Always put parentheses, ( ), around each
constant expression defined by a pre-processor
#define
directive:
#define BOX_SIZE (3 * 10) /* Size of the box in pixels */
Put ( ) around each argument of a parameterized macro:
#define SQUARE(x) ((x) * (x))
Surround macros that contain complete statements with curly braces:
// A fatal error has occurred. Tell user and abort
#define DIE(msg) {printf(msg);exit(8);}
When using the #ifdef/#endif construct for conditional compilation,
put the #define and #undef statements near the top of the program
and comment them.
Whenever possible, use const instead
of #define.
The use of inline functions is
preferred over the use of parameterized macros.
