Simplify serialize_seq and serialize_map implementation

yaml/src/ser.rs

@@ -84,8 +84,7 @@ impl<'a> ser::Serializer for Serializer<'a> {
             Some(len) => yaml::Array::with_capacity(len),
         };
         *self.doc = Yaml::Array(vec);
-        let mut elt_ser = Serializer::new(self.doc);
-        while try!(visitor.visit(&mut elt_ser)).is_some() {
+        while try!(visitor.visit(self)).is_some() {
         }
         Ok(())
     }
@@ -105,8 +104,7 @@ impl<'a> ser::Serializer for Serializer<'a> {
         where V: ser::MapVisitor,
     {
         *self.doc = Yaml::Hash(yaml::Hash::new());
-        let mut elt_ser = Serializer::new(self.doc);
-        while try!(visitor.visit(&mut elt_ser)).is_some() {
+        while try!(visitor.visit(self)).is_some() {
         }
         Ok(())
     }

yaml_tests/tests/test_serde.rs

@@ -84,6 +84,25 @@ fn test_basic_struct() {
     test_serde(thing, yaml);
 }
 
+#[test]
+fn test_nested_vec() {
+    let thing = vec![
+        vec![1, 2, 3],
+        vec![4, 5, 6],
+    ];
+    let yaml = indoc!("
+        ---
+        - 
+          - 1
+          - 2
+          - 3
+        - 
+          - 4
+          - 5
+          - 6");
+    test_serde(thing, yaml);
+}
+
 #[test]
 fn test_nested_struct() {
     #[derive(Serialize, Deserialize, PartialEq, Debug)]