macro_rules! parsing {
    (INNER $head:expr) => {
        $head.parse::<i64>().unwrap()
    };

    (INNER $head:expr, $($tail:expr),*) => {
        parsing!(INNER $($tail),*);
        parsing!(INNER $head);
    };

    ($var:ident, $($vals:expr),*) => {
        let $var = [parsing!(INNER $($vals),*)];
    };
}


fn main() {

    //let mut arr: [i64; 4];
    parsing!(arr, "10", "20", "30", "40");

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