ceph/src/boost/libs/mpl/example/fsm/aux_/STT_impl_gen.hpp

   1
   2 #ifndef BOOST_FSM_HANDLER_INCLUDED
   3 #define BOOST_FSM_HANDLER_INCLUDED
   4
   5 // Copyright Aleksey Gurtovoy 2002-2004
   6 //
   7 // Distributed under the Boost Software License, Version 1.0.
   8 // (See accompanying file LICENSE_1_0.txt or copy at
   9 // http://www.boost.org/LICENSE_1_0.txt)
  10 //
  11 // See http://www.boost.org/libs/mpl for documentation.
  12
  13 // $Id$
  14 // $Date$
  15 // $Revision$
  16
  17 #include <boost/mpl/if.hpp>
  18 #include <boost/mpl/fold.hpp>
  19 #include <boost/mpl/front.hpp>
  20 #include <boost/type_traits/is_same.hpp>
  21
  22 #include <typeinfo>
  23 #include <cassert>
  24
  25 namespace fsm { namespace aux {
  26
  27 namespace mpl = boost::mpl;
  28 using namespace mpl::placeholders;
  29
  30 template< typename Transition >
  31 struct STT_void_row_impl
  32 {
  33     typedef typename Transition::from_state_t   state_t;
  34     typedef typename Transition::fsm_t          fsm_t;
  35     typedef typename Transition::base_event_t   base_event_t;
  36
  37     static long do_process_event(fsm_t&, long state, base_event_t const&)
  38     {
  39         assert(false);
  40         return state;
  41     }
  42
  43     static long do_transition(fsm_t&, long state, base_event_t const&)
  44     {
  45         assert(false);
  46         return state;
  47     }
  48 };
  49
  50
  51 template<
  52       typename PrevRowImpl
  53     , typename Transition
  54     >
  55 struct STT_event_row_impl
  56     : PrevRowImpl
  57 {
  58     typedef typename Transition::from_state_t   state_t;
  59     typedef typename Transition::fsm_t          fsm_t;
  60     typedef typename Transition::base_event_t   base_event_t;
  61
  62     static long do_process_event(fsm_t& fsm, long state, base_event_t const& evt)
  63     {
  64         if (typeid(typename Transition::event_t) == typeid(evt))
  65         {
  66             // typedefs are here to make GCC happy
  67             typedef typename Transition::to_state_t to_state_;
  68             typedef typename Transition::from_state_t from_state_;
  69
  70             return Transition::do_transition(fsm, evt)
  71                 ? to_state_::do_check_invariant(fsm)
  72                 : from_state_::do_check_invariant(fsm)
  73                 ;
  74         }
  75
  76         return PrevRowImpl::do_process_event(fsm, state, evt);
  77     }
  78 };
  79
  80 template<
  81       typename PrevRowImpl
  82     , typename StateType
  83     >
  84 struct STT_state_row_impl
  85     : PrevRowImpl
  86 {
  87     typedef typename PrevRowImpl::fsm_t         fsm_t;
  88     typedef typename PrevRowImpl::base_event_t  base_event_t;
  89
  90     static long do_transition(fsm_t& fsm, long state, base_event_t const& evt)
  91     {
  92         return state == StateType::value
  93             ? PrevRowImpl::do_process_event(fsm, state, evt)
  94             : PrevRowImpl::do_transition(fsm, state, evt)
  95             ;
  96     }
  97
  98     static long do_process_event(fsm_t&, long state, base_event_t const&)
  99     {
 100         assert(false);
 101         return state;
 102     }
 103 };
 104
 105 template<
 106       typename PrevRowImpl
 107     , typename Transition
 108     >
 109 struct STT_row_impl
 110 {
 111     typedef typename mpl::if_<
 112           boost::is_same<
 113               typename PrevRowImpl::state_t
 114             , typename Transition::from_state_t
 115             >
 116         , STT_event_row_impl< PrevRowImpl,Transition >
 117         , STT_event_row_impl<
 118               STT_state_row_impl< PrevRowImpl,typename PrevRowImpl::state_t >
 119             , Transition
 120             >
 121         >::type type;
 122 };
 123
 124
 125 template< typename Transitions >
 126 struct STT_impl_gen
 127 {
 128  private:
 129     typedef typename mpl::front<Transitions>::type first_;
 130     typedef typename mpl::fold<
 131           Transitions
 132         , STT_void_row_impl<first_>
 133         , STT_row_impl<_,_>
 134         >::type STT_impl_;
 135
 136  public:
 137     typedef STT_state_row_impl<
 138           STT_impl_
 139         , typename STT_impl_::state_t
 140         > type;
 141 };
 142
 143 }}
 144
 145 #endif // BOOST_FSM_HANDLER_INCLUDED