[Boost-users] [statechart] Working with state history - compilation errors

6 Sep 2005

      I'm playing with the statechart library, in conjunction with Boost 1.33 
and VC 7.1.  I'm having trouble using the state history functionality; I 
can't get it to compile, even taking into account the useful static 
assertions that ought to be helping me.  Can someone suggest what I might 
be missing?

Here's a boiled down sample: there are 2 top-level states, StateA and 
StateB.  Event2 transitions between them.  When in StateA, Event1 
transitions between 2 sub-states, StateA1 and StateA2.  When transitioning 
from StateB to StateA, I want to use StateA's history to determine which 
of StateA1 and Stae2 become active.  From reading the tutorial, 
references, and sample code, it looks like this should work:
////////////////////////////////////////////////////////////////////
#include <boost/statechart/event.hpp>
#include <boost/statechart/state_machine.hpp>
#include <boost/statechart/simple_state.hpp>
#include <boost/statechart/transition.hpp>
#include <boost/statechart/shallow_history.hpp>

namespace sc = boost::statechart;

//Events
struct Event1 : sc::event<Event1> {};
struct Event2 : sc::event<Event2> {};

//States
struct StateA;
    struct StateA1;
    struct StateA2;
struct StateB;

struct SCTest : sc::state_machine<SCTest, StateA> {};

struct StateA : sc::simple_state<StateA, SCTest, StateA1, 
sc::has_shallow_history> 
{
    typedef sc::transition<Event2, StateB > reactions;
};

struct StateB : sc::simple_state<StateB, SCTest> 
{
    typedef sc::transition<Event2, sc::shallow_history<StateA> > 
reactions;
};

struct StateA1 : sc::simple_state<StateA1, StateA> 
{
    typedef sc::transition<Event1, StateA2> reactions;
};

struct StateA2 : sc::simple_state<StateA2, StateA> 
{
    typedef sc::transition<Event1, StateA1> reactions;
};

int main(int argc, char* argv[]) 
{
    SCTest test;
    return 0;
}

This gives me the following error:
c:\boost\boost\statechart\shallow_history.hpp(34) : error C2027: use of 
undefined type 'boost::STATIC_ASSERTION_FAILURE<x>'
        with
        [
            x=false
        ]
<snip>
        [
            DefaultState=StateA
        ]

etc., and comments at that point in the statechart source direct me to:
"...pass either statechart::has_deep_history or 
statechart::has_full_history as the last parameter of DefaultState's 
context."

This doesn't seem to help, though.  If I use has_deep_history or 
has_full_history in StateA's definition, the errors do not go away.

Any help would be greatly appreciated!

--------------------------------
John Wismar
john.wismar@autozone.com

[Boost-users] [statechart] Working with state history - compilation errors

john.wismar＠autozone.com