#define DECLARE_VECTOR(vector_name) \
  template< int i, int bidon >  \
  struct vector_name \
  {                  \
    enum             \
    {                \
      is_defined = 0 \
    };               \
  }

#define SET_VECTOR_ELEMENT(vector_name, i, element) \
  template< int bidon >         \
  struct vector_name<i, bidon>  \
  {                        \
    enum                   \
    {                      \
      is_defined = 1       \
    };                     \
    typedef element value; \
  }

template< bool b, typename i, typename j >
struct select_value;

template< typename i, typename j >
struct select_value< true, i, j >
{
  enum
  {
    value = i::value
  };
};

template< typename i, typename j >
struct select_value< false, i, j >
{
  enum
  {
    value = j::value
  };
};

template< int i >
struct IntToType
{
  enum
  {
    value = i
  };
};

template< int i, template< int, int > class TypeVector, int IdUnique >
struct LnVector
{
  enum
  {
     value = select_value<
              TypeVector<i, IdUnique >::is_defined,
              LnVector< i + 1, TypeVector, IdUnique >,
              IntToType<i> >::value
  };

};

#define GET_VECTOR_LENGTH( vector_name ) \
  LnVector< 0, vector_name, __LINE__ >::value

#define PUSH_BACK_IN_VECTOR( vector_name, element ) \
  template< int bidon >              \
  struct vector_name< GET_VECTOR_LENGTH(vector_name), bidon > \
  {                        \
    enum                   \
    {                      \
      is_defined = 1       \
    };                     \
    typedef element value; \
  }


DECLARE_VECTOR( MyVector );
SET_VECTOR_ELEMENT( MyVector, 0, int );
SET_VECTOR_ELEMENT( MyVector, 1, float );
PUSH_BACK_IN_VECTOR( MyVector, double );
PUSH_BACK_IN_VECTOR( MyVector, long );


template< typename T, typename U >
struct TypesAreEqual
{
  enum
  {
    value = false
  };
};

template< typename T >
struct TypesAreEqual< T, T >
{
  enum
  {
    value = true
  };
};

#define GET_VECTOR_ELEMENT( vector_name, i ) \
  vector_name< i, __LINE__>::value

int main(int argc, char *argv[])
{
  cout << "lenght : " << GET_VECTOR_LENGTH(MyVector) << endl; // prints 4

  cout << TypesAreEqual< int, GET_VECTOR_ELEMENT(MyVector, 0) >::value << endl; // prints 1
  cout << TypesAreEqual< float, GET_VECTOR_ELEMENT(MyVector, 1) >::value << endl; // prints 1
  cout << TypesAreEqual< double, GET_VECTOR_ELEMENT(MyVector, 2) >::value << endl; //prints 1
  cout << TypesAreEqual< long, GET_VECTOR_ELEMENT( MyVector, GET_VECTOR_LENGTH(MyVector)-1) >::value << endl; // prints 1

  return EXIT_SUCCESS;
}