feat: all tags in the expression templates are now ordered by the type names

Resolves #499

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

@@ -29,6 +29,7 @@
 #include <mp-units/compat_macros.h>
 #include <mp-units/ext/fixed_string.h>
 #include <mp-units/ext/inplace_vector.h>
+#include <mp-units/ext/type_name.h>
 #include <mp-units/ext/type_traits.h>
 #include <mp-units/framework/dimension_concepts.h>
 #include <mp-units/framework/expression_template.h>
@@ -55,7 +56,7 @@ MP_UNITS_EXPORT struct dimension_one;
 namespace detail {
 
 template<typename Lhs, typename Rhs>
-struct base_dimension_less : std::bool_constant<(Lhs::symbol < Rhs::symbol)> {};
+struct base_dimension_less : std::bool_constant<type_name<Lhs>() < type_name<Rhs>()> {};
 
 template<typename T1, typename T2>
 using type_list_of_base_dimension_less = expr_less<T1, T2, base_dimension_less>;

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

@@ -108,7 +108,7 @@ template<Unit T, auto M, typename U>
 [[nodiscard]] consteval auto get_canonical_unit_impl(T, const scaled_unit_impl<M, U>&);
 
 template<Unit Lhs, Unit Rhs>
-struct unit_less : std::bool_constant<(Lhs::symbol < Rhs::symbol)> {};
+struct unit_less : std::bool_constant<type_name<Lhs>() < type_name<Rhs>()> {};
 
 template<typename T1, typename T2>
 using type_list_of_unit_less = expr_less<T1, T2, unit_less>;

test/static/quantity_test.cpp

@@ -518,7 +518,7 @@ static_assert(is_of_type<isq::length(1 * m) - 1 * m, quantity<isq::length[m], in
 static_assert(is_of_type<isq::length(1 * m) - 1 * km, quantity<isq::length[m], int>>);
 static_assert(is_of_type<isq::length(1 * km) - 1 * m, quantity<isq::length[m], int>>);
 
-static_assert(is_of_type<1 * N * (1 * m), quantity<derived_unit<struct si::newton, struct si::metre>{}, int>>);
+static_assert(is_of_type<1 * N * (1 * m), quantity<derived_unit<struct si::metre, struct si::newton>{}, int>>);
 
 static_assert(is_of_type<1 * m * 1, quantity<si::metre, int>>);
 static_assert(is_of_type<1 * m * (1 * one), quantity<si::metre, int>>);
@@ -566,7 +566,7 @@ static_assert(is_of_type<1 * m - 1. * m, quantity<si::metre, double>>);
 static_assert(is_of_type<1. * km - 1 * m, quantity<si::metre, double>>);
 static_assert(is_of_type<1. * m - 1 * km, quantity<si::metre, double>>);
 
-static_assert(is_of_type<1. * N * (1 * m), quantity<derived_unit<struct si::newton, struct si::metre>{}, double>>);
+static_assert(is_of_type<1. * N * (1 * m), quantity<derived_unit<struct si::metre, struct si::newton>{}, double>>);
 
 static_assert(is_of_type<1 * m * 1., quantity<si::metre, double>>);
 static_assert(is_of_type<1 * m * (1. * one), quantity<si::metre, double>>);
@@ -619,7 +619,7 @@ static_assert(is_of_type<1 * m % (1 * km), quantity<si::metre, int>>);
 static_assert(is_of_type<1 * m / s * (1 * s), quantity<si::metre, int>>);
 static_assert(is_of_type<1 * m / s * (1 * h),
                          quantity<derived_unit<struct si::hour, struct si::metre, per<struct si::second>>{}, int>>);
-static_assert(is_of_type<1 * m * (1 * min), quantity<derived_unit<struct si::metre, struct si::minute>{}, int>>);
+static_assert(is_of_type<1 * m * (1 * min), quantity<derived_unit<struct si::minute, struct si::metre>{}, int>>);
 static_assert(is_of_type<1 * s * (1 * Hz), quantity<derived_unit<struct si::hertz, struct si::second>{}, int>>);
 static_assert(is_of_type<1 / (1 * min), quantity<derived_unit<struct one, per<struct si::minute>>{}, int>>);
 static_assert(is_of_type<1 / (1 * Hz), quantity<derived_unit<struct one, per<struct si::hertz>>{}, int>>);

test/static/unit_symbol_test.cpp

@@ -184,7 +184,7 @@ static_assert(unit_symbol(radian) == "rad");
 
 // Physical constants
 static_assert(unit_symbol(si2019::speed_of_light_in_vacuum) == "c");
-static_assert(unit_symbol(gram * standard_gravity * si2019::speed_of_light_in_vacuum) == "c g g₀");
+static_assert(unit_symbol(gram * standard_gravity * si2019::speed_of_light_in_vacuum) == "g c g₀");
 static_assert(unit_symbol(gram / standard_gravity) == "g/g₀");
 static_assert(unit_symbol(kilo<metre> / second / mega<iau::parsec>) == "km Mpc⁻¹ s⁻¹");
 

test/static/unit_test.cpp

@@ -210,8 +210,7 @@ static_assert(kilojoule.symbol == "kJ");
 static_assert(is_of_type<si::kilo<metre>, si::kilo_<metre_>>);
 static_assert(is_of_type<si::kilo<joule>, si::kilo_<joule_>>);
 
-static_assert(
+static_assert(is_of_type<kilometre * metre, derived_unit<metre_, si::kilo_<metre_>>>);  // !!!
-  is_of_type<kilometre * metre, derived_unit<std::remove_const_t<decltype(si::kilo<metre>)>, metre_>>);  // !!!
 static_assert(
   is_of_type<kilometre / metre, derived_unit<std::remove_const_t<decltype(si::kilo<metre>)>, per<metre_>>>);  // !!!
 
@@ -331,9 +330,9 @@ static_assert(is_of_type<standard_gravity / gram, derived_unit<standard_gravity_
 static_assert(is_of_type<gram / standard_gravity, derived_unit<gram_, per<standard_gravity_>>>);
 static_assert(is_of_type<standard_gravity * gram / standard_gravity, gram_>);
 static_assert(is_of_type<speed_of_light_in_vacuum * gram * standard_gravity,
-                         derived_unit<speed_of_light_in_vacuum_, gram_, standard_gravity_>>);
+                         derived_unit<gram_, speed_of_light_in_vacuum_, standard_gravity_>>);
 static_assert(is_of_type<gram * standard_gravity * speed_of_light_in_vacuum,
-                         derived_unit<speed_of_light_in_vacuum_, gram_, standard_gravity_>>);
+                         derived_unit<gram_, speed_of_light_in_vacuum_, standard_gravity_>>);
 
 static_assert(is_same_v<decltype(inverse(second) * metre), decltype(metre / second)>);
 static_assert(is_same_v<decltype(metre * inverse(second)), decltype(metre / second)>);