typedef unsigned char Extbyte;
+/* ID of coded-charset; legacy Mule has only 128 charsets, but there
+ are no limitation about number of coded-charsets in UTF-2000 or
+ Unicode based implementation. */
+typedef unsigned char Charset_ID;
+
/* To the user, a buffer is made up of characters, declared as follows.
In the non-Mule world, characters and Bufbytes are equivalent.
In the Mule world, a character requires (typically) 1 to 4