//#[derive(Debug)]
struct Foo {
    bar: Bar,
}

impl Foo {
    fn inc2(&mut self) -> i32 {
        dbg!("in Foo::inc2");
        self.v += 10;
        self.v
    }
}

impl std::ops::Deref for Foo {
    type Target = Bar;

    fn deref(&self) -> &Self::Target {
        &self.bar
    }
}

impl std::ops::DerefMut for Foo {
    fn deref_mut(&mut self) -> &mut Bar {
        &mut self.bar
    }
}

#[derive(Debug,Clone)]
struct Bar {
    v: i32,
}

impl Bar {
    fn inc(&mut self) -> i32 {
        dbg!("in Bar::inc");
        self.v += 1;
        self.v
    }
}

fn main () {
    let mut x = Bar {v: 5};
    dbg!(&x);
    x.inc();
    dbg!(x.inc());
    dbg!(x.inc());
    dbg!(x.clone());

    let mut y = Foo { bar: x };
    //let y = &mut y;
    y.inc2();
    y.inc();
    dbg!(&y as &Bar);
    dbg!(y.clone());
    dbg!(&*y);
}