static void SetVTable()
        {
            var vt = new SwiftIteratorProtocolVtable();

            vt.func0 = NextFuncReceiver;
            IteratorProtocolPinvokes.SetVtable(ref vt, StructMarshal.Marshaler.Metatypeof(typeof(T)));
        }
 public static extern void SetVtable(ref SwiftIteratorProtocolVtable vtable, SwiftMetatype mt);