From: Shark8 <onewingedshark@gmail.com>
Subject: Re: How best to test for NULL in Ada?
Date: Fri, 3 Jul 2015 19:02:44 -0700 (PDT)
Date: 2015-07-03T19:02:44-07:00 [thread overview]
Message-ID: <c44ae7c4-7e7a-45f1-967d-0b526c3429cf@googlegroups.com> (raw)
In-Reply-To: <mn4k24$ndj$1@loke.gir.dk>
On Thursday, July 2, 2015 at 6:12:53 PM UTC-6, Randy Brukardt wrote:
>
> In Ada 2012 there is a hack available to avoid the use clause. (This comes
> from Tucker Taft, who admitted to doing this during our recent ARG meeting
> in Madrid. He got suitable groans for this usage...)
>
> if Some_Object not in null then
>
> This membership uses the predefined equality for the type of Some_Object,
> and it need not be visible. But this is a hack (it harms readability), and
> it's dangerous if "=" has been redefined (as it always uses the predefined
> "=", not the overridden one). Use at your own risk.
Hm I can see where, if you were writing your own "=" operator for Some_Object's type and it was (a) an access type, and (b) you needed to test for null that could be useful.
next prev parent reply other threads:[~2015-07-04 2:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-02 22:15 How best to test for NULL in Ada? NiGHTS
2015-07-02 23:19 ` Jeffrey R. Carter
2015-07-03 0:12 ` Randy Brukardt
2015-07-04 2:02 ` Shark8 [this message]
2015-07-03 7:30 ` Dmitry A. Kazakov
2015-07-05 23:32 ` NiGHTS
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