ceph/src/boost/libs/fusion/include/boost/fusion/view/single_view/detail/value_at_impl.hpp

   1 /*=============================================================================
   2     Copyright (c) 2011 Eric Niebler
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 ==============================================================================*/
   7
   8 #if !defined(BOOST_FUSION_SINGLE_VIEW_VALUE_AT_IMPL_JUL_07_2011_1348PM)
   9 #define BOOST_FUSION_SINGLE_VIEW_VALUE_AT_IMPL_JUL_07_2011_1348PM
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/mpl/int.hpp>
  13 #include <boost/mpl/assert.hpp>
  14 #include <boost/mpl/equal_to.hpp>
  15 #include <boost/fusion/sequence/intrinsic/value_at.hpp>
  16
  17 namespace boost { namespace fusion
  18 {
  19     struct single_view_tag;
  20
  21     namespace extension
  22     {
  23         template<typename Tag>
  24         struct value_at_impl;
  25
  26         template<>
  27         struct value_at_impl<single_view_tag>
  28         {
  29             template<typename Sequence, typename N>
  30             struct apply
  31             {
  32                 BOOST_MPL_ASSERT((mpl::equal_to<N, mpl::int_<0> >));
  33                 typedef typename Sequence::value_type type;
  34             };
  35         };
  36     }
  37
  38 }}
  39
  40 #endif