# System.Threading

``` diff
 namespace System.Threading {
     public static class Interlocked {
-        [return: NotNullIfNotNullAttribute("location1")]
-        public static T CompareExchange<T>(ref T location1, T value, T comparand) where T : class?;
+        [return: NotNullIfNotNullAttribute("location1")]
+        public static T CompareExchange<T>(ref T location1, T value, T comparand);
-        [return: NotNullIfNotNullAttribute("location1")]
-        public static T Exchange<T>([NotNullIfNotNullAttribute("value")] ref T location1, T value) where T : class?;
+        [return: NotNullIfNotNullAttribute("location1")]
+        public static T Exchange<T>([NotNullIfNotNullAttribute("value")] ref T location1, T value);
     }
 }
```

