C++ has a built in swap function

// swap algorithm example
#include <iostream>
#include <algorithm>
using namespace std;

typedef struct newtypet {
double a, b;
} newtypet;

newtypet old, neww;


int main () {

old.a = 10;
old.b = 20;
neww.a = 1;
neww.b = 2;
cout << old.a << endl;
cout << old.b << endl;
cout << neww.a << endl;
cout << neww.b << endl;
swap(old, neww);
cout << endl;
cout << old.a << endl;
cout << old.b << endl;
cout << neww.a << endl;
cout << neww.b << endl;
return 0;
}