-const char *case_str (const struct ccase *, const struct variable *);
-const char *case_str_idx (const struct ccase *, size_t idx);
+const uint8_t *case_str (const struct ccase *, const struct variable *);
+const uint8_t *case_str_idx (const struct ccase *, size_t idx);
+uint8_t *case_str_rw (struct ccase *, const struct variable *);
+uint8_t *case_str_rw_idx (struct ccase *, size_t idx);