7 trait Changer : Sized {
8 fn change(mut self) -> Self {
13 fn change_again(mut self: Box<Self>) -> Box<Self> {
18 fn set_to(&mut self, a: isize);
22 fn set_to(&mut self, a: isize) {
29 let new_x = x.change();
30 assert_eq!(new_x.a, 55);
32 let x: Box<_> = Box::new(new_x);
33 let new_x = x.change_again();
34 assert_eq!(new_x.a, 45);