added error::error_code

include/matador/utils/error.hpp

@@ -52,6 +52,7 @@ public:
 
   friend std::ostream& operator<<(std::ostream &out, const error &err);
 
+  [[nodiscard]] std::string error_code() const;
   [[nodiscard]] std::string message() const;
   [[nodiscard]] std::string category() const;
   [[nodiscard]] std::error_code ec() const;

source/core/utils/error.cpp

@@ -4,9 +4,12 @@
 #include <algorithm>
 
 namespace matador::utils {
+std::string error::error_code() const {
+  return ec_.message();
+}
 
 std::string error::message() const {
-  return ec_.message();;
+  return error_message_;
 }
 
 std::string error::category() const {