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From: "Randy Brukardt" <randy@rrsoftware.com>
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Subject: Re: GCC 4.0 Ada.Containers Cursor danger.
Date: Wed, 20 Jul 2005 22:18:06 -0500
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Date: 2005-07-20T22:18:06-05:00
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"Matthew Heaney" <mheaney@on2.com> wrote in message
news:1121870089.752445.108320@g49g2000cwa.googlegroups.com...
...
> Cursors confer no greater safety than you get with named access types.
> If this isn't clear, then yes, we need to better job of advertising
> this feature.

I don't agree with this statement. That fact that it is *possible* to check
for dangling cursors shows that. It's completely impractical to do useful
dangling access type checks (we tried to do so in Janus/Ada, but they almost
never detect anything, and break some common Ada 83 idioms).

Since I agree with your assertion that cursors shouldn't be kept around for
long periods, its clear that a bit of additional space/time overhead is
acceptable to get decent checking. As long as the checking is there, there
is not going to be a problem. (Like all Ada checking, it should default to
ON, of course, and be turned off only if critical.)

                                 Randy.