Re: Small improvements to pg_list.h's linitial(), lsecond(), lthird() etc macros

Thanks for 9d299a492.

On Mon, 28 Sep 2020 at 15:35, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Poking around to count remaining uses of those inline functions,
> I found a few places that should be using the macros instead,
> and fixed them.  After that, I notice that list_tail(),
> list_third_cell(), and list_fourth_cell() are entirely unreferenced.
> I'm hesitant to get rid of list_tail(), because it seems like it
> could well be used by extensions.  But I'd bet quite a bit that
> list_third_cell() and list_fourth_cell() are not used anywhere
> anymore.  Should we get rid of them to shave a few microseconds
> from compile times?

I wouldn't object to the removal of list_third_cell() and list_fourth_cell().

I agree to your reasoning with last_tail(). It does seem more likely
that someone would use it. Although, if you'd proposed to remove it
too, I wouldn't have objected.  It's not like it's hard to reimplement
within an extension for any extensions that use it. Though, perhaps it
would maybe be a shame if that was the sole thing we broke for them
when they try compiling their extension in a year's time on the newly
release PG14.

David