A long time ago, the Rust language was a language with typestate. Officially, typestates were dropped long before Rust 1.0. In this entry, I’ll get you in on the worst kept secret of the Rust community: Rust still has typestates. Wait, what’s a typestate? Consider an object representing a file – let’s call that data structure a MyFile. Before a MyFile is opened, it cannot be read. Once a MyFile is