| /*============================================================================= |
| Copyright (c) 2005-2008 Hartmut Kaiser |
| Copyright (c) 2005-2007 Joel de Guzman |
| |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| ==============================================================================*/ |
| #ifndef PHOENIX_SEQUENCE_AT_HPP |
| #define PHOENIX_SEQUENCE_AT_HPP |
| |
| #include <boost/fusion/include/at.hpp> |
| #include <boost/spirit/home/phoenix/core/actor.hpp> |
| #include <boost/spirit/home/phoenix/core/compose.hpp> |
| #include <boost/type_traits/remove_reference.hpp> |
| |
| namespace boost { namespace phoenix |
| { |
| template <int N> |
| struct at_eval |
| { |
| template <typename Env, typename Tuple> |
| struct result |
| { |
| typedef typename Tuple::template result<Env>::type tuple; |
| typedef typename |
| fusion::result_of::at_c< |
| typename remove_reference<tuple>::type, N |
| >::type |
| type; |
| }; |
| |
| template <typename RT, typename Env, typename Tuple> |
| static RT |
| eval(Env const& env, Tuple const& t) |
| { |
| return fusion::at_c<N>(t.eval(env)); |
| } |
| }; |
| |
| template <int N, typename Tuple> |
| inline actor<typename as_composite<at_eval<N>, Tuple>::type> |
| at_c(Tuple const& tup) |
| { |
| return compose<at_eval<N> >(tup); |
| } |
| |
| }} |
| |
| #endif |