simple_state.hpp

support vector clustering for vc++

      outermost_context_base().template clear_shallow_history<
        HistoryContext, orthogonalPosition >();
    }

    template<
      class HistoryContext,
      detail::orthogonal_position_type orthogonalPosition >
    void clear_deep_history()
    {
      outermost_context_base().template clear_deep_history<
        HistoryContext, orthogonalPosition >();
    }

  protected:
    //////////////////////////////////////////////////////////////////////////
    simple_state() : pContext_( 0 ) {}

    ~simple_state()
    {
      // As a result of a throwing derived class constructor, this destructor
      // can be called before the context is set.
      if ( get_pointer( pContext_ ) != 0 )
      {
        if ( this->deferred_events() )
        {
          outermost_context_base().release_events( this );
        }

        pContext_->remove_inner_state( orthogonal_position::value );
      }
    }

  public:
    //////////////////////////////////////////////////////////////////////////
    // The following declarations should be private.
    // They are only public because many compilers lack template friends.
    //////////////////////////////////////////////////////////////////////////
    typedef typename Context::inner_orthogonal_position orthogonal_position;

    // If you receive a
    // "use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>'" or similar
    // compiler error here then either this state resides in a non-existent
    // orthogonal region of the outer state or the outer state does not have
    // inner states.
    BOOST_STATIC_ASSERT( ( mpl::less<
      orthogonal_position,
      typename context_type::no_of_orthogonal_regions >::value ) );

    typedef MostDerived inner_context_type;
    typedef mpl::integral_c< detail::orthogonal_position_type, 0 >
      inner_orthogonal_position;

    typedef typename context_type::event_base_type event_base_type;
    typedef typename context_type::rtti_policy_type rtti_policy_type;

    typedef typename context_type::outermost_context_base_type
      outermost_context_base_type;
    typedef typename context_type::inner_context_ptr_type context_ptr_type;
    typedef typename context_type::state_list_type state_list_type;
    typedef intrusive_ptr< inner_context_type > inner_context_ptr_type;
    typedef typename detail::make_list< InnerInitial >::type
      inner_initial_list;
    typedef typename mpl::size< inner_initial_list >::type
      inner_initial_list_size;
    typedef mpl::integral_c<
      detail::orthogonal_position_type,
      inner_initial_list_size::value > no_of_orthogonal_regions;
    typedef typename mpl::push_front<
      typename context_type::context_type_list,
      context_type >::type context_type_list;

    // If you receive a
    // "use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>'" or similar
    // compiler error here then the direct or indirect context of this state
    // has deep history _and_ this state has two or more orthogonal regions.
    // Boost.Statechart does not currently support deep history in a state whose
    // direct or indirect inner states have two or more orthogonal regions.
    // Please consult the documentation on how to work around this limitation.
    BOOST_STATIC_ASSERT( ( mpl::or_<
      mpl::less<
        no_of_orthogonal_regions,
        mpl::integral_c< detail::orthogonal_position_type, 2 > >,
      mpl::not_<
        typename context_type::inherited_deep_history > >::value ) );

    typedef mpl::bool_< ( historyMode & has_shallow_history ) != 0 >
      shallow_history;
    typedef typename context_type::shallow_history stores_shallow_history;

    typedef mpl::bool_< ( historyMode & has_deep_history ) != 0 >
      deep_history;
    typedef typename mpl::or_<
      deep_history, 
      typename context_type::inherited_deep_history
    >::type inherited_deep_history;
    typedef typename mpl::and_<
      inherited_deep_history,
      mpl::empty< inner_initial_list > >::type stores_deep_history;

    void * operator new( std::size_t size )
    {
      return detail::allocate< MostDerived,
        typename outermost_context_type::allocator_type >( size );
    }

    void operator delete( void * pState )
    {
      detail::deallocate< MostDerived,
        typename outermost_context_type::allocator_type >( pState );
    }

    outermost_context_base_type & outermost_context_base()
    {
      // This assert fails when an attempt is made to access the state machine
      // from a constructor of a state that is *not* a subtype of state<>.
      // To correct this, derive from state<> instead of simple_state<>.
      BOOST_ASSERT( get_pointer( pContext_ ) != 0 );
      return pContext_->outermost_context_base();
    }

    const outermost_context_base_type & outermost_context_base() const
    {
      // This assert fails when an attempt is made to access the state machine
      // from a constructor of a state that is *not* a subtype of state<>.
      // To correct this, derive from state<> instead of simple_state<>.
      BOOST_ASSERT( get_pointer( pContext_ ) != 0 );
      return pContext_->outermost_context_base();
    }

    virtual const state_base_type * outer_state_ptr() const
    {
      typedef typename mpl::if_<
        is_same< outermost_context_type, context_type >,
        outer_state_ptr_impl_outermost,
        outer_state_ptr_impl_non_outermost
      >::type impl;
      return impl::outer_state_ptr_impl( *this );
    }

    virtual detail::reaction_result react_impl(
      const event_base_type & evt,
      typename rtti_policy_type::id_type eventType )
    {
      typedef typename detail::make_list<
        typename MostDerived::reactions >::type reaction_list;
      detail::reaction_result reactionResult =
        local_react< reaction_list >( evt, eventType );

