Just checked the regression testing pages. Most of the testing stations that reported fails for Boost.Rational have switched to pass since I've uploaded updates. Besides the stations that haven't run new tests, and the "teeks" team that run Clang tests although it seemingly isn't actually installed, the newly-run MSVC stations report fails. The old errors are gone, but the new error is: ..\libs\rational\test\rational_test.cpp(1012) : error C2065: 'not' : undeclared identifier ..\libs\rational\test\rational_test.cpp(1012) : error C2146: syntax error : missing ')' before identifier 'dummy' ..\libs\rational\test\rational_test.cpp(1012) : error C2059: syntax error : ')' This happens with MSVC 10.0 and 11.0. Hasn't "not" been an alternate symbol for "!" since C++98? I'll change it to "!", but that doesn't excuse not fixing it for 15 years! What happened? (I think some of the MSVC authors lurk here.) Daryle W.