Re: Dispatch on the result still does not work?

[Adam Beneschan <adam@irvine.com>]

On Jul 12, 1:30 pm, sjw <simon.j.wri...@mac.com> wrote:
> On Jul 12, 6:11 pm, AdaMagica <christoph.gr...@eurocopter.com> wrote:
>
> >   X : T'Class := S'(Value);
> > begin
> >    X := Value; -- Ambiguous?
>
> > You know, I'm not a language lawyer, but after the initialization, X
> > is constrained to the tag with which it was initialized.
>
> > So to me, it should be dispatching as Dmitry expects.
>
> I think GNAT GPL 2009 might just have a problem in this area: this is
> accepted
>
> procedure Q is
>    X : P.T'Class := P.S'(P.Value);
> begin
>    X := P.T'(P.Value);
>
> but this fails
>
> procedure Q is
>    X : P.T'Class := P.T'(P.Value);
> begin
>    X := P.S'(P.Value);
>
> saying 'tag-indeterminate expression must have type "T"(RM 5.2 (6))'

No, that's not a GNAT problem.  The RM paragraph, which GNAT was good
enough to tell you about, specifically says that a tag-indeterminate
expression must have type T in this case.  I kind of think that if a
GNAT error message refers to a specific RM passage, it's probably a
good idea to read that passage before assuming there's a GNAT
problem.....

                               -- Adam