Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!utoday!comeau
From: comeau@utoday.UUCP (Greg Comeau)
Newsgroups: comp.lang.c++
Subject: Re: const enums -- Lawyers opinions??
Keywords: const, enum
Message-ID: <1142@utoday.UUCP>
Date: 10 Jan 90 16:59:04 GMT
References: <963@rna.UUCP> <10197@microsoft.UUCP> <9925@ardent.UUCP>
Reply-To: comeau@.UUCP (Greg Comeau)
Organization: UNIX Today!, Manhasset, NY
Lines: 28

In article <9925@ardent.UUCP> jss@jra.ardent.com () writes:
>In article <10197@microsoft.UUCP> jimad@microsoft.UUCP (JAMES ADCOCK) writes:
>>cfront 2.0 accepts this with the appropriate warning that you're assigning
>>an int to an enum -- when you or individual bits together you end up with
>>values not in the set original defined in the bits enum -- so how can the
>
>The question of what an enum type "really is",  ...a consensus finally
>emerged and both ANSI C and the most recent C++ reference manual agree 
>that they are integral types. This means that its perfectly sensible to
>assign arbitrary integer values to variables of enum type. 
>
>Jerry Schwarz

Although I agree that enum's are now integral types in both dpANSI C and
C++ one must take the semantics of enums into consideration before
saying that they (integrals) are completely convertable amongst each other.
First although enums contain integer constant values (int's actually), they
are not an integer types (a basic type accto ANSI) per se.  Also, although
ANSI C makes no mandation as I recall, in C++ enums are actually types and
therefore although the enumerators values are convertable to int values,
only enumerator values are supposed to be assigned to objects of the
respective enumeration (in other words these is no implicit integral
promotion or conversion when going into an enum lvalue).
-- 
Greg, Comeau Computing, 91-34 120th Street, Richmond Hill, NY, 11418
Also, mag writer for UNIX Today! (SysAdm columnist), Microsoft Systems Journal
(C programming), + others. Also, BIX c.language & c.plus.plus conf. moderator.
Here:attmail!csanta!greg / BIX:comeau / CIS:72331, 3421 / voice:718-849-2355