[Boost-users] [boost-users][bind, signal] how to

From: Igor R (boost.lists_at_[hidden])
Date: 2008-07-16 14:18:15

Hello,

I've got the following design: several functors ("Tasks"), when
executed, "delegate" to a shared Processor object that performs some
coordination between the tasks. The Processor runs the tasks at some
stage, and wants to be notified by the task when it's over.
However, I wouldn't like them to "know" each other. I even wouldn't
like the Processor making assumptions about exact Task's "connection
point" signature/name.
For this purpose I want the Task to pass its "connection point" as a
generic functor - so that the Processor would execute it to subscribe.
However, I haven't managed to bind signal::connect. I'd appreciate any
idea about what's wrong in the following schematic code:
(In the real code the life-time of the objects is managed by means of
shared/weak pointers, which are omitted here for the sake of
simplicity!)

//task.hpp
class Task
{
public:
  typedef signal<void (void)> CompletionEvent;
  void operator ()()
  {
    // forward the execution to the processor;
    (*processor)(bind(&Task::run, this),
      bind(&CompetionEvent::connect, &done_, _1)); // this bind dosen't compile!
  }
private:
  void run();

  Processor *processor_;
  signal<void(void)> done_;
};

// processor.hpp
class Processor
{
public:
  void operator ()(boost::function<void(void)> task,
    boost::function<void(boost::function<void(void)>)> completionNotifier)
  {
    // this way I'd like to call
signal::connect(bind(&Processor::taskDone, this));
    completionNotifier(bind(&Processor::taskDone, this));
  }
private:
  void taskDone();
};

Thank you!