(PECL apcu >= 5.1.0) Atomically fetch or generate a cache entry

(PECL apcu >= 5.0.0) Get iterator key public

(PECL apcu >= 4.0.0) Clears the APCu cache

(PECL apcu >= 4.0.0) Retrieves APCu Shared Memory Allocation information

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

(PECL apcu >= 5.0.0) Get total count public

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

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

(PECL apc >= 3.1.1) Rewinds iterator public

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