What are the differences between async and thread in C++?

What are the differences between async and thread in C++?

In C++, async is used for asynchronous operations, allowing tasks to run in the background without blocking the main thread. Threads, on the other hand, are used for concurrent execution, where multiple threads can run simultaneously.

Can you give me an example of how to use async?

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 about using threads? How does that work?

Using threads in C++ can be done with std::thread. Here's a simple example:

#include <thread>
#include <iostream>

void printMessage() {
    std::cout << "Hello from thread!" << std::endl;
}

int main() {
    std::thread t(printMessage);
    t.join(); // Wait for the thread to finish
}

Which one is better for performance?

It depends on the use case. async is generally easier to use for tasks that can be run in the background, while threads provide more control and can be more efficient for CPU-bound tasks. However, managing threads can be more complex.