[Rust] Borrowing demo

fn main() {
    let v = vec![1, 2, 3];

    // Borrow v to sum
    let s = sum(& v);

    println!("{}", s);

    // v is still accessible
    println!("{}", v[1]);
}

fn sum(v: &Vec<i32>) -> i32 {
    let mut sum = 0;

    for e in v.iter() {
        sum += *e;
    }

    sum
}