text: // Copyright 2008 Christophe Henry
  // henry UNDERSCORE christophe AT hotmail DOT com
  // This is an extended version of the state machine available in the boost::mpl library
  // Distributed under the same license as the original.
  // Copyright for the original version:
  // Copyright 2005 David Abrahams and Aleksey Gurtovoy. 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_STATEMACHINE_H
  #define BOOST_MSM_BACK_STATEMACHINE_H
  
  #include <exception>
  #include <vector>
  #include <functional>
  #include <numeric>
  #include <utility>
  
  #include <boost/detail/no_exceptions_support.hpp>
  
  #include <boost/mpl/contains.hpp>
  #include <boost/mpl/deref.hpp>
  #include <boost/mpl/assert.hpp>
  
  #include <boost/fusion/container/vector/convert.hpp>
  #include <boost/fusion/include/as_vector.hpp>
  #include <boost/fusion/include/as_set.hpp>
  #include <boost/fusion/container/set.hpp>
  #include <boost/fusion/include/set.hpp>
  #include <boost/fusion/include/set_fwd.hpp>
  #include <boost/fusion/include/mpl.hpp>
  #include <boost/fusion/sequence/intrinsic/at_key.hpp>
  #include <boost/fusion/include/at_key.hpp>
  #include <boost/fusion/algorithm/iteration/for_each.hpp>
  #include <boost/fusion/include/for_each.hpp>
  
  #include <boost/assert.hpp>
  #include <boost/ref.hpp>
  #include <boost/type_traits.hpp>
  #include <boost/utility/enable_if.hpp>
  #include <boost/type_traits/is_convertible.hpp>
  
  #include <boost/bind.hpp>
  #include <boost/bind/apply.hpp>
  #include <boost/function.hpp>
  #ifndef BOOST_NO_RTTI
  #include <boost/any.hpp>
  #endif
  
  #include <boost/serialization/base_object.hpp> 
  
  #include <boost/parameter.hpp>
  
  #include <boost/msm/active_state_switching_policies.hpp>
  #include <boost/msm/row_tags.hpp>
  #include <boost/msm/msm_grammar.hpp>
  #include <boost/msm/back/fold_to_list.hpp>
  #include <boost/msm/back/metafunctions.hpp>
  #include <boost/msm/back/history_policies.hpp>
  #include <boost/msm/back/common_types.hpp>
  #include <boost/msm/back/args.hpp>
  #include <boost/msm/back/default_compile_policy.hpp>
  #include <boost/msm/back/dispatch_table.hpp>
  #include <boost/msm/back/no_fsm_check.hpp>
  #include <boost/msm/back/queue_container_deque.hpp>
  
  BOOST_MPL_HAS_XXX_TRAIT_DEF(accept_sig)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(no_automatic_create)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(non_forwarding_flag)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(direct_entry)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(initial_event)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(final_event)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(do_serialize)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(history_policy)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(fsm_check)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(compile_policy)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(queue_container_policy)
  BOOST_MPL_HAS_XXX_TRAIT_DEF(using_declared_table)
  
  #ifndef BOOST_MSM_CONSTRUCTOR_ARG_SIZE
  #define BOOST_MSM_CONSTRUCTOR_ARG_SIZE 5 // default max number of arguments for constructors
  #endif
  
  namespace boost { namespace msm { namespace back
  {
  // event used internally for wrapping a direct entry
  template <class StateType,class Event>
  struct direct_entry_event 
  {
      typedef int direct_entry;
      typedef StateType active_state;
      typedef Event contained_event;
  
      direct_entry_event(Event const& evt):m_event(evt){}
      Event const& m_event;
  };
  
  // This declares the statically-initialized dispatch_table instance.
  template <class Fsm,class Stt, class Event,class CompilePolicy>
  const boost::msm::back::dispatch_table<Fsm,Stt, Event,CompilePolicy>
  dispatch_table<Fsm,Stt, Event,CompilePolicy>::instance;
  
  BOOST_PARAMETER_TEMPLATE_KEYWORD(front_end)
  BOOST_PARAMETER_TEMPLATE_KEYWORD(history_policy)
  BOOST_PARAMETER_TEMPLATE_KEYWORD(compile_policy)
  BOOST_PARAMETER_TEMPLATE_KEYWORD(fsm_check_policy)
  BOOST_PARAMETER_TEMPLATE_KEYWORD(queue_container_policy)
  
  typedef ::boost::parameter::parameters<
      ::boost::parameter::required< ::boost::msm::back::tag::front_end >
    , ::boost::parameter::optional< 
          ::boost::parameter::deduced< ::boost::msm::back::tag::history_policy>, has_history_policy< ::boost::mpl::_ > 
      >
    , ::boost::parameter::optional< 
          ::boost::parameter::deduced< ::boost::msm::back::tag::compile_policy>, has_compile_policy< ::boost::mpl::_ > 
      >
    , ::boost::parameter::optional< 
          ::boost::parameter::deduced< ::boost::msm::back::tag::fsm_check_policy>, has_fsm_check< ::boost::mpl::_ > 
      >
    , ::boost::parameter::optional< 
          ::boost::parameter::deduced< ::boost::msm::back::tag::queue_container_policy>, 
          has_queue_container_policy< ::boost::mpl::_ > 
      >
  > state_machine_signature;
  
  // just here to disable use of proto when not needed
  template <class T, class F,class Enable=void>
  struct make_euml_terminal;
  template <class T,class F>
  struct make_euml_terminal<T,F,typename ::boost::disable_if<has_using_declared_table<F> >::type>
  {};
  template <class T,class F>
  struct make_euml_terminal<T,F,typename ::boost::enable_if<has_using_declared_table<F> >::type>
      : public proto::extends<typename proto::terminal< boost::msm::state_tag>::type, T, boost::msm::state_domain>
  {};
  
  // library-containing class for state machines.  Pass the actual FSM class as
  // the Concrete parameter.
  // A0=Derived,A1=NoHistory,A2=CompilePolicy,A3=FsmCheckPolicy >
  template <
        class A0
      , class A1 = parameter::void_
      , class A2 = parameter::void_
      , class A3 = parameter::void_
      , class A4 = parameter::void_
  >
  class state_machine : //public Derived
      public ::boost::parameter::binding<
              typename state_machine_signature::bind<A0,A1,A2,A3,A4>::type, ::boost::msm::back::tag::front_end
      >::type
      , public make_euml_terminal<state_machine<A0,A1,A2,A3,A4>,
                           typename ::boost::parameter::binding<
                                      typename state_machine_signature::bind<A0,A1,A2,A3,A4>::type, ::boost::msm::back::tag::front_end
                           >::type   
        >
  {
  public:
      // Create ArgumentPack
      typedef typename
          state_machine_signature::bind<A0,A1,A2,A3,A4>::type
          state_machine_args;
  
      // Extract first logical parameter.
      typedef typename ::boost::parameter::binding<
          state_machine_args, ::boost::msm::back::tag::front_end>::type Derived;
  
      typedef typename ::boost::parameter::binding<
          state_machine_args, ::boost::msm::back::tag::history_policy, NoHistory >::type              HistoryPolicy;
  
      typedef typename ::boost::parameter::binding<
          state_machine_args, ::boost::msm::back::tag::compile_policy, favor_runtime_speed >::type    CompilePolicy;
  
      typedef typename ::boost::parameter::binding<
          state_machine_args, ::boost::msm::back::tag::fsm_check_policy, no_fsm_check >::type         FsmCheckPolicy;
  
      typedef typename ::boost::parameter::binding<
          state_machine_args, ::boost::msm::back::tag::queue_container_policy, 
          queue_container_deque >::type                                                               QueueContainerPolicy;
  
  private: 
  
      typedef boost::msm::back::state_machine<
          A0,A1,A2,A3,A4>                             library_sm;
  
      typedef ::boost::function<
          execute_return ()>                          transition_fct;
      typedef ::boost::function<
          execute_return () >                         deferred_fct;
      typedef typename QueueContainerPolicy::
          template In< 
          std::pair<deferred_fct,bool> >::type        deferred_events_queue_t;
      typedef typename QueueContainerPolicy::
          template In<transition_fct>::type           events_queue_t;
  
      typedef typename boost::mpl::eval_if<
          typename is_active_state_switch_policy<Derived>::type,
          get_active_state_switch_policy<Derived>,
          // default
          ::boost::mpl::identity<active_state_switch_after_entry>
      >::type active_state_switching;
  
      typedef bool (*flag_handler)(library_sm const&);
  
      // all state machines are friend with each other to allow embedding any of them in another fsm
      template <class ,class , class, class, class
      > friend class boost::msm::back::state_machine;
  
      // helper to add, if needed, visitors to all states
      // version without visitors
      template <class StateType,class Enable=void>
      struct visitor_fct_helper 
      {
      public:
          visitor_fct_helper(){}
          void fill_visitors(int)
          {
          }
          template <class FCT>
          void insert(int,FCT)
          {
          }
          template <class VISITOR>
          void execute(int,VISITOR)
          {
          }
      };
      // version with visitors
      template <class StateType>
      struct visitor_fct_helper<StateType,typename ::boost::enable_if<has_accept_sig<StateType> >::type> 
      {
      public:
          visitor_fct_helper():m_state_visitors(){}
          void fill_visitors(int number_of_states)
          {
              m_state_visitors.resize(number_of_states);
          }
          template <class FCT>
          void insert(int index,FCT fct)
          {
              m_state_visitors[index]=fct;
          }
          void execute(int index)
          {
              m_state_visitors[index]();
          }
  
  #define MSM_VISITOR_HELPER_EXECUTE_SUB(z, n, unused) ARG ## n vis ## n
  #define MSM_VISITOR_HELPER_EXECUTE(z, n, unused)                                    \
          template <BOOST_PP_ENUM_PARAMS(n, class ARG)>                               \
          void execute(int index BOOST_PP_COMMA_IF(n)                                 \
                       BOOST_PP_ENUM(n, MSM_VISITOR_HELPER_EXECUTE_SUB, ~ ) )         \
          {                                                                           \
              m_state_visitors[index](BOOST_PP_ENUM_PARAMS(n,vis));                   \
          }
          BOOST_PP_REPEAT_FROM_TO(1,BOOST_PP_ADD(BOOST_MSM_VISITOR_ARG_SIZE,1), MSM_VISITOR_HELPER_EXECUTE, ~)
  #undef MSM_VISITOR_HELPER_EXECUTE
  #undef MSM_VISITOR_HELPER_EXECUTE_SUB
      private:
          typedef typename StateType::accept_sig::type                  visitor_fct;
          typedef std::vector<visitor_fct>                              visitors;
  
          visitors                                                      m_state_visitors;
      };
  
      template <class StateType,class Enable=int>
      struct deferred_msg_queue_helper 
      {
          void clear(){}
      };
      template <class StateType>
      struct deferred_msg_queue_helper<StateType,
          typename ::boost::enable_if< 
              typename ::boost::msm::back::has_fsm_deferred_events<StateType>::type,int >::type> 
      {
      public:
          deferred_msg_queue_helper():m_deferred_events_queue(){}
          void clear()
          {
              m_deferred_events_queue.clear();
          }
          deferred_events_queue_t         m_deferred_events_queue;
      };
  
   public: 
      // tags
      typedef int composite_tag;
  
      // in case someone needs to know
      typedef HistoryPolicy               history_policy;
  
      struct InitEvent { };
      struct ExitEvent { };
      // flag handling
      struct Flag_AND
      {
          typedef std::logical_and<bool> type;
      };
      struct Flag_OR
      {
       typedef std::logical_or<bool> type;
      };
      typedef typename Derived::BaseAllStates     BaseState;
      typedef Derived                             ConcreteSM;
  
      // if the front-end fsm provides an initial_event typedef, replace InitEvent by this one
      typedef typename ::boost::mpl::eval_if< 
          typename has_initial_event<Derived>::type,
          get_initial_event<Derived>,
          ::boost::mpl::identity<InitEvent>
      >::type fsm_initial_event;
  
      // if the front-end fsm provides an exit_event typedef, replace ExitEvent by this one
      typedef typename ::boost::mpl::eval_if< 
          typename has_final_event<Derived>::type,
          get_final_event<Derived>,
          ::boost::mpl::identity<ExitEvent>
      >::type fsm_final_event;
  
      template <class ExitPoint>
      struct exit_pt : public ExitPoint
      {
          // tags
          typedef ExitPoint           wrapped_exit;
          typedef int                 pseudo_exit;
          typedef library_sm          owner;
          typedef int                 no_automatic_create;
          typedef typename 
              ExitPoint::event        Event;
          typedef ::boost::function<execute_return (Event const&)>
                                      forwarding_function;
  
          // forward event to the higher-level FSM
          template <class ForwardEvent>
          void forward_event(ForwardEvent const& incomingEvent)
          {
              // use helper to forward or not
              ForwardHelper< ::boost::is_convertible<ForwardEvent,Event>::value>::helper(incomingEvent,m_forward);
          }
          void set_forward_fct(::boost::function<execute_return (Event const&)> fct)
          {
              m_forward = fct;
          }    
          exit_pt():m_forward(){}
          // by assignments, we keep our forwarding functor unchanged as our containing SM did not change
      template <class RHS>
          exit_pt(RHS&):m_forward(){}
          exit_pt<ExitPoint>& operator= (const exit_pt<ExitPoint>& ) 
          { 
              return *this; 
          } 
      private:
           forwarding_function          m_forward;
  
