a nifty feature for c preprocessor

Robert Dewar dewar@adacore.com
Sun Jan 1 05:42:00 GMT 2012


On 12/31/2011 4:44 AM, R A wrote:
>
> alright, here's another example why eval is a good idea:
>
> #define A           17
> #define B           153
> #define N1          ((A + B)/2)  /* intended was (17 + 153)/2 */
>
> #undef  A
> #define A           230
> #define N2          ((A + B)/2) /* intended was (230 + 153)/2 */

Bad example, this is a misuse of the preprocessor in any case!



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