Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!apple!sun-barr!newstop!sun!plx!johnc
From: johnc@plx.UUCP (John C.)
Newsgroups: comp.lang.c++
Subject: Re: enums
Keywords: enum subrange array index
Message-ID: <2205@plx.UUCP>
Date: 11 Jan 90 17:59:48 GMT
References: <963@rna.UUCP> <10197@microsoft.UUCP> <9925@ardent.UUCP> <10215@microsoft.UUCP>
Reply-To: johnc@plx.UUCP (John Ciccarelli)
Organization: Plexus Software, Santa Clara, CA
Lines: 32
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Having used full-featured enums (and subranges -- *sigh* ) 
in other languages, this debate about "should you be prevented from 
assigning an int to an enum without a cast" seems like needless
hand-wringing.  IMHO, *of course* you shouldn't be allowed to do this 
without a cast (this is to offend some diehard original-C types I know).  

But if I have (pardon the loose syntax):

  enum Fruit { Apple, Orange, Banana, Lemon }
  enum Vegetable { Tomato [<==debatable ;-)], Squash, Rutabaga }
  ...
  Fruit fruit;
  Vegetable veg;

then the assignment 'fruit = 1' is as much an error as 
'fruit = Squash' or 'fruit = veg'.

By 'full-featured' enums, I meant (for one thing) the ability 
(in other languages) to declare an array with an 'enum' subscript:
  
  int fruitPrice[ Fruit ];

This is so simple but so powerful.  In the "C++ Primer" I didn't
see a way to do this, probably because it presupposes arrays with
non-zero base subscripts, which I'm pretty sure C++ also lacks.
Both features are conceptually simple but greatly improve readability 
and robustness.  Ditto subrange types.

...My three wishes for today.  (Are the C++ architects listening?)

/John Ciccarelli, Plexus Software (johnc@plx.uucp || ...sun!plx!johnc)
[opinions mine]