template< typename Service> friend void add_service( io_service & ios, Service * svc);
This function is used to add a service to the io_service.
The io_service object that owns the service.
The service object. On success, ownership of the service object is transferred to the io_service. When the io_service object is destroyed, it will destroy the service object by performing:
Thrown if a service of the given type is already present in the io_service.
Thrown if the service's owning io_service is not the io_service object specified by the ios parameter.