Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uunet!kddlab!titcca!sragwa!wsgw!socslgw!diamond
From: diamond@csl.sony.co.jp (Norman Diamond)
Newsgroups: comp.std.c
Subject: Re: sizeof ((rehash *) 0)->again
Message-ID: <11146@riks.csl.sony.co.jp>
Date: 20 Nov 89 01:31:15 GMT
References: <11138@riks.csl.sony.co.jp> <11628@smoke.BRL.MIL>
Reply-To: diamond@ws.sony.junet (Norman Diamond)
Organization: Sony Computer Science Laboratory Inc., Tokyo, Japan
Lines: 22

In article <11628@smoke.BRL.MIL> gwyn@brl.arpa (Doug Gwyn) writes:
>In article <11138@riks.csl.sony.co.jp> diamond@ws.sony.junet (Norman Diamond) writes:
>>Section 3.3.4 says that the result has the named type, i.e. rehash *.
>>Therefore the semantics of -> select a member of the pointed-to type,
>>and sizeof takes its size.
>
>This argument was already made and I disagreed before too.
>My argument is that a null pointer does not point to anything.

In the part of my posting which you deleted, I pointed out where the
standard deliberately does not define a cast null pointer to be a
null pointer constant, unless the cast is to void *.  Therefore the
compiler cannot take advantage at compile time of knowing that this
is a null pointer; it has to wait until execution time (or at least
it has to appear that way).  Execution-time null pointers do in fact
have a type which is known at compile-time.

-- 
Norman Diamond, Sony Corp. (diamond%ws.sony.junet@uunet.uu.net seems to work)
  Should the preceding opinions be caught or     |  James Bond asked his
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