#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>

//#define times_5(n) n + 5    // WRONG
//#define times_5(n) (n * 5)  // BETTER, but still WRONG
#define times_5(n) ((n) * 5)  // GOOD ★

// RULE:  When writing a #define function-like macro that returns anything:
// ∙ Parenthesize every parameter (i.e., n).
// ∙ Parenthesize the entire RHS expression.

int main(int argc, char* argv[]) {
    int n = times_5(5 + 100);  // expect 525
    // After preprocessor, this line ↑ turns to this:
    // int n = ((5 + 100) * 5)
    // … so we will have n == 525 which is correct

    printf("n == %d\n", n);
    
    return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */