+/* Optional flags to influence mbswidth/mbsnwidth behavior. */
+
+/* If this bit is set, assume invalid characters have width 0.
+ Otherwise, return -1 upon finding an invalid or incomplete character. */
+#define MBSW_ACCEPT_INVALID 1
+
+/* If this bit is set, assume unprintable characters have width 1.
+ Otherwise, return -1 upon finding a non-printable character. */
+#define MBSW_ACCEPT_UNPRINTABLE 2
+
+/* Returns the number of screen columns needed for STRING. */
+#define mbswidth gnu_mbswidth /* avoid clash with UnixWare 7.1.1 function */
+extern int mbswidth PARAMS ((const char *string, int flags));
+
+/* Returns the number of screen columns needed for the NBYTES bytes
+ starting at BUF. */
+extern int mbsnwidth PARAMS ((const char *buf, size_t nbytes, int flags));