           // using partial specialization instead of enable_if because of VC8 bug
          template <bool OwnEvent, int Dummy=0>
          struct ForwardHelper
          {
              template <class ForwardEvent>
              static void helper(ForwardEvent const& ,forwarding_function& )
              {
                  // Not our event, assert
                  BOOST_ASSERT(false);
              }
          };
          template <int Dummy>
          struct ForwardHelper<true,Dummy>
          {
              template <class ForwardEvent>
              static void helper(ForwardEvent const& incomingEvent,forwarding_function& forward_fct)
              {
                  // call if handler set, if not, this state is simply a terminate state
                  if (forward_fct)
                      forward_fct(incomingEvent);
              }
          };
  
      };
      template <class EntryPoint>
      struct entry_pt : public EntryPoint
      {
          // tags
          typedef EntryPoint          wrapped_entry;
          typedef int                 pseudo_entry;
          typedef library_sm          owner;
          typedef int                 no_automatic_create;
      };
      template <class EntryPoint>
      struct direct : public EntryPoint
      {
          // tags
          typedef EntryPoint          wrapped_entry;
          typedef int                 explicit_entry_state;
          typedef library_sm          owner;
          typedef int                 no_automatic_create;
      };
      typedef typename get_number_of_regions<typename Derived::initial_state>::type nr_regions;
      // Template used to form rows in the transition table
      template<
          typename ROW
      >
      struct row_
      {
          //typedef typename ROW::Source T1;
          typedef typename make_entry<typename ROW::Source,library_sm>::type T1;
          typedef typename make_exit<typename ROW::Target,library_sm>::type T2;
          typedef typename ROW::Evt transition_event;
          // if the source is an exit pseudo state, then
          // current_state_type becomes the result of get_owner
          // meaning the containing SM from which the exit occurs
          typedef typename ::boost::mpl::eval_if<
                  typename has_pseudo_exit<T1>::type,
                  get_owner<T1,library_sm>,
                  ::boost::mpl::identity<typename ROW::Source> >::type current_state_type;
  
          // if Target is a sequence, then we have a fork and expect a sequence of explicit_entry
          // else if Target is an explicit_entry, next_state_type becomes the result of get_owner
          // meaning the containing SM if the row is "outside" the containing SM or else the explicit_entry state itself
          typedef typename ::boost::mpl::eval_if<
              typename ::boost::mpl::is_sequence<T2>::type,
              get_fork_owner<T2,library_sm>,
              ::boost::mpl::eval_if<
                      typename has_no_automatic_create<T2>::type,
                      get_owner<T2,library_sm>,
                      ::boost::mpl::identity<T2> >
          >::type next_state_type;
  
          // if a guard condition is here, call it to check that the event is accepted
          static bool check_guard(library_sm& fsm,transition_event const& evt)
          {
              if ( ROW::guard_call(fsm,evt,
                                   ::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),
                                   ::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),
                                   fsm.m_substate_list ) )
                  return true;
              return false;
          }
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int region_index, int state, transition_event const& evt)
          {
  
              BOOST_STATIC_CONSTANT(int, current_state = (get_state_id<stt,current_state_type>::type::value));
              BOOST_STATIC_CONSTANT(int, next_state = (get_state_id<stt,next_state_type>::type::value));
              BOOST_ASSERT(state == (current_state));
              // if T1 is an exit pseudo state, then take the transition only if the pseudo exit state is active
              if (has_pseudo_exit<T1>::type::value && 
                  !is_exit_state_active<T1,get_owner<T1,library_sm> >(fsm))
              {
                  return HANDLED_FALSE;
              }
              if (!check_guard(fsm,evt))
              {
                  // guard rejected the event, we stay in the current one
                  return HANDLED_GUARD_REJECT;
              }
              fsm.m_states[region_index] = active_state_switching::after_guard(current_state,next_state);
  
              // the guard condition has already been checked
              execute_exit<current_state_type>
                  (::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),evt,fsm);
              fsm.m_states[region_index] = active_state_switching::after_exit(current_state,next_state);
  
              // then call the action method
              HandledEnum res = ROW::action_call(fsm,evt,
                               ::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),
                               ::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),
                               fsm.m_substate_list);
              fsm.m_states[region_index] = active_state_switching::after_action(current_state,next_state);
  
              // and finally the entry method of the new current state
              convert_event_and_execute_entry<next_state_type,T2>
                  (::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),evt,fsm);
              fsm.m_states[region_index] = active_state_switching::after_entry(current_state,next_state);
              return res;
          }
      };
  
      // row having only a guard condition
      template<
          typename ROW
      >
      struct g_row_
      {
          //typedef typename ROW::Source T1;
          typedef typename make_entry<typename ROW::Source,library_sm>::type T1;
          typedef typename make_exit<typename ROW::Target,library_sm>::type T2;
          typedef typename ROW::Evt transition_event;
          // if the source is an exit pseudo state, then
          // current_state_type becomes the result of get_owner
          // meaning the containing SM from which the exit occurs
          typedef typename ::boost::mpl::eval_if<
                  typename has_pseudo_exit<T1>::type,
                  get_owner<T1,library_sm>,
                  ::boost::mpl::identity<typename ROW::Source> >::type current_state_type;
  
          // if Target is a sequence, then we have a fork and expect a sequence of explicit_entry
          // else if Target is an explicit_entry, next_state_type becomes the result of get_owner
          // meaning the containing SM if the row is "outside" the containing SM or else the explicit_entry state itself
          typedef typename ::boost::mpl::eval_if<
              typename ::boost::mpl::is_sequence<T2>::type,
              get_fork_owner<T2,library_sm>,
              ::boost::mpl::eval_if<
                      typename has_no_automatic_create<T2>::type,
                      get_owner<T2,library_sm>,
                      ::boost::mpl::identity<T2> >
          >::type next_state_type;
  
          // if a guard condition is defined, call it to check that the event is accepted
          static bool check_guard(library_sm& fsm,transition_event const& evt)
          {
              if ( ROW::guard_call(fsm,evt,
                                   ::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),
                                   ::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),
                                   fsm.m_substate_list ))
                  return true;
              return false;
          }
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int region_index, int state, transition_event const& evt)
          {
              BOOST_STATIC_CONSTANT(int, current_state = (get_state_id<stt,current_state_type>::type::value));
              BOOST_STATIC_CONSTANT(int, next_state = (get_state_id<stt,next_state_type>::type::value));
              BOOST_ASSERT(state == (current_state));
              // if T1 is an exit pseudo state, then take the transition only if the pseudo exit state is active
              if (has_pseudo_exit<T1>::type::value && 
                  !is_exit_state_active<T1,get_owner<T1,library_sm> >(fsm))
              {
                  return HANDLED_FALSE;
              }
              if (!check_guard(fsm,evt))
              {
                  // guard rejected the event, we stay in the current one
                  return HANDLED_GUARD_REJECT;
              }
              fsm.m_states[region_index] = active_state_switching::after_guard(current_state,next_state);
  
              // the guard condition has already been checked
              execute_exit<current_state_type>
                  (::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),evt,fsm);
              fsm.m_states[region_index] = active_state_switching::after_exit(current_state,next_state);
              fsm.m_states[region_index] = active_state_switching::after_action(current_state,next_state);
  
              // and finally the entry method of the new current state
              convert_event_and_execute_entry<next_state_type,T2>
                  (::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),evt,fsm);
              fsm.m_states[region_index] = active_state_switching::after_entry(current_state,next_state);
              return HANDLED_TRUE;
          }
      };
  
      // row having only an action method
      template<
          typename ROW
      >
      struct a_row_ 
      {
          //typedef typename ROW::Source T1;
          typedef typename make_entry<typename ROW::Source,library_sm>::type T1;
          typedef typename make_exit<typename ROW::Target,library_sm>::type T2;
          typedef typename ROW::Evt transition_event;
          // if the source is an exit pseudo state, then
          // current_state_type becomes the result of get_owner
          // meaning the containing SM from which the exit occurs
          typedef typename ::boost::mpl::eval_if<
                  typename has_pseudo_exit<T1>::type,
                  get_owner<T1,library_sm>,
                  ::boost::mpl::identity<typename ROW::Source> >::type current_state_type;
  
          // if Target is a sequence, then we have a fork and expect a sequence of explicit_entry
          // else if Target is an explicit_entry, next_state_type becomes the result of get_owner
          // meaning the containing SM if the row is "outside" the containing SM or else the explicit_entry state itself
          typedef typename ::boost::mpl::eval_if<
              typename ::boost::mpl::is_sequence<T2>::type,
              get_fork_owner<T2,library_sm>,
              ::boost::mpl::eval_if<
                      typename has_no_automatic_create<T2>::type,
                      get_owner<T2,library_sm>,
                      ::boost::mpl::identity<T2> >
          >::type next_state_type;
  
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int region_index, int state, transition_event const& evt)
          {
              BOOST_STATIC_CONSTANT(int, current_state = (get_state_id<stt,current_state_type>::type::value));
              BOOST_STATIC_CONSTANT(int, next_state = (get_state_id<stt,next_state_type>::type::value));
              BOOST_ASSERT(state == (current_state));
  
              // if T1 is an exit pseudo state, then take the transition only if the pseudo exit state is active
              if (has_pseudo_exit<T1>::type::value && 
                  !is_exit_state_active<T1,get_owner<T1,library_sm> >(fsm))
              {
                  return HANDLED_FALSE;
              }
              fsm.m_states[region_index] = active_state_switching::after_guard(current_state,next_state);
  
              // no need to check the guard condition
              // first call the exit method of the current state
              execute_exit<current_state_type>
                  (::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),evt,fsm);
              fsm.m_states[region_index] = active_state_switching::after_exit(current_state,next_state);
  
              // then call the action method
              HandledEnum res = ROW::action_call(fsm,evt,
                              ::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),
                              ::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),
                              fsm.m_substate_list);
              fsm.m_states[region_index] = active_state_switching::after_action(current_state,next_state);
  
              // and finally the entry method of the new current state
              convert_event_and_execute_entry<next_state_type,T2>
                  (::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),evt,fsm);
              fsm.m_states[region_index] = active_state_switching::after_entry(current_state,next_state);
              return res;
          }
      };
  
      // row having no guard condition or action, simply transitions
      template<
          typename ROW
      >
      struct _row_
      {
          //typedef typename ROW::Source T1;
          typedef typename make_entry<typename ROW::Source,library_sm>::type T1;
          typedef typename make_exit<typename ROW::Target,library_sm>::type T2;
          typedef typename ROW::Evt transition_event;
          // if the source is an exit pseudo state, then
          // current_state_type becomes the result of get_owner
          // meaning the containing SM from which the exit occurs
          typedef typename ::boost::mpl::eval_if<
                  typename has_pseudo_exit<T1>::type,
                  get_owner<T1,library_sm>,
                  ::boost::mpl::identity<typename ROW::Source> >::type current_state_type;
  
          // if Target is a sequence, then we have a fork and expect a sequence of explicit_entry
          // else if Target is an explicit_entry, next_state_type becomes the result of get_owner
          // meaning the containing SM if the row is "outside" the containing SM or else the explicit_entry state itself
          typedef typename ::boost::mpl::eval_if<
              typename ::boost::mpl::is_sequence<T2>::type,
              get_fork_owner<T2,library_sm>,
              ::boost::mpl::eval_if<
                      typename has_no_automatic_create<T2>::type,
                      get_owner<T2,library_sm>,
                      ::boost::mpl::identity<T2> >
          >::type next_state_type;
  
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int region_index, int state, transition_event const& evt)
          {
              BOOST_STATIC_CONSTANT(int, current_state = (get_state_id<stt,current_state_type>::type::value));
              BOOST_STATIC_CONSTANT(int, next_state = (get_state_id<stt,next_state_type>::type::value));
              BOOST_ASSERT(state == (current_state));
  
              // if T1 is an exit pseudo state, then take the transition only if the pseudo exit state is active
              if (has_pseudo_exit<T1>::type::value && 
                  !is_exit_state_active<T1,get_owner<T1,library_sm> >(fsm))
              {
                  return HANDLED_FALSE;
              }
              fsm.m_states[region_index] = active_state_switching::after_guard(current_state,next_state);
  
              // first call the exit method of the current state
              execute_exit<current_state_type>
                  (::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),evt,fsm);
              fsm.m_states[region_index] = active_state_switching::after_exit(current_state,next_state);
              fsm.m_states[region_index] = active_state_switching::after_action(current_state,next_state);
  
  
              // and finally the entry method of the new current state
              convert_event_and_execute_entry<next_state_type,T2>
                  (::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),evt,fsm);
              fsm.m_states[region_index] = active_state_switching::after_entry(current_state,next_state);
              return HANDLED_TRUE;
          }
      };
      // "i" rows are rows for internal transitions
      template<
          typename ROW
      >
      struct irow_
      {
          typedef typename make_entry<typename ROW::Source,library_sm>::type T1;
          typedef typename make_exit<typename ROW::Target,library_sm>::type T2;
          typedef typename ROW::Evt transition_event;
          typedef typename ROW::Source current_state_type;
          typedef T2 next_state_type;
  
