...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::gregorian::operator<< — operator<< for gregorian::greg_weekday typically streaming: Sun, Mon, Tue, ...
// In header: <boost/date_time/gregorian/greg_facet.hpp> template<typename charT, typename traits> std::basic_ostream< charT, traits > & operator<<(std::basic_ostream< charT, traits > & os, const greg_weekday & wd);