Rust min! and max! macros

min-max.rs

macro_rules! max {
    ($x:expr) => ( $x );
    ($x:expr, $($xs:expr),+) => {
        {
            use std::cmp::max;
            max($x, max!( $($xs),+ ))
        }
    };
}

macro_rules! min {
    ($x:expr) => ( $x );
    ($x:expr, $($xs:expr),+) => {
        {
            use std::cmp::min;
            min($x, min!( $($xs),+ ))
        }
    };
}

fn main() {
    println!("{:?}", max!(2, 5, 9, -42, 5));
    println!("{:?}", min!(2, 5, 9, -42, 5));
}

thanks