Re: [boost] [range] concepts.hpp broken

From: Daniel Walker (daniel.j.walker_at_[hidden])
Date: 2007-10-29 11:18:26

On 10/29/07, Thorsten Ottosen <thorsten.ottosen_at_[hidden]> wrote:
> shunsuke skrev:
> > Thorsten Ottosen wrote:
> >> You would rather see range_mutable_iterator and range_const_iterator there?
> > Yes.
> >
> > I've found an interesting quote in doc/boost_range.html:
> >
> > The special metafunctions range_result_iterator and range_reverse_result_iterator
> > are not part of any Range concept,
> >
> > You knew it.
>
> Well, those docs are so old now, I'm not sure they should be take too
> seriously.
>
> The formulation I'm leaning towards in the new docs are the following:
>
> Single Pass Range:
>
> types:
>
> range_iterator<T>::type
> range_iterator<const T>::type

What if you have a non-const range of const_iterators? It seems like
you still need range_const_iterator.

> range_size<T>::type
>
> expresions:
>
> boost::begin(r)
> boost::end(r)
>
> ...
>
> Random Access Range:
>
> expressions:
> boost::size(r);

This is good. It looks the same as the currently documented concepts
except the syntax of return types of functions needs to be specified;
i.e. the return type of begin(r) may be assigned to
range_iterator<T>::type, etc.

>
> Now, the ways you provide a concept map may involve
> types such as range_mutable_iterator, const_iterator, and functions
> range_begin/range_end.

What do you mean by "concept map?" Are you referring to C++0x
concept_map? Or do you mean these types and functions will help users
implement a type that models a range concept in C++98 terms? I think
the later, but I want to make sure.

Daniel