41 lines
776 B
Rust
41 lines
776 B
Rust
//@ run-pass
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#![allow(unused_assignments)]
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// Drop works for union itself.
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// FIXME(static_mut_refs): this could use an atomic
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#![allow(static_mut_refs)]
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use std::mem::ManuallyDrop;
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struct S;
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union U {
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a: ManuallyDrop<S>
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}
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impl Drop for S {
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fn drop(&mut self) {
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unsafe { CHECK += 10; }
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}
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}
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impl Drop for U {
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fn drop(&mut self) {
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unsafe { CHECK += 1; }
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}
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}
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static mut CHECK: u8 = 0;
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fn main() {
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unsafe {
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let mut u = U { a: ManuallyDrop::new(S) };
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assert_eq!(CHECK, 0);
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u = U { a: ManuallyDrop::new(S) };
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assert_eq!(CHECK, 1); // union itself is assigned, union is dropped, field is not dropped
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*u.a = S;
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assert_eq!(CHECK, 11); // union field is assigned, field is dropped
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}
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}
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