+inline
+std::string TARIFF::ChangePolicyToString(TARIFF::CHANGE_POLICY changePolicy)
+{
+switch (changePolicy)
+    {
+    case ALLOW: return "allow";
+    case TO_CHEAP: return "to_cheap";
+    case TO_EXPENSIVE: return "to_expensive";
+    case DENY: return "deny";
+    }
+return "allow"; // Classic behaviour.
+}
+
+inline
+TARIFF::CHANGE_POLICY TARIFF::StringToChangePolicy(const std::string& value)
+{
+if (strcasecmp(value.c_str(), "to_cheap") == 0)
+    return TO_CHEAP;
+if (strcasecmp(value.c_str(), "to_expensive") == 0)
+    return TO_EXPENSIVE;
+if (strcasecmp(value.c_str(), "deny") == 0)
+    return DENY;
+return ALLOW; // Classic behaviour.
+}
+