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From: jimp@cognos.uucp (Jim Patterson)
Newsgroups: comp.lang.c
Subject: Re: Enum vs Define
Message-ID: <1011@aldebaran.UUCP>
Date: Mon, 29-Jun-87 10:59:02 EDT
Article-I.D.: aldebara.1011
Posted: Mon Jun 29 10:59:02 1987
Date-Received: Wed, 1-Jul-87 04:24:58 EDT
References: <196@dbase.UUCP>
Reply-To: jimp@aldebaran.UUCP (Jim Patterson)
Organization: Cognos Incorporated, Ottawa, Canada
Lines: 25

In article <196@dbase.UUCP> awd@dbase.UUCP (Alastair Dallas) writes:
>This may sound like a beginner's question, but I don't consider myself
>a beginner:  Why use enum instead of #define?  

It's often preferrable to use a language feature rather than a
preprocessor featuure simply because the compiler can then make
more intelligent decisions.  This also extends to the language
support systems such as debuggers.

A good illustration of this is the VAX/VMS debugger which supports
C as a high-level language.  In your example, if you declare a value
x as an enum and then in the debugger say
	EXAMINE x 
the debugger will give you an answer of ERRMSGA or ERRMSGB (assuming
it contains a valid value). If you use #define, then the debugger
will answer 1 or 2.  Having the debugger provide symbolic answers
instead of numeric ones can be a real benefit when you have a lot
of such code and no handy listing.



-- 

Jim Patterson          decvax!utzoo!dciem!nrcaer!cognos!jimp
Cognos Incorporated