Attribute Macro message 

#[message]

Derive actor message convenience methods on a Handle.

Applied to a message enum, this attribute generates an extension trait {Actor}Ext and implements it for Handle<Actor>, giving each enum variant a corresponding async method.

Variant Attributes

• (none) — variant sent with Handle::cast (fire-and-forget); method returns Result<(), ActorDead<()>>.
• #[call] — variant uses Handle::call; method returns Result<(), ActorDead<()>>.
• #[call(ReturnType)] — variant uses Handle::call; method returns Result<ReturnType, ActorDead<()>>.

For #[call] variants the macro appends a respond_to: oneshot::Sender<ReturnType> field to the variant. The actor must send a value through it.

Example

struct MyActor;

#[stagecraft::message(MyActor)]
pub enum MyActorMessage {
    Log { text: String },   // cast: fire-and-forget
    #[call(u64)]
    Count,                   // call: returns u64
}

// The macro generates:
// pub trait MyActorExt {
//     async fn log(&self, text: String) -> Result<(), ActorDead<()>>;
//     async fn count(&self) -> Result<u64, ActorDead<()>>;
// }
// impl MyActorExt for Handle<MyActor> { ... }