// CS0411: The type arguments for method `Hello.World<U>(IFoo<U>)' cannot be inferred from the usage. Try specifying the type arguments explicitly // Line: 16 public interface IFoo<T> { } public class Foo : IFoo<int>, IFoo<string> { } public class Hello { public void World<U> (IFoo<U> foo) { } public void Test (Foo foo) { World (foo); } } class X { static void Main () { } }