Hi! current code of function boost::interprocess::file_lock::swap (in boost 1.38.0) is: #if !defined(BOOST_INTERPROCESS_RVALUE_REFERENCE) && !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED) void swap(detail::moved_object<file_lock> mother) { this->swap(mother.get()); } void swap(file_lock &other) #else void swap(file_lock &&other) #endif { file_handle_t tmp = m_file_hnd; other.m_file_hnd = other.m_file_hnd; other.m_file_hnd = tmp; } Seems, line: other.m_file_hnd = other.m_file_hnd; is wrong. Right version: m_file_hnd = other.m_file_hnd; Ticket https://svn.boost.org/trac/boost/ticket/2766 created. -- Yours sincerely, Anton Ivanov (ai@drweb.com)