Sorting enums with anonymous structs in Rust

sortenum.rs

use std::cmp::Ordering;

#[derive(Eq, Debug, PartialOrd, PartialEq)]
enum Foo {
    A { val: i64 },
    B,
}

// impl PartialEq for Foo {
//     fn eq(&self, other: &Self) -> bool {
//         match (self, other) {
//             (_, Foo::B) => false,
//             (Foo::B, _) => false,
//             (Foo::A { val: l }, Foo::A { val: r }) => l == r,
//         }
//     }
// }

// impl PartialOrd for Foo {
//     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
//         match (self, other) {
//             (_, Foo::B) => Some(Ordering::Less),
//             (Foo::A { val: l }, Foo::A { val: r }) => l.partial_cmp(&r),
//             (Foo::B, _) => Some(Ordering::Greater),
//         }
//     }
// }

impl Ord for Foo {
    fn cmp(&self, other: &Self) -> Ordering {
        match (self, other) {
            (_, Foo::B) => Ordering::Less,
            (Foo::A { val: l }, Foo::A { val: r }) => l.cmp(&r),
            (Foo::B, _) => Ordering::Greater,
        }
    }
}

fn main() {
    let mut foos: Vec<Foo> = vec![Foo::B, Foo::A { val: 128 }, Foo::B, Foo::A { val: 256 }];
    foos.sort();
    println!("{:#?}", foos);
}