Validity of cast(void*)size_t.max

[Nordlöw]

On Tuesday, 27 February 2018 at 20:14:01 UTC, Ali Çehreli wrote:
> And to be sure, one can have an actual object that represents 
> nullness and use its pointer. (Similar to "the null object 
> pattern".)
>
> Ali

Are there any pros to this pattern compared to just using `null` 
in D?