Re: enumration using integers?

[Ted Dennison<dennison@telepath.com>]

In article <3AE04917.DF97BEA0@emw.ericsson.se>, Sven Nilsson says...
>
>Ted Dennison wrote:
>> Hmm. I don't see anything in the above that couldn't have been done by making
>> Distance a sybtype of Integer. Are you saying that you just want an integer type
>> with "holes" in it, so that
>> Dist := 2;
>> would raise a Constraint_Error?
>
>Yepp, that sounds about right. I've been looking for something like that
>in Barnes but I couldn't find it... Any clue?

Ahhh. We have had that discussion here before. If I recall, the consensus was
that there isn't a way to do that which would generally be worth the effort. If
its really important to you to detect invalid assignments in the middle, then
make it private and write your own "assign" routine that checks. 

You can write your own operation to happen upon every " := ", but that requires
that the type be derived from the type Ada.Controlled, which means that it has
to be a tagged type declared in a library-level package spec. You'd also have to
create your own "+", "-", "*", ect. For a simple integer, again probably not
worth the effort.

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