Update Array.h added IsValidIndex

Source/Engine/Core/Collections/Array.h

@@ -737,7 +737,18 @@ public:
             ::Swap(other, *this);
         }
     }
-
+    
+    /// <summary>
+    /// Determines if is valid index.
+    /// </summary>
+    /// <param name="index">The index.</param>
+    /// <returns>
+    ///   <c>true</c> if is valid a index; otherwise, <c>false</c>.
+    /// </returns>
+    bool IsValidIndex(int index) const
+    {
+        return index < _count && index >= 0;
+    }
     /// <summary>
     /// Reverses the order of the added items in the collection.
     /// </summary>