||Bitwise exclusive or assignment operator
assignment-expr := logical-or-expr ^= assignment-expr |
logical-or-expr xor_eq assignment-expr
The xor_eq operator is an assignment operator that
performs bitwise exclusive or. It is equivalent
to logical-or-expr =
assignment-expr, except that
logical-or-expr is evaluated only once.
The keyword xor_eq is interchangeable with the
unsigned bitmask = 0xFFF0;
bitmask ^= 0x0F12; // bitmask becomes 0xF0E2.
or_eq, xor, Chapter 3, <ciso646>