Swift only uses reference counting when working with objects; Structs are optimised using copy-on-write. There's currently work on implementing move and ownership semantics, similar to Rust, but opt-in rather than by default.

I haven’t read that much on Rust, but that should be pretty much it.

Swift has an emphasis on value types, which often are stored on the stack, but only up to a certain size. Copy-on-write makes this feasible - often, those value types are passed by reference until a write actually occurs, but that’s opaque to the dev. Value types can have pointers to reference-counted types - if a value type is passed/copied, any pointer it owns is retained (weirdly enough, they claim that value types have no „lifetime“, but at some point those refs have to be released - we just have to trust the compiler in this).