> Ok, but isn't the question of whether or not something is done at compile or runtime always an implementation detail? The fact that Rust figures out at compile time whether or not to insert the deallocation functions is super awesome, but it doesn't actually change the semantics of the language relative to if has to check flags or reference counts etc.

There is no concept in Swift of a dead object that is in scope. There is in Rust, which is why you see "use of moved value" errors. That is a language difference.