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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Type interchange |
| Date | 2011-12-01 17:35 -0800 |
| Organization | None to speak of |
| Message-ID | <lnobvroive.fsf@nuthaus.mib.org> (permalink) |
| References | (5 earlier) <jb7r0i$9ku$3@dont-email.me> <0.62ba56f0dbe6531a64e1.20111201155527GMT.871usop9qo.fsf@bsb.me.uk> <4ED7AB31.1010500@verizon.net> <ln62hzq5zh.fsf@nuthaus.mib.org> <jb991v$vfv$1@dont-email.me> |
James Kuyper <jameskuyper@verizon.net> writes:
> On 12/01/2011 05:31 PM, Keith Thompson wrote:
>> James Kuyper <jameskuyper@verizon.net> writes:
> ...
>>> 6.2.7p1 itself contains no such wording. It could have been written as:
>>> For two types to be compatible, they must either be the same type, or
>>> covered by one of the additional rules in ...". It wasn't written that way.
> ...
>> Furthermore, under your interpretation, I see nothing saying that
>> int and long must have the same representation to be compatible.
>> An implementation could have 32-bit int and 64-bit long, but if
>> it decides that int and long are compatible types, then the above
>> declarations may be accepted without so much as a warning.
>
> Keep in mind that if an implementation treats a 32-bit int and a 64-bit
> long as being compatible, it can't hide behind the clauses that give
> undefined behavior to code which treats them as compatible. I personally
> don't see how they could conform to those requirements, but if they did
> somehow manage to do so, I don't see any need for a warning except for
> purposes of writing portable code - and as a matter of QoI, I would
> consider providing such warnings to be essential.
One question.
Under what circumstances, if any, may a conforming implementation *not*
issue a diagnostic for the following program?
int main(void) {
int *ip = 0;
long *lp = ip;
return 0;
}
(My answer is that a diagnostic is always required.)
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Will write code for food.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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Type interchange Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-11-30 21:53 +0000
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-11-30 17:29 -0500
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-11-30 15:22 -0800
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-11-30 19:10 -0500
Re: Type interchange Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-01 03:09 +0000
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-01 07:13 -0500
Re: Type interchange Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-01 15:55 +0000
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-01 11:28 -0500
Re: Type interchange Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-01 16:45 +0000
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-01 12:00 -0500
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-12-01 14:31 -0800
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-01 20:18 -0500
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-12-01 17:35 -0800
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-02 12:03 -0500
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-12-02 13:49 -0800
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-02 22:12 -0500
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-12-03 02:01 -0800
Re: Type interchange Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-25 12:47 -0800
Re: Type interchange pete <pfiland@mindspring.com> - 2011-12-01 11:10 -0500
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-01 11:34 -0500
Re: Type interchange Kaz Kylheku <kaz@kylheku.com> - 2011-12-01 17:48 +0000
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-12-01 14:17 -0800
Re: Type interchange pete <pfiland@mindspring.com> - 2011-12-01 17:43 -0500
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-12-01 15:00 -0800
Re: Type interchange pete <pfiland@mindspring.com> - 2011-12-01 19:29 -0500
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-12-01 16:59 -0800
Re: Type interchange pete <pfiland@mindspring.com> - 2011-12-02 08:35 -0500
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-02 08:46 -0500
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-12-02 13:32 -0800
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-12-02 13:30 -0800
Re: Type interchange pete <pfiland@mindspring.com> - 2011-12-02 18:45 -0500
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-11-30 19:17 -0800
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-01 06:50 -0500
Re: Type interchange Keith Thompson <kst-u@mib.org> - 2011-12-01 07:15 -0800
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-01 10:36 -0500
Re: Type interchange pete <pfiland@mindspring.com> - 2011-12-01 11:04 -0500
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-01 11:37 -0500
Re: Type interchange Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-25 13:02 -0800
Re: Type interchange Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-25 13:01 -0800
Re: Type interchange Quentin Pope <qp19433@hotmail.NOSPAM.com> - 2011-12-02 22:15 +0000
Re: Type interchange James Kuyper <jameskuyper@verizon.net> - 2011-12-03 11:39 -0500
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