refactor: quantity::value() renamed to quantity::numerical_value()

According to https://jcgm.bipm.org/vim/en/1.19.html "quantity value" also contains a unit. According to https://jcgm.bipm.org/vim/en/1.20.html "numerical value" is the correct term for just a number.

Resolves #423

example/conversion_factor.cpp

@@ -33,7 +33,7 @@ template<mp_units::Quantity Target, mp_units::Quantity Source>
   requires std::constructible_from<Target, Source>
 inline constexpr double conversion_factor(Target, Source)
 {
-  return mp_units::value_cast<Target::unit>(1. * Source::reference).value();
+  return mp_units::value_cast<Target::unit>(1. * Source::reference).numerical_value();
 }
 
 }  // namespace
@@ -56,5 +56,6 @@ int main()
   std::cout << MP_UNITS_STD_FMT::format("conversion factor from lengthA::unit of {:%q} to lengthB::unit of {:%q}:\n\n",
                                         lengthA, lengthB)
             << MP_UNITS_STD_FMT::format("lengthB.value( {} ) == lengthA.value( {} ) * conversion_factor( {} )\n",
-                                        lengthB.value(), lengthA.value(), conversion_factor(lengthB, lengthA));
+                                        lengthB.numerical_value(), lengthA.numerical_value(),
+                                        conversion_factor(lengthB, lengthA));
 }

example/currency.cpp

@@ -75,14 +75,15 @@ template<Unit auto From, Unit auto To>
 template<ReferenceOf<currency> auto To, ReferenceOf<currency> auto From, typename Rep>
 quantity<To, Rep> exchange_to(quantity<From, Rep> q)
 {
-  return static_cast<Rep>(exchange_rate<q.unit, get_unit(To)>() * q.value()) * To;
+  return static_cast<Rep>(exchange_rate<q.unit, get_unit(To)>() * q.numerical_value()) * To;
 }
 
 template<ReferenceOf<currency> auto To, ReferenceOf<currency> auto From, auto PO, typename Rep>
 quantity_point<To, PO, Rep> exchange_to(quantity_point<From, PO, Rep> q)
 {
   return quantity_point{
-    zero + static_cast<Rep>(exchange_rate<q.unit, get_unit(To)>() * (q - q.absolute_point_origin).value()) * To};
+    zero +
+    static_cast<Rep>(exchange_rate<q.unit, get_unit(To)>() * (q - q.absolute_point_origin).numerical_value()) * To};
 }
 
 int main()

example/include/geographic.h

@@ -74,19 +74,19 @@ using longitude =
 template<class CharT, class Traits, typename T>
 std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const latitude<T>& lat)
 {
-  if (lat.value() > 0)
-    return os << "N" << lat.value();
+  if (lat.numerical_value() > 0)
+    return os << "N" << lat.numerical_value();
   else
-    return os << "S" << -lat.value();
+    return os << "S" << -lat.numerical_value();
 }
 
 template<class CharT, class Traits, typename T>
 std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const longitude<T>& lon)
 {
-  if (lon.value() > 0)
-    return os << "E" << lon.value();
+  if (lon.numerical_value() > 0)
+    return os << "E" << lon.numerical_value();
   else
-    return os << "W" << -lon.value();
+    return os << "W" << -lon.numerical_value();
 }
 
 inline namespace literals {
@@ -129,7 +129,8 @@ struct MP_UNITS_STD_FMT::formatter<geographic::latitude<T>> : formatter<T> {
   auto format(geographic::latitude<T> lat, FormatContext& ctx)
   {
     MP_UNITS_STD_FMT::format_to(ctx.out(), "{}", lat > geographic::latitude<T>::zero() ? 'N' : 'S');
-    return formatter<T>::format(lat > geographic::latitude<T>::zero() ? lat.value() : -lat.value(), ctx);
+    return formatter<T>::format(lat > geographic::latitude<T>::zero() ? lat.numerical_value() : -lat.numerical_value(),
+                                ctx);
   }
 };
 
@@ -139,7 +140,8 @@ struct MP_UNITS_STD_FMT::formatter<geographic::longitude<T>> : formatter<T> {
   auto format(geographic::longitude<T> lon, FormatContext& ctx)
   {
     MP_UNITS_STD_FMT::format_to(ctx.out(), "{}", lon > geographic::longitude<T>::zero() ? 'E' : 'W');
-    return formatter<T>::format(lon > geographic::longitude<T>::zero() ? lon.value() : -lon.value(), ctx);
+    return formatter<T>::format(lon > geographic::longitude<T>::zero() ? lon.numerical_value() : -lon.numerical_value(),
+                                ctx);
   }
 };
 

example/unmanned_aerial_vehicle.cpp

@@ -96,8 +96,9 @@ double GeographicLibWhatsMyOffset(long double /* lat */, long double /* lon */)
 template<earth_gravity_model M>
 hae_altitude<M> to_hae(msl_altitude msl, position<long double> pos)
 {
-  const auto geoid_undulation =
-    isq::height(GeographicLibWhatsMyOffset(pos.lat.value_in(si::degree), pos.lon.value_in(si::degree)) * si::metre);
+  const auto geoid_undulation = isq::height(
+    GeographicLibWhatsMyOffset(pos.lat.numerical_value_in(si::degree), pos.lon.numerical_value_in(si::degree)) *
+    si::metre);
   return height_above_ellipsoid<M> + (msl - mean_sea_level - geoid_undulation);
 }