Re: Override public virtual Functions with private Functions?

From:

Barry <dhb2000@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Tue, 27 May 2008 17:00:33 +0800

Message-ID:

<g1gijr$gdu$1@news.cn99.com>

anon wrote:

dizzy wrote:

Chris Gordon-Smith wrote:

My questions are:-

i) Is overriding public virtual functions with private functions good
practice?
ii) Are there any disadvantages?

In general you should separate interface (the public API the base class
provides) from configurability (the overriding feature). This is also
called the Template Method Pattern and is described in detail here:
http://www.gotw.ca/publications/mill18.htm

Interesting article. It says that in some cases the destructor should be
made protected. I have never thought about it before, and it made me
wonder why would anyone make the destructor private or protected.
So, the question is what are uses of such destructor?

Considering a class wrapping only static function as helper or factory
function, we should make the dtor private not to allow any instance.

We can also make the dtor private and with a static function "destroy"
to allow instance created only by new (no stack allocation)

making the dtor protected, then child class publicly/protectedly
derived from from still has access to it. at this time, you can never
delete a pointer to the base class.

--
Best Regards
Barry