ceph/src/boost/boost/parameter/aux_/yesno.hpp

   1 // Copyright Daniel Wallin, David Abrahams 2005.
   2 // Distributed under the Boost Software License, Version 1.0.
   3 // (See accompanying file LICENSE_1_0.txt or copy at
   4 // http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #ifndef YESNO_050328_HPP
   7 #define YESNO_050328_HPP
   8
   9 namespace boost { namespace parameter { namespace aux {
  10
  11     // types used with the "sizeof trick" to capture the results of
  12     // overload resolution at compile-time.
  13     typedef char yes_tag;
  14     typedef char (&no_tag)[2];
  15 }}} // namespace boost::parameter::aux
  16
  17 #include <boost/mpl/bool.hpp>
  18
  19 namespace boost { namespace parameter { namespace aux {
  20
  21     // mpl::true_ and mpl::false_ are not distinguishable by sizeof(),
  22     // so we pass them through these functions to get a type that is.
  23     ::boost::parameter::aux::yes_tag to_yesno(::boost::mpl::true_);
  24     ::boost::parameter::aux::no_tag to_yesno(::boost::mpl::false_);
  25 }}} // namespace boost::parameter::aux
  26
  27 #include <boost/parameter/config.hpp>
  28
  29 #if defined(BOOST_PARAMETER_CAN_USE_MP11)
  30 #include <boost/mp11/integral.hpp>
  31
  32 namespace boost { namespace parameter { namespace aux {
  33
  34     // mp11::mp_true and mp11::mp_false are not distinguishable by sizeof(),
  35     // so we pass them through these functions to get a type that is.
  36     ::boost::parameter::aux::yes_tag to_yesno(::boost::mp11::mp_true);
  37     ::boost::parameter::aux::no_tag to_yesno(::boost::mp11::mp_false);
  38 }}} // namespace boost::parameter::aux
  39
  40 #endif  // BOOST_PARAMETER_CAN_USE_MP11
  41 #endif  // include guard
  42