On 02/28/2005 07:16 AM, David Abrahams wrote: [snip]
OTOH, I really should have said "make the result of a fold metafunction invokation into a sequence". Would that have been sufficient to make my meaning clear?
Not really. As I said, "fold and reverse_fold don't even have to _return_ sequences." By that I mean that the result of invoking fold might be, e.g. int.
OK, granted, but I need it to be a sequence. I guess what I planned will not work on all results of fold, but it will work on at least some. Right now, I'm just trying to get it to work on what I need at the moment, which is part of a test driver. I guess I'll just write my own begin<fold<Sequence,StartState,ForwardOp> > and put it in my test driver directory. [snip]
OTOH, I haven't really looked at fusion, so maybe I should. It's just I've found mpl very good and I've gotten used to it; hence, I'm reluctant to change.
It's not a change. Fusion is a compatible layer on top of MPL.
My other post mentioned visitors.hpp and its need for fold. How could fusion's tuple be used to implement visitors where the critical need is a StartState superclass for all instantiations of ForwardOp?