ceph/src/boost/boost/type_erasure/is_placeholder.hpp

   1 // Boost.TypeErasure library
   2 //
   3 // Copyright 2011 Steven Watanabe
   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 // $Id$
  10
  11 #ifndef BOOST_TYPE_ERASURE_DETAIL_IS_PLACEHOLDER_HPP_INCLUDED
  12 #define BOOST_TYPE_ERASURE_DETAIL_IS_PLACEHOLDER_HPP_INCLUDED
  13
  14 #include <boost/mpl/bool.hpp>
  15 #include <boost/type_traits/is_base_and_derived.hpp>
  16 #include <boost/type_erasure/placeholder.hpp>
  17
  18 namespace boost {
  19
  20 namespace type_erasure {
  21
  22 /** A metafunction that indicates whether a type is a @ref placeholder. */
  23 template<class T>
  24 struct is_placeholder : ::boost::is_base_and_derived<placeholder, T> {};
  25
  26 }
  27 }
  28
  29 #endif