Re: [Boost-users] iterator_adaptor usage question

Subject: Re: [Boost-users] iterator_adaptor usage question
From: Dave Abrahams (dave_at_[hidden])
Date: 2012-03-14 23:23:38

on Sun Mar 11 2012, "Jeffrey Lee Hellrung, Jr." <jeffrey.hellrung-AT-gmail.com> wrote:

> On Sun, Mar 11, 2012 at 8:27 PM, John M. Dlugosz <mpbecey7gu_at_[hidden]> wrote:
>
>     What is a good way to create both an iterator and a const iterator while only having to specify all my custom behavior once?
>
> Maybe template your iterator on the base iterator, and dispatching when necessary depending on whether that base iterator is the
> const iterator or the mutable iterator? E.g.,
>
> template< class Base >
> struct my_iterator
> Â Â Â  : boost::iterator_adaptor< Base >
> { };
>
> typedef my_iterator< base_iterator > iterator;
> typedef my_iterator< base_const_iterator > const_iterator;

http://www.boost.org/doc/libs/1_49_0/libs/iterator/doc/iterator_facade.html#a-constant-node-iterator
shows how to do it with iterator_facade, and
http://www.boost.org/doc/libs/1_49_0/libs/iterator/doc/iterator_adaptor.html#tutorial-example
extends that to iterator_adaptor

HTH,

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com