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From: jbickers@templar.actrix.gen.nz (John Bickers)
Newsgroups: comp.sys.amiga.misc
Subject: Re: Bitfields in C
Message-ID: <3362.tnews@templar.actrix.gen.nz>
Date: 8 May 91 08:43:57 GMT
References: <214.2826444A@weyr.FIDONET.ORG>
Organization: TAP, NZAmigaUG.
Lines: 18

Quoted from <214.2826444A@weyr.FIDONET.ORG> by David.Plummer@p0.f70.n140.z1.FIDONET.ORG (David Plummer):
> Does anyone know how to build an easily- addressable bitfield array in 
> C?  Exactly what I would like to be able to do it this:                

    Failing anything else, you could try using a macro. So allocate your
    bitfield array like this:

    ULONG   mybits[(NUM_FIELDS + 31)/32];

    #define GETBIT(x)   ( (mybits[x >> 5] & (1L << (x & 31L))) )

    Etc. You might find it nicer to use tables of masks, or functions
    instead of macros, etc.

> David Plummer - via FidoNet node 1:140/22
--
*** John Bickers, TAP, NZAmigaUG.        jbickers@templar.actrix.gen.nz ***
***         "Endless variations, make it all seem new" - Devo.          ***