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From: vilot@csdpie.dec.com (Michael J. Vilot)
Newsgroups: comp.lang.c++
Subject: Visibility Bug in 1.2?
Message-ID: <8901062306.AA16858@decwrl.dec.com>
Date: 6 Jan 89 23:06:25 GMT
Organization: Digital Equipment Corporation
Lines: 45

On p. 196 of "The C++ Programming Language," Bjarne describes the semantics
of class member visibility for derived classes, and says:
 
    "It is also possible to declare some, but not all, of the public members
     of a base class public members of a derived class."
 
He goes on to demonstrate it in an extension to an example.
In the example, he never actually shows an example of code
accessing it ... here's a fragment that fails:

	class Base {
	  int z;
	public:
	  int d, e;
	};

	class Derived : Base {	// Base's members are now private in Derived
	  int a, b, c;	        // also private
	public:
	  Base::d;		// should make Base::d public
	};

	main()
	{
	  Derived y; 
	  y.d =1;    // error reported here
	}

Here's the transcript:
	designer C++ Programming System, release 1.2 Vms4.5.1
	Copyright 1987, Glockenspiel Ltd., Dublin, Ireland
	Glockenspiel System V.3 compatible C pre-processor, release.4
	AT&T C++ Translator, release 1.2 Vms4.5.1
	Copyright 1984 AT&T, Inc. and 1987 Glockenspiel Ltd.
	"test.cxx;0", line 17: error:  d is from private base class
	Error executing command CFXX +L +l +ftest.CXX;0 <test.IXX;0
	C++ Driver terminating. 

Has this been reported before? Is it fixed yet?  Is it also in g++?

==
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