[Boost-users] Re: Iterator adaptor interoperability

From: David Abrahams (dave_at_[hidden])
Date: 2004-02-24 20:45:34

Kris Braun <kris_braun_at_[hidden]> writes:

> Dave Abrahams wrote:
>> Your best bet is to write an type generator:
>> template <class Iterator>
>> struct simple_iterator
>> {
>>     typedef boost::transform_iterator< 
>>         do_nothing< typename Iterator::value_type >
>>       , Iterator
>>     > type;
>> };
>
> Thank you for the quick and clear reply! I'm now
> having a very similar problem with a slightly more
> complicated example (that builds on the first):
>
> template< class Iterator >
> struct harder_iterator {
>     typedef simple_iterator< Iterator >::type
>                             inner_type;
>     typedef boost::indirect_iterator< inner_type >
>                             type;
>
>     static type             Create( const Iterator&
> iter )
>                                 { return type(
> inner_type( iter ) ); }
> };
>
> This "composite" iterator not only has problems with
> comparison, but assignment from non-const to const as
> well. Is there a way to handle this case?

Need more details.  Post a reproducible test that fails compilation
and I might be able to solve your problem.
  
-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com