Data update

Task/JSON/Rust/json-4.rs

@@ -0,0 +1,19 @@
+#[derive(Serialize, Deserialize)]
+struct W { a: i32, b: i32 }  // => { "a": 0, "b": 0 }
+
+#[derive(Serialize, Deserialize)]
+struct X(i32, i32);          // => [0, 0]
+
+#[derive(Serialize, Deserialize)]
+struct Y(i32);               // => 0
+
+#[derive(Serialize, Deserialize)]
+struct Z;                    // => null
+
+#[derive(Serialize, Deserialize)]
+enum E {
+    W { a: i32, b: i32 },    // => { "W": { "a": 0, "b": 0 } }
+    X(i32, i32),             // => { "X": [0, 0] }
+    Y(i32),                  // => { "Y": 0 }
+    Z,                       // => { "Z" }
+}