(PECL apc >= 3.0.0)
apc_delete — Removes a stored variable from the cache
成功时返回 TRUE， 或者在失败时返回 FALSE.
Example #1 A apc_delete() example
<?php
$bar = 'BAR';
apc_store('foo', $bar);
apc_delete('foo');
// this is obviously useless in this form
?>