on Mon Sep 01 2008, "Giovanni Piero Deretta" <gpderetta-AT-gmail.com> wrote:
You could provide an adapted_iterator and also an adapted_range.
My point is that the adapted_range would then have semantically equivalent iterators with a different representation (and an extra indirection), which seems like a waste.
hum, which indirection?
The iterators have to refer to the common data somehow.
<...>
Do you then still need a factored iterator?
You need to be able to take two adapted iterators and turn them into a range. Do you want that range to contain redundant data? I don't.
Hei, maybe this is all that we need! Let's have a metafunction that given an iterator type returns its preferred range type (the associated range). The default might be boost.range or even std::pair. The developer of an iterator adaptor, can specialize the metafunction so that the associate range is the optimum representation for an iterator pair.
Do you think this would be enough? It seems too simple to me, so probably I'm missing something...
It is quite attractive, I must say. I'll give it some thought. -- Dave Abrahams BoostPro Computing http://www.boostpro.com