This is a fine tutorial, but I must note that Rust async programming is a bad way to learn about Rust, and also is a bad way to learn about async programming. You should learn the basics of both Ruts and async programming elsewhere, and then try Rust async programming.

If you disagree, take a look at compile error in https://tokio.rs/tokio/tutorial/streams and think again. That is in fact NOT atypical. (Amusing paradox: you get less errors once you learned, but you get the most terrible errors when you are the least equipped to deal with them.)

To slightly exaggerate, I spend about half my time in Rust support chat channel in my locality to discourage people from trying Rust async programming without getting the basics of Rust. Their logic go: I am interested in Rust only for async network programming, I am not interested in Rust sync network programming, I also learn best by try using something in a project straight away, so I will just learn Rust by writing a Rust async programming project! This literally 100% fails, but people who do this really really want to do it that way, and discouragement doesn't really work, and they get really frustrated, and... I am not sure how to solve this.