on Tue Nov 25 2008, "Daniel Walker" <daniel.j.walker-AT-gmail.com> wrote:
More over, the current state of the Range concepts is indefensible. At least, no one has offered a defense. More specifically, no one has offered a response to the question of what problem is solved or what benefit is gained by removing empty(r) from the concept definitions. I gave a lengthy argument last night as to the benefits of empty(r). No one has countered it. Why should they? Emptiness or non-emptiness are natural, obvious attributes of a range. Why shouldn't a range abstraction such as a generic concept include a method for querying emptiness? It only makes sense.
I don't know what the motivation was, but there's one obvious possibility: if the concept requires boost::begin(r) and boost::end(r), you can write a generic boost::empty(r) function that uses begin and end without putting empty in the concept requirements. -- Dave Abrahams BoostPro Computing http://www.boostpro.com