Add example for C2526

Author: Rageking8

docs/error-messages/compiler-errors-2/compiler-error-c2526.md

@@ -1,13 +1,24 @@
 ---
 description: "Learn more about: Compiler Error C2526"
 title: "Compiler Error C2526"
-ms.date: "11/04/2016"
+ms.date: "03/08/2024"
 f1_keywords: ["C2526"]
 helpviewer_keywords: ["C2526"]
-ms.assetid: 0f8c554c-f990-457e-bcae-b6f273481825
 ---
 # Compiler Error C2526
 
 'identifier1' : C linkage function cannot return C++ class 'identifier2'
 
 A function defined with C linkage cannot return a user-defined type.
+
+```cpp
+// C2526.cpp
+// compile with: /c
+template <typename T>
+class A {};
+
+extern "C" A<int> func()   // C2526
+{
+    return {};
+}
+```