Swap two integers in 'C' programming Without using third variable

While it does have some educational value to show that this is possible, this method has two issues:

• Both a = a + b and a = a - b can cause an overflow.

• I can't imagine many situations where saving a few bytes really makes up for the loss in readability.

It also works with XOR (avoiding the overflow problem):

a = a ^ b
b = a ^ b
a = a ^ b

reduced to one line:

a ^= b ^= a ^= b;