boost/preprocessor/seq/first_n.hpp
# /* ************************************************************************** # * * # * (C) Copyright Paul Mensonides 2002. # * Distributed under the Boost Software License, Version 1.0. (See # * accompanying file LICENSE_1_0.txt or copy at # * http://www.boost.org/LICENSE_1_0.txt) # * * # ************************************************************************** */ # # /* See http://www.boost.org for most recent version. */ # # ifndef BOOST_PREPROCESSOR_SEQ_FIRST_N_HPP # define BOOST_PREPROCESSOR_SEQ_FIRST_N_HPP # # include <boost/preprocessor/config/config.hpp> # include <boost/preprocessor/control/if.hpp> # include <boost/preprocessor/seq/detail/split.hpp> # include <boost/preprocessor/tuple/eat.hpp> # include <boost/preprocessor/tuple/elem.hpp> # # /* BOOST_PP_SEQ_FIRST_N */ # # if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG() # 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))) # else # define BOOST_PP_SEQ_FIRST_N(n, seq) BOOST_PP_SEQ_FIRST_N_I(n, seq) # 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))) # endif # # endif