[Lazarus] IUnknown and reference counting

[Sven Barth]

On 21.03.2013 21:15, Hans-Peter Diettrich wrote:
> Sven Barth schrieb:
>
>>  > Interface delegation is something different from multiple
>> inheritance. The interface implementor and the interfaced object then
>> have nothing in common, the methods of the implementor cannot access
>> elements of the interfaced object.
>>
>> But with only interfaces you inherit merely the syntactical
>> "interface" while with delegation you can also reuse an existing
>> implementation for that interface.
>
> Use an object (class instance) for the same purpose, and you don't have
> to write additional code as well.

Interfaces are there to abstract away the implementation, because you'll 
only have access to those methods that the interface defines. This 
allows for low coupling between components and thus for an improvement 
of code testability and maintainability.

Regards,
Sven