| //@ run-pass | 
 | #[derive(PartialEq, Debug)] | 
 | pub struct Partial<T> { x: T, y: T } | 
 |  | 
 | #[derive(PartialEq, Debug)] | 
 | struct S { val: isize } | 
 | impl S { fn new(v: isize) -> S { S { val: v } } } | 
 | impl Drop for S { fn drop(&mut self) { } } | 
 |  | 
 | pub fn f<T, F>((b1, b2): (T, T), mut f: F) -> Partial<T> where F: FnMut(T) -> T { | 
 |     let p = Partial { x: b1, y: b2 }; | 
 |  | 
 |     // Move of `p` is legal even though we are also moving `p.y`; the | 
 |     // `..p` moves all fields *except* `p.y` in this context. | 
 |     Partial { y: f(p.y), ..p } | 
 | } | 
 |  | 
 | pub fn main() { | 
 |     let p = f((S::new(3), S::new(4)), |S { val: z }| S::new(z+1)); | 
 |     assert_eq!(p, Partial { x: S::new(3), y: S::new(5) }); | 
 | } |