main.rs

struct Hoge {
    agony: String
}

impl Drop for Hoge {
    fn drop(&mut self) {
        println!("drop: {}", self.agony);
    }
}

fn main() {
    let mut h = Hoge { agony: String::from("bye bye") };

    // shadow1: Hoge => &mut Hoge::agony
    let h = &mut h.agony;
    println!("after shadow1: {}", h);
    *h = String::from("hello hello");

    // shadow 2: &mut Hoge::agony => integer
    let h = 123;
    println!("after shadow2: {}", h);
}