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Add non-non-zero test to union-nonzero test

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Peter Todd 2019-05-07 12:17:28 -04:00
parent 76c5229021
commit aa1db2476a
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1 changed files with 8 additions and 0 deletions
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8
src/test/run-pass/union/union-nonzero.rs
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@ -24,10 +24,18 @@ union U2<A: Copy, B: Copy> {
b: B,
}
// Option<E> uses a value other than 0 and 1 as None
#[derive(Clone,Copy)]
enum E {
A = 0,
B = 1,
}
fn main() {
// Unions do not participate in niche-filling/non-zero optimization...
assert!(size_of::<Option<U2<&u8, u8>>>() > size_of::<U2<&u8, u8>>());
assert!(size_of::<Option<U2<&u8, ()>>>() > size_of::<U2<&u8, ()>>());
assert!(size_of::<Option<U2<u8, E>>>() > size_of::<U2<u8, E>>());
// ...even when theoretically possible:
assert!(size_of::<Option<U1<&u8>>>() > size_of::<U1<&u8>>());