// 条件trait

trait GetName {
    fn get_name(&self) -> String;
}

trait ShowName {
    fn show_name(&self);
}

impl<T: GetName> ShowName for T {
    fn show_name(&self) {
        println!("{}", self.get_name());
    }
}

struct Stu {
    name: String,
}

impl GetName for Stu {
    fn get_name(&self) -> String {
        return self.name.clone();
    }
}

fn main() {
    let s = Stu {
        name: String::from("root"),
    };
    s.show_name();
}