Path: csiph.com!weretis.net!feeder8.news.weretis.net!eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Tim Rentsch Newsgroups: comp.lang.c Subject: Re: Dymamic arrays: memory management and naming Date: Tue, 19 Sep 2023 22:17:54 -0700 Organization: A noiseless patient Spider Lines: 22 Message-ID: <86fs39l8xp.fsf@linuxsc.com> References: <20230909132336.99cdb303ad685bc1e40f92df@gmail.moc> <86ediwmk8b.fsf@linuxsc.com> <20230919011018.d9ed14da6e842291d47b69d7@gmail.moc> <86jzsmkqyu.fsf@linuxsc.com> <87led1izo1.fsf@nosuchdomain.example.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: dont-email.me; posting-host="f37cc0880943bcff334da4514aca8b8d"; logging-data="2940954"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+LQtQbXL0g2S+0o9FuvWYBtrr95E1OQ3U=" User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.4 (gnu/linux) Cancel-Lock: sha1:zT5WkG+DOrXFhT+eNhFDNOX+MvE= sha1:gRO6TKapntj4k3G4dzSFGcGZa7g= Xref: csiph.com comp.lang.c:176049 Keith Thompson writes: > Tim Rentsch writes: > [...] > >> Note by the way that sizeof (max_align_t) might not be the same >> as _Alignof (max_align_t). > > Indeed. I was curious about this, so I wrote a small test program that > shows that _Alignof (max_align_t) is 16, but sizeof (max_align_t) is 32 > on the implementation I'm using. That's just what I did. :) > I'm using gcc, which defines max_align_t as a struct containing a long > long, a long double, and optionally a __float128. It could have reduced > the size by making it a union rather than a struct, but there's rarely > (?) any reason to create objects of type max_align_t. AFAICT there is never any reason to use max_align_t as the type in any declaration, excepting perhaps for probing the environment like the little test programs mentioned.