Modern C++ Programming Cookbook

Getting ready

We will use futures, so read the previous recipe to get a quick overview of how they work. Both async() and future are available in the std namespace in the <future> header. 

For the examples in this recipe, we will use the following functions:

    void do_something()    {      // simulate long running operation      {        using namespace std::chrono_literals;        std::this_thread::sleep_for(2s);      }       std::lock_guard<std::mutex> lock(g_mutex);      std::cout << "operation 1 done" << std::endl;     }    void do_something_else()    {      // simulate long running operation      {        using namespace std::chrono_literals;        std::this_thread::sleep_for(1s);      }       std::lock_guard<std::mutex> lock(g_mutex);      std::cout << "operation 2 done" << std::endl;     }    int compute_something()    { // simulate ...