struct Foo {
    b: Bar,
    z: Baz,
}

struct Bar {
    n: u32,
}

impl Bar {
    fn eat(self) -> u32 {
        self.n
    }
}

struct Baz {
    c: char,
}

impl Baz {
    fn get(&self) -> char {
        self.c
    }
}

fn close<F>(f: F) -> char
where F: Fn() -> char {
    f()
}

fn main() {
    let f = Foo{
        b: Bar{ n: 12u32 },
        z: Baz{ c: 'a' },
    };
    let _n = f.b.eat();
    let z = f.z;
    close(|| z.get() );
}