si::base_unit

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Description

The SI base units in PQS are expressed as a subset of normative units. Each SI base unit is associated with one of the SI base quantities. By definition, a base_unit has a conversion_factor of 1.

Signature

si::base_unit<base_quantity>

Headers

#include <pqs/systems/si/unit.hpp>

Individual headers ¹

• #include <pqs/systems/si/units/length_unit.hpp>
• #include <pqs/systems/si/units/time_unit.hpp>
• #include <pqs/systems/si/units/mass_unit.hpp>
• #include <pqs/systems/si/units/temperature_unit.hpp>
• #include <pqs/systems/si/units/current_unit.hpp>
• #include <pqs/systems/si/units/substance_unit.hpp>
• #include <pqs/systems/si/units/intensity_unit.hpp>

Notation

typename	model of	notes
Qb	base_quantity

typename	type	notes
Ub	si::base_unit< Qb >

Provides

concept	result
unit< Ub >	true

inline constant	result
si::is_normative_unit< Ub >	true
si::is_prefixable< Ub >	false. By nature base units don't have prefixes (the kg is a special case where kg is treated as the base unit symbol)
get_measurement_system< Ub >	si_measurement_system
std::is_same_v< get_conversion_factor<Ub>,conversion_factor<std::ratio<1>, exponent10<0> >	true

• [1] As can be seen in the header files,The si base units are derived from base_unit type template rather than typedefs, which allows other dimensionality equivalent and conversion factor equivalent but separate base units for customisation