swap() using pass by pointer

#include <iostream>using namespace std;void swap(int *p1, int *p2);int main(){    cout << "Enter 2 integers: ";    int v1, v2;    cin >> v1 >> v2;    cout << "v1 == " << v1 << ", v2 == " << v2 << endl;    swap(&v1, &v2);    cout << "after swap:" << endl;    cout << "v1 == " << v1 << ", v2 == " << v2 << endl;    return 0;}void swap(int *p1, int *p2){    int temp = *p1;    *p1 = *p2;    *p2 = temp;}