Rust: Clone, Show, Send & friends

deriving.rs

// Clone     - for cloning non-owned resources to
//             make actions that require ownership
//             over them
// Show      - if you ever want to log the value of
//             this enum
// Send      - if you ever want to send it over
//             channel to a different task
// PartialEq - if you want to check if two instances
//             of this enum are the same

#[deriving(Clone, Show, Send, PartialEq)]
enum Command < T: Clone + Show + Send + Message > {
    Peek(Option < uint >),
    PeekResult(Option < T >),
    Push(T),
    Clear,
}