"the last change" for ranges

[Andrei Alexandrescu]

Jason House wrote:
> I feel like there are too many differences between input and forward
> ranges for such a minor difference. Many range functions are written
> assuming no side effects on the caller. This can restrict the use of
> helper functions. It may be best to make their usage different...

So how do you think we should go about it? Also don't forget that any 
ranges should be seamlessly and efficiently treated as input ranges.

Andrei