Description:
------------
The PHP documentation describes a function is_binary() at http://php.interec.es/manual/en/function.is-binary.php that does not exist.  I have tried PHP 4 and 5 on different OS's and all return the same error message: PHP Fatal error:  Call to undefined function is_binary() in /home/greway/test.php on line 2.  I have downloaded the latest PHP 5.2.6 source and grep'ed for is_binary to find that there is not even a mention of this function in the source code.  Am I the only one to every try and use this function?  Or am I doin somthing wrong.

Reproduce code:
---------------
<?php
if (is_binary(1001))
{
echo "Yes";
} else {
echo "No";
}
?>


Expected result:
----------------
Print "Yes"

Actual result:
--------------
PHP Fatal error:  Call to undefined function is_binary() in /home/greway/test.php on line 2