C++ pass function as argument

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;
}

标签：function,count,passFunc,void,argument,C++,funcName,startTime,endTime
来源： https://www.cnblogs.com/Fred1987/p/15660898.html