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From: David Brown <david.brown@hesbynett.no>
Newsgroups: comp.lang.c
Subject: Re: C23 thoughts and opinions
Date: Thu, 23 May 2024 15:25:43 +0200
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On 23/05/2024 14:11, bart wrote:
> On 23/05/2024 02:21, Thiago Adams wrote:
>> Em 5/22/2024 7:53 PM, Keith Thompson escreveu:
> 
>>> But const doesn't mean constant.  It means read-only.
>>> `const int r = rand();` is perfectly valid.
>>>
>>> I dislike the C++ hack of making N a constant expression given
>>> `const int N = 42;`; constexpr made that unnecessary.  C23 makes the
>>> same (IMHO) mistake.
>>>
>>> If I had a time machine, I'd spell "const" as "readonly" and make
>>> "const" mean what "constexpr" now means (evaluated at compile time).
>>>
>>> [...]
>>
>> Everything is a mess: const in C++, the differences from const in C, 
>> etc. constexpr in C23 just makes the mess bigger.
>>
>> auto is a mess as well not well specified for pointer. not sure if we 
>> had this topic here, but auto * p in C is not specified.
>>
>> I would remove from C23
>> - nullptr
>> -auto
>> -constexpr
>> -embed
>>
>> I like the idea of embed but there is no implementation in production 
>> so this is crazy!
> 
> 'embed' was discussed a few months ago. I disagreed with the poor way it 
> was to be implemented: 'embed' notionally generates a list of 
> comma-separated numbers as tokens, where you have to take care of any 
> trailing zero yourself if needed. It would also be hopelessly 
> inefficient if actually implemented like that.

Fortunately, it is /not/ actually implemented like that - it is only 
implemented "as if" it were like that.  Real prototype implementations 
(for gcc and clang - I don't know about other tools) are extremely 
efficient at handling #embed.  And the comma-separated numbers can be 
more flexible in less common use-cases.

(That was also made clear in the previous discussion.  It's been a while 
since you posted much here - it's nice to see you back on form :-) )