Re: [Boost-users] Tuple use/overuse?

26 Jul 2007

      Graham Reitz wrote:
...
Yes, thanks Joel.
I should have used more elements in my example and not called it some_pair.
Oh and BTW, in case you don't know yet, in Fusion, structs and tuples
are interchangeable. IOTW, structs *are* tuples. Sample:

     namespace ns
     {
         struct point
         {
             int x;
             int y;
         };
     }

     BOOST_FUSION_ADAPT_STRUCT(
         ns::point,
         (int, x)
         (int, y)
     )

     /*...*/

     ns::point p = {123, 456};
     std::cout << at_c<0>(p) << std::endl;
     std::cout << at_c<1>(p) << std::endl;

(those at_c<N> thingies are Fusion's get<N> counterparts. Ala MPL!)

It's the same interface as say, for vector<int, int>:

     fusion::vector<int, int> v(123, 456);
     std::cout << at_c<0>(v) << std::endl;
     std::cout << at_c<1>(v) << std::endl;

Or even a boost::array:

     boost::array<int, 2> a(123, 456);
     std::cout << at_c<0>(a) << std::endl;
     std::cout << at_c<1>(a) << std::endl;

Or, of course, a std::pair:

     std::pair<int, int> pr(123, 456);
     std::cout << at_c<0>(pr) << std::endl;
     std::cout << at_c<1>(pr) << std::endl;

Regards,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net