Hi, The following two types are not used anywhere typedef typename ::boost::remove_cv::type rhs_nocv; typedef typename ::boost::remove_cv< typename ::boost::remove_reference< typename ::boost::remove_pointer::type >::type >::type rhs_noptr; Shouldn't them be removed? I have not see the utility of removing the reference typedef typename ::boost::remove_reference::type rhs_noref; Could you explain me why this is needed? I have a little problem with the has_operator_ prefix on the name of the traits. The traits is not checking the class parameter(s) has/have an operator, but that the application of the operator to this/these types is syntactically correct. E.g. has_operator_plus<int, double>::value neither int nor double have an operator+. applicable_operator_plus<int, double>::value or can_apply_operator_plus could be an option. If we wanted to define a trait to see if a class has a member function begin(), i.e. c.begin() is correct, we could name it has_begin. But if we wanted to check if we can call begin(c) how we name the trait, has_begin? Note that in the standard all the traits prefixed by has_ applies to some property the type has. I recognize that this is not to important, but if someone could find a better name ... Forget this last comment if you find it is misplaced. Best, Vicente P.S. Typo: There is at least a BOOST_TT_TRAIT_OP in the documentation to be replaced by -. -- View this message in context: http://boost.2283326.n4.nabble.com/Review-Boost-Type-Traits-Extension-by-Fre... Sent from the Boost - Dev mailing list archive at Nabble.com.