// CS0246: The type or namespace name `IBase' could not be found. Are you missing `Foo' using directive? // Line: 15 namespace Foo { public interface IBase { object X { get; } } } public interface IDerived<T> : Foo.IBase { T X { get; } } public class Test<T> { public class Y : IDerived<T>, IBase { public T X { get { return default (T); } } object Foo.IBase.X { get { return default (T); } } } }