Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!uunet!island!grenada!roger
From: roger@grenada.island.COM (Roger Corman)
Newsgroups: comp.lang.c++
Subject: Re: const vs. static in class declaration
Keywords: const, static, class constants
Message-ID: <139@grenada.island.COM>
Date: 30 Mar 91 00:01:50 GMT
References: <286@dayton.stanford.edu>
Organization: Island Graphics, Santa Rosa, California
Lines: 66

In article <286@dayton.stanford.edu> lma@dayton.Stanford.EDU (Larry Augustin) writes:
>I have a number of integer constants that are part of a class.  What
>is the correct way to go about doing this?  I have been using:
>
>
>   class foo {
>    private:
>	...
>    protected:
>	...
>    public:
>      const int ID      = 258;
>      const int NUMBER  = 259;
>      const int IPORT   = 260;
>	...
>    };
>
>But I've been told that this only works in g++, and isn't standard.  I
>would like to avoid doing anything in my my application that isn't
>portable.
>
Your way does not work with CFront.  Two ways to do this (using 'static
const' and enum) are shown in this example.  Only the enum lets you actually
include the initializer value in the class definition.  The static const
requires that the initializer be outside the class definition (usually the
not in an #include file).
------------------------------------

#include <iostream.h>

class foo
{
public:
	foo(){}
	static const int ID;
	enum {IPORT=100};
};
	
const int foo::ID = 200;

main()
{
	foo f;
	
	cout << f.ID << "\n";
	cout << f.IPORT << "\n";
	cout << foo::IPORT << "\n";
	cout << foo::ID << "\n";
}
	

------------------------------
Roger Corman
Island Graphics
149 Stony Circle, Suite 200
Santa Rosa, CA 95401
(707)523-4465
{uunet,sun,ucbcad!island!roger} 

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