Re: generic extends problem

Hello,

I have got a complex class structure, the signature of the class is:

public abstract class IMultiLayer<T extends IStepable & Painter> extends
CompoundPainter<T> implements IQueue<T>, IViewableLayer, IDataLayer,
IVoidStepable, ILayer

The interfaces are defined like

interface IDataLayer;
interface IStepable;
interface IViewableLayer;

interface IVoidStepable extends IStepable;
interface IReturnStepable extends IStepable;
interface ILayer extends IStepable;
interface IQueue<T> extends Queue<T>

I create classes with

public class myContent implements IStepable, Painter

public class myLayer extends IMultiLayer<myContent>

I can compile the structure with Java 1.8, but I get an
ClassCastException. I have defined a Map
with

Map<String, ILayer> x = new Map();
x.put( "test", new myLayer )
(myLayer) x.get("test"); // the exception is raised on the cast

The message text of the exception is: cannot be cast to IStepable.
I don't understand way the exception is thrown, because the class
implements the correct interface.
If I swap T extends IStepable & Painter to T extends Painter &
IStepable, I get the same exception with
cannot be cast to Painter

I'm a little bite clueless and need a hint to solve the problem