I have a question I'm hoping someone can answer. I've recently started using the iterator_facade class, and it's very useful, but it seems inefficient in some respects. Specifically, the < operator. According to the website docs, this uses the distance_to() function defined by the derived class. That works fine for some iterators, but not others. Often, it's possible to have much more efficient operations than that. Take for example, some data structure of sorted strings. It is not necessary to know how many elements are between two strings to know whether one is before the other. Like 'use empty() rather than size() == 0' in Meyer's _Effective STL_, it would seem that a more efficient solution can be created in many cases. So, is there a way to do this, to override iterator_facade's system, or am I missing something? I have read most of the documentation, but that doesn't mean there isn't something I overlooked. Thanks! Geoff Wedig