What is std::async?

std::async is a function template in C++ introduced by the C++ standard in the <future> header as part of the thread support library from C++11. It is used to run a function asynchronously, allowing the main thread (or other threads) to continue running concurrently.

In summary, std::async is a powerful tool for asynchronous programming in C++, making it easier to run tasks in parallel and manage their results efficiently.

Launching an asynchronous task

To execute a function asynchronously using std::async, we can use the same approaches we used when starting threads in Chapter 3, with the different callable objects.

One approach is using a function pointer:

void func() {
    std::cout << "Using function pointer\n";
}
auto fut1 = std::async(func);

Another approach is using a lambda function:

auto lambda_func = []() {
    std::cout << "Using lambda function\n";
};
auto...