...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< multiply_action >, boost::units::quantity< Unit, X >, X>
// In header: <boost/units/lambda.hpp> template<typename Unit, typename X> struct plain_return_type_2<arithmetic_action< multiply_action >, boost::units::quantity< Unit, X >, X> { // types typedef boost::units::multiply_typeof_helper< boost::units::quantity< Unit, X >, X >::type type; };