          // if a guard condition is here, call it to check that the event is accepted
          static bool check_guard(library_sm& fsm,transition_event const& evt)
          {
              if ( ROW::guard_call(fsm,evt,
                                   ::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),
                                   ::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),
                                   fsm.m_substate_list))
                  return true;
              return false;
          }
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int , int state, transition_event const& evt)
          {
  
              BOOST_STATIC_CONSTANT(int, current_state = (get_state_id<stt,current_state_type>::type::value));
              BOOST_ASSERT(state == (current_state));
              if (!check_guard(fsm,evt))
              {
                  // guard rejected the event, we stay in the current one
                  return HANDLED_GUARD_REJECT;
              }
  
              // call the action method
              HandledEnum res = ROW::action_call(fsm,evt,
                               ::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),
                               ::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),
                               fsm.m_substate_list);
              return res;
          }
      };
  
      // row having only a guard condition
      template<
          typename ROW
      >
      struct g_irow_
      {
          typedef typename make_entry<typename ROW::Source,library_sm>::type T1;
          typedef typename make_exit<typename ROW::Target,library_sm>::type T2;
          typedef typename ROW::Evt transition_event;
          typedef typename ROW::Source current_state_type;
          typedef T2 next_state_type;
  
          // if a guard condition is defined, call it to check that the event is accepted
          static bool check_guard(library_sm& fsm,transition_event const& evt)
          {
              if ( ROW::guard_call(fsm,evt,
                                   ::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),
                                   ::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),
                                   fsm.m_substate_list) )
                  return true;
              return false;
          }
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int , int state, transition_event const& evt)
          {
              BOOST_STATIC_CONSTANT(int, current_state = (get_state_id<stt,current_state_type>::type::value));
              BOOST_ASSERT(state == (current_state));
              if (!check_guard(fsm,evt))
              {
                  // guard rejected the event, we stay in the current one
                  return HANDLED_GUARD_REJECT;
              }
              return HANDLED_TRUE;
          }
      };
  
      // row having only an action method
      template<
          typename ROW
      >
      struct a_irow_ 
      {
          typedef typename make_entry<typename ROW::Source,library_sm>::type T1;
          typedef typename make_exit<typename ROW::Target,library_sm>::type T2;
  
          typedef typename ROW::Evt transition_event;
          typedef typename ROW::Source current_state_type;
          typedef T2 next_state_type;
  
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int , int state, transition_event const& evt)
          {
              BOOST_STATIC_CONSTANT(int, current_state = (get_state_id<stt,current_state_type>::type::value));
              BOOST_ASSERT(state == (current_state));
  
              // call the action method
              HandledEnum res = ROW::action_call(fsm,evt,
                              ::boost::fusion::at_key<current_state_type>(fsm.m_substate_list),
                              ::boost::fusion::at_key<next_state_type>(fsm.m_substate_list),
                              fsm.m_substate_list);
  
              return res;
          }
      };
      // row simply ignoring the event
      template<
          typename ROW
      >
      struct _irow_ 
      {
          typedef typename make_entry<typename ROW::Source,library_sm>::type T1;
          typedef typename make_exit<typename ROW::Target,library_sm>::type T2;
          typedef typename ROW::Evt transition_event;
          typedef typename ROW::Source current_state_type;
          typedef T2 next_state_type;
  
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& , int , int state, transition_event const& )
          {
              BOOST_STATIC_CONSTANT(int, current_state = (get_state_id<stt,current_state_type>::type::value));
              BOOST_ASSERT(state == (current_state));
              return HANDLED_TRUE;
          }
      };
      // transitions internal to this state machine (no substate involved)
      template<
          typename ROW,
          typename StateType
      >
      struct internal_
      {
          typedef StateType current_state_type;
          typedef StateType next_state_type;
          typedef typename ROW::Evt transition_event;
  
          // if a guard condition is here, call it to check that the event is accepted
          static bool check_guard(library_sm& fsm,transition_event const& evt)
          {
              if ( ROW::guard_call(fsm,evt,
                  ::boost::fusion::at_key<StateType>(fsm.m_substate_list),
                  ::boost::fusion::at_key<StateType>(fsm.m_substate_list),
                  fsm.m_substate_list) )
                  return true;
              return false;
          }
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int , int , transition_event const& evt)
          {
              if (!check_guard(fsm,evt))
              {
                  // guard rejected the event, we stay in the current one
                  return HANDLED_GUARD_REJECT;
              }
  
              // then call the action method
              HandledEnum res = ROW::action_call(fsm,evt,
                  ::boost::fusion::at_key<StateType>(fsm.m_substate_list),
                  ::boost::fusion::at_key<StateType>(fsm.m_substate_list),
                  fsm.m_substate_list);
              return res;
          }
      };
      template<
          typename ROW
      >
      struct internal_ <ROW,library_sm>
      {
          typedef library_sm current_state_type;
          typedef library_sm next_state_type;
          typedef typename ROW::Evt transition_event;
  
          // if a guard condition is here, call it to check that the event is accepted
          static bool check_guard(library_sm& fsm,transition_event const& evt)
          {
              if ( ROW::guard_call(fsm,evt,
                  fsm,
                  fsm,
                  fsm.m_substate_list) )
                  return true;
              return false;
          }
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int , int , transition_event const& evt)
          {
              if (!check_guard(fsm,evt))
              {
                  // guard rejected the event, we stay in the current one
                  return HANDLED_GUARD_REJECT;
              }
  
              // then call the action method
              HandledEnum res = ROW::action_call(fsm,evt,
                  fsm,
                  fsm,
                  fsm.m_substate_list);
              return res;
          }
      };
  
      template<
          typename ROW,
          typename StateType
      >
      struct a_internal_
      {
          typedef StateType current_state_type;
          typedef StateType next_state_type;
          typedef typename ROW::Evt transition_event;
  
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int, int, transition_event const& evt)
          {
              // then call the action method
              HandledEnum res = ROW::action_call(fsm,evt,
                  ::boost::fusion::at_key<StateType>(fsm.m_substate_list),
                  ::boost::fusion::at_key<StateType>(fsm.m_substate_list),
                  fsm.m_substate_list);
              return res;
          }
      };
      template<
          typename ROW
      >
      struct a_internal_ <ROW,library_sm>
      {
          typedef library_sm current_state_type;
          typedef library_sm next_state_type;
          typedef typename ROW::Evt transition_event;
  
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int, int, transition_event const& evt)
          {
              // then call the action method
              HandledEnum res = ROW::action_call(fsm,evt,
                  fsm,
                  fsm,
                  fsm.m_substate_list);
              return res;
          }
      };
      template<
          typename ROW,
          typename StateType
      >
      struct g_internal_
      {
          typedef StateType current_state_type;
          typedef StateType next_state_type;
          typedef typename ROW::Evt transition_event;
  
          // if a guard condition is here, call it to check that the event is accepted
          static bool check_guard(library_sm& fsm,transition_event const& evt)
          {
              if ( ROW::guard_call(fsm,evt,
                  ::boost::fusion::at_key<StateType>(fsm.m_substate_list),
                  ::boost::fusion::at_key<StateType>(fsm.m_substate_list),
                  fsm.m_substate_list) )
                  return true;
              return false;
          }
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int, int, transition_event const& evt)
          {
              if (!check_guard(fsm,evt))
              {
                  // guard rejected the event, we stay in the current one
                  return HANDLED_GUARD_REJECT;
              }
              return HANDLED_TRUE;
          }
      };
      template<
          typename ROW
      >
      struct g_internal_ <ROW,library_sm>
      {
          typedef library_sm current_state_type;
          typedef library_sm next_state_type;
          typedef typename ROW::Evt transition_event;
  
          // if a guard condition is here, call it to check that the event is accepted
          static bool check_guard(library_sm& fsm,transition_event const& evt)
          {
              if ( ROW::guard_call(fsm,evt,
                  fsm,
                  fsm,
                  fsm.m_substate_list) )
                  return true;
              return false;
          }
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int, int, transition_event const& evt)
          {
              if (!check_guard(fsm,evt))
              {
                  // guard rejected the event, we stay in the current one
                  return HANDLED_GUARD_REJECT;
              }
              return HANDLED_TRUE;
          }
      };
      template<
          typename ROW,
          typename StateType
      >
      struct _internal_
      {
          typedef StateType current_state_type;
          typedef StateType next_state_type;
          typedef typename ROW::Evt transition_event;
          static HandledEnum execute(library_sm& , int , int , transition_event const& )
          {
              return HANDLED_TRUE;
          }
      };
      template<
          typename ROW
      >
      struct _internal_ <ROW,library_sm>
      {
          typedef library_sm current_state_type;
          typedef library_sm next_state_type;
          typedef typename ROW::Evt transition_event;
          static HandledEnum execute(library_sm& , int , int , transition_event const& )
          {
              return HANDLED_TRUE;
          }
      };
      // Template used to form forwarding rows in the transition table for every row of a composite SM
      template<
          typename T1
          , class Evt
      >
      struct frow
      {
          typedef T1                  current_state_type;
          typedef T1                  next_state_type;
          typedef Evt                 transition_event;
          // tag to find out if a row is a forwarding row
          typedef int                 is_frow;
  
          // Take the transition action and return the next state.
          static HandledEnum execute(library_sm& fsm, int region_index, int , transition_event const& evt)
          {
              // false as second parameter because this event is forwarded from outer fsm
              execute_return res = 
                  (::boost::fusion::at_key<current_state_type>(fsm.m_substate_list)).process_event_internal(evt,false); 
              fsm.m_states[region_index]=get_state_id<stt,T1>::type::value;
              return res;
          }
          // helper metafunctions used by dispatch table and give the frow a new event
          // (used to avoid double entries in a table because of base events)
          template <class NewEvent>
          struct replace_event
          {
              typedef frow<T1,NewEvent> type;
          };
      };
  
      template <class Tag, class Transition,class StateType>
      struct create_backend_stt
      {
      };
      template <class Transition,class StateType>
      struct create_backend_stt<g_row_tag,Transition,StateType>
      {
          typedef g_row_<Transition> type;
      };
      template <class Transition,class StateType>
      struct create_backend_stt<a_row_tag,Transition,StateType>
      {
          typedef a_row_<Transition> type;
      };
      template <class Transition,class StateType>
      struct create_backend_stt<_row_tag,Transition,StateType>
      {
          typedef _row_<Transition> type;
      };
      template <class Transition,class StateType>
      struct create_backend_stt<row_tag,Transition,StateType>
      {
          typedef row_<Transition> type;
      };
      // internal transitions
      template <class Transition,class StateType>
      struct create_backend_stt<g_irow_tag,Transition,StateType>
      {
          typedef g_irow_<Transition> type;
      };
      template <class Transition,class StateType>
      struct create_backend_stt<a_irow_tag,Transition,StateType>
      {
          typedef a_irow_<Transition> type;
      };
      template <class Transition,class StateType>
      struct create_backend_stt<irow_tag,Transition,StateType>
      {
          typedef irow_<Transition> type;
      };
      template <class Transition,class StateType>
      struct create_backend_stt<_irow_tag,Transition,StateType>
      {
          typedef _irow_<Transition> type;
      };
      template <class Transition,class StateType>
      struct create_backend_stt<sm_a_i_row_tag,Transition,StateType>
      {
          typedef a_internal_<Transition,StateType> type;
      };
      template <class Transition,class StateType>
      struct create_backend_stt<sm_g_i_row_tag,Transition,StateType>
      {
          typedef g_internal_<Transition,StateType> type;
      };
      template <class Transition,class StateType>
      struct create_backend_stt<sm_i_row_tag,Transition,StateType>
      {
          typedef internal_<Transition,StateType> type;
      };
      template <class Transition,class StateType>
      struct create_backend_stt<sm__i_row_tag,Transition,StateType>
      {
          typedef _internal_<Transition,StateType> type;
      };
      template <class Transition,class StateType=void>
      struct make_row_tag
      {
          typedef typename create_backend_stt<typename Transition::row_type_tag,Transition,StateType>::type type;
      };
  
      // add to the stt the initial states which could be missing (if not being involved in a transition)
      template <class BaseType, class stt_simulated = typename BaseType::transition_table>
      struct create_real_stt 
      {
          //typedef typename BaseType::transition_table stt_simulated;
          typedef typename ::boost::mpl::fold<
              stt_simulated,mpl::vector0<>,
              ::boost::mpl::push_back< ::boost::mpl::placeholders::_1,
                                       make_row_tag< ::boost::mpl::placeholders::_2 , BaseType > >
          >::type type;
      };
  
      template <class Table,class Intermediate,class StateType>
      struct add_forwarding_row_helper
      {
          typedef typename generate_event_set<Table>::type all_events;
          typedef typename ::boost::mpl::fold<
              all_events, Intermediate,
              ::boost::mpl::push_back< ::boost::mpl::placeholders::_1,
              frow<StateType, ::boost::mpl::placeholders::_2> > >::type type;
      };
      // gets the transition table from a composite and make from it a forwarding row
      template <class StateType,class IsComposite>
      struct get_internal_transition_table
      {
          // first get the table of a composite
          typedef typename recursive_get_transition_table<StateType>::type original_table;
  
