I expected this to work

#include <boost/fusion/include/vector.hpp>
#include <boost/fusion/include/at_c.hpp>

typedef boost::fusion::vector<int, int> V;

int first( const V & v )
{
    return at_c<0>( v );
}

but I find I need a "using namespace boost::fusion;". Why isn't
this covered by ADL?

Thx

- Rob.