Path: csiph.com!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Keith Thompson Newsgroups: comp.lang.c Subject: Re: struct padding question Date: Thu, 23 Mar 2017 08:45:33 -0700 Organization: None to speak of Lines: 31 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: mx02.eternal-september.org; posting-host="1b33b319c9f9fcfff45ec1f5b5f6ee2d"; logging-data="20809"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18tVmCf8rd/tqj2sZ5BwO+J" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) Cancel-Lock: sha1:ply9s9t6CVmrn+RnugJMvCYF6aM= sha1:oRLxs0NtGyA0ye8rROPeNJUvr3c= Xref: csiph.com comp.lang.c:106809 MehdiAmini writes: > On 03/23/2017 02:58 PM, David Brown wrote: >> On 23/03/17 10:58, MehdiAmini wrote: > [...] > >> You may decide that this warning is not a problem - for most code, >> padding bytes are not an issue. Then you simply add "-Wno-padded" to >> your compiler line. This does not change your code, but it hides the >> warning. >> >> Alternatively, you need to re-arrange your struct so that there are no >> paddings needed. >> > > [...] > > Can I use alignas or alignof to fix the warning? Exactly what problem are you trying to solve? The simplest way to avoid the warning is to add "-Wno-padded" to your compiler command line. If you want the structure not to have padding, that's a more complicated question. In some cases you can rearrange the member declarations, but in this case you could add a dummy member to occupy the space that would otherwise be padding. -- Keith Thompson (The_Other_Keith) kst-u@mib.org Working, but not speaking, for JetHead Development, Inc. "We must do something. This is something. Therefore, we must do this." -- Antony Jay and Jonathan Lynn, "Yes Minister"