fn min(iter: &mut std::iter::Iterator<Item = u32>) -> Option<u32> {
    iter.min()
}

fn max(iter: &mut std::iter::Iterator<Item = u32>) -> Option<u32> {
    iter.max()
}

fn main() {
    println!("Hello, world!");
    let mut squares = (0u32..10u32).map(|x| x * x);

    let m1 = max(& mut squares);
    if m1.is_some() {
        println!("Max {}", m1.unwrap());
    }

    let m2 = min(& squares);
    if m2.is_some() {
        println!("min {}", m2.unwrap());
    } else {
        println!("iterator is empty")
    }
}