Re: A: a new bug to old plain C

Hi there!

The code is not invalid and neither of the links posted saying that "const
Foo * const * const" is invalid construction for C.
The links posted just are discussing that it might be UNSAFE to cast "Foo
**" -> "const Foo **" and recommending usage of "Foo **" -> "const Foo *
const *" instead.
It's OK. If you feel that it is unsafe, please don't use it. It is your own
decision.

But the syntax itself "const Foo * const * const" is correct and the
use-case I mentioned is quite simple and evident.
And so I need this code snipped to be compiled transparently over all the
GCC (and platform SDKs) available versions.

Respectfully,
Aleksandr G Povaliaev.


пн, 24 нояб. 2025 г. в 01:48, David Brown <[email protected]>:

> On 23/11/2025 21:45, Александр Поваляев via Gcc-help wrote:
> > Hi there!
> >
>
> This is getting /extremely/ frustrating.  /Please/ find some way to
> learn the C programming language - courses, books, good online resources.
>
> And /please/ believe me when I say that people who have worked with C
> and C++ for decades, studied the standards, who serve on the standards
> committee, know better about these things than you do.  (I'm talking
> about Jonathan here, not myself - he really is a world-class expert here.)
>
> > Either the links you've provided or the links you provided earlier
> > (yesterday) are irrelevant, cause they are just discussing if it is safer
> > to convert "Foo_Type **" to "const Foo_Type **" or not.
> >
>
> The links are highly relevant.  They explain why you cannot convert from
> "char **" to "const char **".  That also explains why you cannot convert
> from "char **" to "const char * const * const".  Adding even more
> "const" qualifiers to the invalid conversion does not somehow magically
> make it work.
>
> > Once again, we are not converting "char** to const char**", we're
> > converting char** to const char * const * const".
> > And we're not discussing if it is safer or not, we are discussing GCC
> > compiler error.
> >
>
> The compiler is generating an error message because you wrote invalid
> code.  The error - or bug, if you like - is in /your/ code.  Not the
> compiler.  GCC is doing its job correctly here.
>
> >
> > Respectfully,
> > Aleksandr G Povaliaev.
> >
>
> I'm sorry, but signing the post with "respectfully" does not make it
> respectful.  You started the thread disrespectfully - insisting that
> there is a bug in GCC when you simply do not understand the relevant
> aspects of the C programming language.  And you have gone downhill since
> then, ignoring and rejecting the help and advice you have been given.
> Getting things wrong once is entirely understandable - this is a subtle
> point of the C language, and you are posting to a "help" list.  Doubling
> down on your ignorance when you have received the help and information
> you need, is a different matter entirely.
>
> Your code is flawed.  You need to fix it.  Mindlessly repeating your
> misunderstandings about how you think C works will not do anything but
> annoy people.
>
> David
>
>