Macro private_enum 

macro_rules! private_enum {
    (enum $commonenum:ident { $( $commonfield:tt )+}) => { ... };
}

Use it to to create, extend and reuse fields from private enum definition.

Example

private_enum!(
    // pub is required before 'enum' when you use public_enum!
    enum WebEventBase {
        PageLoad,
        PageUnload, // , here is required if you want to extend the fields later.
    }
); // It is lazy. Nothing is made yet.

WebEventBase!(); // You have to call it to use the enum.

fn inspect(event: WebEventBase) {
    match event {
        WebEventBase ::PageLoad => println!("page loaded"),
        WebEventBase ::PageUnload => println!("page unloaded"),
    }
}

let load    = WebEventBase::PageLoad;
let unload  = WebEventBase::PageUnload;

inspect(load);
inspect(unload);