1 // CS0452: The type `U' must be a reference type in order to use it as type parameter `UU' in the generic type or method `B.Test<UU>(UU)'
6 public abstract void Foo<U> (U arg) where U : T;
11 public override void Foo<U> (U arg)
16 void Test<UU> (UU a) where UU : class