Re: Dispatch on the result still does not work?

[sjw <simon.j.wright@mac.com>]

On Jul 13, 5:55 pm, Adam Beneschan <a...@irvine.com> wrote:
> On Jul 12, 1:30 pm, sjw <simon.j.wri...@mac.com> wrote:

> > 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.....

OK, mea culpa. However .. if I say P.S'(whatever) and the compiler
tells me it's tag-indeterminate my first reaction is that it must be
confused!

If I hadn't been too taken with the symmetry I'd have realised that I
should have written

procedure Q is
   X : P.T'Class := P.T'(P.Value);
begin
   X := P.T'Class (P.S'(P.Value));

(which (I think) is the 'dynamically tagged' alternative in 5.2(6)
which wasn't mentioned by GNAT).