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Internet Message Format | 1996-08-06 | 1.6 KB

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From: [e-mail] (Johan Wikman)
Newsgroups: comp.lang.c++
Subject: Re: Why use private class members instead of protected?
Date: 14 Jan 1996 08:05:33 GMT
Organization: Nokia Research Center
Message-ID: <[e-mail]>
References: <[e-mail]>
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NNTP-Posting-Host: falcon.research.nokia.fi
In-reply-to: Enno Sandner's message of Fri, 12 Jan 1996 09:32:44 +0100


In article <[e-mail]> Enno Sandner <[e-mail]> writes:

   However an accessor/mutator pair like

           void MyClass :: set_data(const DataType&) { ... }
           DataType MyClass :: get_data() const { return _data; }

   completely avoids this sort of problems. If the 'DataType' uses some
   technique to speed up copying (for example ref-counting) the overhead
   is minimal.

I think you only change the problem into something else. Now if you
ever choose to change the representation of '_data' you face the
problem of converting a DataType to and from whatever type '_data'
is. The problem is still there, it has only changed shape.

In my opinion it fairly seldom makes sense to provide accessor/mutator
functions to the data members of a class. In fact, I get suspicious
when a class reminds you of a data repository instead of reminding you
of something that provides behaviour.

    Johan
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