Re: Can I inherit to reuse code?

From:
El sitio de Numancia <apbarrero@gmail.com>
Newsgroups:
comp.lang.c++.moderated
Date:
Wed, 29 Jul 2009 06:44:23 CST
Message-ID:
<cdc7c7e4-bfca-43be-92ac-89c7d2c7b5e5@c1g2000yqi.googlegroups.com>
On 29 jul, 00:57, DeMarcus <use_my_alias_h...@hotmail.com> wrote:

Now, let's say I already have an abstract base class, then is it really
that bad to put some common used functions in there?


Well, it is not that bad, but might be cleaner if you defined a third
class and include
a member in the abstract base class:

class Helper
{
public:
     Helper();

     void doThis();
     void doThat();

};

class Base
{
public:
     Base();

     virtual void fnc() = 0;

protected:
     virtual void doThis_() { h_.doThis(); };

private:
     Helper h_;
};

class MyClass : public Base
{
public:
     MyClass();

     virtual void fnc() { doThis_(); }

};

When is an abstract base class, except interfaces, necessary anyway?


With a pure abstract class (interface) you separate interface and
implementation; with a concrete (nonabstract at all) base class you
stablish an "is a" relationship (e.g. Dog is an Animal); with an
abstract base class you do both.

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