dirty error example

gistfile1.txt

- (id)fooWithError: (NSError **)outError
{
    id obj = [self barWithThing: @"thing" error: outError];
    if(!obj)
        obj = [self quuxWithThing: @"thing" error: outError];
    return obj;
}

- (id)fooWithError: (NSError **)outError
{
  NSError *innerError;
  id obj = [self barWithThing: @"thing" error: innerError];
  if(!obj) {
    innerError = nil;
    obj = [self quuxWithThing: @"thing" error: innerError];
  }
  if (!obj) outError = &innerError;
  return obj;
}