Both Swift and Rust use reference counting in different ways. Swift uses reference counting for all reference types (classes), but idiomatic Swift encourages u

Both Swift and Rust use reference counting in different ways. Swift uses reference counting for all reference types (classes), but idiomatic Swift encourages using value types over reference types when possible. The chief reason to use a reference type is when you need shared ownership. Value types are not reference counted, though they may contain RC'd fields. Rust has reference counting implemented in a library (Rc and Arc), which is what Rust programmers reach for when they need shared ownership. Rust also has a 1-bit reference count called the drop flag, which is used to dynamically determine when an object's destructor should run.