#[derive(Debug)]
enum Packet {
    Sample{number: u64, total: u64, send_time: u64, core: u16},
}

fn main() {
    let mut a = Packet::Sample{
        number: 0,
        total: 0,
        send_time: 0,
        core: 0,
    };

    match a {
        Packet::Sample {
            ref mut number,
            ref mut total,
            ..
        } => {
            *number = 1;
            *total = 2;
        },
    }

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