ceph/src/boost/boost/metaparse/v1/is_error.hpp

   1 #ifndef BOOST_METAPARSE_V1_IS_ERROR_HPP
   2 #define BOOST_METAPARSE_V1_IS_ERROR_HPP
   3
   4 // Copyright Abel Sinkovics (abel@sinkovics.hu)  2011.
   5 // Distributed under the Boost Software License, Version 1.0.
   6 //    (See accompanying file LICENSE_1_0.txt or copy at
   7 //          http://www.boost.org/LICENSE_1_0.txt)
   8
   9 #include <boost/metaparse/v1/fail_tag.hpp>
  10
  11 #include <boost/mpl/tag.hpp>
  12 #include <boost/mpl/vector.hpp>
  13
  14 #include <boost/type_traits/is_same.hpp>
  15
  16 namespace boost
  17 {
  18   namespace metaparse
  19   {
  20     namespace v1
  21     {
  22       template <class T = boost::mpl::na>
  23       struct is_error :
  24         boost::is_same<
  25           fail_tag,
  26           typename boost::mpl::tag<typename T::type>::type
  27         >
  28       {};
  29
  30       template <>
  31       struct is_error<boost::mpl::na>
  32       {
  33         typedef is_error type;
  34
  35         template <class T = boost::mpl::na>
  36         struct apply : is_error<T> {};
  37       };
  38     }
  39   }
  40 }
  41
  42 #endif
  43