boost::log::binder3rd — Third argument binder.
// In header: <boost/log/utility/functional/bind.hpp> template<typename FunT, typename ThirdArgT> struct binder3rd : private FunT { // types typedef FunT::result_type result_type; // construct/copy/destruct binder3rd(FunT const &, unspecified); // public member functions template<typename T0, typename T1> result_type operator()(T0 const &, T1 const &) const; };