int match_int(substring_t *, int *result);
int match_octal(substring_t *, int *result);
int match_hex(substring_t *, int *result);
int match_int(substring_t *, int *result);
int match_octal(substring_t *, int *result);
int match_hex(substring_t *, int *result);
-void match_strcpy(char *, substring_t *);
-char *match_strdup(substring_t *);
+void match_strcpy(char *, const substring_t *);
+char *match_strdup(const substring_t *);