QuantityOf concept added

src/include/units/dimensions/acceleration.h

@@ -30,7 +30,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<acceleration>> : downcast_to<acceleration> {};
 
   template<typename T>
-  concept bool Acceleration = Quantity<T> && std::same_as<typename T::dimension, acceleration>;
+  concept bool Acceleration = QuantityOf<T, acceleration>;
 
   struct metre_per_second_sq : derived_unit<acceleration, metre, second> {};
   template<> struct downcasting_traits<downcast_from<metre_per_second_sq>> : downcast_to<metre_per_second_sq> {};

src/include/units/dimensions/area.h

@@ -30,7 +30,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<area>> : downcast_to<area> {};
 
   template<typename T>
-  concept bool Area = Quantity<T> && std::same_as<typename T::dimension, area>;
+  concept bool Area = QuantityOf<T, area>;
 
   struct square_millimetre : derived_unit<area, millimetre> {};
   template<> struct downcasting_traits<downcast_from<square_millimetre>> : downcast_to<square_millimetre> {};

src/include/units/dimensions/capacitance.h

@@ -32,7 +32,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<capacitance>> : downcast_to<capacitance> {};
 
   template<typename T>
-  concept bool Capacitance =  Quantity<T> && std::same_as<typename T::dimension, capacitance>;
+  concept bool Capacitance =  QuantityOf<T, capacitance>;
 
   struct farad : derived_unit<capacitance, kilogram, metre, second, ampere> {};
   template<> struct downcasting_traits<downcast_from<farad>> : downcast_to<farad> {};

src/include/units/dimensions/current.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<current>> : downcast_to<current> {};
 
   template<typename T>
-  concept bool Current = Quantity<T> && std::same_as<typename T::dimension, current>;
+  concept bool Current = QuantityOf<T, current>;
 
   struct ampere : unit<current> {};
   template<> struct downcasting_traits<downcast_from<ampere>> : downcast_to<ampere> {};

src/include/units/dimensions/electric_charge.h

@@ -32,7 +32,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<electric_charge>> : downcast_to<electric_charge> {};
 
   template<typename T>
-  concept bool ElectricCharge =  Quantity<T> && std::same_as<typename T::dimension, electric_charge>;
+  concept bool ElectricCharge =  QuantityOf<T, electric_charge>;
 
   struct coulomb : derived_unit<electric_charge, second, ampere> {};
   template<> struct downcasting_traits<downcast_from<coulomb>> : downcast_to<coulomb> {};

src/include/units/dimensions/energy.h

@@ -32,7 +32,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<energy>> : downcast_to<energy> {};
 
   template<typename T>
-  concept bool Energy =  Quantity<T> && std::same_as<typename T::dimension, energy>;
+  concept bool Energy =  QuantityOf<T, energy>;
 
   struct joule : derived_unit<energy, kilogram, metre, second> {};
   template<> struct downcasting_traits<downcast_from<joule>> : downcast_to<joule> {};

src/include/units/dimensions/force.h

@@ -33,7 +33,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<force>> : downcast_to<force> {};
 
   template<typename T>
-  concept bool Force =  Quantity<T> && std::same_as<typename T::dimension, force>;
+  concept bool Force =  QuantityOf<T, force>;
 
   struct newton : derived_unit<force, kilogram, metre, second> {};
   template<> struct downcasting_traits<downcast_from<newton>> : downcast_to<newton> {};

src/include/units/dimensions/frequency.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<frequency>> : downcast_to<frequency> {};
 
   template<typename T>
-  concept bool Frequency =  Quantity<T> && std::same_as<typename T::dimension, frequency>;
+  concept bool Frequency =  QuantityOf<T, frequency>;
 
   struct hertz : derived_unit<frequency, second> {};
   template<> struct downcasting_traits<downcast_from<hertz>> : downcast_to<hertz> {};

src/include/units/dimensions/length.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<length>> : downcast_to<length> {};
 
   template<typename T>
-  concept bool Length = Quantity<T> && std::same_as<typename T::dimension, length>;
+  concept bool Length = QuantityOf<T, length>;
 
