The start on a series about ranges from Eric Niebler:

Range Concepts, Part 1 of 4: Delimited Ranges

By Eric Niebler

From the Article:

I’ve been digging into ranges recently, and I’m finding them to be more than just a pair of iterators. In a series of posts, I’ll be expanding the notion of what a range is to cover some kinds of ranges not easily or efficiently expressible within the STL today: delimited ranges and infinite ranges. This post deals with the problems of representing delimited ranges with STL iterators.