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

Here's another solution.

#include 
#include 
#include 

template  struct typelist { };
template  struct typepair { };

template  struct product;
template  struct append;

template
struct append, typelist> {
  typedef typelist type;
};

template<>
struct product, typelist<>> {
  typedef typelist<> type;
};

template
struct product, typelist> {
  typedef typelist<> type;
};

template
struct product, typelist<>> {
  typedef typelist<> type;
};

template
struct product, typelist> {
  typedef typename
          append,
                          typepair...,
                          typepair...>,
        typename product, typelist>::type>::type type;
};

int main(void)
{
  int s;
  std::cout << abi::__cxa_demangle(
  typeid(product, typelist>::type).name(), 0, 0, &s)     << "\n";
  return 0;
}