...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::log::expressions::is_keyword_descriptor
// In header: <boost/log/expressions/is_keyword_descriptor.hpp> template<typename T, typename VoidT = void> struct is_keyword_descriptor : public false_ { };