Function flash_sort 

pub fn flash_sort<T>(arr: &mut [T], get_key: fn(&T) -> i32)
where
    T: Copy + Clone,

Flash Sort is an algorithm that use the strategy that you can compute the approximate final position directly from the element value, with no comparisons.

Examples

extern crate sort_algorithms;
use sort_algorithms::flash_sort;


let mut arr = vec![7, 6, 5, 2, 4, 3, 1, 0, -1];
flash_sort(&mut arr, |&a| a);
assert_eq!(arr, [-1, 0, 1, 2, 3, 4, 5, 6, 7]);