You gave an IOCCC snippet as an example of a C99 coding trick you know? I mean, the code looks visually cool, but it's funny to explain a code concept using code shaped like an anime character. (At least that's what I think it is.)
x*=02//* */2
-1;
With C89, this is evaluated as "x *= 02 / 2 - 1", or "x *= 0".With C99, this is evaluated as "x *= 02 / -1", or "x *= -2".