The file boost/preprocessor/stringize.hpp contains a trivial bug, for which I have attached a proposed patch. The problem is that there are three incorrect usages of the ## operator. The proposed fix is to simply remove the ## operators, as they are unnecessary. The ## operator joins two tokens and makes a new single token. But all three usages of ## in this file attempt to join an identifier with '(', which does not result in a single token. The action taken by most C/C++ translators in this situation is to rescan the invalid text back into two tokens, which makes the incorrect ## usage innocuous in most situations. However, the behavior is undefined by the C++ and C standards. With our code coverage tool, this improper ## usage results in a warning. *** stringize.hpp.orig Fri Feb 17 10:16:41 2006 --- stringize.hpp Fri Feb 17 10:18:36 2006 *************** *** 20,30 **** # # if BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MSVC() # define BOOST_PP_STRINGIZE(text) BOOST_PP_STRINGIZE_A((text)) ! # define BOOST_PP_STRINGIZE_A(arg) BOOST_PP_STRINGIZE_B ## (arg) ! # define BOOST_PP_STRINGIZE_B(arg) BOOST_PP_STRINGIZE_I ## arg # elif BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MWCC() # define BOOST_PP_STRINGIZE(text) BOOST_PP_STRINGIZE_OO((text)) ! # define BOOST_PP_STRINGIZE_OO(par) BOOST_PP_STRINGIZE_I ## par # else # define BOOST_PP_STRINGIZE(text) BOOST_PP_STRINGIZE_I(text) # endif --- 20,30 ---- # # if BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MSVC() # define BOOST_PP_STRINGIZE(text) BOOST_PP_STRINGIZE_A((text)) ! # define BOOST_PP_STRINGIZE_A(arg) BOOST_PP_STRINGIZE_B(arg) ! # define BOOST_PP_STRINGIZE_B(arg) BOOST_PP_STRINGIZE_I arg # elif BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MWCC() # define BOOST_PP_STRINGIZE(text) BOOST_PP_STRINGIZE_OO((text)) ! # define BOOST_PP_STRINGIZE_OO(par) BOOST_PP_STRINGIZE_I par # else # define BOOST_PP_STRINGIZE(text) BOOST_PP_STRINGIZE_I(text) # endif