How can I use async await in C++?

To use async and await in C++, you can follow a similar approach to what is used in Swift, but with C++'s own syntax and libraries. Here is a brief overview of how you can achieve asynchronous programming in C++:

1. Include the necessary headers:

   #include <future>
   #include <iostream>
   

2. Define an asynchronous function:

   std::future<int> asyncFunction() {
       return std::async(std::launch::async, []() -> int {
           // Simulate a long-running task
           std::this_thread::sleep_for(std::chrono::seconds(2));
           return 42;
       });
   }
   

3. Call the asynchronous function and wait for the result:

   int main() {
       std::future<int> result = asyncFunction();
       std::cout << "Waiting for the result..." << std::endl;
       int value = result.get(); // This will block until the result is ready
       std::cout << "Result: " << value << std::endl;
       return 0;
   }
   

In this example, std::async is used to run a lambda function asynchronously. The std::future object is used to retrieve the result of the asynchronous operation. The get method blocks the calling thread until the result is available.

For more advanced usage, you might want to look into libraries like Boost.Asio or the upcoming C++20 coroutines, which provide more powerful and flexible ways to handle asynchronous operations.

If you are interested in how Swift handles async and await, you can refer to the session A Swift Tour: Explore Swift’s features and design from WWDC 2024, which covers the basics of writing concurrent code in Swift, including tasks, async/await, and actors.