Re: discriminants and tagged types

Re: discriminants and tagged types

[Tucker Taft]

Bob Fletcher (bob@radge.globalnet.co.uk) wrote:

: Is there a restriction on using descriminants in tagged types in Ada 95? 

One restriction is that you cannot give defaults for the
discriminants, so their value needs to be specified when an
object is created.  Also, when you extend a tagged type, you
must inherit the discriminants, or completely replace them with
a new set.

: ... I
: know it can't be done in the GNAT compiler, it spits out an error, but my
: girlfriend swears blind that the CASE tool they are using on the project
: she's working on has produced a tagged type with a discriminant. I warned
: her that I'm pretty sure this won't work, but maybe it's a compiler issue,
: although I can't imagine it would be.

: Bob Fletcher
: <A HREF="mailto:bob@radge.globalnet.co.uk"></A>

--
-Tucker Taft   stt@inmet.com   http://www.inmet.com/~stt/
Intermetrics, Inc.  Burlington, MA  USA

Re: discriminants and tagged types

[Robert I. Eachus]

In article <01bdd676$82f6cfa0$f330ea9e@ukp03332> "Bob Fletcher" <bob@radge.globalnet.co.uk> writes:

 > Is there a restriction on using descriminants in tagged types in Ada 95?

   Yes, you cannot provide defaults for discriminants of a tagged
type. (RM 3.7(11))

 > I know it can't be done in the GNAT compiler, it spits out an error...

   What can't be done?  It could be you are violating 3.7(11) or some
other rule, but I'd have to see the code.
--

					Robert I. Eachus

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