// Comment out PartialEq and uncomment the impl below

#[derive(PartialEq)]
#[derive(Debug)]
enum Maybe<T> {
    Nothing,
    Just(T),
}

// impl<T, U> PartialEq<Maybe<U>> for Maybe<T>
// where
//     T: PartialEq<U>,
// {
//     fn eq(&self, other: &Maybe<U>) -> bool {
//         match (self, other) {
//             (Maybe::Just(a), Maybe::Just(b)) => a.eq(b),
//             (Maybe::Nothing, Maybe::Nothing) => true,
//             _ => false,
//         }
//     }
// }

fn main() {
    assert_eq!(Maybe::Just("a"), Maybe::Just("a".to_owned()));

    println!("Hooray!");
}