Function actix_service::apply_fn_factory

pub fn apply_fn_factory<I, SF, F, Fut, Req, In, Res, Err>(
    service: I, 
    f: F
) -> ApplyFactory<SF, F, Req, In, Res, Err> where
    I: IntoServiceFactory<SF, In>,
    SF: ServiceFactory<In, Error = Err>,
    F: Fn(Req, &SF::Service) -> Fut + Clone,
    Fut: Future<Output = Result<Res, Err>>, 

Service factory that produces apply_fn service.

The In and Out type params refer to the request and response types for the wrapped service.