What are the differences between async and futures in C++14?

What are the differences between async and futures in C++14?

In C++14, async is a function that runs a task asynchronously and returns a std::future object. The future represents a value that will be available at some point in the future.

Can you explain how to use them in a simple example?

Sure! You can use std::async to run a function asynchronously. For example:

#include <future>
#include <iostream>

int compute() {
    return 42;
}

int main() {
    std::future<int> result = std::async(compute);
    std::cout << "Result: " << result.get() << std::endl;
}

What happens if I call get() on a future before the result is ready?

If you call get() on a std::future before the result is ready, it will block the calling thread until the result is available.

Are there any performance considerations I should be aware of?

Yes, using async can introduce overhead due to thread management. It's important to consider the cost of creating threads versus the benefits of parallel execution.