Macro request_endpoints 

macro_rules! request_endpoints {
    () => { ... };
    ($($endpoint:ty),+ $(,)?) => { ... };
}

Compose route types into a RequestEndpointSet value, e.g., request_endpoints![Health, Echo, Status]. Each arm awaits a concrete handler future, so the set is monomorphized. There’s no boxing and it’sno_std-clean.