#include <boost/preprocessor/variadic/to_array.hpp>
#define VAR_DATA a, b, c
BOOST_PP_VARIADIC_TO_ARRAY(VAR_DATA) // expands to (3, (a, b, c))
Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at www.boost.org/LICENSE_1_0.txt)