3 #![allow(unions_with_drop_fields)]
5 #![feature(untagged_unions)]
7 union MaybeItem<T: Iterator> {
17 unsafe fn union_transmute<A, B>(a: A) -> B {
23 let u = U::<String, Vec<u8>> { a: String::from("abcd") };
25 assert_eq!(u.b.len(), 4);
26 assert_eq!(u.b[0], b'a');
28 let b = union_transmute::<(u8, u8), u16>((1, 1));
29 assert_eq!(b, (1 << 8) + 1);
31 let v: Vec<u8> = vec![1, 2, 3];
34 let mi = MaybeItem::<std::slice::Iter<_>> { elem: i.next().unwrap() };
35 assert_eq!(*mi.elem, 2);