cast(size_t)&c != 0, but c is null

[simendsjo]

On Tuesday, 14 May 2013 at 12:20:00 UTC, Andrej Mitrovic wrote:
> On Tuesday, 14 May 2013 at 12:18:20 UTC, simendsjo wrote:
>> Very newbie question coming up :)
>>
>> How does D mark null values for classes?
>> `c is null` returns true, but `&c` isn't 0.
>> So how does D know `c is null`?
>>
>> class C {}
>> C c;
>> assert(c is null);
>> assert(cast(size_t)&c == 0); // fails.
>
> That's the address of the reference. If you want the address of 
> the object:
>
> assert(cast(size_t)cast(void*)c == 0); // passes

Ah. Thanks to you both. Now I have some strange bug where 
somewhere in my code (probably using alias for passing symbols to 
templates), it get's a "wrong" reference...