Here's an example: `Stdin` and `File` both implement the `Read` trait. Therefore, you can write a function that takes the traits that you want to use as input p

Here's an example: `Stdin` and `File` both implement the `Read` trait. Therefore, you can write a function that takes the traits that you want to use as input parameters. fn do_something_with<S: Read>(source: S) { // do something with input source } Then you can do the following: let stdout = io::stdout(); do_something_with(stdout.lock()); let file = File::open(path).unwrap(); do_something_with(file); You're free to narrow down/expand the types/methods that can be used with the function if you add more traits.