NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c++-part2/11105

Internet Message Format | 1996-08-05 | 1.7 KB

Path: zilker.net!usenet
From: [e-mail] (Greg Rickard)
Newsgroups: comp.lang.c++
Subject: Re: private base class vs. private member object
Date: 12 Mar 1996 18:45:04 GMT
Organization: Data Interface Systems Corporation
Message-ID: <4i4gng$[e-mail]>
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Certainly to be able to access the protected methods of another class,
that class must be incorporated as a base class.
Now what about the case where a service MUST be incorporated as a private
member object (i.e., CANNOT be incorporated as a base class)?

>[e-mail] (Greg Rickard) wrote:
>>In Cargill's C++ Programming Style, exercise 3.1 asks the reader to
>>"create a class that obtains the services of another class that must be
>>incorporated as a private base class.  Second, create a class in which a
>>service must be incorporated as a private member object".

In article <4hrl32$[e-mail]>, Rob and Sylvia Worsnop
<[e-mail]> says:
>
>I'm not sure quite what you mean here so there is a risk that I'll
>be answering a question you've not even asked! Anyway , here goes..
>
>If you are asking when to use private base classes and when to use a
>private member object, the answer is that you can use private member
>object only when you can do everything you want with that object's
>public interface.
>If you want to access protected methods use private inheritance.
>Some people just use private inheritance anyway because the code
>is often cleaner.
>Whether you use private member objects or private inheritance doesn't
>matter a great deal. The really important thing is not to confuse
>public inheritance and private inheritance.
>
>Rob.