1 /*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
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 #if !defined(FUSION_VALUE_AT_IMPL_07172005_0952)
8 #define FUSION_VALUE_AT_IMPL_07172005_0952
10 #include <boost/fusion/support/config.hpp>
11 #include <boost/fusion/support/detail/access.hpp>
12 #include <boost/type_traits/is_const.hpp>
13 #include <boost/mpl/eval_if.hpp>
14 #include <boost/mpl/bool.hpp>
16 namespace boost { namespace fusion
22 template <typename Tag>
26 struct value_at_impl<cons_tag>
28 template <typename Sequence, typename N>
33 mpl::bool_<N::value == 0>
34 , mpl::identity<typename Sequence::car_type>
35 , apply<typename Sequence::cdr_type, mpl::int_<N::value-1> >