[boost] Re: input_iterator_facade (was: Re: [iterator facade] Why isdereference const?)

From: Gennadiy Rozental (gennadiy.rozental_at_[hidden])
Date: 2004-05-25 05:14:18

> Rozental, Gennadiy wrote:
> > > I still don't understand which design, yours or mine, is better. It
seems mine
> > > allows to create iterators with smaller number of lines, but maybe
there's
> > > something else.
> >
> > Why do you think so? I would say vice versa, since I do not require
> > constructor in derived class to call found_eof().
>
> My line_iterator declares two constructors and 'get'. Yours defines, for
> stream_line_iterator_impl: one constructor, 'initialize', 'get',
> 'dereference' and 'equal' plus one constructor in
basic_istream_line_iterator
> This is 1 class and 3 member functions vs. 2 classes and 6 member
functions.

I do not put value directly into input_iterator_facade since it too much an
assumption. So I need to method dereference in Policy.
In your implementation input iterators almost never equal. Even though it is
true in many cases. I still believe you couldn't assume it is always the
case. So I need method equal  in Policy.
Actually my implementation was written couple years ago for classic
iostreams. I forgot about getline version you are using when ported for
Boost.Test needs. Once I switch to standard getline, I don't actually need
method initialize anymore for my usage cases. I still not sure is it
required in general. BTW don't you missed to call get() in line_iterator
constructor?
The question remains does we need all that flexibility. I believe - yes.

Gennadiy.