// In header: <boost/compute/iterator/constant_iterator.hpp>
template<typename T> 
class constant_iterator {
public:
  // types
  typedef unspecified                 super_type;     
  typedef super_type::reference       reference;      
  typedef super_type::difference_type difference_type;
  // construct/copy/destruct
  constant_iterator(const T &, size_t = 0);
  constant_iterator(const constant_iterator< T > &);
  constant_iterator< T > & operator=(const constant_iterator< T > &);
  ~constant_iterator();
  // public member functions
  size_t get_index() const;
};