          // we now look for the events the composite has in its internal transitions
          // the internal ones are searched recursively in sub-sub... states
          // we go recursively because our states can also have internal tables or substates etc.
          typedef typename recursive_get_internal_transition_table<StateType, ::boost::mpl::true_>::type recursive_istt;
          typedef typename ::boost::mpl::fold<
                      recursive_istt,::boost::mpl::vector0<>,
                      ::boost::mpl::push_back< ::boost::mpl::placeholders::_1,
                                               make_row_tag< ::boost::mpl::placeholders::_2 , StateType> >
                  >::type recursive_istt_with_tag;
  
          typedef typename ::boost::mpl::insert_range< original_table, typename ::boost::mpl::end<original_table>::type, 
                                                       recursive_istt_with_tag>::type table_with_all_events;
  
          // and add for every event a forwarding row
          typedef typename ::boost::mpl::eval_if<
                  typename CompilePolicy::add_forwarding_rows,
                  add_forwarding_row_helper<table_with_all_events,::boost::mpl::vector0<>,StateType>,
                  ::boost::mpl::identity< ::boost::mpl::vector0<> >
          >::type type;
      };
      template <class StateType>
      struct get_internal_transition_table<StateType, ::boost::mpl::false_ >
      {
          typedef typename create_real_stt<StateType, typename StateType::internal_transition_table >::type type;
      };
      // typedefs used internally
      typedef typename create_real_stt<Derived>::type real_transition_table;
      typedef typename create_stt<library_sm>::type stt;
      typedef typename get_initial_states<typename Derived::initial_state>::type initial_states;
      typedef typename generate_state_set<stt>::type state_list;
      typedef typename HistoryPolicy::template apply<nr_regions::value>::type concrete_history;
  
      typedef typename ::boost::fusion::result_of::as_set<state_list>::type substate_list;
      typedef typename ::boost::msm::back::generate_event_set<
          typename create_real_stt<library_sm, typename library_sm::internal_transition_table >::type
      >::type processable_events_internal_table;
  
      // extends the transition table with rows from composite states
      template <class Composite>
      struct extend_table
      {
          // add the init states
          //typedef typename create_stt<Composite>::type stt;
          typedef typename Composite::stt Stt;
  
          // add the internal events defined in the internal_transition_table
          // Note: these are added first because they must have a lesser prio
          // than the deeper transitions in the sub regions
          // table made of a stt + internal transitions of composite
          typedef typename ::boost::mpl::fold<
              typename Composite::internal_transition_table,::boost::mpl::vector0<>,
              ::boost::mpl::push_back< ::boost::mpl::placeholders::_1,
                                       make_row_tag< ::boost::mpl::placeholders::_2 , Composite> >
          >::type internal_stt;
  
          typedef typename ::boost::mpl::insert_range<
              Stt,
              typename ::boost::mpl::end<Stt>::type,
              internal_stt
              //typename get_internal_transition_table<Composite, ::boost::mpl::true_ >::type
          >::type stt_plus_internal;
  
          // for every state, add its transition table (if any)
          // transformed as frow
          typedef typename ::boost::mpl::fold<state_list,stt_plus_internal,
                  ::boost::mpl::insert_range< 
                          ::boost::mpl::placeholders::_1, 
                          ::boost::mpl::end< ::boost::mpl::placeholders::_1>,
                          get_internal_transition_table< 
                                  ::boost::mpl::placeholders::_2,
                                  is_composite_state< ::boost::mpl::placeholders::_2> > > 
          >::type type;
      };
      // extend the table with tables from composite states
      typedef typename extend_table<library_sm>::type complete_table;
       // build a sequence of regions
       typedef typename get_regions_as_sequence<typename Derived::initial_state>::type seq_initial_states;
      // Member functions
  
      // start the state machine (calls entry of the initial state)
      void start()
      {
           // reinitialize our list of currently active states with the ones defined in Derived::initial_state
           ::boost::mpl::for_each< seq_initial_states, ::boost::msm::wrap<mpl::placeholders::_1> >
                          (init_states(m_states));
          // call on_entry on this SM
          (static_cast<Derived*>(this))->on_entry(fsm_initial_event(),*this);
          ::boost::mpl::for_each<initial_states, boost::msm::wrap<mpl::placeholders::_1> >
              (call_init<fsm_initial_event>(fsm_initial_event(),this));
          // give a chance to handle an anonymous (eventless) transition
          handle_eventless_transitions_helper<library_sm> eventless_helper(this,true);
          eventless_helper.process_completion_event();
      }
  
      // start the state machine (calls entry of the initial state passing incomingEvent to on_entry's)
      template <class Event>
      void start(Event const& incomingEvent)
      {
          // reinitialize our list of currently active states with the ones defined in Derived::initial_state
          ::boost::mpl::for_each< seq_initial_states, ::boost::msm::wrap<mpl::placeholders::_1> >
                          (init_states(m_states));
          // call on_entry on this SM
          (static_cast<Derived*>(this))->on_entry(incomingEvent,*this);
          ::boost::mpl::for_each<initial_states, boost::msm::wrap<mpl::placeholders::_1> >
              (call_init<Event>(incomingEvent,this));
          // give a chance to handle an anonymous (eventless) transition
          handle_eventless_transitions_helper<library_sm> eventless_helper(this,true);
          eventless_helper.process_completion_event();
      }
  
      // stop the state machine (calls exit of the current state)
      void stop()
      {
          do_exit(fsm_final_event(),*this);
      }
  
      // stop the state machine (calls exit of the current state passing finalEvent to on_exit's)
      template <class Event>
      void stop(Event const& finalEvent)
      {
          do_exit(finalEvent,*this);
      }
  
      // Main function used by clients of the derived FSM to make transitions.
      template<class Event>
      execute_return process_event(Event const& evt)
      {
          return process_event_internal(evt,true);
      }
  
      template <class EventType>
      void enqueue_event_helper(EventType const& evt, ::boost::mpl::false_ const &)
      {
          execute_return (library_sm::*pf) (EventType const& evt) = 
              &library_sm::process_event; 
  
          transition_fct f = ::boost::bind(pf,this,evt);
          m_events_queue.m_events_queue.push_back(f);
      }
      template <class EventType>
      void enqueue_event_helper(EventType const& , ::boost::mpl::true_ const &)
      {
          // no queue
      }
  
      void execute_queued_events_helper(::boost::mpl::false_ const &)
      {
          while(!m_events_queue.m_events_queue.empty())
          {
              transition_fct to_call = m_events_queue.m_events_queue.front();
              m_events_queue.m_events_queue.pop_front();
              to_call();
          }
      }
      void execute_queued_events_helper(::boost::mpl::true_ const &)
      {
          // no queue required
      }
      void execute_single_queued_event_helper(::boost::mpl::false_ const &)
      {
          transition_fct to_call = m_events_queue.m_events_queue.front();
          m_events_queue.m_events_queue.pop_front();
          to_call();
      }
      void execute_single_queued_event_helper(::boost::mpl::true_ const &)
      {
          // no queue required
      }
      // enqueues an event in the message queue
      // call execute_queued_events to process all queued events.
      // Be careful if you do this during event processing, the event will be processed immediately
      // and not kept in the queue
      template <class EventType>
      void enqueue_event(EventType const& evt)
      {
          enqueue_event_helper<EventType>(evt, typename is_no_message_queue<library_sm>::type());
      }
  
      // empty the queue and process events
      void execute_queued_events()
      {
          execute_queued_events_helper(typename is_no_message_queue<library_sm>::type());
      }
      void execute_single_queued_event()
      {
          execute_single_queued_event_helper(typename is_no_message_queue<library_sm>::type());
      }
      typename events_queue_t::size_type get_message_queue_size() const
      {
          return m_events_queue.m_events_queue.size();
      }
  
      events_queue_t& get_message_queue()
      {
          return m_events_queue.m_events_queue;
      }
  
      const events_queue_t& get_message_queue() const
      {
          return m_events_queue.m_events_queue;
      }
  
      void clear_deferred_queue()
      {
          m_deferred_events_queue.clear();
      }
  
      deferred_events_queue_t& get_deferred_queue()
      {
          return m_deferred_events_queue.m_deferred_events_queue;
      }
  
      const deferred_events_queue_t& get_deferred_queue() const
      {
          return m_deferred_events_queue.m_deferred_events_queue;
      }
  
      // Getter that returns the current state of the FSM
      const int* current_state() const
      {
          return this->m_states;
      }
  
      template <class Archive>
      struct serialize_state
      {
          serialize_state(Archive& ar):ar_(ar){}
  
          template<typename T>
          typename ::boost::enable_if< 
              typename ::boost::mpl::or_<
                  typename has_do_serialize<T>::type,
                  typename is_composite_state<T>::type
              >::type
              ,void 
          >::type
          operator()(T& t) const
          {
              ar_ & t;
          }
          template<typename T>
          typename ::boost::disable_if< 
              typename ::boost::mpl::or_<
                  typename has_do_serialize<T>::type,
                  typename is_composite_state<T>::type
              >::type
              ,void 
          >::type
          operator()(T&) const
          {
              // no state to serialize
          }
          Archive& ar_;
      };
      
      template<class Archive>
      void serialize(Archive & ar, const unsigned int)
      {
          // invoke serialization of the base class 
          (serialize_state<Archive>(ar))(boost::serialization::base_object<Derived>(*this));
          // now our attributes
          ar & m_states;
          // queues cannot be serialized => skip
          ar & m_history;
          ar & m_event_processing;
          ar & m_is_included;
          // visitors cannot be serialized => skip
          ::boost::fusion::for_each(m_substate_list, serialize_state<Archive>(ar));
      }
  
      // linearly search for the state with the given id
      struct get_state_id_helper 
      {
          get_state_id_helper(int id,const BaseState** res,const library_sm* self_):
          result_state(res),searched_id(id),self(self_) {}
  
          template <class StateType>
          void operator()(boost::msm::wrap<StateType> const&)
          {
              // look for the state id until found
              BOOST_STATIC_CONSTANT(int, id = (get_state_id<stt,StateType>::value));
              if (!*result_state && (id == searched_id))
              {
                  *result_state = &::boost::fusion::at_key<StateType>(self->m_substate_list);
              }
          }
          const BaseState**  result_state;
          int                searched_id;
          const library_sm* self;
      };
      // return the state whose id is passed or 0 if not found
      // caution if you need this, you probably need polymorphic states
      // complexity: O(number of states)
      BaseState* get_state_by_id(int id)
      {
          const BaseState*  result_state=0;
          ::boost::mpl::for_each<state_list, 
              ::boost::msm::wrap< ::boost::mpl::placeholders::_1> > (get_state_id_helper(id,&result_state,this));
          return const_cast<BaseState*>(result_state);
      }
      const BaseState* get_state_by_id(int id) const
      {
          const BaseState*  result_state=0;
          ::boost::mpl::for_each<state_list,
              ::boost::msm::wrap< ::boost::mpl::placeholders::_1> > (get_state_id_helper(id,&result_state,this));
          return result_state;
      }
      // true if the sm is used in another sm
      bool is_contained() const
      {
          return m_is_included;
      }
      // get the history policy class
      concrete_history& get_history()
      {
          return m_history;
      }
      concrete_history const& get_history() const
      {
          return m_history;
      }
      // get a state (const version)
      // as a pointer
      template <class State>
      typename ::boost::enable_if<typename ::boost::is_pointer<State>::type,State >::type
      get_state(::boost::msm::back::dummy<0> = 0) const
      {
          return const_cast<State >
              (&
                  (::boost::fusion::at_key<
                      typename ::boost::remove_const<typename ::boost::remove_pointer<State>::type>::type>(m_substate_list)));
      }
      // as a reference
      template <class State>
      typename ::boost::enable_if<typename ::boost::is_reference<State>::type,State >::type
      get_state(::boost::msm::back::dummy<1> = 0) const
      {
          return const_cast<State >
              ( ::boost::fusion::at_key<
                  typename ::boost::remove_const<typename ::boost::remove_reference<State>::type>::type>(m_substate_list) );
      }
      // get a state (non const version)
      // as a pointer
      template <class State>
      typename ::boost::enable_if<typename ::boost::is_pointer<State>::type,State >::type
      get_state(::boost::msm::back::dummy<0> = 0)
      {
          return &(static_cast<typename boost::add_reference<typename ::boost::remove_pointer<State>::type>::type > 
          (::boost::fusion::at_key<typename ::boost::remove_pointer<State>::type>(m_substate_list)));
      }
      // as a reference
      template <class State>
      typename ::boost::enable_if<typename ::boost::is_reference<State>::type,State >::type
      get_state(::boost::msm::back::dummy<1> = 0)
      {
          return ::boost::fusion::at_key<typename ::boost::remove_reference<State>::type>(m_substate_list);
      }
      // checks if a flag is active using the BinaryOp as folding function
      template <class Flag,class BinaryOp>
      bool is_flag_active() const
      {
          flag_handler* flags_entries = get_entries_for_flag<Flag>();
          bool res = (*flags_entries[ m_states[0] ])(*this);
          for (int i = 1; i < nr_regions::value ; ++i)
          {
              res = typename BinaryOp::type() (res,(*flags_entries[ m_states[i] ])(*this)); 
          }
          return res;
      }
      // checks if a flag is active using no binary op if 1 region, or OR if > 1 regions
      template <class Flag>
      bool is_flag_active() const
      {
          return FlagHelper<Flag,(nr_regions::value>1)>::helper(*this,get_entries_for_flag<Flag>());
      }
      // visit the currently active states (if these are defined as visitable
      // by implementing accept)
      void visit_current_states()
      {
          for (int i=0; i<nr_regions::value;++i)
          {
              m_visitors.execute(m_states[i]);
          }
      }
  #define MSM_VISIT_STATE_SUB(z, n, unused) ARG ## n vis ## n
  #define MSM_VISIT_STATE_EXECUTE(z, n, unused)                                    \
          template <BOOST_PP_ENUM_PARAMS(n, class ARG)>                               \
          void visit_current_states(BOOST_PP_ENUM(n, MSM_VISIT_STATE_SUB, ~ ) )         \
          {                                                                           \
              for (int i=0; i<nr_regions::value;++i)                                                      \
              {                                                                                           \
                  m_visitors.execute(m_states[i],BOOST_PP_ENUM_PARAMS(n,vis));                            \
              }                                                                                           \
          }
          BOOST_PP_REPEAT_FROM_TO(1,BOOST_PP_ADD(BOOST_MSM_VISITOR_ARG_SIZE,1), MSM_VISIT_STATE_EXECUTE, ~)
  #undef MSM_VISIT_STATE_EXECUTE
  #undef MSM_VISIT_STATE_SUB
  
