Swap 2 variables without using a temp variable

Swap two variable contents without using a temp variable

Standard approach:
 a=a+b,
 b=a-b,
 a=a-b


XOR algorithm bitwise operators:
 a=a^b,
 b=a^b,
a=a^b.

How does XOR works ?
true - true = false
true- false = true
false- false = false
false-true = true

Wiki for XOR swap algorithm:
http://en.wikipedia.org/wiki/XOR_swap_algorithm