#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#[repr(u8)]
enum Enum {
    Unit,
    Tuple(bool),
    Struct { a: bool },
}
impl Enum {
    fn discriminant(&self) -> u8 {
        unsafe { *<*const _>::from(self).cast::<u8>() }
    }
}
fn main() {
    let unit_like = Enum::Unit;
    let tuple_like = Enum::Tuple(true);
    let struct_like = Enum::Struct { a: false };
    assert_eq!(0, unit_like.discriminant());
    assert_eq!(1, tuple_like.discriminant());
    assert_eq!(2, struct_like.discriminant());
}