Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
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: Fri, 2 Aug 2024 12:27:47 -0700
Organization: A noiseless patient Spider
Lines: 76
Message-ID: <v8jbvj$2vat1$1@dont-email.me>
References: <IoGcndcJ1Zm83zb7nZ2dnZfqnPWdnZ2d@brightview.co.uk>
 <20240801174026.00002cda@yahoo.com> <v8gi7i$29iu1$1@dont-email.me>
 <slrnvaorkl.34j6.candycanearter07@candydeb.host.invalid>
 <87zfpvfdk4.fsf@nosuchdomain.example.com> <v8ii17$2q5p1$1@dont-email.me>
 <87v80ig4vt.fsf@nosuchdomain.example.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Fri, 02 Aug 2024 21:27:47 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="5a662775f5eb6582259b0411a9796340";
	logging-data="3124129"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/cW10CDT5gkJi5vg43cTdZRuZJnGwJYhE="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:mJnyeJLPNdl2B0XknrC9g7vjlkc=
Content-Language: en-US
In-Reply-To: <87v80ig4vt.fsf@nosuchdomain.example.com>
Bytes: 3279

On 8/2/2024 11:24 AM, Keith Thompson wrote:
> Richard Harnden <richard.nospam@gmail.invalid> writes:
> [...]
>> Is there any reason not to always write ...
>>
>> static const char *s = "hello, world";
>>
>> ... ?
>>
>> You get all the warnings for free that way.
> 
> The "static", if this is at block scope, specifies that the pointer
> object, not the array object, has static storage duration.  If it's at
> file scope it specifies that the name "s" is not visible to other
> translation units.  Either way, use it if that's what you want, don't
> use it if it isn't.
> 
> There's no good reason not to use "const".  (If string literal objects
> were const, you'd have to use "const" here.)
> 
> If you also want the pointer to be const, you can write:
> 
>      const char *const s = "hello, world";
> 

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);
};


struct device_vtable {
   struct object_prv_vtable const object;
   struct device_prv_vtable const device;
};


struct device {
   struct device_vtable const* vtable;
};


#define object_destroy(mp_self) ( \
   (mp_self)->vtable->object.fp_destroy((mp_self)) \
)


#define device_read(mp_self, mp_buf, mp_size) ( \
   (mp_self)->vtable->device.fp_read((mp_self), (mp_buf), (mp_size)) \
)


#define device_write(mp_self, mp_buf, mp_size) ( \
   (mp_self)->vtable->device.fp_write((mp_self), (mp_buf), (mp_size)) \
)
________________________________

;^)