      // puts the given event into the deferred queue
      template <class Event>
      void defer_event(Event const& e)
      {
          // to call this function, you need either a state with a deferred_events typedef
          // or that the fsm provides the activate_deferred_events typedef
          BOOST_MPL_ASSERT(( has_fsm_deferred_events<library_sm> ));
          execute_return (library_sm::*pf) (Event const& evt)= &library_sm::process_event;
          Event temp (e);
          ::boost::function<execute_return () > f= ::boost::bind(pf, this,temp);
          post_deferred_event(f);
      }
  
   protected:    // interface for the derived class
  
       // helper used to fill the initial states
       struct init_states
       {
           init_states(int* const init):m_initial_states(init),m_index(-1){}
  
           // History initializer function object, used with mpl::for_each
           template <class State>
           void operator()(::boost::msm::wrap<State> const&)
           {
               m_initial_states[++m_index]=get_state_id<stt,State>::type::value;
           }
           int* const m_initial_states;
           int m_index;
       };
   public:
       struct update_state
       {
           update_state(substate_list& to_overwrite_):to_overwrite(&to_overwrite_){}
           template<typename StateType>
           void operator()(StateType const& astate) const
           {
               ::boost::fusion::at_key<StateType>(*to_overwrite)=astate;
           }
           substate_list* to_overwrite;
       };
       template <class Expr>
       void set_states(Expr const& expr)
       {
           ::boost::fusion::for_each( 
               ::boost::fusion::as_vector(FoldToList()(expr, boost::fusion::nil())),update_state(this->m_substate_list));
       }
  
       // Construct with the default initial states
       state_machine<A0,A1,A2,A3,A4 >()
           :Derived()
           ,m_events_queue() 
           ,m_deferred_events_queue()
           ,m_history()
           ,m_event_processing(false)
           ,m_is_included(false)
           ,m_visitors()
           ,m_substate_list()
       {
           // initialize our list of states with the ones defined in Derived::initial_state
           ::boost::mpl::for_each< seq_initial_states, ::boost::msm::wrap<mpl::placeholders::_1> >
                          (init_states(m_states));
           m_history.set_initial_states(m_states);
           // create states
           fill_states(this);
       }
       template <class Expr>
       state_machine<A0,A1,A2,A3,A4 >
           (Expr const& expr,typename ::boost::enable_if<typename ::boost::proto::is_expr<Expr>::type >::type* =0)
           :Derived()
           ,m_events_queue() 
           ,m_deferred_events_queue()
           ,m_history()
           ,m_event_processing(false)
           ,m_is_included(false)
           ,m_visitors()
           ,m_substate_list()
       {
           BOOST_MPL_ASSERT_MSG(
               ( ::boost::proto::matches<Expr, FoldToList>::value),
               THE_STATES_EXPRESSION_PASSED_DOES_NOT_MATCH_GRAMMAR,
               (FoldToList));
  
           // initialize our list of states with the ones defined in Derived::initial_state
           ::boost::mpl::for_each< seq_initial_states, ::boost::msm::wrap<mpl::placeholders::_1> >
                          (init_states(m_states));
           m_history.set_initial_states(m_states);
           // create states
           set_states(expr);
           fill_states(this);
       }
       // Construct with the default initial states and some default argument(s)
  #define MSM_CONSTRUCTOR_HELPER_EXECUTE_SUB(z, n, unused) ARG ## n t ## n
  #define MSM_CONSTRUCTOR_HELPER_EXECUTE(z, n, unused)                                \
          template <BOOST_PP_ENUM_PARAMS(n, class ARG)>                               \
          state_machine<A0,A1,A2,A3,A4                                                \
          >(BOOST_PP_ENUM(n, MSM_CONSTRUCTOR_HELPER_EXECUTE_SUB, ~ ),                 \
          typename ::boost::disable_if<typename ::boost::proto::is_expr<ARG0>::type >::type* =0 )                \
          :Derived(BOOST_PP_ENUM_PARAMS(n,t))                                         \
           ,m_events_queue()                                                          \
           ,m_deferred_events_queue()                                                 \
           ,m_history()                                                               \
           ,m_event_processing(false)                                                 \
           ,m_is_included(false)                                                      \
           ,m_visitors()                                                              \
           ,m_substate_list()                                                         \
       {                                                                              \
           ::boost::mpl::for_each< seq_initial_states, ::boost::msm::wrap<mpl::placeholders::_1> > \
                          (init_states(m_states));                                    \
           m_history.set_initial_states(m_states);                                    \
           fill_states(this);                                                         \
       }                                                                              \
          template <class Expr,BOOST_PP_ENUM_PARAMS(n, class ARG)>                    \
          state_machine<A0,A1,A2,A3,A4                                                \
          >(Expr const& expr,BOOST_PP_ENUM(n, MSM_CONSTRUCTOR_HELPER_EXECUTE_SUB, ~ ), \
          typename ::boost::enable_if<typename ::boost::proto::is_expr<Expr>::type >::type* =0 ) \
          :Derived(BOOST_PP_ENUM_PARAMS(n,t))                                         \
           ,m_events_queue()                                                          \
           ,m_deferred_events_queue()                                                 \
           ,m_history()                                                               \
           ,m_event_processing(false)                                                 \
           ,m_is_included(false)                                                      \
           ,m_visitors()                                                              \
           ,m_substate_list()                                                         \
       {                                                                              \
           BOOST_MPL_ASSERT_MSG(                                                      \
           ( ::boost::proto::matches<Expr, FoldToList>::value),                       \
               THE_STATES_EXPRESSION_PASSED_DOES_NOT_MATCH_GRAMMAR,                   \
               (FoldToList));                                                         \
           ::boost::mpl::for_each< seq_initial_states, ::boost::msm::wrap<mpl::placeholders::_1> > \
                          (init_states(m_states));                                    \
           m_history.set_initial_states(m_states);                                    \
           set_states(expr);                                                          \
           fill_states(this);                                                         \
       }
  
       BOOST_PP_REPEAT_FROM_TO(1,BOOST_PP_ADD(BOOST_MSM_CONSTRUCTOR_ARG_SIZE,1), MSM_CONSTRUCTOR_HELPER_EXECUTE, ~)
  #undef MSM_CONSTRUCTOR_HELPER_EXECUTE
  #undef MSM_CONSTRUCTOR_HELPER_EXECUTE_SUB
  
  
  
       // assignment operator using the copy policy to decide if non_copyable, shallow or deep copying is necessary
       library_sm& operator= (library_sm const& rhs)
       {
           if (this != &rhs) 
           {
              Derived::operator=(rhs);
              do_copy(rhs);
           }
          return *this;
       }
       state_machine<A0,A1,A2,A3,A4> 
           (library_sm const& rhs)
           : Derived(rhs)
       {
          if (this != &rhs) 
          {
              // initialize our list of states with the ones defined in Derived::initial_state
              fill_states(this);
              do_copy(rhs);
          }
       }
  
      // the following 2 functions handle the terminate/interrupt states handling
      // if one of these states is found, the first one is used
      template <class Event>
      bool is_event_handling_blocked_helper( ::boost::mpl::true_ const &)
      {
          // if the state machine is terminated, do not handle any event
          if (is_flag_active< ::boost::msm::TerminateFlag>())
              return true;
          // if the state machine is interrupted, do not handle any event
          // unless the event is the end interrupt event
          if ( is_flag_active< ::boost::msm::InterruptedFlag>() && 
              !is_flag_active< ::boost::msm::EndInterruptFlag<Event> >())
              return true;
          return false;
      }
      // otherwise simple handling, no flag => continue
      template <class Event>
      bool is_event_handling_blocked_helper( ::boost::mpl::false_ const &)
      {
          // no terminate/interrupt states detected
          return false;
      }
      // the following functions handle pre/post-process handling  of a message queue
      template <class StateType,class EventType>
      bool do_pre_msg_queue_helper(EventType const&, ::boost::mpl::true_ const &)
      {
          // no message queue needed
          return true;
      }
      template <class StateType,class EventType>
      bool do_pre_msg_queue_helper(EventType const& evt, ::boost::mpl::false_ const &)
      {
          execute_return (library_sm::*pf) (EventType const& evt) = 
              &library_sm::process_event; 
          // if we are already processing an event
          if (m_event_processing)
          {
              // event has to be put into the queue
              transition_fct f = ::boost::bind(pf,this,evt);
              m_events_queue.m_events_queue.push_back(f);
              return false;
          }
          // event can be handled, processing
          m_event_processing = true;
          return true;
      }
      void do_post_msg_queue_helper( ::boost::mpl::true_ const &)
      {
          // no message queue needed
      }
      void do_post_msg_queue_helper( ::boost::mpl::false_ const &)
      {
          m_event_processing = false;
          process_message_queue(this);
      }
      // the following 2 functions handle the processing either with a try/catch protection or without
      template <class StateType,class EventType>
      HandledEnum do_process_helper(EventType const& evt, ::boost::mpl::true_ const &, bool is_direct_call)
      {
          return this->do_process_event(evt,is_direct_call);
      }
      template <class StateType,class EventType>
      HandledEnum do_process_helper(EventType const& evt, ::boost::mpl::false_ const &, bool is_direct_call)
      {
          // when compiling without exception support there is no formal parameter "e" in the catch handler. 
          // Declaring a local variable here does not hurt and will be "used" to make the code in the handler 
          // compilable although the code will never be executed.
          std::exception e;
          BOOST_TRY
          {
              return this->do_process_event(evt,is_direct_call);
          }
          BOOST_CATCH (std::exception& e)
          {
              // give a chance to the concrete state machine to handle
              this->exception_caught(evt,*this,e);
          }
          BOOST_CATCH_END
          return HANDLED_TRUE;
      }
      // handling of deferred events
      // if none is found in the SM, take the following empty main version
      template <class StateType, class Enable = int> 
      struct handle_defer_helper
      {
          handle_defer_helper(deferred_msg_queue_helper<library_sm>& ){}
          void do_pre_handle_deferred()
          {
          }
  
          void do_post_handle_deferred(HandledEnum)
          {
          }
      };
      // otherwise the standard version handling the deferred events
      template <class StateType>
      struct handle_defer_helper
          <StateType, typename enable_if< typename ::boost::msm::back::has_fsm_deferred_events<StateType>::type,int >::type>
      {
          handle_defer_helper(deferred_msg_queue_helper<library_sm>& a_queue):
              events_queue(a_queue),next_deferred_event(){}
          void do_pre_handle_deferred()
          {
          }
  
          void do_post_handle_deferred(HandledEnum handled)
          {
              if (handled == HANDLED_TRUE)
              {
                  // a transition has been taken, it makes sense again to try processing waiting deferred events
                  // reset all events to not tested 
                  for (std::size_t i = 0; i < events_queue.m_deferred_events_queue.size(); ++i)
                  {
                      events_queue.m_deferred_events_queue[i].second=false;
                  }
                  // test first event
                  if (!events_queue.m_deferred_events_queue.empty())
                  {
                      deferred_fct next = events_queue.m_deferred_events_queue.front().first;
                      events_queue.m_deferred_events_queue.pop_front();
                      next();
                  }
              }
              else
              {
                  // look for next deferred event, if any
                  typename deferred_events_queue_t::iterator it = 
                      std::find_if(events_queue.m_deferred_events_queue.begin(),
                                   events_queue.m_deferred_events_queue.end(),
                                   boost::bind(&std::pair<deferred_fct,bool>::second, _1) == false);
                  if (it != events_queue.m_deferred_events_queue.end())
                  {
                      (*it).second = true;
                      deferred_fct next = (*it).first;
                      events_queue.m_deferred_events_queue.erase(it);
                      next();
                  }
              }
          }
  
      private:
          deferred_msg_queue_helper<library_sm>&  events_queue;
          deferred_fct                            next_deferred_event;
      };
  
