How do I handle errors in async C++ code?

How do I handle errors in async C++ code?

In async C++, you can handle errors using try-catch blocks or by checking the status of futures. Would you like an example?

Yes, please provide an example of using futures.

Sure! You can use std::async to run a function asynchronously and then check the future for exceptions like this:

#include <future>
#include <iostream>

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

int main() {
    auto future = std::async(std::launch::async, riskyFunction);
    try {
        future.get(); // This will throw if riskyFunction throws
    } catch (const std::exception& e) {
        std::cout << "Caught an exception: " << e.what() << std::endl;
    }
}

What if I want to handle multiple async tasks?

You can use std::when_all or std::when_any from the future library to wait for multiple futures and handle their results or exceptions accordingly.

Can you explain how std::when_all works?

Certainly! std::when_all takes a collection of futures and returns a new future that becomes ready when all the input futures are ready. You can then check for exceptions from each future.