fprintf(stderr,"default etl::clock precision: %0.8f\n",etl::clock::precision());
fprintf(stderr,"realtime etl::clock precision: %0.8f\n",etl::clock_realtime::precision());
fprintf(stderr,"proctime etl::clock precision: %0.8f\n",etl::clock_proctime::precision());
fprintf(stderr,"default etl::clock precision: %0.8f\n",etl::clock::precision());
fprintf(stderr,"realtime etl::clock precision: %0.8f\n",etl::clock_realtime::precision());
fprintf(stderr,"proctime etl::clock precision: %0.8f\n",etl::clock_proctime::precision());