In my experience it has a solid 90+% of the semantic expressiveness - ADTs, advanced pattern matching, if statements and similar being expressions, traits (spli

In my experience it has a solid 90+% of the semantic expressiveness - ADTs, advanced pattern matching, if statements and similar being expressions, traits (split into "protocols" and "extensions" in Swift), automatic reference counting, a well-defined ownership model (albeit not quite as strict as Rust's), constructs to prevent data races, etc. It lacks things like explicit control over lifetimes, and also defaults to copy-on-write rather than to move semantics - that isn't unsafe, but it does lead to beginners writing programs that compile fine but behave in a way that's surprising to them. It also doesn't expose threads directly (similar to Go only having goroutines), but the concurrency model is quite nice to use. The language is obviously opinionated about its async runtime (Grand Central Dispatch, which is also available on Windows and Linux) so you don't have to wrangle with that yourself though of course it loses the power and flexibility of bringing your own. On the flip side, Swift provides a lot of syntactic sugar that makes it feel faster/smoother to engage with than Rust. For example, enum literals don't have to specify the enum's name wherever their type can be inferred by the compiler. So e.g. when you are pattern matching on an enum value, the match arm `MyEnum::Red => {}` in Rust would just be `case .Red:` in Swift. It isn't much on its own, but each tiny QoL thing like this adds up.