(PHP 5 >= 5.2.0, PHP 7) Returns the peak of memory allocated by PHP

(PECL uopz >= 1.0.0) Implements an interface at runtime

(PHP 4, PHP 5, PHP 7) Set/get the various assert flags

(PHP 7) Clear the most recent error void error_clear_last

(PECL weakref >= 0.1.0) Releases a previously acquired reference

(PECL wincache >= 1.1.0) Retrieves information about user cache memory usage

(PHP 4, PHP 5, PHP 7) Returns an array with the names of all modules compiled and loaded

(PHP 4, PHP 5, PHP 7) Gets the current PHP version

(PHP 5, PHP 7 >= 5.5.0, PHP 7) Sets the process title

(PECL apc >= 3.0.0) Cache a variable in the data store