Early-breaking from Rust's match

Question

I want to switch through many possible cases for x and there\'s one case (here x == 0) where I want to check the result of some additional code to

Answer 1

Something else you could do is make a "self-executing" closure and use a return statement inside. I don't know whether there are any weird performance characteristics of this but syntactically it's pretty clean.

fn main() {
    let x = 1;

    // This closure is just used to catch the "return" statement.
    (|| {
        match x {
            1 => {
                let y = 0;
                /*
                 * do ev1l stuff to y that I don't want to put into the match-guard
                 * as it's simply too much.
                 */

                /* break early ... */
                if y == 0 { return; } // Ok!

                assert!(y != 0, "y was 0!");
                /* do other stuff in here. */
            }
            _ => {}
        }
    })();

    println!("done matching");
}

Here's a playground link showing it working.