feat!: add number concepts

example/include/ranged_representation.h

@@ -38,7 +38,7 @@ template<std::movable T, MP_UNITS_CONSTRAINED_NTTP_WORKAROUND(std::convertible_t
          MP_UNITS_CONSTRAINED_NTTP_WORKAROUND(std::convertible_to<T>) auto Max>
 using is_in_range_t = decltype(is_in_range<T, Min, Max>);
 
-template<std::movable T, MP_UNITS_CONSTRAINED_NTTP_WORKAROUND(std::convertible_to<T>) auto Min,
+template<mp_units::vector_space T, MP_UNITS_CONSTRAINED_NTTP_WORKAROUND(std::convertible_to<T>) auto Min,
          MP_UNITS_CONSTRAINED_NTTP_WORKAROUND(std::convertible_to<T>) auto Max>
 class ranged_representation : public validated_type<T, is_in_range_t<T, Min, Max>> {
 public:
@@ -50,15 +50,44 @@ class ranged_representation : public validated_type<T, is_in_range_t<T, Min, Max
   {
     return ranged_representation(-this->value());
   }
+
+  friend constexpr ranged_representation operator-(const ranged_representation& lhs, const ranged_representation& rhs)
+  {
+    return ranged_representation(lhs.value() - rhs.value());
+  }
+
+  constexpr ranged_representation& operator+=(ranged_representation that)
+  {
+    this->value() += that.value();
+    gsl_Expects(validate(this->value()));
+    return *this;
+  }
+  constexpr ranged_representation& operator-=(ranged_representation that)
+  {
+    this->value() -= that.value();
+    gsl_Expects(validate(this->value()));
+    return *this;
+  }
+  constexpr ranged_representation& operator*=(T rhs)
+  {
+    this->value() *= rhs;
+    gsl_Expects(validate(this->value()));
+    return *this;
+  }
 };
 
 template<typename T, auto Min, auto Max>
 inline constexpr bool mp_units::is_scalar<ranged_representation<T, Min, Max>> = mp_units::is_scalar<T>;
 
+template<typename T, auto Min, auto Max>
+struct mp_units::number_scalar<ranged_representation<T, Min, Max>> : std::type_identity<T> {};
+
 template<typename T, auto Min, auto Max>
 inline constexpr bool mp_units::treat_as_floating_point<ranged_representation<T, Min, Max>> =
   mp_units::treat_as_floating_point<T>;
 
+static_assert(mp_units::vector_space<ranged_representation<int, 17, 29>>);
+
 template<typename T, auto Min, auto Max>
 struct MP_UNITS_STD_FMT::formatter<ranged_representation<T, Min, Max>> : formatter<T> {
   template<typename FormatContext>

example/measurement.cpp

@@ -30,7 +30,7 @@
 
 namespace {
 
-template<typename T>
+template<mp_units::vector_space T>
 class measurement {
 public:
   using value_type = T;
@@ -65,6 +65,18 @@ class measurement {
     return measurement(lhs.value() - rhs.value(), hypot(lhs.uncertainty(), rhs.uncertainty()));
   }
 
+  constexpr measurement& operator+=(measurement that)
+  {
+    value_ = *this + that;
+    return *this;
+  }
+
+  constexpr measurement& operator-=(measurement that)
+  {
+    value_ = *this - that;
+    return *this;
+  }
+
   [[nodiscard]] friend constexpr measurement operator*(const measurement& lhs, const measurement& rhs)
   {
     const auto val = lhs.value() * rhs.value();
@@ -78,6 +90,12 @@ class measurement {
     return measurement(val, val * lhs.relative_uncertainty());
   }
 
+  constexpr measurement& operator*=(const value_type& value)
+  {
+    value_ = *this * value;
+    return *this;
+  }
+
   [[nodiscard]] friend constexpr measurement operator*(const value_type& value, const measurement& rhs)
   {
     const auto val = rhs.value() * value;
@@ -125,7 +143,11 @@ inline constexpr bool mp_units::is_scalar<measurement<T>> = true;
 template<class T>
 inline constexpr bool mp_units::is_vector<measurement<T>> = true;
 
+template<typename T>
+struct mp_units::number_scalar<measurement<T>> : std::type_identity<T> {};
+
 static_assert(mp_units::RepresentationOf<measurement<double>, mp_units::quantity_character::scalar>);
+static_assert(mp_units::vector_space<measurement<double>>);
 
 namespace {
 

src/core/include/mp-units/bits/external/type_list.h

@@ -24,6 +24,7 @@
 
 #include <mp-units/bits/external/hacks.h>  // IWYU pragma: keep
 #include <cstddef>
+#include <type_traits>
 #include <utility>
 
 MP_UNITS_DIAGNOSTIC_PUSH

src/core/include/mp-units/bits/fwd.h

@@ -0,0 +1,34 @@
+// The MIT License (MIT)
+//
+// Copyright (c) 2018 Mateusz Pusz
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#pragma once
+
+#include <mp-units/bits/reference_concepts.h>
+#include <mp-units/bits/representation_concepts.h>
+
+namespace mp_units {
+
+template<Reference auto R, RepresentationOf<get_quantity_spec(R).character> Rep>
+  requires vector_space<Rep>
+class quantity;
+
+}  // namespace mp_units

src/core/include/mp-units/bits/quantity_concepts.h

@@ -22,16 +22,14 @@
 
 #pragma once
 
+#include <mp-units/bits/fwd.h>
 #include <mp-units/bits/quantity_spec_concepts.h>
 #include <mp-units/bits/reference_concepts.h>
 #include <mp-units/bits/representation_concepts.h>
 #include <mp-units/customization_points.h>
 
 namespace mp_units {
 
-template<Reference auto R, RepresentationOf<get_quantity_spec(R).character> Rep>
-class quantity;
-
 #if defined MP_UNITS_COMP_CLANG && MP_UNITS_COMP_CLANG < 17
 template<auto R, typename Rep>
 #else

src/core/include/mp-units/bits/quantity_point_concepts.h

@@ -107,6 +107,7 @@ concept PointOriginFor = PointOrigin<T> && QuantitySpecOf<std::remove_const_t<de
 
 template<Reference auto R, PointOriginFor<get_quantity_spec(R)> auto PO,
          RepresentationOf<get_quantity_spec(R).character> Rep>
+  requires vector_space<Rep>
 class quantity_point;
 
 #if defined MP_UNITS_COMP_CLANG && MP_UNITS_COMP_CLANG < 17

src/core/include/mp-units/customization_points.h

@@ -24,6 +24,7 @@
 
 #include <mp-units/bits/external/hacks.h>
 #include <mp-units/bits/external/type_traits.h>
+#include <mp-units/numbers.h>
 #include <limits>
 #include <type_traits>