Tbh rust-analyzer is still pretty great. What bothers me more is that Kotlin is pretty much the only language without an official language server, because it doesn’t align with their business interests…

It’s opt-in in Swift 5 mode and opt-out in Swift 6 mode, the Swift 6 compiler supports both modes though and lets you migrate a codebase on a module-by-module basis.

Agree that opt-in sort of defeats the point, but in practice it’s a sort of unavoidable compromise (and similar to unsafe Rust there will always be escape hatches)

Swift does have data race safety as of Swift 6 with their actor-based concurrency model and are introducing noncopyable types/a more sophisticated ownership model over the next few releases

Swift fits the description too