The current std.signals assumes that all slots are delegates to Objects.
Is that still required with the new typeinfo stuff in the GC?

I see there's a setTypeInfo in std.gc, but no getTypeInfo.  If it did exist I would guess you could just do

        TypeInfo ti = gc.getTypeInfo(slot.ptr);
        if (derivesFrom(typeid(Object), ti)) {
                Object o = _d_toObject(slot.ptr);
                o.notifyRegister(&unhook);
        }

It would be nice if the class-only restriction could be lifted.

--bb