...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::attributes::operator<< — Stream output operator.
// In header: <boost/log/attributes/named_scope.hpp> template<typename CharT, typename TraitsT> std::basic_ostream< CharT, TraitsT > & operator<<(std::basic_ostream< CharT, TraitsT > & strm, named_scope_list const & sl);