Re: when source code isn't enough

[Bill Wendling <wendling@ganymede.isdn.uiuc.edu>]

Also sprach Peter Jay Salzman:
}
} also, i'm wondering if !! is a double negation or something about C which
} i've never learned:
} 
} #define input_report_key(a,b,c) input_event(a, EV_KEY, b, !!(c))
} 
} if it's a double negation, what possible purpose could it serve?
} 
It returns either 0 or 1 depending on whether c is 0 or not. It can be
used for a number of things...For instance, if input_event takes a
"short or char" but c is something longer (an int or long), then it's
possible for the value of c to lose information if it's packed down into
something smaller (i.e., int c == 256 which is 0 when you cast it to a char,
so you get a false negative).

-- 
|| Bill Wendling			wendling@ganymede.isdn.uiuc.edu
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