Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Muttley@DastardlyHQ.org
Newsgroups: comp.lang.c
Subject: Re: Regarding assignment to struct
Date: Tue, 6 May 2025 10:18:44 -0000 (UTC)
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On Tue, 6 May 2025 11:46:21 +0200
David Brown <david.brown@hesbynett.no> wibbled:
>On 05/05/2025 22:53, Keith Thompson wrote:
>> Muttley@dastardlyhq.com writes:
>> [...]
>>> If you twant o pass an actual array to a function instead of a pointer to
>it,
>>> embedding it in a structure is the only way to do it.
>> 
>> Yes, but that's not necessarily useful.  An array that's a member
>> of a struct can only be of a constant length (unless it's a flexible
>> array member, but that doesn't help).  Functions that work with
>> arrays typically need to deal with arrays of arbitrary length.
>> 
>
>I regularly use arrays with known fixed sizes.  In fact, in my code 
>those are absolutely dominant - it is very rare for me to see or use an 
>array whose size is /not/ fixed at compile time.  Sometimes I will have 

I do a lot of networking code and with packet structures the arrays are
almost always of fixed size. Also with arrays the data is inline so a simple
memcpy() can copy the data from the struct to the output buffer. You can't
do that if you have pointers in the struct. Ditto a simple cast to char * to
use it directly as the ouput.