Jill Ramonsky asked...
> What guarantee do I have that other Unicode characters will not be
> added in the future which have the property "Hex_Digit"?
You don't have a guarantee of much in the future, except as indicated in
the Unicode stability policies.
Realistically, however, you're probably not going to see the addition of
more hex digits, because all sixteen of them are already represented in the
standard.
> How do I write an algorithm which will convert Unicode hex characters
> to hexadecimal which is guaranteed to work for all future versions
> of Unicode?
Use 0-9, A-F, a-f.
Rick
