fix: ordering

include/jvalidate/detail/simple_adapter.h

@@ -127,15 +127,19 @@ public:
     return std::make_unique<GenericConst<value_type>>(const_value());
   }
 
-  template <typename Other>
-  requires std::totally_ordered_with<JSON, typename Other::value_type> std::strong_ordering
-  operator<=>(SimpleAdapter const & rhs) const {
+  auto operator<=>(SimpleAdapter const & rhs) const requires std::totally_ordered<JSON> {
     using ord = std::strong_ordering;
     if (value_ == rhs.value_) {
-      return std::strong_ordering::equal;
+      return ord::equal;
     }
     if (value_ && rhs.value_) {
-      return *value_ <=> *rhs.value_;
+      if (*value_ < *rhs.value_) {
+        return ord::less;
+      }
+      if (*rhs.value_ < *value_) {
+        return ord::greater;
+      }
+      return ord::equal;
     }
     if (value_) {
       return type() == Type::Null ? ord::equivalent : ord::greater;