Here’s a generalized function that will implement any function that
takes two Boolean operands and returns a Boolean result. There are 16
possible such functions, and they are selected according to a mask
which defines the truth table:

bool bitmask_op
(
bool a,
bool b,
unsigned int mask
)
{
return
not a and not b and (mask & 1) != 0
or
not a and b and (mask & 2) != 0
or
a and not b and (mask & 4) != 0
or
a and b and (mask & 8) != 0;
} /*bitmask_op*/

Meanings of some mask values:

mask meaning
0 always false
1 nor
3 not-a (ignore b)
5 not-b (ignore a)
6 exclusive-or
7 nand
8 and
10 b (ignore a)
11 a implies b
12 a (ignore b)
13 b implies a
14 inclusive-or
15 always true