Re: [boost] [range] How to extend Boost.Range?

From: Thorsten Ottosen (nesotto_at_[hidden])
Date: 2005-09-13 13:09:34

Eric Niebler <eric <at> boost-consulting.com> writes:

> 
> 
> Thorsten Ottosen wrote:
> > 
> > Btw, my range_size uses this code
> > 
> > 		template< class T >
> > 		struct add_unsigned;

> > Can anybody spot weaknesses in that approach?
> >  
> 
> Well, you haven't defined a primary template, so add_unsigned<unsigned> 
> will not compile. IMO, your primary template should "typedef T type;". 
> But depending on what you're trying to do, this may work, and it's a lot 
> shorter:
> 
> template< typename Int >
> struct add_unsigned {
>      typedef typename boost::uint_t<
>          sizeof(Int) * CHAR_BIT
>      >::least type;
> };

right, it shorter.

I wanted to remove the need for specializing range_size<>
but apparently this relation does not hold for all implementations:

sizeof( container::size_type ) == sizeof( container::iterator::difference_type )

:-( what a shame.

-Thorsten