@evanw/109859384302551859

https://www.cocoawithlove.com/blog/2016/07/12/type-checker-i...

https://danielchasehooper.com/posts/why-swift-is-slow/

This isn't mentioned at all in the announcement so I'm kind of disappointed.