This sounds like the error I get for attempting partial template instantiation, which is not supported by VC++ compiler. I don't even believe it's supported in VC.Net, so I don't think an upgrade will help much. That's my understanding of the situation. Someone correct me if I'm wrong. I hope that I am ;) Jeff -----Original Message----- From: sen_al2002 [mailto:sen_al2002@yahoo.com] Sent: Wednesday, August 14, 2002 4:11 PM To: Boost-Users@yahoogroups.com Subject: [Boost-Users] Upgrade VisC++ compiler Hi, I am a newbie to all this programmer stuff. I am a physics student doing some computer simulations. I was trying to use the special function atanh from boost libraries but couldn't. The error message reads d:\boost_1_28_0\atanh.hpp(77) : error C2989: 'atanh_helper1_t<T,0>' : template class has already been defined as a non-template class Some advised me to update my VisC++ ver 6.0 compiler. How can I do that? Does anybody out there have any better advise? Thanks sen Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/