sydevs::units< g, m, s, A, K, mol, cd > Struct Template Reference

A template which represents Standard International (SI) units inclusing the base units such as grams, meters, and seconds, and derived units such as meters-per-second-squared. More...

#include <units.h>

Public Types
enum	{   g_ = g , m_ = m , s_ = s , A_ = A ,   K_ = K , mol_ = mol , cd_ = cd }

Public Member Functions
constexpr	units ()=default
	Constructs a unit object. More...
template<int64 g_, int64 m_, int64 s_, int64 A_, int64 K_, int64 mol_, int64 cd_>
constexpr units< g+g_, m+m_, s+s_, A+A_, K+K_, mol+mol_, cd+cd_ >	operator* (units< g_, m_, s_, A_, K_, mol_, cd_ > rhs) const
	Combines two units into one as if the unit on the left were multiplied by that on the right. More...
template<int64 g_, int64 m_, int64 s_, int64 A_, int64 K_, int64 mol_, int64 cd_>
constexpr units< g - g_, m - m_, s - s_, A - A_, K - K_, mol - mol_, cd - cd_ >	operator/ (units< g_, m_, s_, A_, K_, mol_, cd_ > rhs) const
	Combines two units into one as if the unit on the left were divided by that on the right. More...

Detailed Description

template<int64 g, int64 m, int64 s, int64 A, int64 K, int64 mol, int64 cd>
struct sydevs::units< g, m, s, A, K, mol, cd >

A template which represents Standard International (SI) units inclusing the base units such as grams, meters, and seconds, and derived units such as meters-per-second-squared.

The units type can be used to specify an SI unit at compile time as a combination of the 7 base units: grams (g), meters (m), seconds (s), Amperes (A), Kelvin (L), mols (mol), and candelas (cd).

A type alias is defined for dimensionless quantities.

no_units

There is also a type alias for each of the base units:

grams     // Unit of mass
meters    // Unit of distance
seconds   // Unit of duration
amperes   // Unit of electric current
kelvins   // Unit of thermodynamic temperature
moles     // Unit of amount of substance
candelas  // Unit of luminous intensity

For each base unit, the associated value is defined as a constant.

_g    // grams()
_m    // meters()
_s    // seconds()
_A    // amperes()
_K    // kelvins()
_mol  // moles()
_cd   // candelas()

There are two ways to expressed SI derived units. The first is using the template constructor, where each template parameter is the exponent of the corresponding base unit.

units<0, 1, -1, 0, 0, 0, 0>  // meters/second (speed)
units<0, 1, -2, 0, 0, 0, 0>  // meters/second^2 (acceleration)
units<0, 0, 1, 1, 0, 0, 0>   // second*Ampere or coulomb (electric charge)
units<0, -2, 0, 0, 0, 0, 1>  // candelas/meter^2 or lux (illuminance)

The second approach employs the base unit values in conjunction with multiplication and division operators and decltype.

decltype(_m/_s)       // meters/second (speed)
decltype(_m/_s/_s)    // meters/second^2 (acceleration)
decltype(_s*_A)       // second*Ampere or coulomb (electric charge)
decltype (_cd/_m/_m)  // candelas/meter^2 or lux (illuminance)

It is important to note that the units class treats grams, not kilograms, as the base unit for mass. This affects derived quantities such as Newtons.

decltype(_g*_m/_s/_s)  // grams*meters/second^2 or milliNewtons (force)

Member Enumeration Documentation

anonymous enum

template<int64 g, int64 m, int64 s, int64 A, int64 K, int64 mol, int64 cd>

anonymous enum

Enumerator
g_	Grams exponent.
m_	Meters exponent.
s_	Seconds exponent.
A_	Amperes exponent.
K_	Kelvins exponent.
mol_	Moles exponent.
cd_	Candelas exponent.

Constructor & Destructor Documentation

units()

template<int64 g, int64 m, int64 s, int64 A, int64 K, int64 mol, int64 cd>

constexpr sydevs::units< g, m, s, A, K, mol, cd >::units ( )

constexprdefault

Constructs a unit object.

Member Function Documentation

operator*()

template<int64 g, int64 m, int64 s, int64 A, int64 K, int64 mol, int64 cd>

template<int64 g_, int64 m_, int64 s_, int64 A_, int64 K_, int64 mol_, int64 cd_>

constexpr units<g + g_, m + m_, s + s_, A + A_, K + K_, mol + mol_, cd + cd_> sydevs::units< g, m, s, A, K, mol, cd >::operator* ( units< g_, m_, s_, A_, K_, mol_, cd_ >  rhs ) const

inlineconstexpr

Combines two units into one as if the unit on the left were multiplied by that on the right.

operator/()

template<int64 g, int64 m, int64 s, int64 A, int64 K, int64 mol, int64 cd>

template<int64 g_, int64 m_, int64 s_, int64 A_, int64 K_, int64 mol_, int64 cd_>

constexpr units<g - g_, m - m_, s - s_, A - A_, K - K_, mol - mol_, cd - cd_> sydevs::units< g, m, s, A, K, mol, cd >::operator/ ( units< g_, m_, s_, A_, K_, mol_, cd_ >  rhs ) const

inlineconstexpr

Combines two units into one as if the unit on the left were divided by that on the right.

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The documentation for this struct was generated from the following file:

• src/sydevs/core/units.h