5 Quantities and units library [quantities]

5.4 Reference [qty.ref]

5.4.4 Unit [qty.unit]

5.4.4.4 Concepts [qty.unit.concepts]

🔗
template<typename T> concept Unit = SymbolicConstant<T> && std::derived_from<T, unit-interface>; template<typename T> concept PrefixableUnit = Unit<T> && is-derived-from-specialization-of<T, named_unit>(); template<typename T> concept AssociatedUnit = Unit<U> && has-associated-quantity(U{}); template<typename U, auto QS> concept UnitOf = AssociatedUnit<U> && QuantitySpec<decltype(QS)> && QuantitySpecConvertibleTo<get_quantity_spec(U{}), QS> && (get_kind(QS) == get_kind(get_quantity_spec(U{})) || !NestedQuantityKindSpecOf<get_quantity_spec(U{}), QS>); template<auto From, auto To> concept UnitConvertibleTo = // exposition only Unit<decltype(From)> && Unit<decltype(To)> && (convertible(From, To)); template<typename U, auto FromU, auto QS> concept UnitCompatibleWith = // exposition only Unit<U> && Unit<decltype(FromU)> && QuantitySpec<decltype(QS)> && (!AssociatedUnit<U> || UnitOf<U, QS>) && UnitConvertibleTo<FromU, U{}>; template<typename T> concept OffsetUnit = Unit<T> && requires { T::point-origin; }; // exposition only template<typename From, typename To> concept PotentiallyConvertibleTo = // exposition only Unit<From> && Unit<To> && ((AssociatedUnit<From> && AssociatedUnit<To> && implicitly_convertible(get_quantity_spec(From{}), get_quantity_spec(To{}))) || (!AssociatedUnit<From> && !AssociatedUnit<To>));