Add wrapper around mkdir, that throws an exception on errors

MD_STD.php

@@ -49,6 +49,27 @@ final class MD_STD {
 
     }
 
+    /**
+     * Wrapper around mkdir, that throws an exception, if the folder cannot be
+     * created.
+     *
+     * @see https://www.php.net/manual/en/function.mkdir.php
+     *
+     * @param string  $pathname  The directory path.
+     * @param integer $mode      Permissions.
+     * @param boolean $recursive Allows the creation of nested directories
+     *                           specified in the pathname.
+     *
+     * @return void
+     */
+    public static function mkdir(string $pathname, int $mode = 0775, bool $recursive = false) {
+
+        if (\mkdir($pathname, $mode, $recursive) === false) {
+            throw new Exception("Failed to create directory: $pathname");
+        }
+
+    }
+
     /**
      * Gets contents of a folder.
      *