      // At this point we can only safely access pContext_ if the handler did
      // not return do_discard_event!
      switch ( reactionResult )
      {
        case detail::do_forward_event:
          // TODO: The following call to react_impl of our outer state should
          // be made with a context_type:: prefix to call directly instead of
          // virtually. For some reason the compiler complains...
          reactionResult = pContext_->react_impl( evt, eventType );
          break;
        case detail::do_defer_event:
          outermost_context_base().defer_event( evt, this );
          break;
        default:
          break;
      }

      return reactionResult;
    }

    virtual void exit_impl(
      typename base_type::direct_state_base_ptr_type & pSelf,
      typename state_base_type::node_state_base_ptr_type &
        pOutermostUnstableState,
      bool performFullExit )
    {
      inner_context_ptr_type pMostDerivedSelf =
        polymorphic_downcast< MostDerived * >( this );
      pSelf = 0;
      exit_impl( pMostDerivedSelf, pOutermostUnstableState, performFullExit );
    }

    void exit_impl(
      inner_context_ptr_type & pSelf,
      typename state_base_type::node_state_base_ptr_type &
        pOutermostUnstableState,
      bool performFullExit )
    {
      switch ( this->ref_count() )
      {
        case 2:
          if ( get_pointer( pOutermostUnstableState ) ==
            static_cast< state_base_type * >( this ) )
          {
            pContext_->set_outermost_unstable_state(
              pOutermostUnstableState );
            // fall through to next case intended
          }
          else
          {
            break;
          }
        case 1:
        {
          if ( get_pointer( pOutermostUnstableState ) == 0 )
          {
            pContext_->set_outermost_unstable_state(
              pOutermostUnstableState );
          }

          if ( performFullExit )
          {
            pSelf->exit();
            check_store_shallow_history< stores_shallow_history >();
            check_store_deep_history< stores_deep_history >();
          }

          context_ptr_type pContext = pContext_;
          pSelf = 0;
          pContext->exit_impl(
            pContext, pOutermostUnstableState, performFullExit );
          break;
        }
        default:
          break;
      }
    }

    void set_outermost_unstable_state(
      typename state_base_type::node_state_base_ptr_type &
        pOutermostUnstableState )
    {
      pOutermostUnstableState = this;
    }

    template< class OtherContext >
    const typename OtherContext::inner_context_ptr_type & context_ptr() const
    {
      typedef typename mpl::if_<
        is_same< OtherContext, context_type >,
        context_ptr_impl_my_context,
        context_ptr_impl_other_context
      >::type impl;

      return impl::template context_ptr_impl< OtherContext >( *this );
    }

    static void initial_deep_construct(
      outermost_context_base_type & outermostContextBase )
    {
      deep_construct( &outermostContextBase, outermostContextBase );
    }

    static void deep_construct(
      const context_ptr_type & pContext,
      outermost_context_base_type & outermostContextBase )
    {
      const inner_context_ptr_type pInnerContext(
        shallow_construct( pContext, outermostContextBase ) );
      deep_construct_inner< inner_initial_list >(
        pInnerContext, outermostContextBase );
    }

    static inner_context_ptr_type shallow_construct(
      const context_ptr_type & pContext,
      outermost_context_base_type & outermostContextBase )
    {
      const inner_context_ptr_type pInnerContext( new MostDerived );
      pInnerContext->set_context( pContext );
      outermostContextBase.add( pInnerContext );
      return pInnerContext;
    }

    void set_context( const context_ptr_type & pContext )
    {
      BOOST_ASSERT( get_pointer( pContext ) != 0 );
      pContext_ = pContext;
      base_type::set_context(
        orthogonal_position::value, get_pointer( pContext ) );
    }

    template< class InnerList >
    static void deep_construct_inner(
      const inner_context_ptr_type & pInnerContext,
      outermost_context_base_type & outermostContextBase )
    {
      typedef typename mpl::if_<
        mpl::empty< InnerList >,
        deep_construct_inner_impl_empty,
        deep_construct_inner_impl_non_empty
      >::type impl;
      impl::template deep_construct_inner_impl< InnerList >(
        pInnerContext, outermostContextBase );
    }

    template< class LeafState >
    void store_deep_history_impl()
    {
      detail::deep_history_storer<
        context_type::inherited_deep_history::value,
        context_type::deep_history::value
      >::template store_deep_history< MostDerived, LeafState >(
        *pContext_ );
    }

  private:
    //////////////////////////////////////////////////////////////////////////
    struct context_ptr_impl_other_context
    {
      template< class OtherContext, class State >
      static const typename OtherContext::inner_context_ptr_type &
      context_ptr_impl( const State & stt )
      {
        // This assert fails when an attempt is made to access an outer 
        // context from a constructor of a state that is *not* a subtype of
        // state<>. To correct this, derive from state<> instead of
        // simple_state<>.
        BOOST_ASSERT( get_pointer( stt.pContext_ ) != 0 );
        return stt.pContext_->template context_ptr< OtherContext >();
      }
    };
    friend struct context_ptr_impl_other_context;

    struct context_ptr_impl_my_context
    {
      template< class OtherContext, class State >
      static const typename OtherContext::inner_context_ptr_type &
      context_ptr_impl( const State & stt )
      {
        // This assert fails when an attempt is made to access an outer 
        // context from a constructor of a state that is *not* a subtype of
        // state<>. To correct this, derive from state<> instead of
        // simple_state<>.
        BOOST_ASSERT( get_pointer( stt.pContext_ ) != 0 );
        return stt.pContext_;