protocol for using InputRanges

[Walter Bright]

On 3/27/2014 12:50 PM, Andrei Alexandrescu wrote:
> Yah, agreed. -- Andrei

Completely unworkable. To determine if a range is empty or not, it may have to 
actually read from its input. TTYs are an example. Although empty may then cache 
the result, and not read the second time it is called, an observer of TTY could 
see that an item was read from the TTY.