Hi, Most of the boost libraries' implementation is either in header files, or in a compiled library. Class boost::random_device is an exception: the implementation is found in libs/random/random_device.cpp, but this file is not built into any library. This issue has been raised by a Debian user (http://bugs.debian.org/261719) and earlier (http://lists.boost.org/MailArchives/boost-users/msg03506.php) but never addressed. I wanted to confirm whether this is a bug or is by design. Thanks, -Steve