[boost] Re: Functors and Boost::MPL

14 Jul 2004

      Dan wrote:
...
It occurs to me that it should be possible to manage an mpl::vector of
types which are actually functors.
[snip]
I think it should be easy to create the vector, but how does one
construct an object of each type and call operator() on it?
This works:

   #include <boost/mpl/vector.hpp>
   #include <boost/mpl/for_each.hpp>
   #include <boost/bind.hpp>
   #include <boost/bind/apply.hpp>

   struct A
   {
       void operator()();
   };

   struct B
   {
       void operator()();
   };

   ...

   typedef mpl::vector<A, B> v;
   mpl::for_each<v>(boost::apply<void>());

And you could use boost::bind to pass parameters to the functors:

   struct A
   {
       void operator()(int);
   };

   struct B
   {
       void operator()(int);
   };

   ...

   typedef mpl::vector<A, B> v;
   mpl::for_each<v>(
       boost::bind(boost::apply<void>(), _1, 0)
   );

HTH,
-- 
Daniel Wallin