Re: [Boost-users] [range] [mpl] begin/end conflicts with mpl::begin/mpl::end

From: MB (mb2act_at_[hidden])
Date: 2006-01-22 02:11:31

François Duranleau wrote:
> Hi!
> 
> I started to use more extensively Boost.Mpl recently, and I started as 
> well to get ADL-related compile errors when a template argument is an 
> MPL sequence. I could resolve the conflicts within my own code, but I 
> hit one coming from Boost.Range. Here is a simple example that provokes 
> an error (tested with g++ 4.0.3 and Boost 1.33.1):
> 
> #include <boost/mpl/vector.hpp>
> #include <boost/range/begin.hpp>
> #include <vector>
> 
> template < typename T >
> struct dummy {} ;
> 
> void trouble()
> {
>     typedef dummy< ::boost::mpl::vector< int > > vt ;
>     typedef ::std::vector< const vt* > ct ;
> 
>     boost::const_begin( ct() ) ;
> }
> 
> The compiler reports a conflict between boost::begin (called by 
> boost::const_begin in <boost/range/begin.hpp>) and boost::mpl::begin.
> 
> For now, I resolved it simply by changing the function 
> boost::const_begin like this (in <boost/range/begin.hpp>):
> 
> namespace boost
> {
>     template< class T >
>     inline BOOST_DEDUCED_TYPENAME range_const_iterator<T>::type
>     const_begin( const T& r )
>     {
>         return boost::begin( r );
>     }
> }
>                ^^^^^^^
> 
> Similarly for boost::end. However, if that call was really meant to be 
> resolved through ADL, then it seems to me there is a problem, and I 
> don't know if anything can be done.
> 
> Any ideas?

Hi,

I maybe already post it.
I hear ADL dependent way was rejected.
Now that we must always add 'boost::'.
It is obviously a bug of Boost.Range...

Regards,
MB
p-stade.sourceforge.net