Number Swapper

eligundry_number_swapper.cpp

#include <iostream>

using namespace std;

/*
 * Basically, this code right here will swap the
 * values of two variables. I was able to do it
 * in one line, which my professor said should be
 * impossible.
 */

int main()
{
    double a, b;

    cout << "Let's swap two numbers, a & b" << endl;
    cout << "a = ";
    cin >> a;
    cout << "b = ";
    cin >> b;

    // Swap
    cout << "Swap!" << endl;

    /*
     * This how Nick showed us to do it.
     * b += a;
     * a = b - a;
     * b -= a;
     */

    /*
     * This is my way, in two lines, note the comma
     * b += a;
     * b -= a = b - a;
     */

    // And here's my one line solution
    // b -= ((b += a), a = b - a);

    // And here's Stephen Walentik's awesome solution
    b = (a + b) - (a = b);

    cout << "a == " << a << endl;
    cout << "b == " << b << endl;

    return 0;
}

I really like this: b = (a + b) - (a = b);
I think that's clever.