"the last change" for ranges

[Jason House]

Andrei Alexandrescu Wrote:

> MLT wrote:
> > I think that if
> >> R last = r;
> > then after
> >> r.popFront;
> > the order of elements in "last" should not change, no matter what
> > type of range you are dealing with. (That means that input operations
> > would be buffered to the leftmost range that still extsts.)
> > 
> > If I understood the logic of ranges, popFront() just changes the
> > range, and not the elements it points to.
> 
> That's the case for all ranges except input ranges. Consider:
> 
> FileByCharacter
> {
>      private FILE* _f;
>      private dchar _last;
>      bool empty() { return _last == 0xffff; }
>      void popFront() { _last = fgetc(_f); }
>      dchar front() { return _last; }
> }
> 
> Consider what happens when you copy this range around.
> 
> 
> Andrei

You didn't declare FileByCharacter as either a struct or a class? Did I plant a seed? :)