[boost] [config] NO_USER_DEFINED_LITERALS ?

Hello, does Boost.Config provide some macro for the detection of (un)availability of user-defined literals (N2765) ? I could not find any in the docs for 1.51.0 nor by grepping in the boost/config/* files. If not, would there be a big problem adding it (called for example BOOST_NO_USER_DEFINED_LITERALS), please ? Thanks in advance, Best regards, Matus