// In header: <boost/test/data/monomorphic/grid.hpp>
template<typename DataSet1, typename DataSet2> 
class grid {
public:
  // member classes/structs/unions
  struct iterator {
    // types
    typedef decltype(sample_merge(*std::declval< dataset1_iter >(),*std::declval< dataset2_iter >())) iterator_sample;
    // construct/copy/destruct
    explicit iterator(dataset1_iter, DataSet2 const &);
    // public member functions
    auto operator*() const;
    void operator++();
  };
  enum @7 { 
            arity = = boost::decay<DataSet1>::type::arity + boost::decay<DataSet2>::type::arity };
  // construct/copy/destruct
  grid(DataSet1 &&, DataSet2 &&);
  grid(grid &&);
  // public member functions
  data::size_t size() const;
  iterator begin() const;
};