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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: So You Think You Can Const?
Date: Wed, 08 Jan 2025 12:24:47 -0800
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Andrey Tarasevich <andreytarasevich@hotmail.com> writes:

> On 01/07/25 11:32 AM, Julio Di Egidio wrote:
>
>> Assuming, as said, that the data was originally
>> allocated with malloc, is [calling free on a pointer
>> to const something] safe or something can go wrong
>> even in that case?
>
> It is perfectly safe.  One can even argue that standard declaration if
> free` as `void free(void *)` is defective.  It should have been `void
> free(const void *)` from the very beginning.

I think declaring the parameter as 'void *' rather than 'const void *'
is a better choice.  There is a fair chance that calling free() on a
pointer to const anything is a programming error, and it would be good
to catch that.  If it isn't an error, then fixing the diagnostic is
trivial.  If it's a common pattern one could even define an inline
function

  static inline void
  cfree( const void *p ){ free( (void*)p ); }

and call that instead of free().  (Obviously the 'inline' should be
taken out if compiling as C90.)