Function actix_service::apply_cfg_factory

pub fn apply_cfg_factory<SF, Req, F, Cfg, Fut, S>(
    factory: SF, 
    f: F
) -> impl ServiceFactory<Req, Config = Cfg, Response = S::Response, Error = S::Error, Service = S, InitError = SF::InitError> + Clone where
    SF: ServiceFactory<Req, Config = ()>,
    F: Fn(Cfg, &SF::Service) -> Fut,
    SF::InitError: From<SF::Error>,
    Fut: Future<Output = Result<S, SF::InitError>>,
    S: Service<Req>, 

Convert Fn(Config, &ServiceFactory1) -> Future<ServiceFactory2> fn to a service factory.

Service1 get constructed from T factory.