more from case study

src/case_study.rs

@@ -113,6 +113,29 @@ impl Active {
     event_attr!(id, Uuid, id);
 }
 
+
+impl From<Event<Pending>> for Active {
+    fn from(pending: Event<Pending>) -> Active {
+        Active::Pending(pending)
+    }
+}
+
+macro_rules! from_event {
+    ($t:ty, $variant:ident) => {
+        impl From<Event<$t>> for Active {
+            fn from(event: Event<$t>) -> Active {
+                Active::$variant(event)
+            }
+        }
+    }
+}
+
+//from_event!(Pending, Pending);
+from_event!(Sending, Sending);
+from_event!(Sent, Sent);
+from_event!(Ack, Acked);
+from_event!(Finished<Sent>, FinishedNoAck);
+
 #[allow(unused)]
 #[cfg(test)]
 mod tests {