c++boostboost-statechart

Using Boost statechart, how can I transition to a state unconditionally?


I have a state A that I would like to transition to its next state B unconditionally, once the constructor of A has completed. Is this possible?

I tried posting an event from the constructor, which does not work, even though it compiles. Thanks.

Edit: Here is what I've tried so far:

struct A : sc::simple_state< A, Active >
{
    public:
        typedef sc::custom_reaction< EventDoneA > reactions;
        A()
        {
            std::cout << "Inside of A()" << std::endl;
            post_event( EventDoneA() );
        }

        sc::result react( const EventDoneA & )
        {
            return transit< B >();
        }
};

This yields the following runtime assertion failure:

Assertion failed: get_pointer( pContext_ ) != 0, file /includ
e/boost/statechart/simple_state.hpp, line 459

Solution

  • I've updated my OP with my solution, here it is so I can close the question.

    The problem is that you cannot inherit from simple_state to achieve the desired transition, you must inherit from state, which then requires that you modify the constructor accordingly.

    struct A : sc::state< A, Active >
    {
        public:
            typedef sc::custom_reaction< EventDoneA > reactions;
            A( my_context ctx ) : my_base( ctx )
            {
                std::cout << "Inside of A()" << std::endl;
                post_event( EventDoneA() );
            }
    
            sc::result react( const EventDoneA & )
            {
                return transit< B >();
            }
    };