Re: Instantiating a generic formal procedure with an access procedure value

[Tucker Taft <stt@averstar.com>]

Jeff Carter wrote:
> 
> In article <3870E3F1.906FDFF4@averstar.com>,
>   Tucker Taft <stt@averstar.com> wrote:
> > Jeff Carter wrote:
> > >    procedure Op (Item : in out Handle; Item : in Integer);
> >
> > I presume you mean ------------------->>> Element : in Integer <<<
> 
> Yes, thanks for pointing out that error.
> 
> > >       procedure Iterate (Action : in Action_Ptr) is
> > >          procedure Local is new S_U.Iterate (Action => ???);
> > >          -- What do I use here?
> >
> > Action.all is the name of a subprogram.  It happens to have
> > convention "protected" but that is irrelevant to a generic
> > formal subprogram, which should accept subprograms of any
> > convention.
> 
> I don't see why it should have convention "protected", since Action_Ptr
> is defined in the spec of package S and the actual procedure pointed to
> by a call to Iterate must be declared at the library level. However,
> that should be irrelevant.

You're right.  I don't know what made me think that Action was
an access-to-protected subprogram.  I must have been seeing things.

> s.adb:9:10: instantiation abandoned
> s.adb:9:63: missing argument for parameter "Element"
> s.adb:11:10: "Local" is undefined
> 
> I realize that 3.12p is current, but I lack the bandwidth to download
> it right now. It may be a compiler error, and may be corrected in 3.12p
> or in compilers from other vendors, but I'd like confirmation that
> other compilers do accept this.

Your code compiles fine with My Favorite Front End.

This looks like a good old compiler bug.  On the other hand,
it would still help if you included the complete source code,
exactly as it was submitted to GNAT.  For example, I am surprised
GNAT didn't complain about lack of a generic body.
You have included bits and pieces, and it is quite possible that
there was some transcription error when I created a compilable version.

> 
> Thanks for taking the time to think about this.
> --
> Jeff Carter

-- 
-Tucker Taft   stt@averstar.com   http://www.averstar.com/~stt/
Technical Director, Distributed IT Solutions  (www.averstar.com/tools)
AverStar (formerly Intermetrics, Inc.)   Burlington, MA  USA