程序员笔记 （四十三）C++高精度时钟 std::chrono::high_resolution_clock

（一）调用C++高精度时钟 std::chrono::high_resolution_clock

测试usleep()的延时误差

// high_resolution_clock example#include <stdio.h>//#include <iostream>//#include <ctime>//#include <ratio>
#include <chrono>using std::chrono::high_resolution_clock;using std::chrono::duration;using std::chrono::duration_cast;
#include <unistd.h>//usleep(): microsecond-level sleep
int main (){  high_resolution_clock::time_point t1 = high_resolution_clock::now();
  for (int i=0; i<10; ++i) {    usleep(1);  }
  high_resolution_clock::time_point t2 = high_resolution_clock::now();
  duration<double> time_span = duration_cast<duration<double>>(t2 - t1);  printf("It took me %.6F seconds...\n", time_span.count());
  return 0;}

（二）1 小时转换为分钟/秒/毫秒/微秒

#include <iostream>#include <string>#include <chrono>

int main(){  std::chrono::hours hour_time = std::chrono::hours(1);
  std::chrono::minutes minutes_time = std::chrono::duration_cast<std::chrono::minutes>(hour_time);
  std::chrono::seconds seconds_time = std::chrono::duration_cast<std::chrono::seconds>(hour_time);
  std::chrono::milliseconds milliseconds_time = std::chrono::duration_cast<std::chrono::milliseconds>(hour_time);
  std::chrono::microseconds microseconds_time = std::chrono::duration_cast<std::chrono::microseconds>(hour_time);
  std::cout << "1小时可转换为 \n"    << minutes_time.count() << "分钟 \n"    << seconds_time.count() << "秒 \n"    << milliseconds_time.count() << "毫秒 \n"    << microseconds_time.count() << "微秒" << std::endl;
  getchar();  return 0;}