The Barry library has the following exception hierarchy: - std::exception - std::logic_error - std::runtime_error - Barry::Error - Usb::Error - Usb::Timeout - Barry::BadPassword - Barry::BadData - Barry::BadSize - Barry::ErrnoError - Barry::BadPackedFormat - Barry::BadPacket - Barry::JDWP::Error - Barry::JDWP::Timeout Usb::Error All specific USB error exceptions will be derived from this class. Where possible, this class also stores the specific return code from the libusb API, to allow fine grained error handling. Barry::Error All specific Barry error exceptions will be derived from this class. This can be thrown from anywhere inside Barry. std::bad_alloc There is also the remote possibility that there will be memory exceptions from a call to 'new'. In that case, std::bad_alloc will be thrown by the standard C++ libraries. Barry does not catch these errors. std::logic_error Assert-like errors will cause std::logic_error to be thrown. Barry does sometimes throw these, but they should be be exceedingly rare. All of the above exceptions (from std, Barry, and Usb namespaces) are derived from std::exception, so they can all be caught in one statement for the efficient and lazy. :-)