Attribute Macro task 

#[task]

Apply to impl Task for ... blocks (or the Task trait definition itself).

Rewrites every async fn method into a method returning Pin<Box<dyn Future<Output = ...> + Send + 'async_trait>>, the same shape async-trait produces. This makes the methods callable through dyn Task<...>.

Use as #[cano::task].

Two surface forms are supported:

1. Trait-impl form: #[task] impl Task<S> for X { ... } — user writes the trait header.
2. Inherent-impl form: #[task(state = S [, key = K])] impl X { ... } — user writes only the inherent block; the macro builds the trait header and enforces that exactly one of run / run_bare is present.

For compensatable (saga) tasks, use #[cano::saga::task] instead.

Example

use cano::task;

#[task(state = MyState)]
impl MyTask {
    async fn run_bare(&self) -> Result<TaskResult<MyState>, CanoError> {
        Ok(TaskResult::Single(MyState::Done))
    }
}