Re: So You Think You Can Const?

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.)