How do I handle errors in C++ asynchronous programming?

How do I handle errors in C++ asynchronous programming?

In C++, you can handle errors in asynchronous programming using futures and exceptions. When a future is set to an asynchronous task, you can catch exceptions thrown during the task execution.

Can you show me a code example?

Sure! Here's a simple example:

#include <future>
#include <iostream>
#include <stdexcept>

int asyncTask() {
    throw std::runtime_error("Error occurred!");
}

int main() {
    std::future<int> result = std::async(asyncTask);
    try {
        result.get(); // This will throw the exception
    } catch (const std::exception& e) {
        std::cout << "Caught an exception: " << e.what() << std::endl;
    }
    return 0;
}

What if I want to handle multiple asynchronous tasks?

You can use std::when_all to wait for multiple futures and handle exceptions for each task individually. Here's an example:

#include <future>
#include <iostream>
#include <vector>

int asyncTask(int id) {
    if (id % 2 == 0) throw std::runtime_error("Error in task " + std::to_string(id));
    return id;
}

int main() {
    std::vector<std::future<int>> futures;
    for (int i = 0; i < 5; ++i) {
        futures.push_back(std::async(asyncTask, i));
    }
    for (auto& fut : futures) {
        try {
            std::cout << "Result: " << fut.get() << std::endl;
        } catch (const std::exception& e) {
            std::cout << "Caught an exception: " << e.what() << std::endl;
        }
    }
    return 0;
}