preprocessor/seq/first_n.hpp

0001 # /* **************************************************************************
0002 #  *                                                                          *
0003 #  *     (C) Copyright Paul Mensonides 2002.
0004 #  *     Distributed under the Boost Software License, Version 1.0. (See
0005 #  *     accompanying file LICENSE_1_0.txt or copy at
0006 #  *     http://www.boost.org/LICENSE_1_0.txt)
0007 #  *                                                                          *
0008 #  ************************************************************************** */
0009 0010 ">#
0011 # /* See http://www.boost.org for most recent version. */
0012 0013 ">#
0014 # ifndef BOOST_PREPROCESSOR_SEQ_FIRST_N_HPP
0015 # define BOOST_PREPROCESSOR_SEQ_FIRST_N_HPP
0016 0017 ">#
0018 # include <boost/preprocessor/config/config.hpp>
0019 # include <boost/preprocessor/control/if.hpp>
0020 # include <boost/preprocessor/seq/detail/split.hpp>
0021 # include <boost/preprocessor/tuple/eat.hpp>
0022 # include <boost/preprocessor/tuple/elem.hpp>
0023 0024 ">#
0025 # /* BOOST_PP_SEQ_FIRST_N */
0026 0027 ">#
0028 # if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
0029 #    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)))
0030 # else
0031 #    define BOOST_PP_SEQ_FIRST_N(n, seq) BOOST_PP_SEQ_FIRST_N_I(n, seq)
0032 #    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)))
0033 # endif
0034 0035 ">#
0036 # endif