std::cmp

Function max_by_key

1.53.0 · Source 
pub fn max_by_key<T, F, K>(v1: T, v2: T, f: F) -> T
where
    F: FnMut(&T) -> K,
    K: Ord,
Expand description

Returns the element that gives the maximum value from the specified function.

Returns the second argument if the comparison determines them to be equal.

§Examples

use std::cmp;

let result = cmp::max_by_key(-2, 1, |x: &i32| x.abs());
assert_eq!(result, -2);

let result = cmp::max_by_key(-2, 2, |x: &i32| x.abs());
assert_eq!(result, 2);