C++ Simple Thread Pool

Question

I am trying to implement a simple thread pool in c++ as follows:

class worker {
public:
    worker();
    thread mThread;
private:
    void run();
};

worker::worker() {
    (this->mThread = thread(&worker::run, this)).detach();
}

class threadpool {
public:
    threadpool(int size);
    void addTask();
private:
    vector<worker> workers;
};

But when I add the constructor of threadpool:

threadpool::threadpool(int size) {
    this->workers = vector<worker>(size, worker());
}

I get an "attempting to reference a deleted function" error which as far as I know it means that somewhere in my code I am trying to copy a thread. Is there any way to solve this problem?

Answer 1

Smallest possible change is to:

threadpool::threadpool(int size) {
    this->workers = vector<worker>(size);
}

That said, initialiser lists are sweet.

threadpool::threadpool(int size)
  : workers{size}
{ }

(You should change from int size to size_t or - if you're feeling saintly - vector<worker>::size_type ).

It was the provision of a prototypical worker() object that requested copying, the implicit constructor for which was deleted because you'd provided an explicit default constructor.