C++ pass function as argument
阿新 • • 發佈:2021-12-08
void retrieveTime5(char *dtValue); void showTime6(); void passFunc(void(*funcName)()); int main() { passFunc(&showTime6); return 0; } void passFunc(void(*funcName)()) { chrono::time_point<chrono::system_clock> startTime; chrono::time_point<chrono::system_clock> endTime; startTime=chrono::system_clock::now(); printf("Started in passFunc!\n"); (*funcName)(); endTime=chrono::system_clock::now(); printf("Ended in passFunc!\n"); cout<<"Time cost:" <<chrono::duration_cast<chrono::seconds>(endTime-startTime).count()<<" seconds," <<chrono::duration_cast<chrono::milliseconds>(endTime-startTime).count()<<"milliseconds," <<chrono::duration_cast<chrono::microseconds>(endTime-startTime).count()<<" microseconds," <<chrono::duration_cast<chrono::nanoseconds>(endTime-startTime).count()<<" nanoseconds."<<endl; } void showTime6() { char *dtValue=(char*)malloc(20); for(int i=0;i<10;i++) { retrieveTime5(dtValue); printf("Index=%d,value=%s\n",i,dtValue); sleep(1); } free(dtValue); } void retrieveTime5(char *dtValue) { time_t rawTime = time(NULL); struct tm tmInfo = *localtime(&rawTime); strftime(dtValue, 20, "%Y%m%d%H%M%S", &tmInfo); }
Declare
void passFunc(void(*funcName)());
Implement
void passFunc(void(*funcName)()) { (*funcName)(); }
Invoke
int main() { passFunc(&showTime6); return 0; }