Re: [boost] Re: string_algo Formal Review

From: Pavol Droba (droba_at_[hidden])
Date: 2003-10-22 12:07:55

On Wed, Oct 22, 2003 at 12:32:51PM -0400, David Abrahams wrote:
> Pavol Droba <droba_at_[hidden]> writes:
> 
> > On Wed, Oct 22, 2003 at 09:34:44AM -0400, David Abrahams wrote:
> >> Pavol Droba <droba_at_[hidden]> writes:
> >> 
> >> > On Tue, Oct 21, 2003 at 05:48:27PM -0400, David Abrahams wrote:
> >
> > [snip]
> >  
> >> >
> >> > Sorry, the definition is not exact. I have used the C++ syntax, but
> >> > I merely wanted to list the requiremnts. The fact is, that it is not
> >> > required, that f.e. a container have .begin() member function. It is
> >> > only required, that such a function is accessible. Having the
> >> > container_traits and freestanding begin(), it is well defined for
> >> > C-arrays.
> >> 
> >> You still need a tight definition of the requirements.
> >>
> >
> > Definition will be provided in docs. The format will be the same as the
> > concept definitions which are already there. 
> >
> > As far as I see, this concept should be defined in the terms of operations 
> > that are provided by container_traits.
> >
> > <example>
> >
> > 	Valid expressions | Return Types                                      | Effects
> > 						 	|                                                   |
> > 	begin(C) 			| container_const_iterator<C>::type when C is const | returns an iterator pointing
> > 							| container_iterator<C>:type  when C is mutable     | to the first element in the container
> >
> > 	end(C) 				| container_const_iterator<C>::type when C is const | returns an iterator pointing
> > 							| container_iterator<C>::type when C is mutable     | after the last element in the container
> >
> > 	size(C)				| container_size_type<C>::type                      | returns the number of elements in the container
> >
> > </example>
> >
> > container_traits can be then described as a facility which provides this interface for
> > build-in types like C-arrays and STL containers
> 
> Then you also need to decide whether those functions are meant to be
> called with or without the boost::qualification.
> 
Koenig lookup should help here, but you are right, this is an issue, which has to be addressed.
And to be hones, I don't have a clear idea what is the best solution.

Any ideas out there?

Pavol