Update macro to use #[index] attributes

- Also use proper types for index.
 - Update DB interface to be more flexible for index params

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

heromodels/src/db.rs

@@ -1,3 +1,5 @@
+use std::borrow::Borrow;
+
 use crate::models::{Index, Model};
 use serde::{Deserialize, Serialize};
 
@@ -22,9 +24,11 @@ where
     type Error: std::fmt::Debug;
 
     /// Get all items where the given index field is equal to key.
-    fn get<I>(&self, key: &I::Key) -> Result<Vec<V>, Error<Self::Error>>
+    fn get<I, Q>(&self, key: &Q) -> Result<Vec<V>, Error<Self::Error>>
     where
-        I: Index<Model = V>;
+        I: Index<Model = V>,
+        I::Key: Borrow<Q>,
+        Q: ToString + ?Sized;
 
     /// Get an object from its ID. This does not use an index lookup
     fn get_by_id(&self, id: u32) -> Result<Option<V>, Error<Self::Error>>;
@@ -33,9 +37,11 @@ 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: &I::Key) -> Result<(), Error<Self::Error>>
+    fn delete<I, Q>(&self, key: &Q) -> Result<(), Error<Self::Error>>
     where
-        I: Index<Model = V>;
+        I: Index<Model = V>,
+        I::Key: Borrow<Q>,
+        Q: ToString + ?Sized;
 
     /// Delete an object with a given ID
     fn delete_by_id(&self, id: u32) -> Result<(), Error<Self::Error>>;