r30m-ownership-2.rs

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

    // vector.iter_mut().map(|e| e.add(1));
    // ERROR: cannot borrow `*vector` as mutable, as it is behind a `&` reference

    for item in vector {
        sum = sum + item
    }

    sum
}

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

    println!("sum of {:?}: {}", v, s); // Now valid
}