PrefixType renamed to PrefixFamily + units hierarchy PNG fixed

src/include/units/concepts.h

@@ -42,11 +42,16 @@ concept basic_arithmetic = // exposition only
 
 } // namespace detail
 
-// PrefixType
-struct prefix_type;
+// PrefixFamily
+struct prefix_family;
 
+/**
+ * @brief A concept matching a prefix family
+ * 
+ * Satisfied by all types derived from `prefix_family`
+ */
 template<typename T>
-concept PrefixType = std::derived_from<T, prefix_type>;
+concept PrefixFamily = std::derived_from<T, prefix_family>;
 
 // Prefix
 // TODO gcc:92150
@@ -56,11 +61,16 @@ concept PrefixType = std::derived_from<T, prefix_type>;
 //   template<typename T>
 //   inline constexpr bool is_prefix = false;
 
-//   template<typename PrefixType, Ratio R, basic_fixed_string Symbol>
-//   inline constexpr bool is_prefix<prefix<PrefixType, R, Symbol>> = true;
+//   template<typename PrefixFamily, Ratio R, basic_fixed_string Symbol>
+//   inline constexpr bool is_prefix<prefix<PrefixFamily, R, Symbol>> = true;
 
 // }  // namespace detail
 
+/**
+ * @brief A concept matching a symbol prefix
+ * 
+ * Satisfied by all instantiations of `prefix`.
+ */
 template<typename T>
 //  concept Prefix = detail::is_prefix<T>;
 concept Prefix = true;
@@ -73,11 +83,19 @@ inline constexpr bool is_ratio = false;
 
 } // namespace detail
 
+/**
+ * @brief A concept matching a ratio
+ * 
+ * Satisfied by all instantiations of `ratio`.
+ */
 template<typename T>
 concept Ratio = detail::is_ratio<T>;
 
-
-// UnitRatio
+/**
+ * @brief A concept matching unit's ratio
+ * 
+ * Satisfied by all types that satisfy `Ratio<R>` and for which `R::num > 0` and `R::den > 0`
+ */
 template<typename R>
 concept UnitRatio = Ratio<R> && R::num > 0 && R::den > 0; // double negatives not allowed
 
@@ -85,10 +103,14 @@ concept UnitRatio = Ratio<R> && R::num > 0 && R::den > 0; // double negatives no
 template<UnitRatio R, typename U>
 struct scaled_unit;
 
+/**
+ * @brief A concept matching all unit types in the library
+ * 
+ * Satisfied by all unit types derived from the instantiation of :class:`scaled_unit`.
+ */
 template<typename T>
 concept Unit = is_derived_from_instantiation<T, scaled_unit>;
 
-// BaseDimension
 template<basic_fixed_string Symbol, Unit U>
   requires U::is_named
 struct base_dimension;
@@ -112,6 +134,11 @@ inline constexpr bool is_base_dimension<base_dimension<Name, Params...>> = true;
 
 }  // namespace detail
 
+/**
+ * @brief A concept matching all base dimensions in the library.
+ * 
+ * Satisfied by all dimension types derived from the instantiation of `base_dimension`.
+ */
 template<typename T>
 concept BaseDimension = detail::is_base_dimension<typename T::base_type_workaround>;
 
@@ -123,6 +150,11 @@ inline constexpr bool is_exp = false;
 
 }  // namespace detail
 
+/**
+ * @brief A concept matching dimension's exponents.
+ * 
+ * Satisfied by all instantiations of :class:`exp`.
+ */
 template<typename T>
 concept Exponent = detail::is_exp<T>;
 
@@ -135,10 +167,20 @@ struct derived_dimension_base;
 
 } // namespace detail
 
+/**
+ * @brief A concept matching all derived dimensions in the library.
+ * 
+ * Satisfied by all dimension types derived from the instantiation of `detail::derived_dimension_base`.
+ */
 template<typename T>
 concept DerivedDimension = is_instantiation<downcast_base_t<T>, detail::derived_dimension_base>;
 
 // Dimension
+/**
+ * @brief A concept matching all dimensions in the library. 
+ * 
+ * Satisfied by all dimension types for which either `BaseDimension<T>` or `DerivedDimension<T>` is `true`.
+ */
 template<typename T>
 concept Dimension = BaseDimension<T> || DerivedDimension<T>;
 
@@ -163,6 +205,15 @@ struct dimension_unit_impl<D> {
 template<Dimension D>
 using dimension_unit = detail::dimension_unit_impl<D>::type;
 
+/**
+ * @brief A concept matching only units of a specified dimension.
+ * 
+ * Satisfied by all unit types that satisfy `Unit<U>`, `Dimension<D>`, and for which
+ * `U::reference` and `dimension_unit<D>::reference` denote the same unit type.
+ * 
+ * @tparam U Type to verify.
+ * @tparam D Dimension type to use for verification.
+ */
 template<typename U, typename D>
 concept UnitOf =
   Unit<U> &&
@@ -177,6 +228,11 @@ inline constexpr bool is_quantity = false;
 
 }  // namespace detail
 
+/**
+ * @brief A concept matching all quantities in the library.
+ * 
+ * Satisfied by all instantiations of :class:`quantity`.
+ */
 template<typename T>
 concept Quantity = detail::is_quantity<T>;
 
@@ -193,11 +249,22 @@ inline constexpr bool is_wrapped_quantity<T> = Quantity<typename T::value_type>
 
 }  // namespace detail
 
+/**
+ * @brief A concept matching types that wrap quantity objects.
+ * 
+ * Satisfied by all wrapper types that satisfy `Quantity<typename T::value_type>`
+ * recursively (i.e. `std::optional<si::length<si::metre>>`).
+ */
 template<typename T>
 concept WrappedQuantity = detail::is_wrapped_quantity<T>;
 
 // Scalar
+/**
+ * @brief A concept matching non-Quantity types.
+ * 
+ * Satisfied by types that satisfy `(!Quantity<T>) && (!WrappedQuantity<T>) && std::regular<T>`.
+ */
 template<typename T>
-concept Scalar = (!Quantity<T>) && (!WrappedQuantity<T>) && std::regular<T>; // && std::totally_ordered<T>;// && detail::basic_arithmetic<T>;
+concept Scalar = (!Quantity<T>) && (!WrappedQuantity<T>) && std::regular<T>; // TODO: && std::totally_ordered<T>;// && detail::basic_arithmetic<T>;
 
 }  // namespace units