Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Kaz Kylheku <433-929-6894@kylheku.com>
Newsgroups: comp.lang.c
Subject: Re: Word For Today: =?UTF-8?Q?=E2=80=9CUglification=E2=80=9D?=
Date: Tue, 12 Mar 2024 03:30:55 -0000 (UTC)
Organization: A noiseless patient Spider
Lines: 22
Message-ID: <20240311202758.193@kylheku.com>
References: <uso6or$3t3jn$3@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Injection-Date: Tue, 12 Mar 2024 03:30:55 -0000 (UTC)
Injection-Info: dont-email.me; posting-host="103d6665e02695c45444ee5fbac9bd46";
	logging-data="101344"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/gud0bg//B6KlWWlCXqUiBuPe4AOzR7N0="
User-Agent: slrn/pre1.0.4-9 (Linux)
Cancel-Lock: sha1:kBQkGucaMTKp6f2cckv1hA+qxx8=
Bytes: 1783

On 2024-03-12, Lawrence D'Oliveiro <ldo@nz.invalid> wrote:
> From /usr/include/«arch»/bits/select.h on my Debian system:
>
>     #define __FD_ZERO(s) \
>       do {									      \
>         unsigned int __i;							      \
>         fd_set *__arr = (s);						      \

This assignment has value; it checks that, loosely speaking,
s is an "assignment compatible" pointer with a fd_set *,
so that there is a diagnostic if the macro is applied to
an object of the wrong type.

>         for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i)	      \
>           __FDS_BITS (__arr)[__i] = 0;					      \

Here, I would have done memset(__arr, 0, sizeof *__arr).

-- 
TXR Programming Language: http://nongnu.org/txr
Cygnal: Cygwin Native Application Library: http://kylheku.com/cygnal
Mastodon: @Kazinator@mstdn.ca