unit Namespace Reference

Classes
struct	Unit
	Generic unit type for compile-time conformability testing. More...

Typedefs
typedef Unit< long double, Millimeter, Lenght >	U_mm
typedef Unit< long double, Millimeter, Speed >	U_mm_s
typedef Unit< long double, Millimeter, Accel >	U_mm_s2
typedef Unit< long double, Degree, Lenght >	U_deg
typedef Unit< long double, Degree, Speed >	U_deg_s
typedef Unit< long double, Degree, Accel >	U_deg_s2

Enumerations
enum	UnitBase : uint8_t { Millimeter , Degree }
	Base units for conformability testing.
enum	UnitType : uint8_t { Lenght , Speed , Accel }
	Unit types for conformability testing.

Functions
template<typename T , UnitBase B, UnitType U>
constexpr Unit< T, B, U >	operator* (const long double f, const Unit< T, B, U > u)
static constexpr U_mm	operator""_mm (long double mm)
static constexpr U_mm_s	operator""_mm_s (long double mm_s)
static constexpr U_mm_s2	operator""_mm_s2 (long double mm_s2)
static constexpr U_deg	operator""_deg (long double deg)
static constexpr U_deg_s	operator""_deg_s (long double deg_s)
static constexpr U_deg_s2	operator""_deg_s2 (long double deg_s2)

Detailed Description

Introduce a minimal Unit class that can be used for conformability, type checking and conversion at compile time. Template parameters are abused to create unique types, which then can go through (explicit) overload and conversion. Despite looking daunting, usage is quite straightforward once the appropriate aliases and inline operators are defined:

U_mm distance = 10.0_mm;
auto another = 20.5_mm;
auto sum = distance + another;

auto angle = 15.0_deg;
auto test = distance + angle; // compile time error

Template parameters are only used for type checking. Unit contains a single value Unit<T>::v and is thus well suited for parameter passing and inline initialization.

Conversion to physical steps is done in modules::motion through the sister class modules::motion::AxisUnit, modules::motion::unitToAxisUnit and modules::motion::unitToSteps, which also ensures quantities from different axes are not mixed together. AxisUnit are the normal type that should be used at runtime.