-const char* service_state_to_string(ServiceState i);
-ServiceState service_state_from_string(const char *s);
-
-const char* service_restart_to_string(ServiceRestart i);
-ServiceRestart service_restart_from_string(const char *s);
+const char* service_state_to_string(ServiceState i) _const_;
+ServiceState service_state_from_string(const char *s) _pure_;