The Function template std::async runs the operate file asynchronously (perhaps in a separate thread which might become a Element of a thread pool) and returns a std::future which will finally keep the results of that functionality connect with. one) Behaves just as if (two) is called with policy being std::launch::async https://alphawireless.com/future-proofing-american-utilities-why-900-mhz-is-critical-for-utility-communications/