-char *offtostr (off_t, char *);
-char *imaxtostr (intmax_t, char *);
-char *umaxtostr (uintmax_t, char *);
+char *imaxtostr (intmax_t, char *) __attribute_warn_unused_result__;
+char *inttostr (int, char *) __attribute_warn_unused_result__;
+char *offtostr (off_t, char *) __attribute_warn_unused_result__;
+char *uinttostr (unsigned int, char *) __attribute_warn_unused_result__;
+char *umaxtostr (uintmax_t, char *) __attribute_warn_unused_result__;