BitArray - Is there one?

[Dmitry Olshansky]

>
> Not at all. Once you established that it's not a pointer namely since
> every pointer to size_t is word aligned (unless constructed by hand).
> You could use it's lowest bit as marker then. It's 0 state won't disturb
> pointer usual semantics, when it's set to 1 it's obviously
>
... in-place bit array. So it's cheap tag for your union.

-- 
Dmitry Olshansky