Mailinglist Archive: opensuse-programming (118 mails)

[John Lamb <J.D.Lamb@xxxxxxxxxxxxxx>]

Verdi March wrote:
> Thanks to all.
>
> So, instead of letting customization via inheritance, I simply add a
> method to class Process that set the proper function, i.e
> Process::setCustomFunction(int (*f)(int, char*[]));

I think you can use inheritance if you did something like the following. 
(The private base class constructor has a similar effect to using a pure 
virtual fucntion.)

class Process {
private:
  typedef int (*callback)( int, char** );
protected:
  Process( const callback run ) : run( run ){}
public:
  const callback run;
};

class Test : public Process {
public:
  Test() : Process( &Test::run ){}
private:
  static int run( int x, char** c ){ ... }
};

This should let you use inheritance if you want. For example you could 
create an instance with:

Process* process = new Test();

and then call

cfunction( process->run );

and that should work. You could even make a subclass singleton if that's 
appropriate.

OTOH, this could be a rather longwinded way of creating a number of 
similar functions, especially if you don't actually need polymorphism.

--
JDL

Non enim propter gloriam, diuicias aut honores pugnamus set propter
libertatem solummodo quam Nemo bonus nisi simul cum vita amittit.