[boost] Re: ABC similar to noncopyable

From: Miki Jovanovic (miki_at_[hidden])
Date: 2000-02-23 16:31:22

"jon jagger" <jon.jagge-_at_[hidden]> wrote: 
>      class derived : public abc
>      {
>      };
> 
>      abc * ptr = new derived;
>      delete ptr;

You are using a bad example. Try this:

class ICommand : public abc {
  public:
    virtual void execute() = 0;
};

class MyCommand : ICommand {
  public:
    virtual void execute() { /* do something */ }
};

ICommand *pCmd = new MyCommand;
delete pCmd;

In this case it is IMPERATIVE.

The only benefit of abc I really want is this: once you declare a
virtual destructor, it always stays virtual. So, if you are designing
an abstract base class, it 99% of the cases it needs a virtual
destructor. abc class should not be visible from the outside. The
derived class should only get the benefit of implicitly having a
virtual destroctor.

Cheers,

Miki.