Re: [boost] [fusion] pop_back doesn't work on fwd sequences

Subject: Re: [boost] [fusion] pop_back doesn't work on fwd sequences
From: Joel de Guzman (joel_at_[hidden])
Date: 2011-08-11 11:46:03

On 8/11/2011 5:08 PM, Joel de Guzman wrote:
> On 8/11/2011 12:19 PM, Eric Niebler wrote:
>> On 8/10/2011 3:06 PM, Joel de Guzman wrote:
>>> On 8/11/2011 4:04 AM, Joel de Guzman wrote:
>>>
>>>> Hmmmm. now that I think about it, it is also possible to change the
>>>> implementation of pop_back to make it so that it would not need
>>>> to use 'prior'. The end iterator can be abstracted such that it
>>>> compares equal to i through next(i). I'll see if that works out.
>>>
>>> Yep. It works like a charm. I have a fix. Now this works:
>>>
>>>     {
>>>         list<int, int> l(1, 2);
>>>         std::cout << pop_back(l) << std::endl;
>>>         BOOST_TEST((pop_back(l) == make_list(1)));
>>>     }
>>>
>>> Now, indeed, the docs works as advertized.
>>>
>>> Thanks for your nudging, Eric. I truly appreciate it. You get my
>>> neurons humming. Committed to trunk. I'd welcome a quick review
>>> before I make this official.
>>
>> Very clever! Looks good to me.
> 
> Cool. Now I notice that pop_back_iterator is the workings of a
> reusable iterator_adapter.

Ok, so now we have a fusion iterator_adapter. pop_back_iterator is the first
client. Refactoring + QOI stuff. Docs to follow when i get time in the weekend
(note to self).

Regards,
-- 
Joel de Guzman
http://www.boostpro.com
http://boost-spirit.com