I am trying to upgrade from Boost 1.52 to 1.55. Everything is fine with Clang 3.3, but I get this error with G++ 4.5.1: In file included from /netDISKS/master/netmt/LINUX_INTF14/cgi/boost/1.55.0/Include/libboost/boost/system/error_code.hpp:18:0, from /netDISKS/master/netmt/LINUX_INTF14/cgi/boost/1.55.0/Include/libboost/boost/filesystem/path_traits.hpp:23, from /netDISKS/master/netmt/LINUX_INTF14/cgi/boost/1.55.0/Include/libboost/boost/filesystem/path.hpp:25, from bssConfig.h:24, from bssConfig.cc:13: /netDISKS/master/netmt/LINUX_INTF14/cgi/boost/1.55.0/Include/libboost/boost/noncopyable.hpp:27:37: error: 'boost::noncopyable_::noncopyable::noncopyable()' declared with non-public access cannot be defaulted in the class body /netDISKS/master/netmt/LINUX_INTF14/cgi/boost/1.55.0/Include/libboost/boost/noncopyable.hpp:28:22: error: 'boost::noncopyable_::noncopyable::~noncopyable()' declared with non-public access cannot be defaulted in the class body The OS is Linux Fedora 14. The compiler is gcc version 4.5.1 20100924 (Red Hat 4.5.1-4). I am compiling with these flags: -march=core2 -msse4.1 -m64 -mpc64 -std=c++0x -pedantic-errors -mieee-fp -fPIC -pthread -O2 -g -fno-strict-aliasing -fno-tree-ccp -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell@blueskystudios.com Blue Sky Studioshttp://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560 Follow Blue Sky Studios on Facebook http://www.facebook.com/BlueSkyStudios and Twitter http://twitter.com/#%21/blueskystudios