Warp wrote:
> Darren New <dne### [at] sanrrcom> wrote:
>> Indeed. Especially if you use something like reference counting and deal 
>> with circular references specially or something.
> 
>   What I meant is that,

Oh, I see. Yes, I guess that would work. Probably an excellent way to do it, 
especially if you store enough info about things that you can do compacting 
collections.

>   On a different note, one example where I think the RAII mechanism is
> better than the Java-style GC mechanism is that RAII allows you to
> implement copy-on-write semantics (ie. "lazy copying") for objects.

I understand what you're saying, but this is a bad example for Java because 
that's exactly how it would work in Java, because strings are immutable, so 
your "+=" returns a brand new string. :-)  That's why Java has a 
StringBuilder as well as a String.

>   Of course CoW requires reference counting of the data (or, more precisely,
> it needs a way to tell if the data is being shared or not). I don't know
> how you would do that in Java (transparently, or at all).

Very difficult in Java to think of a way, offhand. I don't think you can 
overload pure assignment in C#, so I don't think you could do the same sort 
of thing there easily either.

>   This is possible transparently in C++ because of RAII: When objects are
> created, copied, assigned and destroyed, you can specify what happens.

I think it's more because you can overload the assignment operator, not the 
RAII as such. Maybe you count that as part of RAII.

-- 
Darren New, San Diego CA, USA (PST)
   Serving Suggestion:
     "Don't serve this any more. It's awful."

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