| // Copyright 2008 Christophe Henry |
| // henry UNDERSCORE christophe AT hotmail DOT com |
| // This is taken from Boost.Proto's documentation |
| // Copyright for the original version: |
| // Copyright 2008 Eric Niebler. 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 BOOST_MSM_BACK_FOLD_TO_LIST_H |
| #define BOOST_MSM_BACK_FOLD_TO_LIST_H |
| |
| #include <boost/msm/proto_config.hpp> |
| #include <boost/proto/core.hpp> |
| #include <boost/proto/transform.hpp> |
| #include <boost/fusion/container/list/cons.hpp> |
| |
| namespace boost { namespace msm { namespace back |
| { |
| struct state_copy_tag |
| { |
| }; |
| ::boost::proto::terminal<state_copy_tag>::type const states_={{}}; |
| struct FoldToList |
| : ::boost::proto::or_< |
| // Don't add the states_ terminal to the list |
| ::boost::proto::when< |
| ::boost::proto::terminal< state_copy_tag > |
| , ::boost::proto::_state |
| > |
| // Put all other terminals at the head of the |
| // list that we're building in the "state" parameter |
| , ::boost::proto::when< |
| ::boost::proto::terminal< ::boost::proto::_> |
| , boost::fusion::cons< ::boost::proto::_value, ::boost::proto::_state>( |
| ::boost::proto::_value, ::boost::proto::_state |
| ) |
| > |
| // For left-shift operations, first fold the right |
| // child to a list using the current state. Use |
| // the result as the state parameter when folding |
| // the left child to a list. |
| , ::boost::proto::when< |
| ::boost::proto::shift_left<FoldToList, FoldToList> |
| , FoldToList( |
| ::boost::proto::_left |
| , ::boost::proto::call<FoldToList( ::boost::proto::_right, ::boost::proto::_state )> |
| ) |
| > |
| > |
| {}; |
| |
| }}} |
| |
| #endif //BOOST_MSM_BACK_FOLD_TO_LIST_H |
| |