How do I use futures in C++?

How do I use futures in C++?

In C++, futures are part of the standard library and allow you to retrieve values from asynchronous operations. You can use std::async to run a function asynchronously and get a future object.

Can you show me a simple example?

Sure! Here's a basic example:

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

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

int main() {
    std::future<int> result = std::async(asyncFunction);
    std::cout << "Waiting for result..." << std::endl;
    std::cout << "Result: " << result.get() << std::endl;
    return 0;
}

What happens if the asynchronous function throws an exception?

If the asynchronous function throws an exception, calling get() on the future will rethrow that exception. You can handle it using a try-catch block.

Are there any limitations to using futures?

Yes, futures can only be used once. After calling get(), the future is no longer valid. Also, they can introduce overhead due to thread management.