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From: cramer@optilink.UUCP (Clayton Cramer)
Newsgroups: comp.lang.c
Subject: Re: Unions
Keywords: What can they be used for?
Message-ID: <580@optilink.UUCP>
Date: 20 Oct 88 17:35:43 GMT
References: <322@hrc.UUCP>
Organization: Optilink Corporation, Petaluma, CA
Lines: 29

In article <322@hrc.UUCP>, dan@hrc.UUCP (Dan Troxel VP) writes:
> 
> Except for the memory savings, what are Unions suited for?
> -- 
> Dan Troxel VP of Computer Operations @ 

They can be useful for showing that several different possible alternatives
are just that -- alternatives.  Consider:

        union uTag
            {
            int     CmdTblJumpIndex;
            PFI     FuncToExecute;
            char*   SystemCmdToRun;
            }   ActionToTake;

vs.

            int     CmdTblJumpIndex;
            PFI     FuncToExecute;
            char*   SystemCmdToRun;

The first example shows that all three are alternatives, and in fact,
if you tried to write code that used two of them at once, it wouldn't
work correctly.
        
-- 
Clayton E. Cramer
..!ames!pyramid!kontron!optilin!cramer