29 lines
977 B
Rust
29 lines
977 B
Rust
//@ run-pass
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#[derive(PartialEq, Debug)]
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pub struct Partial<T> { x: T, y: T }
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#[derive(PartialEq, Debug)]
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struct S { val: isize }
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impl S { fn new(v: isize) -> S { S { val: v } } }
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impl Drop for S { fn drop(&mut self) { } }
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pub type Two<T> = (Partial<T>, Partial<T>);
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pub fn f<T, F>((b1, b2): (T, T), (b3, b4): (T, T), mut f: F) -> Two<T> where F: FnMut(T) -> T {
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let p = Partial { x: b1, y: b2 };
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let q = Partial { x: b3, y: b4 };
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// Move of `q` is legal even though we have already moved `q.y`;
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// the `..q` moves all fields *except* `q.y` in this context.
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// Likewise, the move of `p.x` is legal for similar reasons.
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(Partial { x: f(q.y), ..p }, Partial { y: f(p.x), ..q })
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}
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pub fn main() {
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let two = f((S::new(1), S::new(3)),
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(S::new(5), S::new(7)),
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|S { val: z }| S::new(z+1));
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assert_eq!(two, (Partial { x: S::new(8), y: S::new(3) },
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Partial { x: S::new(5), y: S::new(2) }));
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}
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