+// Wrapper to check if the first element to be shifted is set to given value
+function shift_array (&$array, $value, $key = '0') {
+ // Is the element set and value matches?
+ assert(is_array($array));
+ assert(isset($array[$key]));
+ assert($array[$key] === $value);
+
+ // Shift it
+ array_shift($array);
+}
+
+// Wrapper for str_pad() with left padding zeros
+function padLeftZero ($str, $amount = 2) {
+ // Is str_pad() there?
+ if (function_exists('str_pad')) {
+ // Use prependZeros()
+ return prependZeros($str, $amount);
+ } else {
+ // Pad it
+ return str_pad($str, $amount, '0', STR_PAD_LEFT);
+ }
+}
+