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// run-pass
use std::mem;
// Univariant C-like enum
#[repr(i32)]
enum Univariant {
X = 17
}
#[repr(u16)]
enum UnivariantWithoutDescr {
Y
}
#[repr(u8)]
enum UnivariantWithData {
Z(u8),
}
pub fn main() {
{
assert_eq!(4, mem::size_of::<Univariant>());
assert_eq!(17, Univariant::X as i32);
let enums: &[Univariant] =
&[Univariant::X, Univariant::X, Univariant::X];
let ints: &[i32] = unsafe { mem::transmute(enums) };
// check it has the same memory layout as i32
assert_eq!(&[17, 17, 17], ints);
}
{
assert_eq!(2, mem::size_of::<UnivariantWithoutDescr>());
let descr = UnivariantWithoutDescr::Y as u16;
let enums: &[UnivariantWithoutDescr] =
&[UnivariantWithoutDescr::Y, UnivariantWithoutDescr::Y, UnivariantWithoutDescr::Y];
let ints: &[u16] = unsafe { mem::transmute(enums) };
// check it has the same memory layout as u16
assert_eq!(&[descr, descr, descr], ints);
}
{
assert_eq!(2, mem::size_of::<UnivariantWithData>());
match UnivariantWithData::Z(4) {
UnivariantWithData::Z(x) => assert_eq!(x, 4),
}
}
}
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