Is the other-kind-of-null really necessary in Nullable and Variant?

[Idan Arye]

On Monday, 29 April 2013 at 12:23:04 UTC, deadalnix wrote:
> On Sunday, 28 April 2013 at 16:33:19 UTC, Idan Arye wrote:
>> When you use `std.typecons.Nullable` with a type that already 
>> accept `null` values, you get two types of nulls - the 
>> `Nullable`'s null state the the regular type's `null`:
>>
>>    Nullable!string a;
>>    writeln(a.isNull()); //prints "true"
>>    a = null;
>>    writeln(a.isNull()); //prints "false"
>>    a.nullify();
>>    writeln(a.isNull()); //prints "true"
>>
>
> All types should be non nullable. Problem solved.

*All* types? Even object references and pointers?