From: Keith Thompson <kst@cts.com>
Subject: Re: Interfaces.C and void *
Date: 1999/09/22
Date: 1999-09-22T00:00:00+00:00 [thread overview]
Message-ID: <yeck8piix2g.fsf@king.cts.com> (raw)
In-Reply-To: 87btavxw93.fsf@deneb.cygnus.argh.org
Florian Weimer <fw@deneb.cygnus.argh.org> writes:
[...]
> Is there really no portable equivalent of a C void * in Interfaces.C?
> I used Interfaces.C.Strings.chars_ptr, which should be quite portable in
> practice, but AFAIK, ISO C doesn't require the representation of void *
> and char * to be identical.
Yes, it does.
ANSI/ISO 9899-1990, section 6.1.2.5, says:
A pointer to void shall have the same representation and alignment
requirements as a pointer to a character type. Similarly,
pointers to qualified or unqualified versions of compatible types
shall have the same representation and alignment requirements.
[Footnote: The same representation and alignment requirements are
meant to imply interchangeability as arguments to functions,
return values from functions, and members of unions.] Pointers to
other types need not have the same representation and alignment
requirements.
Yes, a void_ptr type would be a good addition to Interfaces.C.
--
Keith Thompson (The_Other_Keith) kst@cts.com <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://www.sdsc.edu/~kst>
"Oh my gosh! You are SO ahead of your time!" -- anon.
prev parent reply other threads:[~1999-09-22 0:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-09-22 0:00 Interfaces.C and void * Florian Weimer
1999-09-22 0:00 ` Ted Dennison
1999-09-22 0:00 ` Tucker Taft
1999-09-22 0:00 ` Keith Thompson [this message]
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