Macro CHECK_NUMBER?

[Pavel Janík]

Hi,

in lisp.h we have:

#define CHECK_NUMBER(x, i) \
  do { if (!INTEGERP ((x))) x = wrong_type_argument (Qintegerp, (x)); } while 
(0)

What is the purpose of having two arguments? What is the meaning of i?
Things like this should IMHO: a. be commented or b. not be present in the
sources (or c. I should buy new glasses).

Thanks for the explanation.
-- 
Pavel Janík

die_if_kernel("Whee... Hello Mr. Penguin", current->tss.kregs);
                  -- 2.2.16 arch/sparc/kernel/traps.c