Question

I have he following interface:

template <class T>
class AbstractTask {
public:
    virtual void BindTaskCompleted(AbstractTask<T> &bindedTask)=0;
    virtual void Join(TaskResult<T>)=0;
};

And the following implentation:

template <class T>
class SlaveTask: public AbstractTask<T> {
public:
    typedef boost::function<void(TaskResult<T>)> joinFunction;

    void BindTaskCompleted(AbstractTask<T> &bindedTask)
    {
        /////////////WORK OK//////////////////////////////  
        //bindedTask.Join(result);

        /////////////COMPILATION ERROR/////////////////////
        slaveTaskCompletionFunction=boost::bind(&AbstractTask<T>::Join,bindedTask,result);
    }

     void Join(TaskResult<T> r)
    {
        slaveTaskCompletionFunction(r);
    }

private:
    joinFunction slaveTaskCompletionFunction;
    TaskResult<T> result;

};

I’m trying to bind the virtual Join Method of a AbstractTask implementation to a boost::function with the same signature. boost::bind throws 77 compilation errors and I fail to see why.

I thought at first that boost::bind couldn’t be use with virtual method but this doesn’t seem to be the case:
Virtual function and boost bind strange behavior

Thanks in advance for your help!

Thomas

Answer 1

The problem is you’ve bound all of the arguments, but the boost::function and how you’re using it typedef indicates it wants 1 argument.

Change it to the following.

slaveTaskCompletionFunction=boost::bind(&AbstractTask<T>::Join,&bindedTask,_1);

Edit: Also, you had a slicing problem when you passed in bindedTask by reference. You either have to pass it in by pointer, or use boost::ref; otherwise, boost::bind attempts to make a copy of the AbstractTask<T>, and will end up only copying the interface.