Over on github I uploaded a more advanced version of the ThreadPool class from the Thread Pool with C++11 entry. It allows to get std::futures as return values of the enqueue method.

Example usage:

    ThreadPool pool(4);
    
    std::future<std::string> str = 
        pool.enqueue<std::string>(
        []()
        {
            return "hello world";
        }
    );
    
    std::future<int> x = 
        pool.enqueue<int>(
        []()
        {
            return 42;
        }
    );
    
    std::cout << str.get() << ' ' 
              << x.get() << std::endl;