How do I handle errors in C++ std::async?

How do I handle errors in C++ std::async?

In C++, you can handle errors in std::async by using std::future to retrieve the result and check for exceptions.

Can you show me a code example?

Sure! Here's a simple example:

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

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

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

What happens if I don't catch the exception?

If you don't catch the exception, it will propagate and terminate the program, leading to an unhandled exception error.

Are there any best practices for using std::async?

Yes, it's best to avoid using std::async for long-running tasks, prefer std::thread for more control, and always handle exceptions.