template< typename Service> Service & use_service( io_service & ios);
This function is used to locate a service object that corresponds to the
given service type. If there is no existing implementation of the service,
then the io_service
will create a new instance of the service.
The io_service
object that owns the service.
The service interface implementing the specified service type. Ownership of the service interface is not transferred to the caller.
This overload is preserved for backwards compatibility with services that
inherit from io_service::service
.