The Stopwatch package provides ways to measure intervals of program
  execution time. The package consists of a single class, Stopwatch.
  Typically, you use this class during the performance-tuning phase of
  program development.

  Objects of the Stopwatch class measure program execution time and
  return the result in floating-point seconds.  The class includes the
  start, stop, and reset functions familiar to users of a mechanical
  stopwatch.

  You can time the entire program or select certain portions of the
  program to time; for example, a specified loop or program module.  You
  can create a different Stopwatch object for each independent program
  activity, and name each according to the activity you intend to
  measure.

  Header:

 	#include <stopwatch.hxx>