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From: Ben Bacarisse <ben@bsb.me.uk>
Newsgroups: comp.lang.c
Subject: Re: No warning at implicit removal of const. Was: relearning C: why does an in-place change to a char* segfault?
Date: Mon, 05 Aug 2024 12:03:08 +0100
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"Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> writes:

> On 8/4/2024 6:06 PM, Ben Bacarisse wrote:
>> "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> writes:
>> 
>>> On 8/2/2024 3:29 PM, Ben Bacarisse wrote:
>>>> "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> writes:
>>>>
>>>>> For some reason I had a sort of a habit wrt const pointers:
>>>>>
>>>>> (experimental code, no ads, raw text...)
>>>>> https://pastebin.com/raw/f52a443b1
>>>>>
>>>>> ________________________________
>>>>> /* Interfaces
>>>>> ____________________________________________________________________*/
>>>>> #include <stddef.h>
>>>>>
>>>>>
>>>>> struct object_prv_vtable {
>>>>>     int (*fp_destroy) (void* const);
>>>>> };
>>>>>
>>>>>
>>>>> struct device_prv_vtable {
>>>>>     int (*fp_read) (void* const, void*, size_t);
>>>>>     int (*fp_write) (void* const, void const*, size_t);
>>>>> };
>>>> Why?  It seems like an arbitrary choice to const qualify some pointer
>>>> types and some pointed-to types (but never both).
>>>
>>> I just wanted to get the point across that the first parameter, aka, akin
>>> to "this" in C++ is a const pointer. Shall not be modified in any way shape
>>> or form. It is as it is, so to speak:
>>>
>>> void foo(struct foobar const* const self);
>>>
>>> constant pointer to a constant foobar, fair enough?
>> No.  If you intended a const pointer to const object why didn't you
>> write that?  My point was that the consts seems to be scattered about
>> without any apparent logic and you've not explained why.
>> 
>>>>> ;^)
>>>> Does the wink mean I should not take what you write seriously?  If so,
>>>> please ignore my question.
>>>
>>> The wink was meant to show my habit in basically a jestful sort of
>>> way.
>> Your habit of what?
>
> To write the declaration with names and the const access I want, so:
>
> extern void (void const* const ptr);
>
> void (void const* const ptr)
> {
>    // ptr is a const pointer to a const void
> }

I don't think you are following what I'm, saying.  If you think there
might be some value in finding out, you could as a few questions.  I
won't say it again ;-)

-- 
Ben.