XBT_PUBLIC(void) MSG_function_register(const char *name,
xbt_main_func_t code);
XBT_PUBLIC(void) MSG_function_register_default(xbt_main_func_t code);
XBT_PUBLIC(void) MSG_function_register(const char *name,
xbt_main_func_t code);
XBT_PUBLIC(void) MSG_function_register_default(xbt_main_func_t code);