How to create the Cartesian product of a type list?

Question

I\'d like to create the cross product of a list of types using variadic templates.

Here\'s what I have so far:

#include 
#include <         


        

Answer 1

Somehow my brain is fried: I think I'm using more code than is needed but, at least, it has the desired results (although I didn't fix the memory leak):

#include 
#include 
#include 

template struct type_list {};

template struct type_pair {};

template
  struct row
{
  typedef type_list...> type;
};

template  struct concat;
template 
struct concat, type_list>
{
    typedef type_list type;
};

template 
struct expand
{
    typedef type_list type;
};
template <> struct expand<> { typedef type_list<> type; };
template 
struct expand, L...>
{
    typedef typename concat::type, typename expand::type>::type type;
};

template
  struct cross_product
{
    typedef typename expand::type...>>::type type;

};

int main()
{
  int s;
  typedef cross_product::type result;
  std::cout << abi::__cxa_demangle(typeid(result).name(), 0, 0, &s) << std::endl;

  return 0;
}