text: //
  //
  //
  /// @brief A private memeber function used to check the pointer pointing
  /// the end of the array. The pointer for the begin is the @c data or @c
  /// data[0] itself.
  //
  /// @return A pointer with the same type of the current array.
  //
  constexpr data_type *data_end() const
  {
  	return data + data_length();
  };
  