Re: [Boost-users] Random access to sequences

18 Aug 2005


      Stephen Gross writes:
...
I read up on boost::mpl::at<...>. It's pretty cool, but I wanted to make it 
a little easier to use. I found it a little annoying to have to type out 
'int_<...>' for the index number, so I created a struct to automate that 
feature:
==========================
template<typename SEQ, int IDX>
struct atIdx
{
  typedef typename boost::mpl::at<SEQ, boost::mpl::int_<IDX> >::type type;
};
==========================
With the struct above, you can do the following:
=============================
typedef boost::mpl::vector<int, char, int> t;
atIdx<t, 0>::type i; // This line is shorter than the one below:
/* atIdx<t, boost::mpl::int_<0> >::type i; */
=============================
Is this feature already available in boost somewhere? If I've reinvented the 
wheel, I'll be happy to use an existing implementation...
See http://www.boost.org/libs/mpl/doc/refmanual/at-c.html.

-- 
Aleksey Gurtovoy
MetaCommunications Engineering