      // handling of eventless transitions
      // if none is found in the SM, nothing to do
      template <class StateType, class Enable = void> 
      struct handle_eventless_transitions_helper
      {
          handle_eventless_transitions_helper(library_sm* , bool ){}
          void process_completion_event(){}
      };
      // otherwise 
      template <class StateType>
      struct handle_eventless_transitions_helper
          <StateType, typename enable_if< typename ::boost::msm::back::has_fsm_eventless_transition<StateType>::type >::type>
      {
          handle_eventless_transitions_helper(library_sm* self_, bool handled_):self(self_),handled(handled_){}
          void process_completion_event()
          {
              typedef typename ::boost::mpl::deref<
                  typename ::boost::mpl::begin<
                      typename find_completion_events<StateType>::type
                          >::type
              >::type first_completion_event;
              if (handled)
              {
                  self->process_event(first_completion_event() );
              }
          }
   
      private:
          library_sm* self;
          bool        handled;
      };
  
      // helper class called in case the event to process has been found in the fsm's internal stt and is therefore processable
      template<class Event>
      struct process_fsm_internal_table
      {
          typedef typename ::boost::mpl::has_key<processable_events_internal_table,Event>::type is_event_processable;
  
          // forward to the correct do_process
          static void process(Event const& evt,library_sm* self_,HandledEnum& result)
          {
              do_process(evt,self_,result,is_event_processable());
          }
      private:
          // the event is processable, let's try!
          static void do_process(Event const& evt,library_sm* self_,HandledEnum& result, ::boost::mpl::true_)
          {
              if (result != HANDLED_TRUE)
              {
                  typedef dispatch_table<library_sm,complete_table,Event,CompilePolicy> table;
                  HandledEnum res_internal = table::instance.entries[0](*self_, 0, self_->m_states[0], evt);
                  result = (HandledEnum)((int)result | (int)res_internal);
              }
          }
          // version doing nothing if the event is not in the internal stt and we can save ourselves the time trying to process
          static void do_process(Event const& ,library_sm* ,HandledEnum& , ::boost::mpl::false_)
          {
              // do nothing
          }
      };
  
      template <class StateType,class Enable=void>
      struct region_processing_helper 
      {
      public:
          region_processing_helper(library_sm* self_,HandledEnum& result_)
              :self(self_),result(result_){}
          template<class Event>
          void process(Event const& evt)
          {
              // use this table as if it came directly from the user
              typedef dispatch_table<library_sm,complete_table,Event,CompilePolicy> table;
              // +1 because index 0 is reserved for this fsm
              HandledEnum res =
                  table::instance.entries[self->m_states[0]+1](
                  *self, 0, self->m_states[0], evt);
              result = (HandledEnum)((int)result | (int)res);
              // process the event in the internal table of this fsm if the event is processable (present in the table)
              process_fsm_internal_table<Event>::process(evt,self,result);
          }
          library_sm*     self;
          HandledEnum&    result;
      };
      // version with visitors
      template <class StateType>
      struct region_processing_helper<StateType,typename ::boost::enable_if< 
                          ::boost::mpl::is_sequence<typename StateType::initial_state> >::type> 
      {
          private:
          // process event in one region
          template <class region_id,int Dummy=0>
          struct In
          {
              template<class Event>
              static void process(Event const& evt,library_sm* self_,HandledEnum& result_)
              {
                  // use this table as if it came directly from the user
                  typedef dispatch_table<library_sm,complete_table,Event,CompilePolicy> table;
                  // +1 because index 0 is reserved for this fsm
                  HandledEnum res =
                      table::instance.entries[self_->m_states[region_id::value]+1](
                      *self_, region_id::value , self_->m_states[region_id::value], evt);
                  result_ = (HandledEnum)((int)result_ | (int)res);
                  In< ::boost::mpl::int_<region_id::value+1> >::process(evt,self_,result_);
              }
          };
          template <int Dummy>
          struct In< ::boost::mpl::int_<nr_regions::value>,Dummy>
          {
              // end of processing
              template<class Event>
              static void process(Event const& evt,library_sm* self_,HandledEnum& result_)
              {
                  // process the event in the internal table of this fsm if the event is processable (present in the table)
                  process_fsm_internal_table<Event>::process(evt,self_,result_);
              }
          };
          public:
          region_processing_helper(library_sm* self_,HandledEnum& result_)
              :self(self_),result(result_){}
          template<class Event>
          void process(Event const& evt)
          {
              In< ::boost::mpl::int_<0> >::process(evt,self,result);
          }
  
          library_sm*     self;
          HandledEnum&    result;
      };
  
      // Main function used internally to make transitions
      // Can only be called for internally (for example in an action method) generated events.
      template<class Event>
      execute_return process_event_internal(Event const& evt, bool is_direct_call)
      {
          HandledEnum ret_handled=HANDLED_FALSE;
          // if the state machine has terminate or interrupt flags, check them, otherwise skip
          if (is_event_handling_blocked_helper<Event>
                  ( ::boost::mpl::bool_<has_fsm_blocking_states<library_sm>::type::value>() ) )
              return HANDLED_TRUE;
          // if a message queue is needed and processing is on the way
          if (!do_pre_msg_queue_helper<Event>
                  (evt,::boost::mpl::bool_<is_no_message_queue<library_sm>::type::value>()) )
          {
              // wait for the end of current processing
              return HANDLED_TRUE;
          }
          else
          {
              // prepare the next deferred event for handling
              // if one defer is found in the SM, otherwise skip
              handle_defer_helper<library_sm> defer_helper(m_deferred_events_queue);
              defer_helper.do_pre_handle_deferred();
              // process event
              HandledEnum handled = this->do_process_helper<Event>
                  (evt,::boost::mpl::bool_<is_no_exception_thrown<library_sm>::type::value>(),is_direct_call);
              if (handled)
              {
                  ret_handled = handled;
              }
  
              // process completion transitions BEFORE any other event in the pool (UML Standard 2.3 15.3.14)
              handle_eventless_transitions_helper<library_sm> eventless_helper(this,(handled == HANDLED_TRUE));
              eventless_helper.process_completion_event();
  
              // after handling, take care of the deferred events
              defer_helper.do_post_handle_deferred(handled);
  
              // now check if some events were generated in a transition and was not handled
              // because of another processing, and if yes, start handling them
              do_post_msg_queue_helper(::boost::mpl::bool_<is_no_message_queue<library_sm>::type::value>());
  
              return ret_handled;
          }       
      }
  
      // minimum event processing without exceptions, queues, etc.
      template<class Event>
      HandledEnum do_process_event(Event const& evt, bool is_direct_call)
      {
          HandledEnum handled = HANDLED_FALSE;
          // dispatch the event to every region
          region_processing_helper<Derived> helper(this,handled);
          helper.process(evt);
  
          // if the event has not been handled and we have orthogonal zones, then
          // generate an error on every active state 
          // for state machine states contained in other state machines, do not handle
          // but let the containing sm handle the error, unless the event was generated in this fsm 
          // (by calling process_event on this fsm object, is_direct_call == true)
          // completion events do not produce an error
          if ( (!is_contained() || is_direct_call) && !handled && !is_completion_event<Event>::type::value)
          {
              for (int i=0; i<nr_regions::value;++i)
              {
                  this->no_transition(evt,*this,this->m_states[i]);
              }
          }
          return handled;
      }
  
      // default row arguments for the compilers which accept this
      template <class Event>
      bool no_guard(Event const&){return true;}
      template <class Event>
      void no_action(Event const&){}
  
  #ifndef BOOST_NO_RTTI
      HandledEnum process_any_event( ::boost::any const& evt);
  #endif
  
  private:
      // composite accept implementation. First calls accept on the composite, then accept on all its active states.
      void composite_accept()
      {
          this->accept();
          this->visit_current_states();
      }
  
  #define MSM_COMPOSITE_ACCEPT_SUB(z, n, unused) ARG ## n vis ## n
  #define MSM_COMPOSITE_ACCEPT_SUB2(z, n, unused) boost::ref( vis ## n )
  #define MSM_COMPOSITE_ACCEPT_EXECUTE(z, n, unused)                                      \
          template <BOOST_PP_ENUM_PARAMS(n, class ARG)>                                   \
          void composite_accept(BOOST_PP_ENUM(n, MSM_COMPOSITE_ACCEPT_SUB, ~ ) )               \
          {                                                                               \
              this->accept(BOOST_PP_ENUM_PARAMS(n,vis));                                        \
              this->visit_current_states(BOOST_PP_ENUM(n,MSM_COMPOSITE_ACCEPT_SUB2, ~));        \
          }
          BOOST_PP_REPEAT_FROM_TO(1,BOOST_PP_ADD(BOOST_MSM_VISITOR_ARG_SIZE,1), MSM_COMPOSITE_ACCEPT_EXECUTE, ~)
  #undef MSM_COMPOSITE_ACCEPT_EXECUTE
  #undef MSM_COMPOSITE_ACCEPT_SUB
  #undef MSM_COMPOSITE_ACCEPT_SUB2
  
      // helper used to call the init states at the start of the state machine
      template <class Event>
      struct call_init
      {
          call_init(Event const& an_event,library_sm* self_):
                  evt(an_event),self(self_){}
          template <class State>
          void operator()(boost::msm::wrap<State> const&)
          {
              execute_entry(::boost::fusion::at_key<State>(self->m_substate_list),evt,*self);
          }
      private:
          Event const& evt;
          library_sm* self;
      };
      // helper for flag handling. Uses OR by default on orthogonal zones.
      template <class Flag,bool orthogonalStates>
      struct FlagHelper 
      {
          static bool helper(library_sm const& sm,flag_handler* )
          {
              // by default we use OR to accumulate the flags
              return sm.is_flag_active<Flag,Flag_OR>();
          }
      };
      template <class Flag>
      struct FlagHelper<Flag,false>
      {
          static bool helper(library_sm const& sm,flag_handler* flags_entries)
          {
              // just one active state, so we can call operator[] with 0
              return flags_entries[sm.current_state()[0]](sm);
          }
      };
      // handling of flag
      // defines a true and false functions plus a forwarding one for composite states
      template <class StateType,class Flag>
      struct FlagHandler
      {
          static bool flag_true(library_sm const& )
          {
              return true;
          }
          static bool flag_false(library_sm const& )
          {
              return false;
          }
          static bool forward(library_sm const& fsm)
          {
              return ::boost::fusion::at_key<StateType>(fsm.m_substate_list).template is_flag_active<Flag>();
          }
      };
      template <class Flag>
      struct init_flags
      {
      private:
          // helper function, helps hiding the forward function for non-state machines states.
          template <class T>
          void helper (flag_handler* an_entry,int offset, ::boost::mpl::true_ const &  )
          {
              // composite => forward
              an_entry[offset] = &FlagHandler<T,Flag>::forward;
          }
          template <class T>
          void helper (flag_handler* an_entry,int offset, ::boost::mpl::false_ const &  )
          {
              // default no flag
              an_entry[offset] = &FlagHandler<T,Flag>::flag_false;
          }
          // attributes
          flag_handler* entries;
  
      public:
          init_flags(flag_handler* entries_)
              : entries(entries_)
          {}
  
          // Flags initializer function object, used with mpl::for_each
          template <class StateType>
          void operator()( ::boost::msm::wrap<StateType> const& )
          {
              typedef typename get_flag_list<StateType>::type flags;
              typedef typename ::boost::mpl::contains<flags,Flag >::type found;
              typedef typename is_composite_state<StateType>::type composite;
  
              BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,StateType>::type::value));
              if (found::type::value)
              {
                  // the type defined the flag => true
                  entries[state_id] = &FlagHandler<StateType,Flag>::flag_true;
              }
              else
              {
                  // false or forward
                  typedef typename ::boost::mpl::and_<
                              typename is_composite_state<StateType>::type,
                              typename ::boost::mpl::not_<
                                      typename has_non_forwarding_flag<Flag>::type>::type >::type composite_no_forward;
  
                  helper<StateType>(entries,state_id,::boost::mpl::bool_<composite_no_forward::type::value>());
              }
          }
      };
      // maintains for every flag a static array containing the flag value for every state
      template <class Flag>
      flag_handler* get_entries_for_flag() const
      {
          BOOST_STATIC_CONSTANT(int, max_state = (mpl::size<state_list>::value));
  
          static flag_handler flags_entries[max_state];
          // build a state list
          ::boost::mpl::for_each<state_list, boost::msm::wrap< ::boost::mpl::placeholders::_1> >
                          (init_flags<Flag>(flags_entries));
          return flags_entries;
      }
  
      // helper used to create a state using the correct constructor
      template <class State, class Enable=void>
      struct create_state_helper
      {
          static void set_sm(library_sm* )
          {
              // state doesn't need its sm
          }
      };
      // create a state requiring a pointer to the state machine
      template <class State>
      struct create_state_helper<State,typename boost::enable_if<typename State::needs_sm >::type>
      {
          static void set_sm(library_sm* sm)
          {
              // create and set the fsm
              ::boost::fusion::at_key<State>(sm->m_substate_list).set_sm_ptr(sm);
          }
      };
          // main unspecialized helper class
          template <class StateType,int ARGS>
          struct visitor_args;
  
  #define MSM_VISITOR_ARGS_SUB(z, n, unused) BOOST_PP_CAT(_,BOOST_PP_ADD(n,1))
  #define MSM_VISITOR_ARGS_TYPEDEF_SUB(z, n, unused) typename StateType::accept_sig::argument ## n
  
