Function std_tools::max

pub fn max<I>(iterable: I) -> Option<<I as IntoIterator>::Item> where
    I: IntoIterator,
    <I as IntoIterator>::Item: Ord, 

Return the maximum value of the iterable.

IntoIterator enabled version of Iterator::max.

use itertools::max;

assert_eq!(max(0..10), Some(9));