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From: Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups: comp.lang.c
Subject: Re: on why declare a struct with a single array in it
Date: Sat, 20 Nov 2021 15:52:32 -0800
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David Brown <david.brown@hesbynett.no> writes:
> On 19/11/2021 21:52, Keith Thompson wrote:
[...]
>> Perhaps -- but typically that information is not stored in the pointer
>> itself.  If it were, all void* values would have to store that extra
>> information.
>> 
>> (I think it's easier to store bookkeeping data before the allocated
>> space.  If you store it after the space, it's hard to know where it is.)
>
> That's the most common way for a simple malloc/free system.
>
> It has always struck me as a mistake that C did things that way - in my
> opinion, "free" should have taken an additional parameter of the size
> for the deallocation.

Meh.  That would have introduced another rich source of programming
errors (passing the wrong size).  Probably most implementations would
have kept track of the size anyway, so they could detect errors.  As
long as they're keeping track, why make the user do so as well?

Perhaps a lower-level allocator might be more efficient if user code is
required to keep track, but I don't think it would be all that useful
for most applications.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */