ToStr

In order to have a default implementaton of to_str() you need to add #[deriving(ToStr, Rand)]

#[deriving(ToStr, Rand)]
enum Weapons {
  Sword,
  Club,
  Gaze
}

println(Club.to_str);

// => Club

The alternative, workin' in most cases, would be using format!. The formatting string {:?} means it will use reflection to display the struct name and values. This is similar to Ruby's #inspect.

enum Monsters {
  Goblin,
  Orc
}

fn main() {
  println(format!("{:?}", Orc));
}

// => Orc