use function pointer as parameter

//here is a simple demo:

#include <iostream>

using namespace std;

void fun(void (*p_fun)());//attention: here '(*p_fun)' ,the parentheres cannot be omitted

                                       //this means 'p_fun' is a function pointer
void fun1();
void fun2();
int main() {
    fun(fun1);
    fun(fun2);
    return 0;
}

void fun1(void) {
    cout<<"this is fun1!"<<endl;
}

void fun2(void) {
    cout<<"this is fun2!"<<endl;
}

void fun(void (*p_fun)()) {
    (*p_fun)();
}