ceph/src/boost/libs/python/include/boost/python/detail/is_wrapper.hpp

   1 // Copyright David Abrahams 2004. Distributed under the Boost
   2 // Software License, Version 1.0. (See accompanying
   3 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   4 #ifndef IS_WRAPPER_DWA2004723_HPP
   5 # define IS_WRAPPER_DWA2004723_HPP
   6
   7 # include <boost/python/detail/prefix.hpp>
   8 # include <boost/mpl/bool.hpp>
   9
  10 namespace boost { namespace python {
  11
  12 template <class T> class wrapper;
  13
  14 namespace detail
  15 {
  16   typedef char (&is_not_wrapper)[2];
  17   is_not_wrapper is_wrapper_helper(...);
  18   template <class T>
  19   char is_wrapper_helper(wrapper<T> const volatile*);
  20
  21   // A metafunction returning true iff T is [derived from] wrapper<U>
  22   template <class T>
  23   struct is_wrapper
  24     : mpl::bool_<(sizeof(detail::is_wrapper_helper((T*)0)) == 1)>
  25   {};
  26
  27 }}} // namespace boost::python::detail
  28
  29 #endif // IS_WRAPPER_DWA2004723_HPP