  #define MSM_VISITOR_ARGS_EXECUTE(z, n, unused)                                              \
      template <class StateType>                                                              \
      struct visitor_args<StateType,n>                                                        \
      {                                                                                       \
          template <class State>                                                              \
          static typename enable_if_c<!is_composite_state<State>::value,void >::type          \
          helper (library_sm* sm,                                                             \
          int id,StateType& astate)                                                           \
          {                                                                                   \
              sm->m_visitors.insert(id, boost::bind(&StateType::accept,                       \
                  ::boost::ref(astate) BOOST_PP_COMMA_IF(n) BOOST_PP_ENUM(n, MSM_VISITOR_ARGS_SUB, ~) ));   \
          }                                                                                   \
          template <class State>                                                              \
          static typename enable_if_c<is_composite_state<State>::value,void >::type           \
          helper (library_sm* sm,                                                             \
          int id,StateType& astate)                                                           \
          {                                                                                   \
              void (StateType::*caccept)(BOOST_PP_ENUM(n, MSM_VISITOR_ARGS_TYPEDEF_SUB, ~ ) )           \
                                          = &StateType::composite_accept;                     \
              sm->m_visitors.insert(id, boost::bind(caccept,             \
              ::boost::ref(astate) BOOST_PP_COMMA_IF(n) BOOST_PP_ENUM(n, MSM_VISITOR_ARGS_SUB, ~) ));                 \
          }                                                                                   \
  };
  BOOST_PP_REPEAT(BOOST_PP_ADD(BOOST_MSM_VISITOR_ARG_SIZE,1), MSM_VISITOR_ARGS_EXECUTE, ~)
  #undef MSM_VISITOR_ARGS_EXECUTE
  #undef MSM_VISITOR_ARGS_SUB
  
  // the IBM compiler seems to have problems with nested classes
  // the same seems to apply to the Apple version of gcc 4.0.1 (just in case we do for < 4.1)
  // and also to MS VC < 8
  #if defined (__IBMCPP__) || (__GNUC__ == 4 && __GNUC_MINOR__ < 1) || (defined(_MSC_VER) && (_MSC_VER < 1400))
       public:
  #endif
      template<class ContainingSM>
      void set_containing_sm(ContainingSM* sm)
      {
          m_is_included=true;
          ::boost::fusion::for_each(m_substate_list,add_state<ContainingSM>(this,sm));
      }
  #if defined (__IBMCPP__) || (__GNUC__ == 4 && __GNUC_MINOR__ < 1) || (defined(_MSC_VER) && (_MSC_VER < 1400))
       private:
  #endif
      // A function object for use with mpl::for_each that stuffs
      // states into the state list.
      template<class ContainingSM>
      struct add_state
      {
          add_state(library_sm* self_,ContainingSM* sm)
              : self(self_),containing_sm(sm){}
  
          // State is a sub fsm with exit pseudo states and gets a pointer to this fsm, so it can build a callback
          template <class StateType>
          typename ::boost::enable_if<
              typename is_composite_state<StateType>::type,void >::type
          new_state_helper(boost::msm::back::dummy<0> = 0) const
          {
              ::boost::fusion::at_key<StateType>(self->m_substate_list).set_containing_sm(containing_sm);
          }
          // State is a sub fsm without exit pseudo states and does not get a callback to this fsm
          // or state is a normal state and needs nothing except creation
          template <class StateType>
          typename ::boost::enable_if<
              typename boost::mpl::and_<typename boost::mpl::not_
                                                      <typename is_composite_state<StateType>::type>::type,
                                        typename boost::mpl::not_
                                                      <typename is_pseudo_exit<StateType>::type>::type
                     >::type,void>::type
          new_state_helper( ::boost::msm::back::dummy<1> = 0) const
          {
              //nothing to do
          }
          // state is exit pseudo state and gets callback to target fsm
          template <class StateType>
          typename ::boost::enable_if<typename is_pseudo_exit<StateType>::type,void >::type
          new_state_helper( ::boost::msm::back::dummy<2> = 0) const
          {
              execute_return (ContainingSM::*pf) (typename StateType::event const& evt)= 
                  &ContainingSM::process_event;
              ::boost::function<execute_return (typename StateType::event const&)> fct = 
                  ::boost::bind(pf,containing_sm,_1);
              ::boost::fusion::at_key<StateType>(self->m_substate_list).set_forward_fct(fct);
          }
          // for every defined state in the sm
          template <class State>
          void operator()( State const&) const
          {
              //create a new state with the defined id and type
              BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value));
  
              this->new_state_helper<State>(),
              create_state_helper<State>::set_sm(self);
              // create a visitor callback
              visitor_helper(state_id,::boost::fusion::at_key<State>(self->m_substate_list),
                             ::boost::mpl::bool_<has_accept_sig<State>::type::value>());
          }
      private:
          // support possible use of a visitor if accept_sig is defined
          template <class StateType>
          void visitor_helper(int id,StateType& astate, ::boost::mpl::true_ const & ) const
          {
              visitor_args<StateType,StateType::accept_sig::args_number>::
                  template helper<StateType>(self,id,astate);
          }
          template <class StateType>
          void visitor_helper(int ,StateType& , ::boost::mpl::false_ const &) const
          {
              // nothing to do
          }
  
          library_sm*      self;
          ContainingSM*    containing_sm;
      };
  
       // helper used to copy every state if needed
       struct copy_helper
       {
           copy_helper(library_sm* sm):
             m_sm(sm){}
           template <class StateType>
           void operator()( ::boost::msm::wrap<StateType> const& )
           {
              BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,StateType>::type::value));
              // possibly also set the visitor
              visitor_helper<StateType>(state_id);
  
              // and for states that keep a pointer to the fsm, reset the pointer
              create_state_helper<StateType>::set_sm(m_sm);
           }
           template <class StateType>
           typename ::boost::enable_if<typename has_accept_sig<StateType>::type,void >::type
               visitor_helper(int id) const
           {
               visitor_args<StateType,StateType::accept_sig::args_number>::template helper<StateType>
                   (m_sm,id,::boost::fusion::at_key<StateType>(m_sm->m_substate_list));
           }
           template <class StateType>
           typename ::boost::disable_if<typename has_accept_sig<StateType>::type,void >::type
               visitor_helper(int) const
           {
               // nothing to do
           }
  
           library_sm*     m_sm;
       };
       // helper to copy the active states attribute
       template <class region_id,int Dummy=0>
       struct region_copy_helper
       {
           static void do_copy(library_sm* self_,library_sm const& rhs)
           {
               self_->m_states[region_id::value] = rhs.m_states[region_id::value];
               region_copy_helper< ::boost::mpl::int_<region_id::value+1> >::do_copy(self_,rhs);
           }
       };
       template <int Dummy>
       struct region_copy_helper< ::boost::mpl::int_<nr_regions::value>,Dummy>
       {
           // end of processing
           static void do_copy(library_sm*,library_sm const& ){}
       };
       // copy functions for deep copy (no need of a 2nd version for NoCopy as noncopyable handles it)
       void do_copy (library_sm const& rhs,
                ::boost::msm::back::dummy<0> = 0)
       {
           // deep copy simply assigns the data
           region_copy_helper< ::boost::mpl::int_<0> >::do_copy(this,rhs);
           m_events_queue = rhs.m_events_queue;
           m_deferred_events_queue = rhs.m_deferred_events_queue;
           m_history = rhs.m_history;
           m_event_processing = rhs.m_event_processing;
           m_is_included = rhs.m_is_included;
           m_substate_list = rhs.m_substate_list;
           // except for the states themselves, which get duplicated
  
           ::boost::mpl::for_each<state_list, ::boost::msm::wrap< ::boost::mpl::placeholders::_1> >
                          (copy_helper(this));
       }
  
       // helper used to call the correct entry/exit method
       // unfortunately in O(number of states in the sub-sm) but should be better than a virtual call
       template<class Event,bool is_entry> 
       struct entry_exit_helper
       {
           entry_exit_helper(int id,Event const& e,library_sm* self_):
              state_id(id),evt(e),self(self_){}
           // helper for entry actions
           template <class IsEntry,class State>
           typename ::boost::enable_if<typename IsEntry::type,void >::type
           helper( ::boost::msm::back::dummy<0> = 0)
           {
               BOOST_STATIC_CONSTANT(int, id = (get_state_id<stt,State>::value));
               if (id == state_id)
               {
                   execute_entry<State>(::boost::fusion::at_key<State>(self->m_substate_list),evt,*self);
               }
           }
           // helper for exit actions
           template <class IsEntry,class State>
           typename boost::disable_if<typename IsEntry::type,void >::type
           helper( ::boost::msm::back::dummy<1> = 0)
           {
               BOOST_STATIC_CONSTANT(int, id = (get_state_id<stt,State>::value));
               if (id == state_id)
               {
                   execute_exit<State>(::boost::fusion::at_key<State>(self->m_substate_list),evt,*self);
               }
           }
           // iterates through all states to find the one to be activated
           template <class State>
           void operator()( ::boost::msm::wrap<State> const&)
           {
               entry_exit_helper<Event,is_entry>::template helper< ::boost::mpl::bool_<is_entry>,State >();
           }
       private:
           int            state_id;
           Event const&   evt;
           library_sm*    self;
       };
  
       // helper to start the fsm
       template <class region_id,int Dummy=0>
       struct region_start_helper
       {
           template<class Event>
           static void do_start(library_sm* self_,Event const& incomingEvent)
           {
               //forward the event for handling by sub state machines
               ::boost::mpl::for_each<state_list, ::boost::msm::wrap< ::boost::mpl::placeholders::_1> >
                   (entry_exit_helper<Event,true>(self_->m_states[region_id::value],incomingEvent,self_));
               region_start_helper
                   < ::boost::mpl::int_<region_id::value+1> >::do_start(self_,incomingEvent);
           }
       };
       template <int Dummy>
       struct region_start_helper< ::boost::mpl::int_<nr_regions::value>,Dummy>
       {
           // end of processing
           template<class Event>
           static void do_start(library_sm*,Event const& ){}
       };
       // start for states machines which are themselves embedded in other state machines (composites)
       template <class Event>
       void internal_start(Event const& incomingEvent)
       {
           region_start_helper< ::boost::mpl::int_<0> >::do_start(this,incomingEvent);
           // give a chance to handle an anonymous (eventless) transition
           handle_eventless_transitions_helper<library_sm> eventless_helper(this,true);
           eventless_helper.process_completion_event();
       }
  
       template <class StateType>
       struct find_region_id 
       {
           template <int region,int Dummy=0>
           struct In
           {
               enum {region_index=region};
           };
           // if the user provides no region, find it!
           template<int Dummy>
           struct In<-1,Dummy>
           {
               typedef typename build_orthogonal_regions<
                   library_sm,
                   initial_states 
               >::type all_regions;
               enum {region_index= find_region_index<all_regions,StateType>::value };
           };         
           enum {region_index = In<StateType::zone_index>::region_index };
       };
       // helper used to set the correct state as active state upon entry into a fsm
       struct direct_event_start_helper 
       {
           direct_event_start_helper(library_sm* self_):self(self_){}
           // this variant is for the standard case, entry due to activation of the containing FSM
           template <class EventType,class FsmType>
           typename ::boost::disable_if<typename has_direct_entry<EventType>::type,void>::type
               operator()(EventType const& evt,FsmType& fsm, ::boost::msm::back::dummy<0> = 0)
           {
               (static_cast<Derived*>(self))->on_entry(evt,fsm);
               self->internal_start(evt);
           }
  
           // this variant is for the direct entry case (just one entry, not a sequence of entries)
           template <class EventType,class FsmType>
           typename ::boost::enable_if<
               typename ::boost::mpl::and_<
                          typename ::boost::mpl::not_< typename is_pseudo_entry<
                                      typename EventType::active_state>::type >::type,
                          typename ::boost::mpl::and_<typename has_direct_entry<EventType>::type,
                                                      typename ::boost::mpl::not_<typename ::boost::mpl::is_sequence
                                                              <typename EventType::active_state>::type >::type 
                                                      >::type>::type,void
                                    >::type
           operator()(EventType const& evt,FsmType& fsm, ::boost::msm::back::dummy<1> = 0)
           {
               (static_cast<Derived*>(self))->on_entry(evt,fsm);
               int state_id = get_state_id<stt,typename EventType::active_state::wrapped_entry>::value;
               BOOST_STATIC_ASSERT(find_region_id<typename EventType::active_state::wrapped_entry>::region_index >= 0);
               BOOST_STATIC_ASSERT(find_region_id<typename EventType::active_state::wrapped_entry>::region_index < nr_regions::value);
               // just set the correct zone, the others will be default/history initialized
               self->m_states[find_region_id<typename EventType::active_state::wrapped_entry>::region_index] = state_id;
               self->internal_start(evt.m_event);
           }
  
