messing with trait objects

src/service/rooms/auth_chain/data.rs

@@ -2,6 +2,6 @@ use std::collections::HashSet;
 use crate::Result;
 
 pub trait Data {
-    fn get_cached_eventid_authchain(&self, shorteventid: u64) -> Result<HashSet<u64>>;
+    fn get_cached_eventid_authchain(&self, shorteventid: u64) -> Result<Option<HashSet<u64>>>;
     fn cache_eventid_authchain(&self, shorteventid: u64, auth_chain: &HashSet<u64>) -> Result<()>;
 }

src/service/rooms/auth_chain/mod.rs

@@ -5,11 +5,11 @@ pub use data::Data;
 
 use crate::Result;
 
-pub struct Service<D: Data> {
-    db: D,
+pub struct Service {
+    db: Box<dyn Data>,
 }
 
-impl<D: Data> Service<D> {
+impl Service {
     #[tracing::instrument(skip(self))]
     pub fn get_cached_eventid_authchain<'a>(
         &'a self,