Re: Private Virtual Methods

From:

Seungbeom Kim <musiphil@bawi.org>

Newsgroups:

comp.lang.c++.moderated

Date:

Wed, 25 Apr 2012 21:20:52 -0700 (PDT)

Message-ID:

<jn9olh$v4q$1@usenet.stanford.edu>

On 2012-04-24 16:16, Dan McLeran wrote:

My blog post on Private Virtual Methods (a.k.a. Non-virtual
Interface idiom): http://wumbocode.com/wordpress/?p=266

Contrary to what you say, the example fails to "illustrate the power
of this idea and why you should add this technique to your arsenal
[...]." Since Automobile::go() and Automobile::stop() do nothing more
than calling the virtual functions, the example would have worked
equally well without the public non-virtual functions and with the
virtual functions as public:

class Automobile {
public:
     // ...
     virtual void go() = 0;
     virtual void stop() = 0;
};

The examples at
<http://en.wikibooks.org/wiki/More_C%2B%2B_Idioms/Non-Virtual_Interface>,
which your blog post also mentions, illustrate the usefulness of the
non- virtual interface idiom far better by showing how to perform in
public non-virtual functions some common operations such as
acquiring/releasing locks or checking pre-/post-conditions.

--
Seungbeom Kim

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