1# /* Copyright (C) 2001
2# * Housemarque Oy
3# * http://www.housemarque.com
4# *
5# * Distributed under the Boost Software License, Version 1.0. (See
6# * accompanying file LICENSE_1_0.txt or copy at
7# * http://www.boost.org/LICENSE_1_0.txt)
8# */
9#
10# /* Revised by Paul Mensonides (2002) */
11#
12# /* See http://www.boost.org for most recent version. */
13#
14# ifndef BOOST_PREPROCESSOR_LIST_FILTER_HPP
15# define BOOST_PREPROCESSOR_LIST_FILTER_HPP
16#
17# include <boost/preprocessor/config/config.hpp>
18# include <boost/preprocessor/control/if.hpp>
19# include <boost/preprocessor/list/fold_right.hpp>
20# include <boost/preprocessor/tuple/elem.hpp>
21# include <boost/preprocessor/tuple/rem.hpp>
22#
23# /* BOOST_PP_LIST_FILTER */
24#
25# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
26# define BOOST_PP_LIST_FILTER(pred, data, list) BOOST_PP_TUPLE_ELEM(3, 2, BOOST_PP_LIST_FOLD_RIGHT(BOOST_PP_LIST_FILTER_O, (pred, data, BOOST_PP_NIL), list))
27# else
28# define BOOST_PP_LIST_FILTER(pred, data, list) BOOST_PP_LIST_FILTER_I(pred, data, list)
29# define BOOST_PP_LIST_FILTER_I(pred, data, list) BOOST_PP_TUPLE_ELEM(3, 2, BOOST_PP_LIST_FOLD_RIGHT(BOOST_PP_LIST_FILTER_O, (pred, data, BOOST_PP_NIL), list))
30# endif
31#
32# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
33# define BOOST_PP_LIST_FILTER_O(d, pdr, elem) BOOST_PP_LIST_FILTER_O_D(d, BOOST_PP_TUPLE_ELEM(3, 0, pdr), BOOST_PP_TUPLE_ELEM(3, 1, pdr), BOOST_PP_TUPLE_ELEM(3, 2, pdr), elem)
34# else
35# define BOOST_PP_LIST_FILTER_O(d, pdr, elem) BOOST_PP_LIST_FILTER_O_I(d, BOOST_PP_TUPLE_REM_3 pdr, elem)
36# define BOOST_PP_LIST_FILTER_O_I(d, im, elem) BOOST_PP_LIST_FILTER_O_D(d, im, elem)
37# endif
38#
39# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_DMC()
40# define BOOST_PP_LIST_FILTER_O_D(d, pred, data, res, elem) (pred, data, BOOST_PP_IF(pred(d, data, elem), (elem, res), res))
41# else
42# define BOOST_PP_LIST_FILTER_O_D(d, pred, data, res, elem) (pred, data, BOOST_PP_IF(pred##(d, data, elem), (elem, res), res))
43# endif
44#
45# /* BOOST_PP_LIST_FILTER_D */
46#
47# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
48# define BOOST_PP_LIST_FILTER_D(d, pred, data, list) BOOST_PP_TUPLE_ELEM(3, 2, BOOST_PP_LIST_FOLD_RIGHT_ ## d(BOOST_PP_LIST_FILTER_O, (pred, data, BOOST_PP_NIL), list))
49# else
50# define BOOST_PP_LIST_FILTER_D(d, pred, data, list) BOOST_PP_LIST_FILTER_D_I(d, pred, data, list)
51# define BOOST_PP_LIST_FILTER_D_I(d, pred, data, list) BOOST_PP_TUPLE_ELEM(3, 2, BOOST_PP_LIST_FOLD_RIGHT_ ## d(BOOST_PP_LIST_FILTER_O, (pred, data, BOOST_PP_NIL), list))
52# endif
53#
54# endif
55

source code of boost/boost/preprocessor/list/filter.hpp