Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!cornell!uw-beaver!mit-eddie!killer!pollux!dalsqnt!rpp386!jfh
From: jfh@rpp386.UUCP (John F. Haugh II)
Newsgroups: comp.lang.c
Subject: Re: Optimal structure field ordering
Message-ID: <3747@rpp386.UUCP>
Date: 9 Jul 88 00:32:46 GMT
References: <163@navtech.uucp> <806@garth.UUCP> <254@obie.UUCP> <3459@rpp386.UUCP> <5233@ihlpf.ATT.COM>
Reply-To: jfh@rpp386.UUCP (The Beach Bum)
Organization: Big "D" Home for Wayward Hackers
Lines: 27

In article <5233@ihlpf.ATT.COM> nevin1@ihlpf.UUCP (00704a-Liber,N.J.) writes:
>In article <3459@rpp386.UUCP> jfh@rpp386.UUCP (The Beach Bum) writes:
>>it could be serious for any language to not specify how it rearranges
>>structures.  it could make it impossible for separate compilation to
>>work, period.
>
>Not quite true.  As long as the compiler internally arranges the fields in
>a structure the same way, no problems occur.  There is no need for you, the
>user of a compiler, to know what order fields are stored in, as long as the
>compiler is self-consistent (unless you are doing something like a block
>move into a structure).

provided there exists exactly one compiler in the entire universe.  for
without the assurance, via an agreed upon or written standard, that the
structures are arranged in a common fashion, no two ``self consistent''
compilers are neccessarily going to produce the same structure ordering.

and therein lies the beauty of a standard.  while separate compilation
may not be such a huge issue, using multiple compilers on a single machine,
is.

- john.
-- 
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