Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!zaphod.mps.ohio-state.edu!rpi!batcomputer!lijewski
From: lijewski@batcomputer.tn.cornell.edu (Mike Lijewski)
Newsgroups: comp.std.c++
Subject: Re: request for comments
Message-ID: <1991Feb3.212909.16251@batcomputer.tn.cornell.edu>
Date: 3 Feb 91 21:29:09 GMT
References: <95@tdatirv.UUCP> <70305@microsoft.UUCP> <1991Feb02.165526.1933@nowhere.uucp>
Organization: Cornell National Supercomputer Facility
Lines: 41

In article <1991Feb02.165526.1933@nowhere.uucp> sking@nowhere.uucp (Steven King) writes:
>In article <70305@microsoft.UUCP> jimad@microsoft.UUCP (Jim ADCOCK) writes:
>>
>>a number of other ways to make derived types.  Also, it has been pointed 
>>out to me that now that enums are distinct types, perhaps they too should
>>be candidates for operator overloading:
>>
>>"An operator function must either be a member function or take at least one
>>argument of class type, enum type,  or of a type derived from a class 
>>or enum type."
>
>   There are is a problem with allowing operator overloading, or even
> operators at all, on enums. Given 
>
> enum modes { rd_ok = 1, wr_ok = 2, ex_ok = 4 } ;
>
> for ( modes m = rd_ok ; m < ex_ok ; m++ ) // this is accepted by Cfront 2.0!
>
>   What does _m++_ do? The problem with arbitrary arithmatic manipulations
> of enum's are alluded to in ARM ( sorry, dont have the # ).

It is a bug that m++ is accepted.  In a ARM-conforming C++ implementation
this would be a bug since what you have is

  m = (int)(m + 1);

and integers cannot be assigned to enums.

>
>-- 
>                                        ..!cs.utexas.edu!ut-emx!nowhere!sking
>
>been dazed and confused for so long its true; wanted an OS, never bargined for
>you. Lotsa people hacking, few of them know, kernal of unix was created below...


-- 
Mike Lijewski  (H)607/272-0238 (W)607/254-8686
Cornell National Supercomputer Facility
ARPA: mjlx@eagle.cnsf.cornell.edu  BITNET: mjlx@cornellf.bitnet
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