Re: more inheritance patterns

From:
"Alf P. Steinbach" <alfps@start.no>
Newsgroups:
comp.lang.c++
Date:
Fri, 27 Jun 2008 05:54:38 +0200
Message-ID:
<--CdnR-gSMYd-fnVnZ2dnUVZ_qfinZ2d@posted.comnet>
* Mick Charles Beaver:

At work, someone showed me a way to avoid virtual functions while
maintaining an interface class.

Basically,

class _MyClass {
void Method;
};

#if defined(LINUX)
#include "linux/MyLinuxClass.h"
class MyClass : public MyLinuxClass {};

#elif defined(WINDOWS)
#include "windows/MyWindowsClass.h"
class MyClass : public MyWindowsClass {};
#endif

Then, throughout the code base, MyClass would be used, following the
interface defined in _MyClass, while still allowing platform-specific
code where needed.


Well your description is woefully incomplete. Here are some problems:

  1. Name that starts with underscore followed by uppercase, "_MyClass",
     is reserved for the implementation.

  2. Non-virtual member functions can't be overridden.

  3. Direct includes of platform-specific definitions pollutes namespaces
     with platform-specific things.

For problem 3 you may look up the PIMPL idiom.

My question is, where could I read about more constructions like this?


Believe me, you don't want to, except where they're discussed in depth as
*anti-patterns*.

My coworker called it an "inheritance pattern." I'd love to learn more
about them (even though I'm sure a case can be made for avoiding this
style).


It needs no case. It's braindead. You don't need to make a case to avoid eating
rotten worm-infested apples, at least not when shiny fresh good apples are all
around, some for free, and you're not starving to the point of eating flies. :-)

Cheers, & hth.,

- Alf

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