What are some examples of asynchronous programming in C++?

What are some examples of asynchronous programming in C++?

Asynchronous programming in C++ can be achieved using features like std::async, futures, and promises. Would you like to see a specific example?

Yes, please show me an example using std::async.

Sure! Here's a simple example:

#include <iostream>
#include <future>
#include <chrono>

int asyncTask() {
    std::this_thread::sleep_for(std::chrono::seconds(2));
    return 42;
}

int main() {
    std::future<int> result = std::async(std::launch::async, asyncTask);
    std::cout << "Waiting for result..." << std::endl;
    std::cout << "Result: " << result.get() << std::endl;
}

This code runs asyncTask asynchronously and retrieves the result after waiting.

What if I want to handle exceptions in asynchronous tasks?

You can handle exceptions by using a try-catch block within the asynchronous function. Here's an updated example:

int asyncTask() {
    try {
        // Simulate work
        throw std::runtime_error("Error occurred!");
    } catch (...) {
        return -1; // Indicate an error
    }
}

Then, check the result in the main function to see if an error occurred.

Thanks! Can you explain how futures and promises work?