Path: utzoo!utgpu!water!watmath!clyde!bellcore!faline!ulysses!allegra!mit-eddie!uw-beaver!ssc-vax!cxsea!blm
From: blm@cxsea.UUCP
Newsgroups: comp.lang.c
Subject: Re: structure comparison
Message-ID: <2330@cxsea.UUCP>
Date: 15 Jan 88 16:40:51 GMT
References: <1322@sugar.UUCP> <1942@ho95e.ATT.COM> <1373@sugar.UUCP> <2456@ihlpe.ATT.COM> <10175@mimsy.UUCP>
Reply-To: blm@cxsea.UUCP (Brian Matthews)
Organization: Computer X Inc.
Lines: 22
Posted: Fri Jan 15 11:40:51 1988

Chris Torek (chris@mimsy.UUCP) writes:
|In article <2456@ihlpe.ATT.COM> woods@ihlpe.ATT.COM (Swan) writes:
|>The problem is that the compiler cannot be sure how many bytes in the
|>structures to compare for [in]equality.
|This is easily solved by simply defining it to compare all elements
|of the structure and no holes.  Unions become problematical, but
|this, too, is easily solved, by outlawing comparison of things that
|contain unions.

What do you do about things like char x[10]?  How does the compiler know
that (and if) you want to compare a null-terminated string, as opposed to
every character?  Also, what about the fairly common practice of having
the last item be of indeterminate size (at compile time)?

In my opinion, there are too many special cases to make structure
comparison useful (and usable).

-- 
Brian L. Matthews                               "A power tool is not a toy.
...{mnetor,uw-beaver!ssc-vax}!cxsea!blm          Unix is a power tool."
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