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:369
typename units::detail::squared_impl< U >::type squared
represents the unit type of class U squared
Definition: base.h:1165
Unit Conversion Library namespace.
Definition: data.h:31
square_kilometer
Definition: area.h:47
square_kilometers
Definition: area.h:47
squared< angle::degrees > UNIT_ADD(solid_angle, spat, spats, sp, unit< std::ratio< 4 >, steradians, std::ratio< 1 > >) using namespace solid_angle
sq_km
Definition: area.h:47
Class representing SI base unit types.
Definition: base.h:757
Type representing an arbitrary unit.
Definition: base.h:884