struct A {
    v: usize
}


fn b(a: A) -> A {
    println!("p {:p}", &a.v);
    a
    // A { v: a.v }
}

fn main() {
  let a = A { v: 100 };
  println!("p {:p}", &a.v);
  let a = b(a);
  println!("p {:p}", &a.v);
}