Macros Pitfalls
Operator Precedence Errors: SQR(a + b); is expanded to: a + b*a + b and not: (a + b)*(a + b) Solution : Put parentheses (or braces) around Macro #define SQR(x) ((x) * (x))
Side Effects Errors: SQR(i++); expanded to: i++ * i++ which increments i twice.
Unnecessary Function Calls: SQR(long_function(a,b,c)); will evaluate the function twice.
There are no general solutions for the last two errors - so be cautious and wise !