...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::icl::has_difference<boost::gregorian::date_duration>
// In header: <boost/icl/gregorian.hpp> struct has_difference<boost::gregorian::date_duration> { // types typedef has_difference type; // public member functions BOOST_STATIC_CONSTANT(bool, value = true); };