Hi, I'm trying to link an app using boost threads and stlport on gcc 2.95(linux), and its coming back with an undefined reference: Debug/threadex.o: In function `threadex::go(void)': .../threadex.cpp:37: undefined reference to `boost::thread::thread(boost::function0<void, boost::empty_function_policy, boost::empty_function_mixin, allocator<boost::function_base> > const &)' and the offending code is new boost::thread(threadex_caller(this)); where theadex_caller looks like this struct threadex_caller { threadex_caller(threadex*); void operator()(); }; I think the problem is the allocator template parameter of boost::function0, a clue is given if I don't link against the pthread library, I get the following undefined reference (amongst others) Debug/libboost_thread.a(thread.o): In function `boost::thread::thread(boost::function0<void, boost::empty_function_policy, boost::empty_function_mixin, _STL::allocator<boost::function_base> > const &)': .../src/thread.cpp:112: undefined reference to `pthread_create' where you can see that the thread::thread function expects a function0 with an _STL::allocator<>, not a plain allocator<> I also think that the problem is that the thread.hpp isn't getting the namespace mapping function, but why? TIA Sam