Method has_property

inst/include/Rcpp/module/class.h:303–305

            return vec_methods.find(m) != vec_methods.end() ;
        }
        bool has_property( const std::string& m){
            return properties.find(m) != properties.end() ;
        }
        bool property_is_readonly( const std::string& p) {
            typename PROPERTY_MAP::iterator it = properties.find( p ) ;
            if( it == properties.end() ) throw std::range_error( "no such property" ) ;