...You can run rustfmt with Rust 1.24 and above. Rustfmt tries to work on as much Rust code as possible. Sometimes, the code doesn't even need to compile! In general, we are looking to limit areas of instability; in particular, post-1.0, the formatting of most code should not change as Rustfmt improves. However, there are some things that Rustfmt can't do or can't do well (and thus where formatting might change significantly, even post-1.0). We would like to reduce the list of limitations over time. You can run Rustfmt by just typing rustfmt filename if you used cargo install. ...