Stringification of a macro value

Posted by SF. on Stack Overflow See other posts from Stack Overflow or by SF.
Published on 2010-04-16T13:25:19Z Indexed on 2010/04/16 13:43 UTC
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concatenation

I faced a problem - I need to use a macro value both as string and as integer.

 #define RECORDS_PER_PAGE 10

 /*... */

 #define REQUEST_RECORDS \
      "SELECT Fields FROM Table WHERE Conditions" \
      " OFFSET %d * " #RECORDS_PER_PAGE \
      " LIMIT " #RECORDS_PER_PAGE ";"

 char result_buffer[RECORDS_PER_PAGE][MAX_RECORD_LEN];

 /* ...and some more uses of RECORDS_PER_PAGE, elsewhere... */

This fails with a message about "stray #", and even if it worked, I guess I'd get the macro names stringified, not the values. Of course I can feed the values to the final method ( "LIMIT %d ", page*RECORDS_PER_PAGE ) but it's neither pretty nor efficient. It's times like this when I wish the preprocessor didn't treat strings in a special way and would process their content just like normal code. For now, I cludged it with #define RECORDS_PER_PAGE_TXT "10" but understandably, I'm not happy about it.

How to get it right?

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