Self-referencing template parameters

[Erik Rasmussen]

One way that I have found java's generics to be useful is in doing 
something like this:

---
public abstract class Animal<T extends Animal<T>>
{
   public abstract T[] procreate(T mate);
}

public class Monkey extends Animal<Monkey>
{
   public Monkey[] procreate(Monkey mate)
   {
      // make sweet monkey love
   }
}
---

Although you're not strictly forced to by the compiler, if you make it a 
policy to always make your template variable the same as your concrete 
subclass, then you have forced any class that extends Animal to provide 
a way to "procreate" with its own kind.

I seem to be unable to implement this pattern in D.  The following 
doesn't work:

---
abstract class Animal(T : Animal!(T))
{
   abstract T[] procreate(T mate);
}
---

It doesn't like that template definition on the first line.  It says, 
"template instance does not match any template declaration".

Any ideas?

Cheers,
Erik