Revert "Use == operator to simplify code"

This reverts commit ef0c7be.

Author: casperlamboo

src/eval.cpp

@@ -331,7 +331,21 @@ bool operator==(const CuraFormulaeEngine::eval::Value& lhs, const CuraFormulaeEn
         const auto& map_lhs = std::get<std::unordered_map<std::string, CuraFormulaeEngine::eval::Value>>(lhs.value);
         const auto& map_rhs = std::get<std::unordered_map<std::string, CuraFormulaeEngine::eval::Value>>(rhs.value);
 
-    return map_lhs == map_rhs;
+        if (map_lhs.size() != map_rhs.size())
+        {
+            return false;
+        }
+
+        for (const auto& [key, val_lhs] : map_lhs)
+        {
+            const auto it = map_rhs.find(key);
+            if (it == map_rhs.end() || val_lhs != it->second)
+            {
+                return false;
+            }
+        }
+
+        return true;
     }
 
     return false;