#include <boost/preprocessor/seq/first_n.hpp>
#define SEQ (a)(b)(c)(d)(e)
BOOST_PP_SEQ_FIRST_N(2, SEQ) // expands to (a)(b)
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)