(PECL apcu >= 4.0.0) Retrieves cached information from APCu's data store

(PECL apc >= 3.1.1) Checks if current position is valid

(PECL apcu >= 4.0.0) Updates an old value with a new value

(PECL apcu >= 5.0.0) Get iterator key public

(PECL apc >= 3.0.0) Loads a set of constants from the cache

(PECL apc >= 2.0.0) Retrieves APC's Shared Memory Allocation information

(PECL apc >= 3.1.1) Move pointer to next item

(PECL apcu >= 4.0.0) Clears the APCu cache

(PECL apc >= 3.1.4) Output a binary dump of cached files and user variables to a file

(PECL apcu >= 4.0.0) Removes a stored variable from the cache