Re: [boost] [proprocessor] PP challenge!

From: Paul Mensonides (pmenso57_at_[hidden])
Date: 2006-11-04 16:36:38

> -----Original Message-----
> From: boost-bounces_at_[hidden] 
> [mailto:boost-bounces_at_[hidden]] On Behalf Of Eric Niebler

> I have a preprocessing task that exceeds my limited 
> abilities. If any PP gurus want to step in and prevent me 
> from hurting myself further, I would be very grateful.
> 
> My problem is this: I want to mpl::and_ together a bunch of 
> predicates. 
> mpl::and_ has a limit of 4 arguments. So this is wrong:
> 
>    mpl::and_< pred1, pred2, pred3, pred4, pred5 >
> 
> but this is ok:
> 
>    mpl::and_< pred1, pred2, pred3, mpl::and_< pred4, pred5 > >
> 
> The challenge, should you choose to accept it, is to write 
> some PP magic that, given a MAKE_PREDICATE(z, n, data) macro 
> and a max arity (which is greater than 4!), generates a 
> properly nested mpl::and_-ing of the predicates.

Do you have a sequence (i.e. a selection) of predicates already or are they all
"pred1", "pred2", etc.?

Regards,
Paul Mensonides