Enums chapter from the Guide contains incorrect example code

[Valve]

Currently it is:

enum Ordering {
    Less,
    Equal,
    Greater,
}

fn cmp(a: int, b: int) -> Ordering {
    if a < b { Less }
    else if a > b { Greater }
    else { Equal }
}

fn main() {
    let x = 5i;
    let y = 10i;

    let ordering = cmp(x, y);

    if ordering == Less {
        println!("less");
    } else if ordering == Greater {
        println!("greater");
    } else if ordering == Equal {
        println!("equal");
    }
}

This does not compile:

error: binary operation `==` cannot be applied to type `Ordering`

Required modifications:

#[deriving(PartialEq)]
enum Ordering {
    Less,
    Equal,
    Greater,
}

[steveklabnik]

As the guide says, this enum is provided by Rust, and so you're not supposed to define it.

[href]

For what it's worth, I stumbled upon this issue as well while learning Rust. I tried an example with my own Enum and the error given by the compiler lead me here.

[jaxx]

same here,

although this works:

fn main()
{
    let x = 5i;
    let y = 10i;

    match cmp(x, y)
    {
        Less => println!("less"),
        Equal => println!("equal"),
        Greater => println!("greater")
    }
}