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Groups > comp.lang.c > #176707
| From | Tim Rentsch <tr.17687@z991.linuxsc.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Libraries using longjmp for error handling |
| Date | 2023-09-28 23:20 -0700 |
| Organization | A noiseless patient Spider |
| Message-ID | <86h6ndh55s.fsf@linuxsc.com> (permalink) |
| References | (4 earlier) <87jzsae7jm.fsf@bsb.me.uk> <20230928183129.fb386b543c40cd56340ca40f@gmail.moc> <20230928093424.111@kylheku.com> <8634yxj3uh.fsf@linuxsc.com> <20230928161154.506@kylheku.com> |
Kaz Kylheku <864-117-4973@kylheku.com> writes:
> On 2023-09-28, Tim Rentsch <tr.17687@z991.linuxsc.com> wrote:
>
>> Kaz Kylheku <864-117-4973@kylheku.com> writes:
>>
>>> On 2023-09-28, Anton Shepelev <anton.txt@gmail.moc> wrote:
>>>
>>>> Ben Bacarisse to Anton Shepelev:
>>>>
>>>>> To nit-pick a bit, in C, there is no need to declare
>>>>> anything if you want to ignore an "output parameter".
>>>>> Taking strtod as a (poor) example:
>>>>>
>>>>> double d = strtod(str, &(char *){0});
>>>>
>>>> Ah, but this is one of the strangest and craziest
>>>> innovations of post-modern C -- the ability to pass a
>>>> pointer (as it were) to a literal, rather than to a proper
>>>> variable.
>>>
>>> Two things:
>>>
>>> Firstly, it's not a true literal because it is a mutable object in
>>> automatic storage.
>>
>> It most definitely is a literal, both in the original meaning
>
> Let's examine our use of the article "a".
>
> #include <stdio.h>
>
> void fun(int c)
> {
> char x;
>
> if (c > 0) {
> printf("%p\n", (void *) &(char *){&x});
> fun(c - 1);
> }
> }
>
> [...]
> What is literal about it?
It refers an anonymous object whose initial value is determined
by the tokens making up the literal. That meaning of the term
"literal" is about 60 years old. (That meaning didn't use the
word "object" but did refer to memory that in the context of
the C standard would be called an object.)
> C99 said that a compound literal "is an expression that
> provides access to an anonymous object".
>
> Why can't we call that expression "anonymous object designator"
> or something? If we have "char *p = 0", p is a primary
> expression which designates an object, and not a literal.
You could call it a rhinoceros if you wanted to, but that
wouldn't change what the C standard calls it, or what the
original meaning of the word literal is, or that both the
term compound literal and the orginal meaning of literal
share the key property of referring to an anonymous object.
> If we then have (char *){p} we get an anonymous object that is
> initialized with a copy of p, and that expression designates it
> in much the same way as p designates its object.
They differ in one key respect: in the case of a variable, we
have to give the variable a name, and refer to the object by its
name, but in the case of a compound literal, there is no name,
and we refer to the object "by what it is". That's why it's
called a literal.
