Attribute Macro app 

#[app]

Generates a main entry point for a RustStream service.

Place it on a synchronous, argument-free function that builds and returns an application - impl App (the recommended form, hiding the composed type parameters) or a concrete RustStream<_>. The expansion keeps the function and adds a main that hands it to ruststream::runtime::cli::run_main, producing a binary that understands the run and asyncapi gen commands with no hand-written runtime boilerplate.

#[ruststream::app]
fn app() -> impl App {
    RustStream::new(AppInfo::new("svc", "0.1.0")).register_broker(MemoryBroker::new())
}

The attribute takes the runtime arguments of #[tokio::main]: flavor = "current_thread" runs the service on a current-thread runtime, worker_threads = n sizes the default multi-threaded one (flavor = "multi_thread" names the default). A service whose CPU-bound subscriptions run on dedicated threads (threads(n)) sizes the runtime for its I/O alone.

#[ruststream::app(flavor = "current_thread")]
fn app() -> impl App {
    RustStream::new(AppInfo::new("svc", "0.1.0")).register_broker(MemoryBroker::new())
}