More ergonomic guard api

syndicate-server/src/main.rs

@@ -108,7 +108,7 @@ async fn main() -> ActorResult {
             }));
         }
 
-        let gatekeeper = Cap::guard(Arc::clone(Language::arc()), t.create(
+        let gatekeeper = Cap::guard(Language::arc(), t.create(
             syndicate::entity(Arc::clone(&server_config_ds))
                 .on_asserted(gatekeeper::handle_assertion)));
 

syndicate/src/actor.rs

@@ -2246,13 +2246,14 @@ impl Cap {
     /// `Cap` automatically decodes presented `AnyValue`s into
     /// instances of `M`.
     pub fn guard<L: 'static + Sync + Send, M: 'static + Send>(
-        literals: Arc<L>,
+        literals: &Arc<L>,
         underlying: Arc<Ref<M>>,
     ) -> Arc<Self>
     where
         M: for<'a> Unparse<&'a L, AnyValue>,
         M: for<'a> Parse<&'a L, AnyValue>,
     {
+        let literals = Arc::clone(literals);
         Self::new(&Arc::new(Ref {
             mailbox: Arc::clone(&underlying.mailbox),
             facet_id: underlying.facet_id,

syndicate/src/relay.rs

@@ -761,7 +761,7 @@ impl Entity<AnyValue> for RelayEntity {
     fn sync(&mut self, t: &mut Activation, peer: Arc<Ref<Synced>>) -> ActorResult {
         self.relay_ref.lock().as_mut().expect("initialized")
             .send_event(t, self.oid.clone(), P::Event::Sync(Box::new(P::Sync {
-                peer: Cap::guard(Arc::new(()), peer)
+                peer: Cap::guard(&Arc::new(()), peer)
             })))
     }
 }