Fighting with alias this: bugs or features?

[osa]

On 10/26/2010 05:09 PM, Andrei Alexandrescu wrote:
> Thanks. Defining opAssign for Bar will allow you to use the syntax bar =
> null and have it nullify the reference.

I feel stupid, but I do not see how to nullify the Bar reference inside 
of opAssign. Again, my problem is that I have
	Bar x = new Bar( ... );
and I want x to become null. Is there a workaround for 'cannot 
implicitly convert expression (null) of type void* to Foo' which does 
not involve low-level trickery like *cast(void**)&x = null?