Path: csiph.com!eternal-september.org!feeder.eternal-september.org!nntp.eternal-september.org!.POSTED!not-for-mail From: Tim Rentsch Newsgroups: comp.lang.c Subject: Re: function pointer question Date: Wed, 07 Jan 2026 07:35:17 -0800 Organization: A noiseless patient Spider Lines: 24 Message-ID: <86bjj5phai.fsf@linuxsc.com> References: <10j7rs6$7c9e$1@dont-email.me> <20260102091518.226@kylheku.com> <10j96mn$jrsp$1@dont-email.me> <10j9enb$p6ts$2@dont-email.me> <10j9g71$pr9o$1@dont-email.me> <10jb3j5$17gcb$3@dont-email.me> <10jbsp0$1gf7e$1@dont-email.me> <10jc02j$1hk1n$1@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Date: Wed, 07 Jan 2026 15:35:20 +0000 (UTC) Injection-Info: dont-email.me; posting-host="96c89593a79aadfcc4daf354c711affa"; logging-data="798811"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19gNiLQtdvn8U40znv1wiHmfk8Sjhk8vrI=" User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.4 (gnu/linux) Cancel-Lock: sha1:YG6vqZ43wvdwNbCo48fQpCsC0pw= sha1:pGNiYs9jSskaG50e19YEPIjkA8w= Xref: csiph.com comp.lang.c:396265 Andrey Tarasevich writes: > On Sat 1/3/2026 12:04 PM, Chris M. Thomasson wrote: > >> struct object_prv_vtable { >> int (*fp_destroy) (void* const); >> }; > > And interesting piece of trivia about C function types and function > type compatibility rules is that: > > 1. Top-level qualifiers on function parameters are preserved as part > of function type. Not completely wrong but not exactly right either. > However, such top-level qualifiers are ignored when > determining function type compatibility. It's easier to take the point of view that top-level qualifiers for function parameters don't participate in the type of the function as a whole. Taking that view is easier to understand and gives results that are indistinguishable from the actual rules.