[RFC/Patch] What about using seekoff(-1, ...) for unbuffered underflow?

[pcarlini@unitus.it]

> >I'm looking a bit into the new framework for unbuffered input,
> >and I'd rather prefer having sbumpc() simple as it was before.
> 
> ... and seeking after every input? Don't think that's going to fly.
> There have been performance bugs about this in the past.

Well, seeking after every _unbuffered getc()_ (vs. buffered and/or sbumpc)!

On the other hand, an heavier sbumpc() affects any sbumpc(), buffered or not 
and I think that, for top performance, people really want a fast unbuffered 
sbumpc(). Also, the underflow call should be checked for its return value.

Paolo.