Question

#define MAX 7
#define BUFFER 16
#define MODULO 8

typedef struct {
int x;
} BLAH;

if I have:

  checkWindow(BLAH *b) {  
  int mod;   
  mod = b.MODULO; 
  }

Specifically can I access MODULO from the BLAH structure?

Answer 1

I think you misunderstand the meaning of preprocessor definitions. #define-d items only look like variables, but they are not variables in the classical sense of the word: they are text substitutions. They are interpreted by the preprocessor, before the compiler gets to see the text of your program. By the time the preprocessor is done, the text of the program has no references to MAX, BUFFER, or MODULO: their occurrences are substituted with 7, 16, and 8. That is why you cannot access #define-d variables: there are no variables to access.