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Re: [vox-tech] C preprocessor - "soft reference"?
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Re: [vox-tech] C preprocessor - "soft reference"?



On Thu 18 Jan 07,  1:49 PM, Micah Cowan <micah@cowan.name> said:
> On Thu, 2007-01-18 at 13:20 -0800, Micah Cowan wrote:
> 
> > #define CHECK_FOR_NULLITITY(var) \
> > 	if ( (var) == NULL ) \
> > 	{ \
> > 		printf("%s is null.\n", #var); \
> > 		exit(EXIT_FAILURE); \
> > 	}
> 
> Forgot to point out, that since the # stringizing operator produces a
> string literal, you might make things just /slightly/ more efficient by
> taking advantage of C's string literal concatenation:
> 
> #define CHECK_FOR_NULLITITY(var) \
> 	if ( (var) == NULL ) \
> 	{ \
> 		puts( #var " is null." ); \
> 		exit(EXIT_FAILURE); \
> 	}
 
Cool.  I never knew this.  Thanks!

> Also, in real applications you might consider printing that to stderr,
> since that's where most folks expect error logging to happen--and
> especially if you put other, legit text on stdout.
 
Yeah, in the real code I did.  I was actually using cerr (it's C++ code).  I
wrote the email off the top of my head, and I'm not sure why my mind
automatically translated to C.

Many thanks for the good info!  I never saw the stringization operator
before.

Pete

-- 
How VBA rounds a number depends on the number's internal representation.
You cannot always predict how it will round when the rounding digit is 5.
If you want a rounding function that rounds according to predictable rules,
you should write your own.
              -- MSDN, on Microsoft VBA's "stochastic" rounding function

Peter Jay Salzman, email: p@dirac.org web: http://www.dirac.org/p    
PGP Fingerprint: B9F1 6CF3 47C4 7CD8 D33E  70A9 A3B9 1945 67EA 951D
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