The Function template std::async operates the perform file asynchronously (probably in a very separate thread which could be a Portion of a thread pool) and returns a std::future that could ultimately hold the result of that operate phone. one) Behaves like (two) known as with plan remaining std::start::async std::future referring https://alphawireless.com/future-proofing-american-utilities-why-900-mhz-is-critical-for-utility-communications/