Added missing SingleArgCollection for &[T: SingleArg]. (#47)

* Added missing SingleArgCollection for &[T: SingleArg].

* Added unit tests to verify slices can be used as SingleArgCollection.

src/resp/to_args.rs

@@ -452,6 +452,8 @@ impl SingleArgCollection<Vec<u8>> for CommandArgs {}
 
 impl<T, const N: usize> SingleArgCollection<T> for [T; N] where T: SingleArg {}
 
+impl<T> SingleArgCollection<T> for &[T] where T: SingleArg {}
+
 impl<T> SingleArgCollection<T> for Vec<T> where T: SingleArg {}
 
 impl<A, T> SingleArgCollection<T> for SmallVec<A>
@@ -499,6 +501,13 @@ where
 {
 }
 
+impl<K, V> KeyValueArgsCollection<K, V> for &[(K, V)]
+where
+    K: SingleArg,
+    V: SingleArg,
+{
+}
+
 impl<K, V> KeyValueArgsCollection<K, V> for (K, V)
 where
     K: SingleArg,

src/tests/command_args.rs

@@ -37,6 +37,11 @@ async fn key_value_collection() -> Result<()> {
     let len = client.hset("key", items).await?;
     assert_eq!(2, len);
 
+    client.del("key").await?;
+    let items = [("field1", "value1"), ("field2", "value2")];
+    let len = client.hset("key", items.as_slice()).await?;
+    assert_eq!(2, len);
+
     client.close().await?;
 
     Ok(())
@@ -58,6 +63,11 @@ async fn set_collection() -> Result<()> {
     let len = client.sadd("key", items).await?;
     assert_eq!(2, len);
 
+    client.del("key").await?;
+    let items = ["member1", "member2"];
+    let len = client.sadd("key", items.as_slice()).await?;
+    assert_eq!(2, len);
+
     client.del("key").await?;
     let items = vec!["member1", "member2"];
     let len = client.sadd("key", items).await?;