Re: ScopeGuard

From: William Kempf (sirwillard_at_[hidden])
Date: 2000-11-07 14:35:02

--- In boost_at_[hidden], Thomas Maeder <maeder_at_g...> wrote:
> jbandela_at_u... wrote:
> > 
> > Has anyone else seen the Generic Programming article this month on
> > CUJ Expert Forum? I personally was pretty impressed by it. I was
> > wondering if anybody else shares my opinion, and if in the future 
it
> > or something like it could be incorporated into the boost library?
> 
> It would be interesting to integrate the approach with the lambda 
library.

Some months back I wrote a class very similar to this for use in my 
COM programming.  It took any valid functor type as a call back (so 
LL would work great with it... only my compiler doesn't like LL).  In 
addition it kept a "stack" of such callbacks instead of taking only a 
single callback.  This made it much nicer to work with when there 
were multiple operations that would need to be rolled back.  If 
there's interest I can clean things up and boostify them for 
submission into Boost.

Example useage of my class (name changes to be more in line with 
boost):

void func()
{
   scope_guard guard;

   add_record(...);
   // roll back the add if an exception occurs
   guard.push(bind(remove_record, ...));

   update_record(...);
   // roll back the changes if an exception occurs
   guard.push(bind(update_record, ...));

   // illustrates dismissing a single operation
   scope_guard::cookie c1 = guard.push(bind(update_record, ...));
   guard.dismiss(c1);

   // illustrates dismissing all registered operations
   guard.dismiss();
}

Bill Kempf