#[derive(Debug)]
pub struct Jo { ip: String }

#[derive(Debug)]
pub enum Data {
    Join(Jo),
    Pos(u8),
}

trait Protocols
{
    fn join(self);
}

impl Protocols for Data
{
    fn join(self) {
        println!("{:?}", self.ip); //<------------- ?
    }
}

fn main() {
    let data = Data::Join(Jo{ip:"me".to_string()});
    data.join();
}