Re: Subverting 'Access for Sub-programs

["David C. Hoos, Sr." <david.c.hoos.sr@ada95.com>]

Anton Gibbs wrote in message <37A71EF1.2201@dera.gov.uk>...
>Dear Ada Community,
>
>Can someone please advise me on the best way to subvert the language
>rules that prevent the use of 'Access on a locally declared procedure ?
>
>For normal objects it is possible to use 'Unchecked_Access but for
>sub-programs this is not allowed.
>
>"Why does this idiot want to do this ?" I hear you ask.
>
>Well it seemed reasonable enough to me within a wider application, the
>essence of which I have distilled into a few lines below.
>

The real problem is that the compiler cannnot know that procedure Main
will have a lifetime as long as the entire program -- for there is
nothing that says (at _compile_ time) that procedure Main is the _Main_
procedure.

Since the subprogram to which you wish to provide access is nested
within this procedure, its lifetime cannot be guaranteed _at compile
time_ to exceed the lifetime of the subprogram(s) to which the
access is passed.

The solution is simply to declare the procedure Print_If_Even at
library level -- either in a library-level package, or as a
standalone library procedure.

So... no subversion is necessary - just adhere as described, and
you'll be fine.