true or false.
Expressions are of the form (var & constant1) == constant2 or
(var | constant1) == constant2, where constant1
and constant2 are incompatible bitmask constants.
Example:
// Incompatible mask: as the last byte in mask is zero,
// something like 0x1200 would be possible, but not 0x1234
if ((mask & 0xFF00) == 0x1234) {...}