The boost version of is_class doesn't seem to be compatible with lambdas in my target compiler. Am I missing something? Any patches/fixes you can think of? Sadly, I can't just use the tr1 version since this is being used internally within a boost library (boost::parameter in my case). BOOST_AUTO_TEST_CASE( test_is_class ) { auto f = [](double x){return x;}; // static_assert(boost::is_class<decltype(f)>::value, "Failure"); //Compiler failure line 81 of boost/type_traits/is_class.hpp static_assert(std::tr1::is_class<decltype(f)>::value, "Failure"); //Works using the built in tr1 for the compiler }