# define BOOST_PREPROCESSOR_VARIADIC_HPP
#
# include <boost/preprocessor/variadic/elem.hpp>
+# include <boost/preprocessor/variadic/has_opt.hpp>
# include <boost/preprocessor/variadic/size.hpp>
# include <boost/preprocessor/variadic/to_array.hpp>
# include <boost/preprocessor/variadic/to_list.hpp>