// In header: <boost/test/data/monomorphic/singleton.hpp>
template<typename T> 
class singleton {
public:
  // types
  typedef boost::decay< T >::type sample;
  // member classes/structs/unions
  struct iterator {
    // construct/copy/destruct
    explicit iterator(singleton< T > const *);
    // public member functions
    sample const & operator*() const;
    void operator++();
  };
  enum @9 { arity = = 1 };
  // construct/copy/destruct
  explicit singleton(T &&);
  singleton(singleton &&);
  // public member functions
  T const & value() const;
  data::size_t size() const;
  iterator begin() const;
};