On 02/28/2005 10:01 AM, David Abrahams wrote: [snip]
That's misguided it seems to me. Your tuple_type is not a specialization of fold. Are you really interested in making specializations of fold into sequences?
You're folding some kind of cons cell, right? Don't you want to implement begin and end on that?
template <class A, class B> struct begin<inherit<A,B> > { ... };
or something? Yes. But how do I know what A or B is. It has to be the result of size<Sequence>-1 applications of ForwardOp. Is there a way to get this other than fold<Sequence,StartState,ForwardOp>::type ? Hmmm. This is what get_side_type does with Index == 0. Maybe I could use that.
BTW, get_side_type is also in vault. [snip]
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?
I'm not the guy to ask, sorry. Joel is the fusion expert, and... I mean no offense by this, but I find your code hard to read and understand, so I'm trying to be helpful while not getting entangled in looking at its details because I think it will cost me too much time.
OK. Thanks for the help :)