The memory management strategies in Rust and Swift are similar. The big performance hit in Swift would come in method dispatch where it’s following Objective C strategies which would result in indirect calls for object methods. This is possible in Rust (using Box(dyn trait)), but discouraged in critical paths in favor of either static dispatch by means of enums or reified calls through Rust generics. Swift has similar capabilities, of course, but with both languages, the best performance reqires consciously making choices in development.