Tomas Puverle wrote:
It's not an empty range, it's more like a pointer to somewhere random.
This is not the case - there are plenty of iterators which have valid semantics when default constructed, including some in the standard library.
Sure there are, but that's irrelevant. The standard doesn't require iterators that have been constructed to be in a valid state, and that's all there is to it. It's not a matter of choice of design. It's a matter of following the standard. In your specific case it's not a problem, but iterator_range aims at being generic. As I said, if it was just me, I would have designed the iterator concepts differently so as *not* to require default construction, which standard iterator concepts do, and that is bringing the singular states in.