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From: Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups: comp.lang.c
Subject: Re: question about nullptr
Date: Fri, 12 Jul 2024 17:30:09 -0700
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scott@slp53.sl.home (Scott Lurndal) writes:
> Kaz Kylheku <643-408-1753@kylheku.com> writes:
>>On 2024-07-12, Scott Lurndal <scott@slp53.sl.home> wrote:
>>> Kaz Kylheku <643-408-1753@kylheku.com> writes:
>>>>On 2024-07-12, Richard Harnden <richard.nospam@gmail.invalid> wrote:
>>>>> Don't you use '\n'? Surely nobody would say 0x0a?
>>>
>>>>But, see, nobody in their right mind would say '\012` for that. '\0'
>>>>an octal escape sequence like '\012', not a role-based character
>>>>abstraction like '\n'.
>
> Because '\012' is a character.   012 is an int.  Using the former
> ensures that any overflow will be detected at compile time and make
> it clear to any future reader that the author intended it to be a
> character, not an integer.

'\012' is a character constant.  012 is an integer constant.  Both are
of type int, and both have the same value, 10.

It's true that an octal character constant with a value exceeding
UCHAR_MAX is a constraint violation (like '\400' if UCHAR_MAX is 255),
and if you provide more than 3 digits the result is a multi-character
constant, which is likely to trigger a warning.  But any overflow would
almost certainly be the result of a typo, and guarding against that
doesn't strike me as a good reason to use one kind of constant over
another.

Having said that, I absolutely do prefer to use character constants for
character data ('\012' or '\x0a' if I want a character with value 10, or
more likely '\n' if I want a newline).  But that's for the benefit of
the reader, not of the compiler.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */