Re: fastgetattr & isNull

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: fastgetattr & isNull
Date: 2010-01-06 18:40:24
Message-ID: 603c8f071001061040mb0b755fp6047cbb6532a3def@mail.gmail.com
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On Wed, Jan 6, 2010 at 1:38 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> Well, that comment is a bit misleading too, since a pointer with a
>> NULL value might work but a literal NULL certainly doesn't.
>
> I think "(bool *) NULL" would work.  What your compiler is complaining
> about is trying to dereference a "void *" expression.
>
> In practice, the people we'd need to reach with a comment would be ones
> who had working code before --- and working code, in this context, would
> most likely be code that was passing a pointer variable that contained
> null.  But as I said, I don't think it really requires any comment.

I was less thinking of people whose code might break and more thinking
of people who might be trying to understand the preconditions for
using the macro. But on further reflection I think a lot more
documentation would be needed to really make that clear, so I'll skip
it for now.

...Robert

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