Function rand::sample

pub fn sample<T, I, R>(rng: &mut R, iterable: I, amount: usize) -> Vec<T> where
    I: IntoIterator<Item = T>,
    R: Rng, 

Randomly sample up to amount elements from an iterator.

Example

use rand::{thread_rng, sample};

let mut rng = thread_rng();
let sample = sample(&mut rng, 1..100, 5);
println!("{:?}", sample);