RAW POWER OF ITERATIVE LOOP

Bask in the glory of such genius:
http://dis.4chan.org/read/prog/1323226650/65

here is a slower version,which handles the problem of people abusing the macro.
int c,*temp;
#define fact(x) ;for(temp=&x,c=*temp-1;c;c--)*temp*=c;
main(){
int x=5;fact(x);
printf("%d",x);
}