add tests to deserializing sequences into a tuple

src/de.rs

@@ -199,13 +199,13 @@ pub trait Deserializer<E>: Iterator<Result<Token, E>> {
     fn expect_null(&mut self, token: Token) -> Result<(), E> {
         match token {
             Null => Ok(()),
-            TupleStart(_) => {
+            TupleStart(_) | SeqStart(_) => {
                 match try!(self.expect_token()) {
                     End => Ok(()),
                     token => Err(self.syntax_error(token, [EndKind])),
                 }
             }
-            token => Err(self.syntax_error(token, [NullKind, TupleStartKind])),
+            token => Err(self.syntax_error(token, [NullKind, TupleStartKind, SeqStartKind])),
         }
     }
 

src/json/mod.rs

@@ -2897,6 +2897,13 @@ mod tests {
         test_parse_ok([
             ("[[3], [1, 2]]", vec!(vec!(3i), vec!(1, 2))),
         ]);
+
+        let v: () = from_iter("[]".chars()).unwrap();
+        assert_eq!(v, ());
+
+        test_parse_ok([
+            ("[1, 2, 3]", (1u, 2u, 3u)),
+        ]);
     }
 
     #[test]