Re: Add pg_nodiscard decorations to Bitmapset functions

On Tue, Sep 08, 2026 at 05:13:08PM +0200, Jan Nidzwetzki wrote:
> The functions in bitmapset.h that return a Bitmapset * either build a
> new set or recycle their input, so ignoring the return value is always a
> bug.
>
> Commit c617aea6acd introduced the macro pg_nodiscard, which generates a
> compiler warning when the result of a function call is ignored. The List
> functions in pg_list.h have the same requirement, and commit a378ba49a5c
> added pg_nodiscard to most of them.
>
> However, bitmapset.h was never adjusted. The attached patch adds
> pg_nodiscard to all functions there that return a Bitmapset *.

This seems generally reasonable to me. In fact, it looks like this idea
was brought up and then deferred during some other Bitmapset work earlier
in the year [0].

[0] https://postgr.es/m/3432490.1776524971%40sss.pgh.pa.us

--
nathan