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Libraries using longjmp for error handling (was: Re: More on NNTP testing) Blue-Maned_Hawk <bluemanedhawk@invalid.invalid> - 2023-09-27 22:52 +0000
Re: Libraries using longjmp for error handling (was: Re: More on NNTP testing) Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2023-09-28 08:19 +0800
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-28 02:18 +0100
Re: Libraries using longjmp for error handling Blue-Maned_Hawk <bluemanedhawk@invalid.invalid> - 2023-09-28 22:30 +0000
Re: Libraries using longjmp for error handling scott@slp53.sl.home (Scott Lurndal) - 2023-09-28 22:33 +0000
Re: Libraries using longjmp for error handling Anton Shepelev <anton.txt@gmail.moc> - 2023-09-29 01:41 +0300
Re: Libraries using longjmp for error handling scott@slp53.sl.home (Scott Lurndal) - 2023-09-28 23:45 +0000
Re: Libraries using longjmp for error handling Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-09-28 17:35 -0700
Re: Libraries using longjmp for error handling David Brown <david.brown@hesbynett.no> - 2023-09-29 16:49 +0200
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-28 18:24 -0700
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-29 03:19 +0100
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-29 07:46 -0700
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-29 21:02 +0100
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-29 21:56 -0700
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-10-01 00:06 +0100
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-30 20:35 -0700
Re: Libraries using longjmp for error handling Anton Shepelev <anton.txt@gmail.moc> - 2023-10-01 14:44 +0300
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-10-01 15:45 +0100
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-10-01 09:28 -0700
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-10-01 20:49 +0100
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-10-02 02:31 -0700
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-10-02 23:55 +0100
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-10-03 05:01 -0700
Re: Libraries using longjmp for error handling Anton Shepelev <anton.txt@gmail.moc> - 2023-09-29 23:58 +0300
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-10-01 02:52 -0700
Re: Libraries using longjmp for error handling Anton Shepelev <anton.txt@gmail.moc> - 2023-10-01 14:33 +0300
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-28 01:48 +0100
Re: Libraries using longjmp for error handling (was: Re: More on NNTP testing) Kaz Kylheku <864-117-4973@kylheku.com> - 2023-09-28 05:11 +0000
Re: Libraries using longjmp for error handling (was: Re: More on NNTP testing) Kaz Kylheku <864-117-4973@kylheku.com> - 2023-09-28 06:26 +0000
Re: Libraries using longjmp for error handling (was: Re: More on NNTP testing) Anton Shepelev <anton.txt@gmail.moc> - 2023-09-28 16:02 +0300
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-28 14:44 +0100
Re: Libraries using longjmp for error handling Anton Shepelev <anton.txt@gmail.moc> - 2023-09-28 18:31 +0300
Re: Libraries using longjmp for error handling Kaz Kylheku <864-117-4973@kylheku.com> - 2023-09-28 16:43 +0000
Re: Libraries using longjmp for error handling scott@slp53.sl.home (Scott Lurndal) - 2023-09-28 17:00 +0000
Re: Libraries using longjmp for error handling Kaz Kylheku <864-117-4973@kylheku.com> - 2023-09-28 17:16 +0000
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-28 19:38 +0100
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-28 16:05 -0700
Re: Libraries using longjmp for error handling Kaz Kylheku <864-117-4973@kylheku.com> - 2023-09-29 00:26 +0000
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-28 23:20 -0700
Re: Libraries using longjmp for error handling Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-09-28 18:31 -0700
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-29 03:24 +0100
Re: Libraries using longjmp for error handling Kaz Kylheku <864-117-4973@kylheku.com> - 2023-09-29 03:12 +0000
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-28 22:45 -0700
Re: Libraries using longjmp for error handling Spiros Bousbouras <spibou@gmail.com> - 2023-09-29 12:02 +0000
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-29 08:10 -0700
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-29 17:03 +0100
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-29 10:15 -0700
Re: Libraries using longjmp for error handling gazelle@shell.xmission.com (Kenny McCormack) - 2023-09-29 17:17 +0000
Re: Libraries using longjmp for error handling Kaz Kylheku <864-117-4973@kylheku.com> - 2023-09-29 18:53 +0000
Re: Libraries using longjmp for error handling Anton Shepelev <anton.txt@gmail.moc> - 2023-09-29 18:11 +0300
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-29 10:20 -0700
Re: Libraries using longjmp for error handling Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-09-29 11:30 -0700
Re: Libraries using longjmp for error handling Kaz Kylheku <864-117-4973@kylheku.com> - 2023-09-29 18:31 +0000
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-28 19:27 +0100
Re: Libraries using longjmp for error handling Kaz Kylheku <864-117-4973@kylheku.com> - 2023-09-28 20:24 +0000
Re: Libraries using longjmp for error handling Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-28 22:23 +0100
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-28 15:43 -0700
Re: Libraries using longjmp for error handling Kaz Kylheku <864-117-4973@kylheku.com> - 2023-09-28 23:11 +0000
Re: Libraries using longjmp for error handling Anton Shepelev <anton.txt@gmail.moc> - 2023-09-29 17:23 +0300
Re: Libraries using longjmp for error handling Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-09-29 08:19 -0700
Re: Libraries using longjmp for error handling David Brown <david.brown@hesbynett.no> - 2023-09-28 21:57 +0200
Re: Libraries using longjmp for error handling Richard Kettlewell <invalid@invalid.invalid> - 2023-09-30 09:37 +0100
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