[Boost-users] Re: boost::iterator_facade problem with postfix increment proxy

From: Thomas Witt (witt_at_[hidden])
Date: 2005-03-21 18:24:24

David Abrahams wrote:
> 
> If that's the case, the iterator_facade is choosing
> postfix_increment_proxy instead of writable_postfix_increment_proxy,
> on the basis of the fact that you haven't given the iterator a proxy
> reference type.  I'm not sure I understand the logic behind it, but
> iterator_facade assumes that if your readable iterator doesn't support
> forward traversal, it must have a proxy reference in order to also be
> writable.  If you have a counterexample, it would be good to see it.
> 
> [Jeremy, Thomas: Can you shed any light on this assumption?

Sorry, but no.

>  Also, it
> looks like we left out the requirement that a single-pass iterator is
> also an incrementable iterator.  Am I mistaken?  If not, I'd like to
> fix the docs: http://tinyurl.com/2dm3h]

Hmm, the requirements table header says:

'Single Pass Iterator Requirements (in addition to Incrementable 
Iterator and Equality Comparable)'

Isn't that sufficient?

Thomas

-- 
Thomas Witt
witt_at_[hidden]