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

between 2 snippets below, 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 there better way write this? because doesn't work:

fn main() {     let pair = 7;      match pair {         > 5 => println!("yeah"),         _ => println!("no"),     } } 

the version not bind matched variable preferred:

fn main() {     let pair = 7;      match pair {         _ if pair > 5 => println!("yeah"),         _ => println!("no"),     } } 

this shortest version with match. of course, example use if.

i'm surprised first version not give warning unused variables.

ah, me being silly. variable is used here, in pattern guard. ^_^