ceph/src/boost/libs/statechart/include/boost/statechart/detail/reaction_dispatcher.hpp

   1 #ifndef BOOST_STATECHART_REACTION_DISPATCHER_HPP_INCLUDED
   2 #define BOOST_STATECHART_REACTION_DISPATCHER_HPP_INCLUDED
   3 //////////////////////////////////////////////////////////////////////////////
   4 // Copyright 2008 Andreas Huber Doenni
   5 // Distributed under the Boost Software License, Version 1.0. (See accompany-
   6 // ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 //////////////////////////////////////////////////////////////////////////////
   8
   9
  10
  11 #include <boost/statechart/result.hpp>
  12
  13 #include <boost/mpl/if.hpp>
  14
  15 #include <boost/polymorphic_cast.hpp> // boost::polymorphic_downcast
  16 #include <boost/type_traits/is_same.hpp>
  17
  18
  19
  20 namespace boost
  21 {
  22 namespace statechart
  23 {
  24 namespace detail
  25 {
  26
  27
  28
  29 //////////////////////////////////////////////////////////////////////////////
  30 template< class Event >
  31 struct no_context
  32 {
  33   void no_function( const Event & );
  34 };
  35
  36 //////////////////////////////////////////////////////////////////////////////
  37 template<
  38   class Reactions, class State, class EventBase, class Event,
  39   class ActionContext, class IdType >
  40 class reaction_dispatcher
  41 {
  42   private:
  43     struct without_action
  44     {
  45       static result react( State & stt, const EventBase & )
  46       {
  47         return Reactions::react_without_action( stt );
  48       }
  49     };
  50
  51     struct base_with_action
  52     {
  53       static result react( State & stt, const EventBase & evt )
  54       {
  55         return Reactions::react_with_action( stt, evt );
  56       }
  57     };
  58
  59     struct base
  60     {
  61       static result react(
  62         State & stt, const EventBase & evt, const IdType & )
  63       {
  64         typedef typename mpl::if_<
  65           is_same< ActionContext, detail::no_context< Event > >,
  66           without_action, base_with_action
  67         >::type reaction;
  68         return reaction::react( stt, evt );
  69       }
  70     };
  71
  72     struct derived_with_action
  73     {
  74       static result react( State & stt, const EventBase & evt )
  75       {
  76         return Reactions::react_with_action(
  77           stt, *polymorphic_downcast< const Event * >( &evt ) );
  78       }
  79     };
  80
  81     struct derived
  82     {
  83       static result react(
  84         State & stt, const EventBase & evt, const IdType & eventType )
  85       {
  86         if ( eventType == Event::static_type() )
  87         {
  88           typedef typename mpl::if_<
  89             is_same< ActionContext, detail::no_context< Event > >,
  90             without_action, derived_with_action
  91           >::type reaction;
  92           return reaction::react( stt, evt );
  93         }
  94         else
  95         {
  96           return detail::result_utility::make_result( detail::no_reaction );
  97         }
  98       }
  99     };
 100
 101   public:
 102     static reaction_result react(
 103       State & stt, const EventBase & evt, const IdType & eventType )
 104     {
 105       typedef typename mpl::if_<
 106         is_same< Event, EventBase >, base, derived
 107       >::type reaction;
 108       return result_utility::get_result(
 109         reaction::react( stt, evt, eventType ) );
 110     }
 111 };
 112
 113
 114
 115 } // namespace detail
 116 } // namespace statechart
 117 } // namespace boost
 118
 119
 120
 121 #endif