if ("/"->file_exists ()) ...                                                   /* "ERR_NOT_A_FILE" */

if ("/"->directory_exists ()) ...                                              /* 1 */

if ("./text.txt"->file_exists ()) ...                                          /* 1 */

if ("./text.txt"->directory_exists ()) ...                                     /* "ERR_NOT_A_DIRECTORY" */

