Function actix_service::map_config

pub fn map_config<T, U, F, C>(factory: U, f: F) -> MapConfig<T, F, C> where
    T: ServiceFactory,
    U: IntoServiceFactory<T>,
    F: Fn(C) -> T::Config, 

Adapt external config argument to a config for provided service factory

Note that this function consumes the receiving service factory and returns a wrapped version of it.