feat: representation type template parameter added to value convertion functions

Resolves #588

src/core/include/mp-units/framework/quantity.h

@@ -199,6 +199,20 @@ public:
     return quantity<detail::make_reference(quantity_spec, ToU{}), Rep>{*this};
   }
 
+  template<RepresentationOf<get_quantity_spec(R).character> ToRep>
+    requires detail::QuantityConvertibleTo<quantity, quantity<reference, ToRep>>
+  [[nodiscard]] constexpr QuantityOf<quantity_spec> auto in() const
+  {
+    return quantity<reference, ToRep>{*this};
+  }
+
+  template<RepresentationOf<get_quantity_spec(R).character> ToRep, detail::UnitCompatibleWith<unit, quantity_spec> ToU>
+    requires detail::QuantityConvertibleTo<quantity, quantity<detail::make_reference(quantity_spec, ToU{}), ToRep>>
+  [[nodiscard]] constexpr QuantityOf<quantity_spec> auto in(ToU) const
+  {
+    return quantity<detail::make_reference(quantity_spec, ToU{}), ToRep>{*this};
+  }
+
   template<detail::UnitCompatibleWith<unit, quantity_spec> ToU>
     requires requires(quantity q) { value_cast<ToU{}>(q); }
   [[nodiscard]] constexpr QuantityOf<quantity_spec> auto force_in(ToU) const
@@ -206,6 +220,20 @@ public:
     return value_cast<ToU{}>(*this);
   }
 
+  template<RepresentationOf<get_quantity_spec(R).character> ToRep>
+    requires requires(quantity q) { value_cast<ToRep>(q); }
+  [[nodiscard]] constexpr QuantityOf<quantity_spec> auto force_in() const
+  {
+    return value_cast<ToRep>(*this);
+  }
+
+  template<RepresentationOf<get_quantity_spec(R).character> ToRep, detail::UnitCompatibleWith<unit, quantity_spec> ToU>
+    requires requires(quantity q) { value_cast<ToU{}, ToRep>(q); }
+  [[nodiscard]] constexpr QuantityOf<quantity_spec> auto force_in(ToU) const
+  {
+    return value_cast<ToU{}, ToRep>(*this);
+  }
+
   // data access
   template<Unit U>
     requires(U{} == unit)

src/core/include/mp-units/framework/quantity_point.h

@@ -284,6 +284,20 @@ public:
     return ::mp_units::quantity_point{quantity_ref_from(PO).in(ToU{}), PO};
   }
 
+  template<RepresentationOf<get_quantity_spec(R).character> ToRep>
+    requires detail::QuantityConvertibleTo<quantity_type, quantity<reference, ToRep>>
+  [[nodiscard]] constexpr QuantityPointOf<quantity_spec> auto in() const
+  {
+    return ::mp_units::quantity_point{quantity_ref_from(PO).template in<ToRep>(), PO};
+  }
+
+  template<RepresentationOf<get_quantity_spec(R).character> ToRep, detail::UnitCompatibleWith<unit, quantity_spec> ToU>
+    requires detail::QuantityConvertibleTo<quantity_type, quantity<detail::make_reference(quantity_spec, ToU{}), ToRep>>
+  [[nodiscard]] constexpr QuantityPointOf<quantity_spec> auto in(ToU) const
+  {
+    return ::mp_units::quantity_point{quantity_ref_from(PO).template in<ToRep>(ToU{}), PO};
+  }
+
   template<detail::UnitCompatibleWith<unit, quantity_spec> ToU>
     requires requires(quantity_type q) { value_cast<ToU{}>(q); }
   [[nodiscard]] constexpr QuantityPointOf<quantity_spec> auto force_in(ToU) const
@@ -291,6 +305,20 @@ public:
     return ::mp_units::quantity_point{quantity_ref_from(PO).force_in(ToU{}), PO};
   }
 
+  template<RepresentationOf<get_quantity_spec(R).character> ToRep>
+    requires requires(quantity_type q) { value_cast<ToRep>(q); }
+  [[nodiscard]] constexpr QuantityPointOf<quantity_spec> auto force_in() const
+  {
+    return ::mp_units::quantity_point{quantity_ref_from(PO).template force_in<ToRep>(), PO};
+  }
+
+  template<RepresentationOf<get_quantity_spec(R).character> ToRep, detail::UnitCompatibleWith<unit, quantity_spec> ToU>
+    requires requires(quantity_type q) { value_cast<ToU{}, ToRep>(q); }
+  [[nodiscard]] constexpr QuantityPointOf<quantity_spec> auto force_in(ToU) const
+  {
+    return ::mp_units::quantity_point{quantity_ref_from(PO).template force_in<ToRep>(ToU{}), PO};
+  }
+
   // conversion operators
   template<typename QP_, QuantityPointLike QP = std::remove_cvref_t<QP_>>
     requires(point_origin == quantity_point_like_traits<QP>::point_origin) &&