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
This is an older version of Boost and was released in 2024. The current version is 1.90.0.
boost::units::abstract::mass_unit_tag
// In header: <boost/units/systems/abstract.hpp> struct mass_unit_tag : public base_unit< mass_unit_tag, mass_dimension, -29 > { };