   // SI units
   struct metre : unit<length> {};

src/include/units/dimensions/luminous_intensity.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<luminous_intensity>> : downcast_to<luminous_intensity> {};
 
   template<typename T>
-  concept bool LuminousIntensity = Quantity<T> && std::same_as<typename T::dimension, luminous_intensity>;
+  concept bool LuminousIntensity = QuantityOf<T, luminous_intensity>;
 
   struct candela : unit<luminous_intensity> {};
   template<> struct downcasting_traits<downcast_from<candela>> : downcast_to<candela> {};

src/include/units/dimensions/mass.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<mass>> : downcast_to<mass> {};
 
   template<typename T>
-  concept bool Mass = Quantity<T> && std::same_as<typename T::dimension, mass>;
+  concept bool Mass = QuantityOf<T, mass>;
 
   struct gram : unit<mass, ratio<1, 1000>> {};
   template<> struct downcasting_traits<downcast_from<gram>> : downcast_to<gram> {};

src/include/units/dimensions/power.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<power>> : downcast_to<power> {};
 
   template<typename T>
-  concept bool Power =  Quantity<T> && std::same_as<typename T::dimension, power>;
+  concept bool Power =  QuantityOf<T, power>;
 
   struct watt : derived_unit<power, kilogram, metre, second> {};
   template<> struct downcasting_traits<downcast_from<watt>> : downcast_to<watt> {};

src/include/units/dimensions/pressure.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<pressure>> : downcast_to<pressure> {};
 
   template<typename T>
-  concept bool Pressure =  Quantity<T> && std::same_as<typename T::dimension, pressure>;
+  concept bool Pressure =  QuantityOf<T, pressure>;
 
   struct pascal : derived_unit<pressure, kilogram, metre, second> {};
   template<> struct downcasting_traits<downcast_from<pascal>> : downcast_to<pascal> {};

src/include/units/dimensions/substance.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<substance>> : downcast_to<substance> {};
 
   template<typename T>
-  concept bool Substance = Quantity<T> && std::same_as<typename T::dimension, substance>;
+  concept bool Substance = QuantityOf<T, substance>;
 
   struct mole : unit<substance> {};
   template<> struct downcasting_traits<downcast_from<mole>> : downcast_to<mole> {};

src/include/units/dimensions/temperature.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<temperature>> : downcast_to<temperature> {};
 
   template<typename T>
-  concept bool ThermodynamicTemperature = Quantity<T> && std::same_as<typename T::dimension, temperature>;
+  concept bool ThermodynamicTemperature = QuantityOf<T, temperature>;
 
   struct kelvin : unit<temperature> {};
   template<> struct downcasting_traits<downcast_from<kelvin>> : downcast_to<kelvin> {};

src/include/units/dimensions/time.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<time>> : downcast_to<time> {};
 
   template<typename T>
-  concept bool Time = Quantity<T> && std::same_as<typename T::dimension, time>;
+  concept bool Time = QuantityOf<T, time>;
 
   struct second : unit<time> {};
   template<> struct downcasting_traits<downcast_from<second>> : downcast_to<second> {};

src/include/units/dimensions/velocity.h

@@ -31,7 +31,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<velocity>> : downcast_to<velocity> {};
 
   template<typename T>
-  concept bool Velocity = Quantity<T> && std::same_as<typename T::dimension, velocity>;
+  concept bool Velocity = QuantityOf<T, velocity>;
 
   struct metre_per_second : derived_unit<velocity, metre, second> {};
   template<> struct downcasting_traits<downcast_from<metre_per_second>> : downcast_to<metre_per_second> {};

src/include/units/dimensions/voltage.h

@@ -34,7 +34,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<voltage>> : downcast_to<voltage> {};
 
   template<typename T>
-  concept bool Voltage =  Quantity<T> && std::same_as<typename T::dimension, voltage>;
+  concept bool Voltage =  QuantityOf<T, voltage>;
 
   struct volt : derived_unit<voltage, kilogram, metre, second, ampere> {};
   template<> struct downcasting_traits<downcast_from<volt>> : downcast_to<volt> {};

src/include/units/dimensions/volume.h

@@ -30,7 +30,7 @@ namespace std::experimental::units {
   template<> struct downcasting_traits<downcast_from<volume>> : downcast_to<volume> {};
 
   template<typename T>
-  concept bool Volume = Quantity<T> && std::same_as<typename T::dimension, volume>;
+  concept bool Volume = QuantityOf<T, volume>;
 
   struct cubic_millimetre : derived_unit<volume, millimetre> {};
   template<> struct downcasting_traits<downcast_from<cubic_millimetre>> : downcast_to<cubic_millimetre> {};

src/include/units/quantity.h

@@ -41,6 +41,9 @@ namespace std::experimental::units {
   template<typename T>
   concept bool Quantity = detail::is_quantity<T>;
 
+  template<typename T, typename D>
+  concept bool QuantityOf = Quantity<T> && Dimension<D> && std::same_as<typename T::dimension, D>;
+
   // Scalar
 
   template<typename T>