One last time: annoying warning

[Roberto Bagnara]

Dear GiNaC developer,

I was composing my fourth message about the the unused parameter
in line 84 in basic.h (GiNaC 1.0.11) and about the trivial and
100% safe patch I have proposed to fix it.  In another window
I was creating a new CVS repository for GiNaC so that we could
avoid patching your releases manually over and over again.
I was lucky enough to have the inspiration to double check
the archives of ginac-devel at ginac.de before hitting the "send"
button.  Having discovered that I was not completely ignored
during all this time, I had a chance to erase a message you
would not have liked.  (I don't think replies to messages sent
to ginac-devel should only be sent to the list, but anyway
I have now subscribed it: from what I can see this entitles
me to receive also some more spam).

I would now like to discuss the issue on purely technical
grounds.  The point is that we need to replace  the following
line (84) of basic.h

         virtual void destroy(bool call_parent) { }

with the following

         virtual void destroy(bool /* call_parent */) { }

We cannot follow the advice of Christian Bauer (*) to tell the
compiler not to warn about unused parameters for the simple
reason that we find these warnings very useful in our
development work.  In contrast, I believe the patch I am
repeatedly proposing:

1) complies with the C++ standard;
2) does not cause problems with any the versions of all the C++
    compilers we know of;
3) preserves the information about what the bool parameter is;
4) is good both for users that run with warnings on and for those
    switching them off.

I would be very grateful if someone could tell me what is so
wrong with it that we have to set up a paraller CVS repository
for GiNaC.
Thanks a lot

     Roberto


(*) "I suggest turning off that compiler warning. Yes, I'm serious."

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it