...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::units::base_unit
// In header: <boost/units/base_unit.hpp> template<typename Derived, typename Dim, long N> class base_unit : public ordinal< N > { public: // types typedef Dim dimension_type; // The dimensions of this base unit. typedef Derived type; // Provided for mpl compatability. typedef unspecified unit_type; // The unit corresponding to this base unit. };
Defines a base unit. To define a unit you need to provide the derived class (CRTP), a dimension list and a unique integer.
* struct my_unit : boost::units::base_unit<my_unit, length_dimension, 1> {}; *
It is designed so that you will get an error message if you try to use the same value in multiple definitions.