Q:

Ambigous PHP error message

Having this:
...
private $responseBuffer = array();
...

and within this line:
$lm = end(array_values($this->responseBuffer));

I get 
Error: Only variables should be passed by reference (2048)
as both end and array_values are built in and do not have a call-by-referenceI'm puzzled, any one an idea?
(purpose: get the latest value out of $responseBuffer)

A:

end function receives the arguement by reference, do like this:
$var = array_values($this->responseBuffer);
$lm = end($var);

