Question

I’m a computer science student. I know “conflicting return type specified” usually means you’re using a function before it’s declared but this one is a little different. Due to strict assignment guidelines, I’m implementing a task scheduler (our own multi-threader) and in one class called Task, in Task.h we have :

void Task::Start(){
    int * returnval = new int;
    *returnval = pthread_create(&thread_id,NULL,tfunc,this);        
    delete returnval;
}

then in another file, schedulable.h, we have:

int Schedulable::Start(){ 
    try{ 
        Task::Start();
        return 0; 
    }catch(int e) { return 1; } 
}

When I compile it, I have a “conflicting return type” error:

In file included from scheduler.H:59, from task_test_step2.cpp:9: schedulable.H:162: error: conflicting return type specified for ‘virtual int Schedulable::Start()’ task.h:157: error: overriding ‘virtual void Task::Start()’

Any ideas how I can get this to stop happening?

Answer 1

The problem is that Schedulable::Start overrides Task::Start and changes the return type from void to int. You probably want to make Task::Start return an int too:

int Task::Start(){
    // no need to use new here!
    int returnval = pthread_create(&thread_id,NULL,tfunc,this);        
    return returnval;
}