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From: ballou@brahms (Kenneth R. Ballou)
Newsgroups: comp.lang.c
Subject: Re: Why are typedef names in the same name space as variable names?
Message-ID: <307@cartan.Berkeley.EDU>
Date: Sat, 15-Nov-86 18:50:11 EST
Article-I.D.: cartan.307
Posted: Sat Nov 15 18:50:11 1986
Date-Received: Sun, 16-Nov-86 02:25:13 EST
References: <1092@spice.cs.cmu.edu>
Sender: daemon@cartan.Berkeley.EDU
Reply-To: ballou@brahms (Kenneth R. Ballou)
Distribution: net
Organization: Math Dept. UC Berkeley
Lines: 33

In article <1092@spice.cs.cmu.edu> jgm@spice.cs.cmu.edu (John Myers) writes:
>In article <4220@ut-ngp.UUCP> dlnash@ut-ngp.UUCP (Donald L. Nash) writes:
>>Why are typedef names in the same name space as variable names?...
>
>If they weren't, then what would the output of the following program be?
>
>#include <stdio.h>
>main()
>{
>    typedef car foo;
Is this a typo, and supposed to be typedef char foo ?
>    long foo;
>    
>    printf("%d\n",sizeof(foo));
>}

I don't see that there is a question here.  Sizeof is *NOT* a function, as was
quite thoroughly discussed some time back in this group.  Note that (foo) in
this case is the syntax of a type cast, and in this case, sizeof returns 
the size of a datum of type foo (in this case, 1).  If, however, you were to
write  sizeof foo , you would then get the size of a long integer on your
machine.  References:  K&R:  page 126 (explains sizeof (object) and also
points out that sizes are given in unspecified units called "bytes," which
are the same size as a char); page 187 (gives two forms of the *operator*
sizeof, namely  sizeof expression  and  sizeof (type-name) ); page 188 (defines
the meaning of the constructs involving sizeof and also notes that "byte"
is the space required to hold a char *in all existing implementations*).

--------
Kenneth R. Ballou		...!ucbvax!brahms!ballou
Department of Mathematics	ballou@brahms.berkeley.edu
University of California
Berkeley, California  94720