...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::format_named_scope
// In header: <boost/log/expressions/formatters/named_scope.hpp> template<typename CharT> format_named_scope_actor< fallback_to_none, CharT > format_named_scope(attribute_name const & name, const CharT * element_format);