Just applying the previous workarounds to the new compiler version - they are still needed: cvs diff -u -wb -- boost\thread\read_write_mutex.hpp (in directory E:\sourceforge\devel\boost\) Index: boost/thread/read_write_mutex.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/thread/read_write_mutex.hpp,v retrieving revision 1.9 diff -u -w -b -r1.9 read_write_mutex.hpp --- boost/thread/read_write_mutex.hpp 11 Jul 2005 15:06:07 -0000 1.9 +++ boost/thread/read_write_mutex.hpp 22 Feb 2006 23:14:00 -0000 @@ -53,7 +53,7 @@ typedef detail::thread::scoped_timed_lock<Mutex> scoped_timed_lock; read_write_mutex_impl(read_write_scheduling_policy::read_write_schedulin g_policy_enum sp); -#if !BOOST_WORKAROUND(__BORLANDC__,<= 0x564) +#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x581)) ~read_write_mutex_impl(); #endif and cvs diff -u -wb -- libs\thread\src\read_write_mutex.cpp (in directory E:\sourceforge\devel\boost\) Index: libs/thread/src/read_write_mutex.cpp =================================================================== RCS file: /cvsroot/boost/boost/libs/thread/src/read_write_mutex.cpp,v retrieving revision 1.23 diff -u -w -b -r1.23 read_write_mutex.cpp --- libs/thread/src/read_write_mutex.cpp 27 Aug 2005 10:25:15 -0000 1.23 +++ libs/thread/src/read_write_mutex.cpp 22 Feb 2006 22:01:14 -0000 @@ -379,7 +379,7 @@ , m_readers_next(true) {} -#if !BOOST_WORKAROUND(__BORLANDC__, <= 0x564) +#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x581)) template<typename Mutex> read_write_mutex_impl<Mutex>::~read_write_mutex_impl() { Given the low visibility of thread maintainers, and low risk of change, should I just proceed and commit the changes? -- AlisdairM