Re: [boost] Re: class proposal

From: Noel Yap (Noel.Yap_at_[hidden])
Date: 2003-04-24 10:30:29

"Justin M. Lewis" wrote:
> And, it's not either pass in a whole object or pass in a pointer, you're
> forgetting references.  This new class takes in a reference, and stores
> that.  It doesn't do anything with pointers.

I didn't really forget references.  IMHO, references are pointers that
are implicitly dereferenced.  At the machine level, they are typically
treated the same (eg address is passed by value).

> And, again, returning an object isn't always desirable, you could be copying
> large objects for no reason.  You may not call a copy constructor, but an =
> operator is being used.

My reply to this was to use smart pointers.  But as Terje Slettebø
pointed out (but I got distracted by work before sending out my reply),
smart pointers don't resolve the problem that the object may still
change from underneath.

I still think there's no need for the proposed wrapper class since:

  void f( T& value_may_change_, T const& value_may_not_change_ );

is still an acceptible alternative.  IOW, if users stick to using T&
only to indicate values that may change, and T const& to indicate values
that may not change, the wrapper class has no added value (forgive the
unintended pun).

Noel
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