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