Merge pull request #67 from ville-h/24972

24972

Author: steveklabnik

src/24972.rs

@@ -0,0 +1,22 @@
+use rustc_serialize::{Encodable, Decodable};
+use std::fmt::Display;
+
+
+pub trait Entity : Decodable + Encodable + Sized {
+    type Key: Clone + Decodable + Encodable + ToString + Display + Eq + Ord + Sized;
+
+    fn id(&self) -> Self::Key;
+
+    fn find_by_id(id: Self::Key) -> Option<Self>;
+}
+
+pub struct DbRef<E: Entity> {
+    pub id: E::Key,
+}
+
+impl<E> DbRef<E>
+ where E: Entity {
+    fn get(self) -> Option<E> {
+        E::find_by_id(self.id)
+    }
+ }