Return the number of fractional seconds that it takes to evaluate action.

Measure the number of fractional seconds that it takes to evaluate action, and print msg postfixed with the measured time in millisecond resolution.

Return a high-resolution time stamp in fractional SI seconds. The duration is guaranteed to be monotonically increasing and have at least millisecond resolution.

Return the smallest time difference in seconds that ticksstd/time/timer/ticks: () -> ndet duration can measure.