41#if !defined(DISABLE_PREDEFINED_UNITS) || defined(ENABLE_PREDEFINED_AREA_UNITS)
42UNIT_ADD(area, square_meter, square_meters, sq_m,
49UNIT_ADD(area, hectare, hectares, ha,
unit<
std::ratio<10000>, square_meters>)
#define UNIT_ADD_CATEGORY_TRAIT(unitCategory)
Macro to create the is_category_unit type trait.
Definition: base.h:381
typename units::detail::squared_impl< U >::type squared
represents the unit type of class U squared
Definition: base.h:1177
Unit Conversion Library namespace.
Definition: angle.h:31
square_kilometer
Definition: area.h:47
square_kilometers
Definition: area.h:47
sq_km
Definition: area.h:47
unit< std::ratio< 1, 180 >, radians, std::ratio< 1 > > UNIT_ADD(angle, arcsecond, arcseconds, arcsec, unit< std::ratio< 1, 60 >, arcminutes >) using namespace angle
Class representing SI base unit types.
Definition: base.h:769
Type representing an arbitrary unit.
Definition: base.h:896