Custom is_same implementation added

src/include/units/bits/dimension_op.h

@@ -30,15 +30,15 @@ namespace units {
 // equivalent_dim
 namespace detail {
 
+template<BaseDimension D1, BaseDimension D2>
+using equivalent_base_dim = std::conjunction<std::bool_constant<D1::symbol == D2::symbol>,
+                                             same_unit_reference<typename D1::base_unit, typename D2::base_unit>>;
+
 template<Dimension D1, Dimension D2>
 struct equivalent_dim_impl : std::false_type {};
 
 template<BaseDimension D1, BaseDimension D2>
-struct equivalent_base_dim : std::conjunction<std::bool_constant<D1::symbol == D2::symbol>,
-                                        same_unit_reference<typename D1::base_unit, typename D2::base_unit>> {};
-
-template<BaseDimension D1, BaseDimension D2>
-struct equivalent_dim_impl<D1, D2> : std::disjunction<std::is_same<D1, D2>, equivalent_base_dim<D1, D2>> {};
+struct equivalent_dim_impl<D1, D2> : std::disjunction<is_same<D1, D2>, equivalent_base_dim<D1, D2>> {};
 
 template<Exponent E1, Exponent E2>
 struct equivalent_exp : std::false_type {};
@@ -54,7 +54,7 @@ template<typename... Es1, typename... Es2>
 struct equivalent_derived_dim<derived_dimension_base<Es1...>, derived_dimension_base<Es2...>> : std::conjunction<equivalent_exp<Es1, Es2>...> {};
 
 template<DerivedDimension D1, DerivedDimension D2>
-struct equivalent_dim_impl<D1, D2> : std::disjunction<std::is_same<D1, D2>, equivalent_derived_dim<downcast_base_t<D1>, downcast_base_t<D2>>> {};
+struct equivalent_dim_impl<D1, D2> : std::disjunction<is_same<D1, D2>, equivalent_derived_dim<downcast_base_t<D1>, downcast_base_t<D2>>> {};
 
 } // namespace detail
 

src/include/units/bits/external/type_traits.h

@@ -46,6 +46,16 @@ struct conditional_impl<true> {
 template<bool B, typename T, typename F>
 using conditional = detail::conditional_impl<B>::template type<T, F>;
 
+// is_same
+template<class T, class U>
+inline constexpr bool is_same_v = false;
+
+template<class T>
+inline constexpr bool is_same_v<T, T> = true;
+
+template<class T, class U>
+using is_same = std::bool_constant<is_same_v<T, U>>;
+
 // is_instantiation_of
 namespace detail {
 

src/include/units/bits/to_string.h

@@ -74,11 +74,11 @@ constexpr auto prefix_or_ratio_text()
     return basic_fixed_string("");
   }
   else {
-    if constexpr (!std::is_same_v<PrefixFamily, no_prefix>) {
+    if constexpr (!is_same_v<PrefixFamily, no_prefix>) {
       // try to form a prefix
       using prefix = downcast<detail::prefix_base<PrefixFamily, R>>;
 
-      if constexpr(!std::is_same_v<prefix, prefix_base<PrefixFamily, R>>) {
+      if constexpr(!is_same_v<prefix, prefix_base<PrefixFamily, R>>) {
         // print as a prefixed unit
         return prefix::symbol;
       }

src/include/units/unit.h

@@ -63,7 +63,7 @@ template<Dimension D, auto R>
 using downcast_unit = downcast<scaled_unit<R, typename dimension_unit<D>::reference>>;
 
 template<Unit U1, Unit U2>
-struct same_unit_reference : std::is_same<typename U1::reference, typename U2::reference> {};
+struct same_unit_reference : is_same<typename U1::reference, typename U2::reference> {};
 
 /**
  * @brief An unnamed unit