use record exported types

hello/platforms/apple/HelloAppleDemoApp/ViewController.swift

@@ -1,10 +1,7 @@
-// 
-
-import UIKit
 import Hello
+import UIKit
 
 class ViewController: UIViewController {
-
   override func viewDidLoad() {
     super.viewDidLoad()
 //     Do any additional setup after loading the view.
@@ -15,6 +12,7 @@ class ViewController: UIViewController {
       let str = await Hello.sayAfter(ms: 1500, who: "Async")
       print(str)
     }
-  }
-}
 
+    print(Hello.addObj(a: RustDemoObj(value: 1), b: RustDemoObj(value: 2)))
+  }
+}

hello/src/lib.rs

@@ -57,3 +57,15 @@ pub async fn say_after(ms: u64, who: String) -> String {
         .unwrap_err();
     format!("Hello, {who}!")
 }
+
+#[derive(uniffi::Record)]
+pub struct RustDemoObj {
+    pub value: i64,
+}
+
+#[uniffi::export]
+pub fn add_obj(a: &RustDemoObj, b: &RustDemoObj) -> RustDemoObj {
+    RustDemoObj {
+        value: a.value + b.value,
+    }
+}