cc65/testcode/compiler/pptest3.c

#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);