Re: Separate iterator operators from iterator traits?

From: darylew_at_[hidden]
Date: 2001-09-23 16:04:58

Check out

    http://groups.yahoo.com/group/boost/files/dlw_oprs2.zip

Daryle Walker
[posting through web interface]

--- In boost_at_y..., "David Abrahams" <david.abrahams_at_r...> 
wrote:
> That seems like a good idea. Why don't you post a patch?
> 
> Please include documentation changes.
> Please also try to make your changes minimal, to ease the 
> review and integration process.

> ----- Original Message -----
> From: "Daryle Walker" <darylew_at_m...>
> To: "Boost" <boost_at_y...>
> Sent: Monday, September 03, 2001 2:42 PM
> Subject: [boost] Separate iterator operators from iterator traits?
> 
> 
> > In <boost/operators.hpp>, we have templates like:
> >
> >
> > ==============================================
> > template <class T,
> >           class V,
> >           class D = std::ptrdiff_t,
> >           class P = V*,
> >           class R = V&>
> > struct bidirectional_iterator_helper
> >   : equality_comparable1<T
> >   , unit_steppable<T
> >   , dereferenceable<T, P
> >   , boost::iterator<std::bidirectional_iterator_tag, V, D, P, R
> >     > > > > {};
> >
> > ==============================================
> >
> > where the operator helpers are attached to the iterator base.  
> > Maybe we can do a separation like:
> >
> >
> > ==============================================
> > template <class T, class P, class B = 
> >   ::boost::detail::empty_base>
> > struct bidirectional_iterator_operators
> >     : equality_comparable1<T
> >     , unit_steppable<T
> >     , dereferenceable<T, P, B
> >       > > > {};
> >
> > //...
> >
> > template <class T,
> >           class V,
> >           class D = std::ptrdiff_t,
> >           class P = V*,
> >           class R = V&>
> > struct bidirectional_iterator_helper
> >   : bidirectional_iterator_operators <T, P
> >   , boost::iterator<std::bidirectional_iterator_tag, V, D, P, R
> >     > > {};
> >
> > ==============================================
> >
> > in case we need to supply the iterator base in a different 
> > manner (like now when I'm trying to use these operators with
> > an iterator based off a reverse iterator of another
> > iterator class I defined).