The Function template std::async operates the function f asynchronously (potentially within a separate thread which might be described as a Element of a thread pool) and returns a std::future that can finally keep the results of that functionality contact. 1) Behaves as though (2) is termed with coverage staying std::start::async https://alphawireless.com/future-proofing-american-utilities-why-900-mhz-is-critical-for-utility-communications/