- * The @a str is passed as argument to your @a error_msg, as follows:
- * @verbatim throw std::invalid_argument(simgrid::xbt::string_printf(error_msg, str)); @endverbatim
+ * The @a str is concatenated to your @a error_msg, as follows:
+ * @verbatim throw std::invalid_argument(simgrid::xbt::string_printf("%s: %s", error_msg, str)); @endverbatim