gistfile1.rs

struct Foo {
    x: int
}

impl Foo: Drop {
    fn finalize() {
        io::println(fmt!("drop: %?", ptr::to_unsafe_ptr(&self)));
    }
}

fn main() {
    let mut x = Foo { x: 2 };

    io::println("before first drop");
    x = Foo { x: 3 };

    io::println("before second drop");
}