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From: richard@aiai.ed.ac.uk (Richard Tobin)
Newsgroups: comp.lang.c,gnu.emacs.bug,comp.emacs
Subject: Re: GNU Emacs, memory usage, releasing
Message-ID: <1508@skye.ed.ac.uk>
Date: 5 Jan 90 17:00:31 GMT
References: <1558@aber-cs.UUCP> <32534@news.Think.COM> <S_W2=5ggpc2@ficc.uu.net> <1990Jan2.151615.19098@talos.uu.net> <USER.90Jan3094015@pmax27.osf.org> <1990Jan3.151427.12532@ux1.cso.uiuc.edu>
Reply-To: richard@aiai.UUCP (Richard Tobin)
Organization: AIAI, University of Edinburgh, Scotland
Lines: 21

In article <1990Jan3.151427.12532@ux1.cso.uiuc.edu> mcdonald@aries.scs.uiuc.edu (Doug McDonald) writes:
>  This seems to me to be disgusting. Why not just define these
>  "things" (the pointer with 8 bits of something else stuck in somewhere)
>  as 
>  
>  struct THING {
>  char * ptr;
>  char tag;
>  }

Because this will typically make each THING take up twice as much
space, which is often unacceptable. 

If portability is more of a concern than speed, one approach is to
use bitfields and treat the "address" as an array subscript.

-- Richard
-- 
Richard Tobin,                       JANET: R.Tobin@uk.ac.ed             
AI Applications Institute,           ARPA:  R.Tobin%uk.ac.ed@nsfnet-relay.ac.uk
Edinburgh University.                UUCP:  ...!ukc!ed.ac.uk!R.Tobin