title: How accurate is std::chrono?
body: <p><code>std::chrono</code> advertises that it can report results down to the nanosecond level. On a typical x86_64 Linux or Windows machine, how accurate would one expect this to be? What would be the error bars for a measurement of 10 ns, 10 µs, 10 ms, and 10 s, for example?</p>