__callStatic(), call_user_func_array(), references, and PHP 5.3.1

Question

I\'ve been reading around on SO, and elsewhere, however I can\'t seem to find anything conclusive.

Is there any way to effectively carry references through this call

Answer 1

This is a fun one.

TestClass::testFunction(&$string);

This works, but it also throws a call-time-pass-by-reference warning.

The main issue is that __callStatic's second argument comes in by value. It's creating a copy of the data, unless that data is already a reference.

We can duplicate the calling error thusly:

call_user_func_array('testFunction', array( $string ));
// PHP Warning:  Parameter 1 to testFunction() expected to be a reference, value given

call_user_func_array('testFunction', array( &$string ));
echo $string;
// 'helloworld'

I tried to modify the __callStatic method to copy the array deeply by reference, but that didn't work either.

I'm pretty sure that the immediate copy caused by __callStatic is going to be a killer here, and that you won't be able to do this without enough hoop jumping to make it a bit sticker, syntax-wise.