What is the preferred way of matching a variable with a pattern guard that doesn't use the matched value?

Question

Between the two snippets below, which is the better / preferred one?

fn main() {
    let pair = 7;

    match pair {
        pair if pair > 5 => println!("Yeah"),
        _ => println!("No"),
    }
}

fn main() {
    let pair = 7;

    match pair {
        _ if pair > 5 => println!("Yeah"),
        _ => println!("No"),
    }
}

And is there a better way to write this? Because this doesn't work:

fn main() {
    let pair = 7;

    match pair {
        > 5 => println!("Yeah"),
        _ => println!("No"),
    }
}

Answer 1

The version that does not bind the matched variable is preferred:

fn main() {
    let pair = 7;

    match pair {
        _ if pair > 5 => println!("Yeah"),
        _ => println!("No"),
    }
}

This is the shortest version with a match. Of course, this example could just use an if.

I'm actually surprised that the first version does not give a warning about unused variables.

Ah, this was me being silly. The variable is used here, in the pattern guard. ^_^