Hi Jeff,
I had a quick look, and I immediately noticed that you (still, I guess?)
are incrementing the _pos member upon dereferencing the first time...is there some reason you don't increment it unconditionally in operator++? I'm guessing the end result is the same, given the pair of boolean flags encoding the state, but it's a "code surprise", which increases the cognitive overhead to read it :)
Oh, and after thinking about this a little, effectively incrementing your position within operator* will make operator== behave strangely :/
I don't remember why I was thinking that increasing the pos inside the operator* was a good idea. I have to sit down at home tonight or tomorrow and go over my tests again. Will let you know when I have the next version. Thanks again for your insight, Christian