Arithmetic operators: added example of a compound assignment with cast (#825)

Author: pkulikov

snippets/csharp/language-reference/operators/ArithmeticOperators.cs

@@ -28,6 +28,7 @@ public static void Examples()
 
             Console.WriteLine("==== Compound assignment");
             CompoundAssignment();
+            CompoundAssignmentWithCast();
 
             Console.WriteLine("==== Special cases");
             CheckedUnchecked();
@@ -194,6 +195,21 @@ private static void CompoundAssignment()
             // </SnippetCompoundAssignment>
         }
 
+        private static void CompoundAssignmentWithCast()
+        {
+            // <SnippetCompoundAssignmentWithCast>
+            byte a = 200;
+            byte b = 100;
+            
+            var c = a + b;
+            Console.WriteLine(c.GetType());  // output: System.Int32
+            Console.WriteLine(c);  // output: 300
+
+            a += b;
+            Console.WriteLine(a);  // output: 44
+            // </SnippetCompoundAssignmentWithCast>
+        }
+
         private static void CheckedUnchecked()
         {
             // <SnippetCheckedUnchecked>