[boost] Re: New Iterator Adapters - filter_iterator

From: David Abrahams (dave_at_[hidden])
Date: 2003-07-03 17:55:01

Thomas Witt <witt_at_[hidden]> writes:

> John,
>
> John R. Bandela wrote:
>> Should filter_iterator use iterator_facade as its base instead of
>> iterator_adapter? It seems the iterator_adapter is incorrectly implementing
>> advance.
>
> I wouldn't say that it is incorrectly implementing advance. AFAICS
> the problem is that there is no way to restrict the functionality
> that iterator_adaptor provides in a derived class. 

Sure there is; you can supply a non-compiling templated advance
operation if you want to disable it.

> I am not yet decided what the right fix to this issue is, maybe a
> mix in based implementation of iterator_adaptor is the right way to
> go.

Careful; I don't really have a clear picture of what you have in mind,
but that might make bloated iterators since few compilers implement
EBO under multiple-inheritance.

>> Regards,
>> John Bandela
>>
>> PS: I don't know if this is the place to ask, but I have updated
>> tokenizer to the new iterator adapters. Is there some place it
>> should be placed pending release of the new iterator_adapters?
>
> I was under the impression that Dave is gonna move it to the main
> trunk real soon, so keeping it on your local disk for a few more
> days might be the easiest solution. Dave?

I'm on vacation until the 6th at least.  Joel volunteered to make that
move, though I'm not sure what his schedule looks like.  If he's
bitten off more than he can chew I may jump in to help out.  Joel?

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com