fn iterator_sum() {
    let v1 = vec![1, 2, 3];

    let v1_iter = v1.iter();

    let total: i32 = v1_iter.sum();

    println!("{}", total);


    let v1_iter = v1.iter();

    let total_plus_one: i32 = v1_iter.map(|x| x + 1).sum();

    println!("{}", total_plus_one);


    let v1_iter = v1.iter();

    let v1_plus_one: Vec<i32> = v1_iter.map(|x| x + 1).collect();

    println!("{:?}", v1_plus_one);

}

fn main() {
    iterator_sum();
}