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Diffstat (limited to 'tests/ui/union/union-generic-rpass.rs')
-rw-r--r-- | tests/ui/union/union-generic-rpass.rs | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/tests/ui/union/union-generic-rpass.rs b/tests/ui/union/union-generic-rpass.rs new file mode 100644 index 000000000..25f1f5050 --- /dev/null +++ b/tests/ui/union/union-generic-rpass.rs @@ -0,0 +1,34 @@ +// run-pass +// revisions: mirunsafeck thirunsafeck +// [thirunsafeck]compile-flags: -Z thir-unsafeck + +#![allow(dead_code)] + +use std::mem::ManuallyDrop; + +union MaybeItem<T: Iterator> { + elem: ManuallyDrop<T::Item>, + none: (), +} + +union U<A, B> where A: Copy, B: Copy { + a: A, + b: B, +} + +unsafe fn union_transmute<A, B>(a: A) -> B where A: Copy, B: Copy { + U { a }.b +} + +fn main() { + unsafe { + let b = union_transmute::<(u8, u8), u16>((1, 1)); + assert_eq!(b, (1 << 8) + 1); + + let v: Vec<u8> = vec![1, 2, 3]; + let mut i = v.iter(); + i.next(); + let mi = MaybeItem::<std::slice::Iter<_>> { elem: ManuallyDrop::new(i.next().unwrap()) }; + assert_eq!(**mi.elem, 2); + } +} |