Comment by markasoftware

IMO type safety requires both language features and a mindset where you take efforts to keep things type safe. Your example has only the former.

For example, in a Rust web app, you can choose to use String for encoded URLs, unencoded URL fragments, escaped html, unescaped HTML, usernames, etc. Or you can choose to use newtypes and carefully design all APIs to only take and return the correct newtypes.