Expand index trait to also include key type

Signed-off-by: Lee Smet <lee.smet@hotmail.com>

heromodels/src/db.rs

@@ -22,7 +22,7 @@ where
     type Error: std::fmt::Debug;
 
     /// Get all items where the given index field is equal to key.
-    fn get<I>(&self, key: K) -> Result<Vec<V>, Error<Self::Error>>
+    fn get<I>(&self, key: &I::Key) -> Result<Vec<V>, Error<Self::Error>>
     where
         I: Index<Model = V>;
 
@@ -33,7 +33,7 @@ where
     fn set(&self, value: &V) -> Result<(), Error<Self::Error>>;
 
     /// Delete all items from the db with a given index.
-    fn delete<I>(&self, key: K) -> Result<(), Error<Self::Error>>
+    fn delete<I>(&self, key: &I::Key) -> Result<(), Error<Self::Error>>
     where
         I: Index<Model = V>;
 
@@ -66,4 +66,3 @@ impl<E> From<bincode::error::EncodeError> for Error<E> {
         Error::Encode(value)
     }
 }
-