using System; using System.Collections.Generic; public class TestClass<T1> : SequencedBase<T1>, IIndexedSorted<T1> { void Test () { TestClass<T1> tt = null; tt.Foo (this); } public void Foo<U> (IEnumerable<U> items) { } public class Nested : ICloneable { public object Clone () { return null; } } } public abstract class SequencedBase<T2> : DirectedCollectionBase<T2>, IDirectedCollectionValue<T2> { public T2 Field; } public abstract class DirectedCollectionBase<T3> : CollectionBase<T3>, IDirectedCollectionValue<T3> { IEnumerator<T3> IEnumerable<T3>.GetEnumerator () { return null; } System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator () { return null; } } public abstract class CollectionBase<T4> : CollectionValueBase<T4> { } public abstract class CollectionValueBase<T5> : EnumerableBase<T5>, ICollectionValue<T5> { } public abstract class EnumerableBase<T6> : IEnumerable<T6> { IEnumerator<T6> IEnumerable<T6>.GetEnumerator () { return null; } System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator () { return null; } } public interface IDirectedCollectionValue<T7> : ICollectionValue<T7>, IDirectedEnumerable<T7> { } public interface ICollectionValue<T8> : IEnumerable<T8> { } public interface IIndexedSorted<T9> : ISorted<T9>, IIndexed<T9> { } public interface ISorted<T10> : ISequenced<T10> { } public interface ISequenced<T11> : IDirectedCollectionValue<T11> { } public interface IDirectedEnumerable<T12> : IEnumerable<T12> { } public interface IIndexed<T13> : ISequenced<T13> { } class C { public static void Main () { var c = new TestClass<string> (); } }