Function out::max_by_cached_key

pub fn max_by_cached_key<T, K: Ord>(
    v: &mut [T], 
    n: usize, 
    f: impl FnMut(&T) -> K
) -> &mut [T]

Get the n largest items with a key extraction function.

The key function is called only once per element, but for simple key functions max_by_key is likely to be faster.

This function is stable, i.e. it preserves the order of equal elements.

Panics

Panics if n > len.

Examples

let mut v = [-5_i32, 4, 1, -3, 2];
let max = out::max_by_cached_key(&mut v, 3, |a| a.abs());
assert_eq!(max, [-3, 4, -5]);