           // this variant is for the fork entry case (a sequence on entries)
           template <class EventType,class FsmType>
           typename ::boost::enable_if<
               typename ::boost::mpl::and_<
                      typename ::boost::mpl::not_<
                                      typename is_pseudo_entry<typename EventType::active_state>::type >::type,
                      typename ::boost::mpl::and_<typename has_direct_entry<EventType>::type,
                                                  typename ::boost::mpl::is_sequence<
                                                                  typename EventType::active_state>::type 
                                                  >::type>::type,void 
                                  >::type
           operator()(EventType const& evt,FsmType& fsm, ::boost::msm::back::dummy<2> = 0)
           {
               (static_cast<Derived*>(self))->on_entry(evt,fsm);
               ::boost::mpl::for_each<typename EventType::active_state, 
                                      ::boost::msm::wrap< ::boost::mpl::placeholders::_1> >
                                                          (fork_helper<EventType>(self,evt));
               // set the correct zones, the others (if any) will be default/history initialized
               self->internal_start(evt.m_event);
           }
  
           // this variant is for the pseudo state entry case
           template <class EventType,class FsmType>
           typename ::boost::enable_if<
               typename is_pseudo_entry<typename EventType::active_state >::type,void
                                      >::type
           operator()(EventType const& evt,FsmType& fsm, ::boost::msm::back::dummy<3> = 0)
           {
               // entry on the FSM
               (static_cast<Derived*>(self))->on_entry(evt,fsm);
               int state_id = get_state_id<stt,typename EventType::active_state::wrapped_entry>::value;
               BOOST_STATIC_ASSERT(find_region_id<typename EventType::active_state::wrapped_entry>::region_index >= 0);
               BOOST_STATIC_ASSERT(find_region_id<typename EventType::active_state::wrapped_entry>::region_index < nr_regions::value);
               // given region starts with the entry pseudo state as active state
               self->m_states[find_region_id<typename EventType::active_state::wrapped_entry>::region_index] = state_id;
               self->internal_start(evt.m_event);
               // and we process the transition in the zone of the newly active state
               // (entry pseudo states are, according to UML, a state connecting 1 transition outside to 1 inside
               self->process_event(evt.m_event);
           }
       private:
           // helper for the fork case, does almost like the direct entry
           library_sm* self;
           template <class EventType>
           struct fork_helper
           {
               fork_helper(library_sm* self_,EventType const& evt_):
                  helper_self(self_),helper_evt(evt_){}
               template <class StateType>
               void operator()( ::boost::msm::wrap<StateType> const& )
               {
                   int state_id = get_state_id<stt,typename StateType::wrapped_entry>::value;
                   BOOST_STATIC_ASSERT(find_region_id<typename StateType::wrapped_entry>::region_index >= 0);
                   BOOST_STATIC_ASSERT(find_region_id<typename StateType::wrapped_entry>::region_index < nr_regions::value);
                   helper_self->m_states[find_region_id<typename StateType::wrapped_entry>::region_index] = state_id;
               }
           private:
               library_sm*        helper_self;
               EventType const&   helper_evt;
           };
       };
  
       // helper for entry
       template <class region_id,int Dummy=0>
       struct region_entry_exit_helper
       {
           template<class Event>
           static void do_entry(library_sm* self_,Event const& incomingEvent)
           {
               self_->m_states[region_id::value] = 
                   self_->m_history.history_entry(incomingEvent)[region_id::value];
               region_entry_exit_helper
                   < ::boost::mpl::int_<region_id::value+1> >::do_entry(self_,incomingEvent);
           }
           template<class Event>
           static void do_exit(library_sm* self_,Event const& incomingEvent)
           {
               ::boost::mpl::for_each<state_list, ::boost::msm::wrap< ::boost::mpl::placeholders::_1> >
                   (entry_exit_helper<Event,false>(self_->m_states[region_id::value],incomingEvent,self_));
               region_entry_exit_helper
                   < ::boost::mpl::int_<region_id::value+1> >::do_exit(self_,incomingEvent);
           }
       };
       template <int Dummy>
       struct region_entry_exit_helper< ::boost::mpl::int_<nr_regions::value>,Dummy>
       {
           // end of processing
           template<class Event>
           static void do_entry(library_sm*,Event const& ){}
           template<class Event>
           static void do_exit(library_sm*,Event const& ){}
       };
       // entry/exit for states machines which are themselves embedded in other state machines (composites)
       template <class Event,class FsmType>
       void do_entry(Event const& incomingEvent,FsmType& fsm)
       {
          // by default we activate the history/init states, can be overwritten by direct_event_start_helper
          region_entry_exit_helper< ::boost::mpl::int_<0> >::do_entry(this,incomingEvent);
          // block immediate handling of events
          m_event_processing = true;
          // if the event is generating a direct entry/fork, set the current state(s) to the direct state(s)
          direct_event_start_helper(this)(incomingEvent,fsm);
          // handle messages which were generated and blocked in the init calls
          m_event_processing = false;
          // look for deferred events waiting
          handle_defer_helper<library_sm> defer_helper(m_deferred_events_queue);
          defer_helper.do_post_handle_deferred(HANDLED_TRUE);
          process_message_queue(this);
       }
       template <class Event,class FsmType>
       void do_exit(Event const& incomingEvent,FsmType& fsm)
       {
          // first recursively exit the sub machines
          // forward the event for handling by sub state machines
          region_entry_exit_helper< ::boost::mpl::int_<0> >::do_exit(this,incomingEvent);
          // then call our own exit
          (static_cast<Derived*>(this))->on_exit(incomingEvent,fsm);
          // give the history a chance to handle this (or not).
          m_history.history_exit(this->m_states);
          // history decides what happens with deferred events
          if (!m_history.process_deferred_events(incomingEvent))
          {
              clear_deferred_queue();
          }
       }
  
      // the IBM and VC<8 compilers seem to have problems with the friend declaration of dispatch_table
  #if defined (__IBMCPP__) || (defined(_MSC_VER) && (_MSC_VER < 1400))
       public:
  #endif
      // no transition for event.
      template <class Event>
      static HandledEnum call_no_transition(library_sm& , int , int , Event const& )
      {
          return HANDLED_FALSE;
      }
      // no transition for event for internal transitions (not an error).
      template <class Event>
      static HandledEnum call_no_transition_internal(library_sm& , int , int , Event const& )
      {
          //// reject to give others a chance to handle
          //return HANDLED_GUARD_REJECT;
          return HANDLED_FALSE;
      }
      // called for deferred events. Address set in the dispatch_table at init
      template <class Event>
      static HandledEnum defer_transition(library_sm& fsm, int , int , Event const& e)
      {
          fsm.defer_event(e);
          return HANDLED_DEFERRED;
      }
      // called for completion events. Default address set in the dispatch_table at init
      // prevents no-transition detection for completion events
      template <class Event>
      static HandledEnum default_eventless_transition(library_sm&, int, int , Event const&)
      {
          return HANDLED_FALSE;
      }
  #if defined (__IBMCPP__) || (defined(_MSC_VER) && (_MSC_VER < 1400))
       private:
  #endif
      // puts a deferred event in the queue
      void post_deferred_event(deferred_fct& deferred)
      {
          m_deferred_events_queue.m_deferred_events_queue.push_back(std::make_pair(deferred,true));
      }
      // removes one event from the message queue and processes it
      template <class StateType>
      void process_message_queue(StateType*, 
                                 typename ::boost::disable_if<typename is_no_message_queue<StateType>::type,void >::type* = 0)
      {
          if (!m_events_queue.m_events_queue.empty())
          {
              transition_fct to_call = m_events_queue.m_events_queue.front();
              m_events_queue.m_events_queue.pop_front();
              to_call();
          }
      }
      template <class StateType>
      void process_message_queue(StateType*, 
                                 typename ::boost::enable_if<typename is_no_message_queue<StateType>::type,void >::type* = 0)
      {
          // nothing to process
      }
      // helper function. In cases where the event is wrapped (target is a direct entry states)
      // we want to send only the real event to on_entry, not the wrapper.
      template <class EventType>
      static 
      typename boost::enable_if<typename has_direct_entry<EventType>::type,typename EventType::contained_event const& >::type
      remove_direct_entry_event_wrapper(EventType const& evt,boost::msm::back::dummy<0> = 0)
      {
          return evt.m_event;
      }
      template <class EventType>
      static typename boost::disable_if<typename has_direct_entry<EventType>::type,EventType const& >::type
      remove_direct_entry_event_wrapper(EventType const& evt,boost::msm::back::dummy<1> = 0)
      {
          // identity. No wrapper
          return evt;
      }
      // calls the entry/exit or on_entry/on_exit depending on the state type
      // (avoids calling virtually)
      // variant for FSMs
      template <class StateType,class EventType,class FsmType>
      static
          typename boost::enable_if<typename is_composite_state<StateType>::type,void >::type
          execute_entry(StateType& astate,EventType const& evt,FsmType& fsm,boost::msm::back::dummy<0> = 0)
      {
          // calls on_entry on the fsm then handles direct entries, fork, entry pseudo state
          astate.do_entry(evt,fsm);
      }
      // variant for states
      template <class StateType,class EventType,class FsmType>
      static
          typename ::boost::disable_if<
              typename ::boost::mpl::or_<typename is_composite_state<StateType>::type,
                                         typename is_pseudo_exit<StateType>::type >::type,void >::type
      execute_entry(StateType& astate,EventType const& evt,FsmType& fsm, ::boost::msm::back::dummy<1> = 0)
      {
          // simple call to on_entry
          astate.on_entry(remove_direct_entry_event_wrapper(evt),fsm);
      }
      // variant for exit pseudo states
      template <class StateType,class EventType,class FsmType>
      static
          typename ::boost::enable_if<typename is_pseudo_exit<StateType>::type,void >::type
      execute_entry(StateType& astate,EventType const& evt,FsmType& fsm, ::boost::msm::back::dummy<2> = 0)
      {
          // calls on_entry on the state then forward the event to the transition which should be defined inside the 
          // contained fsm
          astate.on_entry(evt,fsm);
          astate.forward_event(evt);
      }
      template <class StateType,class EventType,class FsmType>
      static
          typename ::boost::enable_if<typename is_composite_state<StateType>::type,void >::type
      execute_exit(StateType& astate,EventType const& evt,FsmType& fsm, ::boost::msm::back::dummy<0> = 0)
      {
          astate.do_exit(evt,fsm);
      }
      template <class StateType,class EventType,class FsmType>
      static
          typename ::boost::disable_if<typename is_composite_state<StateType>::type,void >::type
      execute_exit(StateType& astate,EventType const& evt,FsmType& fsm, ::boost::msm::back::dummy<1> = 0)
      {
          // simple call to on_exit
          astate.on_exit(evt,fsm);
      }
  
      // helper allowing special handling of direct entries / fork
      template <class StateType,class TargetType,class EventType,class FsmType>
      static
          typename ::boost::disable_if<
              typename ::boost::mpl::or_<typename has_explicit_entry_state<TargetType>::type,
                                         ::boost::mpl::is_sequence<TargetType> >::type,void>::type
      convert_event_and_execute_entry(StateType& astate,EventType const& evt, FsmType& fsm, ::boost::msm::back::dummy<1> = 0)
      {
          // if the target is a normal state, do the standard entry handling
          execute_entry<StateType>(astate,evt,fsm);
      }
      template <class StateType,class TargetType,class EventType,class FsmType>
      static
          typename ::boost::enable_if<
              typename ::boost::mpl::or_<typename has_explicit_entry_state<TargetType>::type,
                                         ::boost::mpl::is_sequence<TargetType> >::type,void >::type
      convert_event_and_execute_entry(StateType& astate,EventType const& evt, FsmType& fsm, ::boost::msm::back::dummy<0> = 0)
      {
          // for the direct entry, pack the event in a wrapper so that we handle it differently during fsm entry
          execute_entry(astate,msm::back::direct_entry_event<TargetType,EventType>(evt),fsm);
      }
  
      // creates all the states
      template <class ContainingSM>
      void fill_states(ContainingSM* containing_sm=0)
      {
          // checks that regions are truly orthogonal
          FsmCheckPolicy::template check_orthogonality<library_sm>();
          // checks that all states are reachable
          FsmCheckPolicy::template check_unreachable_states<library_sm>();
  
          BOOST_STATIC_CONSTANT(int, max_state = (mpl::size<state_list>::value));
          // allocate the place without reallocation
          m_visitors.fill_visitors(max_state);
          ::boost::fusion::for_each(m_substate_list,add_state<ContainingSM>(this,containing_sm));
  
      }
  
  private:
      template <class StateType,class Enable=void>
      struct msg_queue_helper 
      {
      public:
          msg_queue_helper():m_events_queue(){}
          events_queue_t              m_events_queue;
      };
      template <class StateType>
      struct msg_queue_helper<StateType,
          typename ::boost::enable_if<typename is_no_message_queue<StateType>::type >::type> 
      {
      };
  
      template <class Fsm,class Stt, class Event, class Compile>
      friend struct dispatch_table;
  
      // data members
      int                             m_states[nr_regions::value];
      msg_queue_helper<library_sm>    m_events_queue;
      deferred_msg_queue_helper
          <library_sm>                m_deferred_events_queue;
      concrete_history                m_history;
      bool                            m_event_processing;
      bool                            m_is_included;
      visitor_fct_helper<BaseState>   m_visitors;
      substate_list                   m_substate_list;
  
  
  };
  
  } } }// boost::msm::back
  #endif //BOOST_MSM_BACK_STATEMACHINE_H
  
  