...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::lambda::plain_return_type_2<arithmetic_action< minus_action >, X, boost::units::quantity< BOOST_UNITS_DIMENSIONLESS_UNIT(System), Y >>
// In header: <boost/units/lambda.hpp> template<typename System, typename X, typename Y> struct plain_return_type_2<arithmetic_action< minus_action >, X, boost::units::quantity< BOOST_UNITS_DIMENSIONLESS_UNIT(System), Y >> { // types typedef boost::units::subtract_typeof_helper< X, boost::units::quantity< BOOST_UNITS_DIMENSIONLESS_UNIT(System), Y > >::type type; };