On Mon, Sep 22, 2014 at 07:21:46PM +0200, Sven Barth wrote: > Am 22.09.2014 17:11 schrieb "Jonas Maebe" <jonas.ma...@elis.ugent.be>: > > > > > > On 22 Sep 2014, at 16:44, Peter Popov wrote: > > > >> Another comment: If referenced objects all derive from a single base, > then, the user cannot possibly have another hierarchy, which uses ref. > objects. As I mentioned earlier, I do this explicitly for an object well > down my hierarchy. So, it seems to me you still need something like: > >> > >> -- code -- > >> > >> > >> TRefObject = referenced class(TWhateverBase) > >> end; > > > > > > I would strongly recommend against that. Referenced and unreferenced > objects are completely different beasts with different behaviours. If you > allow that, you get all kinds of problems down the line. E.g. you either > have to forbid assigning a TRefObject to a TWhateverBase (which runs > counter to a very basic OOP principle), or allow it and then have the > programmer deal with the resulting reference counting mess-ups. > > As written in my RFC I would go the "allow it" route and provide mechanisms > to manually access the reference count from a non-reference counted > variable (thus being implemented in TObject). Optionally one could add a > warning that is off by default that one could use for such cases. This > approach is necessary, because we'd otherwise need to introduce overloads > for e.g. RTTI functionality in TypInfo or to introduce some compiler magic > for them (I don't like either of these two possibilities).
Sven At the risk of starting a flame war I have been pondering this question since these threads have started: Why has there been so many messages on this list debating the pros and cons of reference counting objects? The beauty of the Pascal language is in its structure ie: procedures,functions,OOP. Why does it need to be a functional programming language as well when there are Haskell, Lisp, Scheme and other functional languages that have already done the hard work. John _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
