Re: [Boost-users] dereference problems with iterator_facade

From: David Abrahams (dave_at_[hidden])
Date: 2008-08-21 21:14:09

on Tue Aug 19 2008, e r <erwann.rogard-AT-gmail.com> wrote:

> hello,
>
> i have a build error when i try to use an iterator derived from
> iterator_facade<Iter> with Iter an iterator over a const Range. It's the
> const that causes the error. See the *.hpp below and an example.

The problem is that the reference type of Iter is value_type& when it
should be value_type const&.  The value_type of a constant iterator is
still non-const, and you're getting the Value parameter by asking the
value_type of BaseIter.

> any other suggestion to improve the *hpp also appreciated.

Use iterator_adaptor; all your problems will go away and your code will
get smaller.

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