[Boost-users] Problem compiling a statemachine with "class" instead of "struct"

10 Feb 2009

      Hi folks,

we have run into an interesting problem when compiling
one of our state machines using the boost state chart templates.

If we instantiate a state like this:

struct Active : public boost::statechart::simple_state< Active,  
PRX5StateMachine >
{
	public:
		Active() : m_data("") {}
		~Active() {}

		std::string & Data() { return m_data;}

		const std::string& Data() const	{ return m_data; }

	private:
		std::string m_data;
};

and use it in our code, everything compiles fine. As soon as we
change the declaration to

	class Active : public boost::statechart::simple_state< Active,  
PRX5StateMachine >

we get massive compiler errors, which look like this:

/usr/include/boost/statechart/simple_state.hpp:832: error: within this  
context
/usr/include/boost/statechart/state_machine.hpp:243: error: ‘typedef  
struct boost::statechart::detail::rtti_policy  
boost::statechart::state_machine<PRX5StateMachine, Active,  
std::allocator<void>,  
boost::statechart::null_exception_translator>::rtti_policy_type’ is  
inaccessible

Is it mandatory to inherit from simple_state via a struct and not from  
a class?

Thanks for any inputs on this. On request I post two source  
directories which
show the problem.

Cheers,

Rudi

[Boost-users] Problem compiling a statemachine with "class" instead of "struct"

Rudolf Leitgeb