on Sat Nov 22 2008, "Andrey Semashev" <andrey.semashev-AT-gmail.com> wrote:
The documentation of the iterator_range states for several functions, such as size() and operator[], that these functions depend on the iterator nature. I believe, empty() could just do the same - rely on the ability to compare iterators, even default-initialized ones. Of course, this should be clearly stated in the docs.
I think that's the right approach. In other words, provided that default-initialized instances of Iter can be compared, and compare equal, the empty() member of a default-initialized iterator_range<Iter> produces defined behavior. Frankly, you don't even need to be that explicit: just write the semantics of empty as begin(r) == end(r) and you're done. Of course, more explicit documentation could be helpful. -- Dave Abrahams BoostPro Computing http://www.boostpro.com