Re: RecentAction doesn't derive from RecentChooser

[José Alburquerque <jaalburquerque cox net>]

José Alburquerque wrote:
> José Alburquerque wrote:
>   
> > Jonathon Jongsma wrote:
> >   
> >     
> > > ABI means Application Binary Interface.  The (huge) benefit of keeping
> > > the ABI stable is that you can switch out the shared gtkmm library to a
> > > newer version and have the apps that link against the library work
> > > exactly as they worked on the old version.  If the ABI of the library
> > > had changed from one version to the next, any applications that used the
> > > library would need to be recompiled, you couldn't just switch to a newer
> > > version of the library.  
> > > For example, if gtkmm changed its ABI and your linux distribution
> > > updated to that new version of gtkmm, every single application that used
> > > gtkmm would have to be updated as well.
> > > That's the short answer for why maintaining ABI compatibility is a good
> > > thing.
> > > I don't know all of the guidelines for maintaining ABI compatibility,
> > > but I know that you have to be very careful with virtual functions,
> > > since they affect the size of an object (by changing the vtable), but
> > > adding regular functions should be ok.
> > >   
> > >     
> > >       
> > Thanks so much for that, it's already very clear from your explanation!  
> > What about constructors?  Do they also affect the size of objects?
> >
> >   
> >     
> Searching a bit more, I found the following two links:
>
> http://scm.opendap.org:8090/trac/wiki/libdapABIStability
> http://www.cprogramming.com/tutorial/size_of_class_object.html
>
> I don't see anything in them that would lead me to believe that adding 
> constructors (as in the case of regular functions) would affect ABI 
> compatibility.  Thanks.
>
>   
Though from KDE development, I should also add this other link:

http://techbase.kde.org/index.php?title=Policies/Binary_Compatibility_Issues_With_C%2B%2B

The "Do's and Don'ts" section really clarified the constructor question 
for me by saying:

   You can...

       * add new non-virtual functions including signals and slots and
         constructors.

       ...

-Jose