Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Struct template static_root

boost::units::static_root — Take a scalar root of a dimension list.

// In header: <boost/units/dimension.hpp>

template<typename DL, typename Rt> 
struct static_root {
  // types
  typedef unspecified type;
};