fix: gcc-12 compilation fixed

Resolves #632

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

@@ -48,9 +48,11 @@ template<typename T>
 concept SymbolicArg = (!std::is_const_v<T>) && (!std::is_reference_v<T>);
 
 template<typename T>
-concept SymbolicConstant =
-  SymbolicArg<T> && std::is_empty_v<T> && std::is_trivial_v<T> && std::semiregular<T> && std::is_final_v<T>;
-
+concept SymbolicConstant = SymbolicArg<T> && std::is_empty_v<T> && std::is_trivial_v<T> &&
+#if !MP_UNITS_COMP_GCC || MP_UNITS_COMP_GCC > 12
+                           std::semiregular<T> &&
+#endif
+                           std::is_final_v<T>;
 
 /**
  * @brief Type list type used by the expression template framework

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

@@ -117,8 +117,8 @@ concept ChildQuantitySpecOf = (is_child_of(Child, Parent));
 
 template<auto To, auto From>
 concept NestedQuantityKindSpecOf =
-  QuantitySpec<decltype(From)> && QuantitySpec<decltype(To)> && (!SameQuantitySpec<get_kind(From), get_kind(To)>) &&
-  ChildQuantitySpecOf<To, get_kind(From)._quantity_spec_>;
+  QuantitySpec<MP_UNITS_REMOVE_CONST(decltype(From))> && QuantitySpec<MP_UNITS_REMOVE_CONST(decltype(To))> &&
+  (!SameQuantitySpec<get_kind(From), get_kind(To)>) && ChildQuantitySpecOf<To, get_kind(From)._quantity_spec_>;
 
 template<auto From, auto To>
 concept QuantitySpecConvertibleTo =