On Iteration

[dsimcha]

== Quote from Andrei Alexandrescu (SeeWebsiteForEmail at erdani.org)'s article
> I consider changing a bit D's range model following the better
> understanding reflected in this article:
> http://erdani.com/publications/on-iteration.html
> If you have any thoughts and if you can help with the implementation,
> please let us know.
> Andrei

Can you detail a little more what you're proposing?  I read your article this
morning, though admittedly I skimmed over some of the examples that looked like
things I had already been using in my code since ranges were released.  The only
thing I noticed was the save() function for forward ranges.  This resolves the old
wart that input ranges vs. forward ranges are strictly a convention, and I think
it's a good idea.  Other than that, again, please distill what you're proposing.