"Keith MacDonald"
That's just what I needed! It makes much more sense now that you have explained that iterator_adaptor adapts a base class, rather than an iterator, as originally documented.
I was quoting the same documentation you referred to.
The concept is amazingly powerful, and now that I've cleared the first hurdle, I'm much more inclined to explore other uses.
Glad to know it's useful.
I've adapted your example to implement begin() and end() methods, with a little test, and have attached the code. I hope you can include such an example with the library.
I'd love to. If I'm to use your code wholesale, I'll need you to add the standard boost copyright and license reference. -- Dave Abrahams Boost Consulting www.boost-consulting.com