#define str(s)		# s
#define xstr(s)		str(s)
#define debug(s, t)	printf("x" # s "= %d, x" # t "= %s", \
			       x ## s, x ## t)
#define INCFILE(n)	vers ## n	// Comment
#define glue(a,b)	a ## b
#define xglue(a,b)	glue(a,b)
#define HIGHLOW		"hello"
#define LOW		LOW ", world"

debug (1, 2);
fputs (str (strncmp("abc\0d", "abc", '\4') // Comment
	    == 0) str (: @\n), s);
glue (HIGH, LOW);
xglue (HIGH, LOW);