Concepts usage improved

src/include/units/bits/stdconcepts.h

@@ -29,17 +29,13 @@ namespace mp {
 
   namespace std_concepts {
 
-    namespace detail {
-      template<class T, class U>
-      concept bool SameHelper = std::is_same_v<T, U>;
-    }
+    template<typename T, typename U>
+    concept bool Same = std::is_same_v<T, U>;
 
-    template<class T, class U>
-    concept bool Same = detail::SameHelper<T, U>&& detail::SameHelper<U, T>;
-
-    template<class From, class To>
-    concept bool ConvertibleTo = std::is_convertible_v<From, To>&& requires(From (&f)())
-    {
+    template<typename From, typename To>
+    concept bool ConvertibleTo =
+      std::is_convertible_v<From, To> &&
+      requires(From (&f)()) {
         static_cast<To>(f());
       };
 

src/include/units/quantity.h

@@ -48,7 +48,7 @@ namespace units {
 
   // treat_as_floating_point
 
-  template<class Rep>
+  template<typename Rep> // todo Conceptify that
   inline constexpr bool treat_as_floating_point = std::is_floating_point_v<Rep>;
 
   // quantity_cast

src/include/units/si/frequency.h

@@ -36,21 +36,11 @@ namespace units {
   using gigahertz = unit<dimension_frequency, std::giga>;
   using terahertz = unit<dimension_frequency, std::tera>;
 
-  template<Unit U = hertz, typename Rep = std::intmax_t>
+  template<Unit U = hertz, Number Rep = std::intmax_t>
   using frequency = quantity<dimension_frequency, U, Rep>;
 
-  namespace detail {
-
   template<typename T>
-    struct is_frequency : std::false_type {};
-
-    template<Unit U, typename Rep>
-    struct is_frequency<frequency<U, Rep>> : std::true_type {};
-
-  }
-
-  template<typename T>
-  concept bool Frequency = detail::is_frequency<T>::value;
+  concept bool Frequency =  Quantity<T> && Same<typename T::dimension, dimension_frequency>;
 
   // ...
 

src/include/units/si/length.h

@@ -34,21 +34,11 @@ namespace units {
   using meter = unit<dimension_length, std::ratio<1>>;
   using kilometer = unit<dimension_length, std::kilo>;
 
-  template<Unit U = meter, typename Rep = std::intmax_t>
+  template<Unit U = meter, Number Rep = std::intmax_t>
   using length = quantity<dimension_length, U, Rep>;
 
-  namespace detail {
-
   template<typename T>
-    struct is_length : std::false_type {};
-
-    template<Unit U, typename Rep>
-    struct is_length<length<U, Rep>> : std::true_type {};
-
-  }
-
-  template<typename T>
-  concept bool Length = detail::is_length<T>::value;
+  concept bool Length = Quantity<T> && Same<typename T::dimension, dimension_length>;
 
   namespace literals {
 

src/include/units/si/time.h

@@ -36,21 +36,12 @@ namespace units {
   using minute = unit<dimension_time, std::ratio<60>>;
   using hour = unit<dimension_time, std::ratio<3600>>;
 
-  template<Unit U = second, typename Rep = std::intmax_t>
+  template<Unit U = second, Number Rep = std::intmax_t>
   using time = quantity<dimension_time, U, Rep>;
 
-  namespace detail {
 
   template<typename T>
-    struct is_time : std::false_type {};
-
-    template<Unit U, typename Rep>
-    struct is_time<time<U, Rep>> : std::true_type {};
-
-  }
-
-  template<typename T>
-  concept bool Time = detail::is_time<T>::value;
+  concept bool Time = Quantity<T> && Same<typename T::dimension, dimension_time>;
 
   // ...
 

src/include/units/si/velocity.h

@@ -34,21 +34,11 @@ namespace units {
   using kilometer_per_hour = unit<dimension_velocity, std::ratio<1000, 3600>>;
   using mile_per_hour = unit<dimension_velocity, std::ratio<44'704, 100'000>>;
 
-  template<Unit U = meter_per_second, typename Rep = std::intmax_t>
+  template<Unit U = meter_per_second, Number Rep = std::intmax_t>
   using velocity = quantity<dimension_velocity, U, Rep>;
 
-  namespace detail {
-
   template<typename T>
-    struct is_velocity : std::false_type {};
-
-    template<Unit U, typename Rep>
-    struct is_velocity<velocity<U, Rep>> : std::true_type {};
-
-  }
-
-  template<typename T>
-  concept bool Velocity = detail::is_velocity<T>::value;
+  concept bool Velocity = Quantity<T> && Same<typename T::dimension, dimension_velocity>;
 
   // ...