#[derive(Debug, Clone)]
struct Stu {
    name: String,
    age: u32,
}

fn main() {
    let name = String::from("root");
    let age = 3;
    let s = Stu { name, age };
    println!("{:#?}", s);
    println!("{:?}", s);

    let s2 = Stu { ..s };
    println!("{:?} {}", s2, s2.name);
}