...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_1<unary_arithmetic_action< plus_action >, boost::units::unit< Dim, System >>
// In header: <boost/units/lambda.hpp> template<typename Dim, typename System> struct plain_return_type_1<unary_arithmetic_action< plus_action >, boost::units::unit< Dim, System >> { // types typedef boost::units::unary_plus_typeof_helper< boost::units::unit< Dim, System > >::type type; };