How do exceptions work with std::async in C++?

Can you explain how exceptions are handled with std::async in C++?

Sure! When using std::async, if an exception is thrown in the asynchronous task, it will be captured and can be retrieved using the future object.

What happens if I don't call get() on the future?

If you don't call get() on the future, the exception will not be rethrown, and it will lead to a call to std::terminate when the future is destroyed.

Is there a way to check if an exception occurred without calling get()?

Yes, you can use the wait_for() or wait() methods to check if the task is done, but you still need to call get() to access the exception.

Can you give an example of handling exceptions with std::async?

Certainly! Here's a simple example:

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

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

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