Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!olivea!tardis!tymix!uunet!taumet!steve
From: steve@taumet.com (Stephen Clamage)
Newsgroups: comp.lang.c++
Subject: Re: use of const within a class to dimension arrays (can do?)
Message-ID: <775@taumet.com>
Date: 20 Jun 91 16:08:36 GMT
References: <359@secola.Columbia.NCR.COM>
Distribution: comp.lang.c++
Organization: Taumetric Corporation, San Diego
Lines: 33

jmartin@secola.Columbia.NCR.COM (John Martinez) writes:

>Is there any way to use a const within a class as the size of an array
>which is also a member of the class?

No, unless you use an enum constant (ugh).

>class Minimal {
>   static const int ARRAY_SIZE;
>   static int array[ARRAY_SIZE];   // "error - constant expression required"
>};
>const int Minimal::ARRAY_SIZE=10;

>This generates an error, presumably because ARRAY_SIZE, while const, doesn't
>count as _really_ constant until it is given a value.

No, the array size must be a compile-time constant, and declaring a member
	static const int ARRAY_SIZE;
or
	const int ARRAY_SIZE;
does not create a compile-time constant, but does create storage for a
class field.

I agree that this is a language deficiency.  At the moment, the best
you can do is this:

class Minimal {
   enum { ARRAY_SIZE = 10 };
   static int array[ARRAY_SIZE];
};
-- 

Steve Clamage, TauMetric Corp, steve@taumet.com