ceph/src/boost/libs/parameter/include/boost/parameter/aux_/is_maybe.hpp

   1 // Copyright Daniel Wallin, David Abrahams 2010. Use, modification and
   2 // distribution is subject to the Boost Software License, Version 1.0. (See
   3 // accompanying file LICENSE_1_0.txt or copy at
   4 // http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #ifndef BOOST_PARAMETER_IS_MAYBE_050329_HPP
   7 #define BOOST_PARAMETER_IS_MAYBE_050329_HPP
   8
   9 #include <boost/type_traits/is_base_and_derived.hpp>
  10
  11 namespace boost {
  12 namespace parameter {
  13 namespace aux {
  14
  15 struct maybe_base {};
  16
  17 template <class T>
  18 struct is_maybe
  19   : is_base_and_derived<maybe_base, T>
  20 {};
  21
  22 } // namespace aux
  23 } // namespace parameter
  24 } // namespace boost
  25
  26 #endif // BOOST_PARAMETER_IS_MAYBE_050329_HPP