Re: [boost] iterator_adaptors

From: Arun Sivaramakrishnan (aruns_at_[hidden])
Date: 2001-01-21 00:04:46

> 
> 
> On Sun, 21 Jan 2001, Arun Sivaramakrishnan wrote:
> 
> >    Most often ,I wouldnt want to write a functor everytime I use
> > transform_adaptor(or projection_adaptor)
> 
> This looks like what I thought that I had seen.  Did you send it
> before?  To me, not boost?
> 
I sent that last night to you and not to boost.
.Sorry about the names (projection_iterator not adaptor) 
.I must confess I was half asleep when I wrote that.

> Anyway, I agree that projection_iterator is broken.  You seem to
> be about the only one who has used the adaptors other than those
> of us involved in the developement.
> 
> Projection iterator has reference semantics.  The adapted iterator,
> const or non-const, determines the input to the function object.
> The output of the function object must be a const/non-const reference.
> The problem is extracting the value_type for the projection_iterator.
> Given that, the other four traits are determined from it and the
> adapted iterator.
> 
> I have a revised version which requires the value type as a template
> parameter.  Template<Value, Function, Iterator, Traits = ..>.  Would
> you like to try it?  Does that sound like a reasonable solution?

Reasonable,though not an ideal solution considering 
the constraints here.

Thanks ,
arun