ceph/src/boost/boost/preprocessor/tuple/elem.hpp

   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 (2002-2011) */
  11 # /* Revised by Edward Diener (2011,2014,2020) */
  12 #
  13 # /* See http://www.boost.org for most recent version. */
  14 #
  15 # ifndef BOOST_PREPROCESSOR_TUPLE_ELEM_HPP
  16 # define BOOST_PREPROCESSOR_TUPLE_ELEM_HPP
  17 #
  18 # include <boost/preprocessor/cat.hpp>
  19 # include <boost/preprocessor/config/config.hpp>
  20 # include <boost/preprocessor/facilities/expand.hpp>
  21 # include <boost/preprocessor/facilities/overload.hpp>
  22 # include <boost/preprocessor/tuple/rem.hpp>
  23 # include <boost/preprocessor/variadic/elem.hpp>
  24 # include <boost/preprocessor/tuple/detail/is_single_return.hpp>
  25 #
  26 # if BOOST_PP_VARIADICS_MSVC
  27 #     define BOOST_PP_TUPLE_ELEM(...) BOOST_PP_TUPLE_ELEM_I(BOOST_PP_OVERLOAD(BOOST_PP_TUPLE_ELEM_O_, __VA_ARGS__), (__VA_ARGS__))
  28 #     define BOOST_PP_TUPLE_ELEM_I(m, args) BOOST_PP_TUPLE_ELEM_II(m, args)
  29 #     define BOOST_PP_TUPLE_ELEM_II(m, args) BOOST_PP_CAT(m ## args,)
  30 /*
  31   Use BOOST_PP_REM_CAT if it is a single element tuple ( which might be empty )
  32   else use BOOST_PP_REM. This fixes a VC++ problem with an empty tuple and BOOST_PP_TUPLE_ELEM
  33   functionality. See tuple_elem_bug_test.cxx.
  34 */
  35 #     define BOOST_PP_TUPLE_ELEM_O_2(n, tuple) \
  36          BOOST_PP_VARIADIC_ELEM(n, BOOST_PP_EXPAND(BOOST_PP_TUPLE_IS_SINGLE_RETURN(BOOST_PP_REM_CAT,BOOST_PP_REM,tuple) tuple)) \
  37          /**/
  38 # else
  39 #     define BOOST_PP_TUPLE_ELEM(...) BOOST_PP_OVERLOAD(BOOST_PP_TUPLE_ELEM_O_, __VA_ARGS__)(__VA_ARGS__)
  40 #     define BOOST_PP_TUPLE_ELEM_O_2(n, tuple) BOOST_PP_VARIADIC_ELEM(n, BOOST_PP_REM tuple)
  41 # endif
  42 # define BOOST_PP_TUPLE_ELEM_O_3(size, n, tuple) BOOST_PP_TUPLE_ELEM_O_2(n, tuple)
  43 #
  44 # /* directly used elsewhere in Boost... */
  45 #
  46 # define BOOST_PP_TUPLE_ELEM_1_0(a) a
  47 #
  48 # define BOOST_PP_TUPLE_ELEM_2_0(a, b) a
  49 # define BOOST_PP_TUPLE_ELEM_2_1(a, b) b
  50 #
  51 # define BOOST_PP_TUPLE_ELEM_3_0(a, b, c) a
  52 # define BOOST_PP_TUPLE_ELEM_3_1(a, b, c) b
  53 # define BOOST_PP_TUPLE_ELEM_3_2(a, b, c) c
  54 #
  55 # endif