Re: implicit casts from void*

John Naylor <johncnaylorls@gmail.com> writes:
> I received on off-list report that commit e2809e3a101 causes an error
> when building an extension written in C++, since $subject is in a
> header file. The fix is simply to add an explicit cast, so I plan to
> push the attached soon.

Hmpfh.  No objection to your patch, but I wonder why
"headerscheck --cplusplus" didn't find this?  Can we get it
to do so?

> Bikeshedding: We could additionally change the pg_crc*.c files to make
> them consistent, but I have not done that yet. It seems we prefer
> explicit casts anyway but don't enforce that.

Meh.  There are an awful lot of places where we assume such casts
are okay.  I'm willing to adopt a stricter definition in header
files, but it feels like requiring it in .c files is useless
make-work.  As a perhaps not quite exact parallel, we mostly
don't object to writing

    if (ptr)

as a shortcut for

    if (ptr != NULL)

though it's hard to see the former as anything but an implicit
cast to boolean.

            regards, tom lane