Re: Formal Subprogram Access

["Randy Brukardt" <randy@rrsoftware.com>]

"Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org> wrote in message 
news:p5mflm$ibq$1@dont-email.me...
> On 02/10/2018 04:03 AM, Randy Brukardt wrote:
>>
>> Why do you think this is correct? I can't read 3.10.2(32/5) in a way 
>> which
>> would prevent using a formal subprogram in this way (assuming that the
>> profile matches, which is does trivially in this case). Indeed, there is
>> specifically an exception allowing "an anonymous access type of an access
>> parameter."
>
> IIRC, you can't take 'Access of some attributes that act as subprograms, 
> but you can use them as the actual for a generic formal subprogram. So a 
> generic can't take 'Access of a generic formal subprogram.

There's no such rule in the RM. As Christoph noted, a generic formal 
subprogram has convention Ada, 'Access is allowed. If you pass an attribute 
to it, you have to wrap it in a real subprogram for this reason. (There is a 
lot of code specifically to do this in Janus/Ada, it probably never has been 
tested outside of a single ACATS test -- I don't think anyone ever has had a 
reason to pass an attribute like Succ as a formal subprogram.)

If you rename such an attribute, however, the convention stays the same, so 
'Access isn't allowed then. But renaaming a formal subprogram certainly 
shouldn't change whether or not 'Access is allowed.

As I said, file a bug report. Even if I'm wrong about the legality of 
'Access on a formal subprogram, the renames should work the same way.

                                    Randy.