Re: _Optional: a type qualifier to indicate pointer nullability

[Christopher Bazley <cs99cjb@gmail.com>]

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On Sat, 4 Feb 2023 at 23:53, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:

>
>
> On Sat, 4 Feb 2023, 21:23 Christopher Bazley, <cs99cjb@gmail.com> wrote:
>
>>
>>
>> On Sat, 4 Feb 2023 at 20:40, Jonathan Wakely <jwakely.gcc@gmail.com>
>> wrote:
>>
>>>
>>> On Sat, 4 Feb 2023, 17:01 Christopher Bazley via Gcc, <gcc@gcc.gnu.org>
>>> wrote:
>>>
>>>>
>>>> Does the lack of support for Clang's nullability qualifiers in GCC
>>>> indicate
>>>> a greater likelihood for my proposed feature to be accepted into GCC?
>>>
>>>
>>> No, I don't think so. I think it would be better to support the same
>>> qualifiers as Clang, not diverge in this way.
>>>
>>
>> Clang’s _Nullable qualifier is broken and pretty useless (even according
>> to the code owner), so good luck with that.
>>
>
> But marking pointer arguments as non-null is already supported in GCC
> (with an attribute on the function, not the argument). Supporting a nonnull
> attribute on individual arguments seems useful to me. Far more than marking
> pointers as maybe-null, which is already true for all pointers.
>

Sorry, but I get the feeling that you didn’t read my article. If you could
spare the time, it would help you to understand where I’m coming from.
Saying “it’s already true that all pointers can be null [therefore there’s
no need for ‘_Optional’ in the type system]” is as facile as saying “it’s
already true that all values in Python can be None”.

I’d sooner trust Guido van Rossum on this question than Bjarne Stroustrup,
since the former actually *likes* C and uses it, whereas the latter
describes C as a perverse mess (and certainly doesn’t use it).
-- 
Christopher Bazley