1 # /* **************************************************************************
2 #  *                                                                          *
3 #  *     (C) Copyright Paul Mensonides 2002.
4 #  *     Distributed under the Boost Software License, Version 1.0. (See
5 #  *     accompanying file LICENSE_1_0.txt or copy at
6 #  *     http://www.boost.org/LICENSE_1_0.txt)
7 #  *                                                                          *
8 #  ************************************************************************** */
9 #
10 # /* See http://www.boost.org for most recent version. */
11 #
12 # ifndef BOOST_PREPROCESSOR_SEQ_FIRST_N_HPP
13 # define BOOST_PREPROCESSOR_SEQ_FIRST_N_HPP
14 #
15 # include <boost/preprocessor/config/config.hpp>
16 # include <boost/preprocessor/control/if.hpp>
17 # include <boost/preprocessor/seq/detail/split.hpp>
18 # include <boost/preprocessor/tuple/eat.hpp>
19 # include <boost/preprocessor/tuple/elem.hpp>
20 #
21 # /* BOOST_PP_SEQ_FIRST_N */
22 #
23 # if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
24 #    define BOOST_PP_SEQ_FIRST_N(n, seq) BOOST_PP_IF(n, BOOST_PP_TUPLE_ELEM, BOOST_PP_TUPLE_EAT_3)(2, 0, BOOST_PP_SEQ_SPLIT(n, seq (nil)))
25 # else
26 #    define BOOST_PP_SEQ_FIRST_N(n, seq) BOOST_PP_SEQ_FIRST_N_I(n, seq)
27 #    define BOOST_PP_SEQ_FIRST_N_I(n, seq) BOOST_PP_IF(n, BOOST_PP_TUPLE_ELEM, BOOST_PP_TUPLE_EAT_3)(2, 0, BOOST_PP_SEQ_SPLIT(n, seq (nil)))
28 # endif
29 #
30 # endif
31