Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!ai-lab!jym
From: jym@wheaties.ai.mit.edu (Jym Dyer)
Newsgroups: comp.lang.c
Subject: Re: malloc() and sizeof
Message-ID: <1460@wheat-chex.ai.mit.edu>
Date: 3 Apr 89 21:15:18 GMT
References: <510@lakesys.UUCP> <9969@smoke.BRL.MIL>
Reply-To: jym@wheaties.ai.mit.edu (Jym Dyer)
Organization: Ono-Sendai
Lines: 14

In article <9969@smoke.BRL.MIL> gwyn@brl.arpa (Doug Gwyn) writes:
>In article <510@lakesys.UUCP> chad@lakesys.UUCP (Chad Gibbons) writes:
>>	struct foo tmp = (struct foo *)malloc(sizeof *tmp);
>
> Sizeof comes in two flavors, sizeof(type) and sizeof object.  In the
> latter case the object-expression is not evaluated, only its type is
> used.  Therefore the above usage is perfectly legitimate.

It should be pointed out that object can be in parentheses.  This fact
 is not lost on those who prefer to use sizeof like a function instead
  of the operator that it is.

Also, the example has a typo in it.  The `tmp' variable must be declared
 as a pointer to struct foo, not as a struct foo.
  <_Jym_>