eclipse出现的问题

1.如果想注释掉某几行代码，可以如下操作：

#if 0////自己写的计时clock_t start;clock_t end;start = clock();cv::Mat localimg = GetFeatureMap(ipm_image, outliers);end = clock();double time_duration= (double)(end-start)/CLOCKS_PER_SEC;//printf("Time is:\n");printf("\n");std::cout<<"The Function GetFeatureMap's TIME:"<<time_duration*1000<<"ms"<<std::endl;#elsedouble start = (double)getTickCount();//printf("start:%d ms\n",int(start*1000));cv::Mat localimg = GetFeatureMap(ipm_image, outliers);double end = (double)getTickCount();//printf("end:%d ms\n",int(end*1000));printf("'Time is:%f\n",((end-start)*1000/getTickFrequency()));#endif