(PHP 4 >= 4.1.0, PHP 5, PHP 7) Returns an associative array with the names of all the constants and their

(PHP 5 >= 5.5.5, PHP 7, PECL ZendOpcache > 7.0.2) Get status information about the cache

(PECL weakref >= 0.1.0) Checks whether the object referenced still exists

(PECL runkit >= 0.7.0) Runkit Sandbox Class -- PHP Virtual Machine

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

(PECL apc >= 3.1.4) Load a binary dump into the APC file/user cache

(PECL weakref >= 0.2.0) Advances to the next map element

(PHP 5, PHP 7) Prints a backtrace void debug_print_backtrace

(PHP 5 >= 5.3.0, PHP 7) Activates the circular reference collector

(PECL apc >= 3.1.1) Increase a stored number