Merge subroutine like a rustaceans

rust_merge.rs

fn Merge(c: Vec<i32>, d: Vec<i32>) -> Vec<i32> {
    let l: usize = c.len() + d.len();

    // initialize result array
    let mut b: Vec<i32> = vec!(0; l);

    // initialize readers indexes
    let mut i: usize = 0;
    let mut j: usize = 0;

    for k in 0..l {
      // get value or None from the two array
      let (c_value, d_value) = (c.get(i), d.get(j));

      // safe and neat  
      match (c_value, d_value) {
            (None, None) => break,
            (None, Some(_)) => {
                b[k] = d[j];
                j += 1;
            },
            (Some(_), None) => {
                b[k] = c[i];
                i += 1;
            },
            (Some(_), Some(_)) =>  match c_value.unwrap() < d_value.unwrap() {
                true => {
                    b[k] = c[i];
                    b[k+1] = d[j];
                    i += 1;
                },
                false => {
                    b[k] = d[j];
                    b[k+1] = c[i];
                    j += 1;
                }
            }
        }
    }

    return b

}