+extern int utf16_to_utf8(const char *utf16_str, size_t utf16_nbytes,
+ char **utf8_str_ret, size_t *utf8_nbytes_ret);
+
+extern int utf8_to_utf16(const char *utf8_str, size_t utf8_nbytes,
+ char **utf16_str_ret, size_t *utf16_nbytes_ret);
+
+/* util.c */