boost/preprocessor/facilities/is_empty_or_1.hpp

   1 # /* **************************************************************************
   2 #  *                                                                          *
   3 #  *     (C) Copyright Paul Mensonides 2003.
   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_FACILITIES_IS_EMPTY_OR_1_HPP
  13 # define BOOST_PREPROCESSOR_FACILITIES_IS_EMPTY_OR_1_HPP
  14 #
  15 # include <boost/preprocessor/control/iif.hpp>
  16 # include <boost/preprocessor/facilities/empty.hpp>
  17 # include <boost/preprocessor/facilities/identity.hpp>
  18 # include <boost/preprocessor/facilities/is_1.hpp>
  19 # include <boost/preprocessor/facilities/is_empty.hpp>
  20 #
  21 # /* BOOST_PP_IS_EMPTY_OR_1 */
  22 #
  23 # define BOOST_PP_IS_EMPTY_OR_1(x) \
  24     BOOST_PP_IIF( \
  25         BOOST_PP_IS_EMPTY(x BOOST_PP_EMPTY()), \
  26         BOOST_PP_IDENTITY(1), \
  27         BOOST_PP_IS_1 \
  28     )(x) \
  29     /**/
  30 #
  31 # endif