add narrative and break things

src/clients/momento/commands/sorted_set_add.rs

@@ -17,6 +17,10 @@ pub async fn sorted_set_add(
     if request.members.len() == 1 {
         let (member, score) = request.members.first().unwrap();
 
+        // here we are able to borrow from the Arc<[u8]> and get a &[u8]
+        // we deref the &f64 to get a f64. It's Copy, so that's fine. Members
+        // might be long slices, so avoiding a clone is very nice.
+
         let r = SortedSetPutElementRequest::new(cache_name, &*request.key, &**member, *score)
             .ttl(CollectionTtl::new(request.ttl, false));
 
@@ -28,10 +32,30 @@ pub async fn sorted_set_add(
 
         record_result!(result, SORTED_SET_ADD)
     } else {
-        let d: Vec<(Vec<u8>, f64)> = request
+        // there's a couple of ways we can do this, but essentially we need to
+        // transform our Arc<[u8]> into something that implements Into<Vec<u8>>
+        // our obvious options are to just convert to_vec() to get a Vec<u8>,
+        // but this requires copying the members.
+
+        // this works, we use IntoIter because we can. It doesn't really make
+        // much of a difference
+
+        // let d: Vec<(Vec<u8>, f64)> = request
+        //     .members
+        //     .into_iter()
+        //     .map(|(m, s)| (m.to_vec(), s))
+        //     .collect();
+
+        // the other way would be like how we do above, we can borrow from the
+        // Arc<[u8]> to get a &[u8]. Since we're just going to borrow, we must
+        // use plain iter() to get borrows from the Arc<T> that's still in the
+        // `SortedSetAdd` request.
+
+        // this does not work!
+        let d: Vec<(&[u8], f64)> = request
             .members
-            .into_iter()
-            .map(|(m, s)| (m.to_vec(), s))
+            .iter()
+            .map(|(m, s)| (&**m, *s))
             .collect();
 
         let r = SortedSetPutElementsRequest::new(cache_name, &*request.key, d)