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

john.wismar@autozone.com wrote:

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 #include #include #include #include

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 {};

struct StateA : sc::simple_state { typedef sc::transition reactions; };

struct StateB : sc::simple_state { typedef sc::transition reactions; };

struct StateA1 : sc::simple_state { typedef sc::transition reactions; };

struct StateA2 : sc::simple_state { typedef sc::transition 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!

I'm still using boost::fsm, but if the history mechanism hasn't changed in the transition to boost:statechart then I believe you need to change: struct StateB : sc::simple_state { typedef sc::transition reactions; }; to say: struct StateB : sc::simple_state { typedef sc::transition reactions; }; cheers, mick