using namespace std;
#include <iostream>

/* Calling directly, by reference and as pointers (by address), and
also using templates ... lots of examples of swap methods. */

void swapper1(int left, int right) {
        // This one WILL NOT WORK. It pointelessy swaps copied of variables.
        int holder = left;
        left = right;
        right = holder;
        }

void swapper2(int& left, int& right) {
        // references - left and right are aliases to the main variables
        int holder = left;
        left = right;
        right = holder;
        }

void swapper3(int * left, int * right) {
        // Call by address - swap over what is at the addresses
        int holder = *left;
        *left = *right;
        *right = holder;
        }

template <typename SORTOF>
void anyswap(SORTOF& left, SORTOF& right) {
        // Reference again - this example also templated
        SORTOF holder = left;
        left = right;
        right = holder;
        }

int main() {

        int r = 15;
        int s = 26;

        swapper1(r,s);
        cout << r << " " << s << endl;
        // no swap - just mucked about with copies!

        swapper2(r,s);
        cout << r << " " << s << endl;
        // swapped - used references

        swapper3(&r,&s);
        cout << r << " " << s << endl;
        // swapped back - used pointers

        anyswap(r,s);
        cout << r << " " << s << endl;
        // swapped again - template and references

        float boat = 23.7;
        float duck = 45.3;
        anyswap(boat,duck);
        cout << boat << " " << duck << endl;

}

/* Sample Output

munchkin:cppn11 grahamellis$ ./clever
15 26
26 15
15 26
26 15
45.3 23.7
munchkin:cppn11 grahamellis$

*/