Re: [Boost-Users] Re: [BGL] Best way to abort an algorithm from withi n a visitor?

From: Steve M. Robbins (steven.robbins_at_[hidden])
Date: 2002-09-19 13:38:34

On Thu, Sep 19, 2002 at 11:04:12AM -0700, Jeff Faust wrote:

> > > Exceptions are meant for exceptional cases. [...]
> >
> > Define "exceptional cases". How exceptions work is well defined, and
> > therefore can be understood, whereas an "exceptional case" is always
> > assumed to be intuitively obvious.
> 
> Something unexpected.  The example give by the original poster is describing
> a normal execution.  This is not unexpected.  It's strange to think that
> what occurs in the catch block is not error recover/reporting, but normal
> and expected execution.  This is not an obvious usage of exceptions.

I think you're imposing your own experience on the question.  In the
case at hand, using an exception seemed perfectly natural to *me*, for
all the reasons that Jeremy just outlined.  It is clear from the discussion
that I'm not alone in viewing this as a normal use of exceptions.

Think of it this way: the normal course of action for a "visitor" is
to process a node.  Reaching the "end node" is an exceptional case.

-Steve