[fpc-pascal] Out of scope method?

[Marco van de Voort]

In our previous episode, Ryan Joseph said:
> > See http://freepascal.org/docs-html/current/ref/refse48.html#x101-1230007.7
> > for an example.
> > 
> > See also http://wiki.freepascal.org/How_To_Use_Interfaces
> 
> "All COM interfaces use reference counting. This means that whenever an interface is assigned to a variable, it?s reference count is updated. Whenever the variable goes out of scope, the reference count is automatically decreased. When the reference count reaches zero, usually the instance of the class that implements the interface, is freed.?
> 
> Shouldn?t destroy be called in this example when TestScope exists?

No, since you don't declare an interface variable, but a class variable.

There are a zillion Delphi faqs about this, but the crux is to use

var
  scope:IInterface;

And reference counting as garbage collection method has been discussed to
dead on various maillists and forums. Both Delphi and Lazarus/FPC.