How do I force to pass an argument by reference?

Hi, I can't understand why the pass_by_ref argument of ZEND_ARG_OBJ_INFO() doesn't work for me. I want just the same fatal error, as the standard usort() function returns, if the argument is not a variable: usort([1,0]); Fatal error: Only variables can be passed by reference The following code should enable the same functionality, but it doesn't: ZEND_BEGIN_ARG_INFO_EX(arginfo_bufferevent__construct, 0, 0, 1) ZEND_ARG_OBJ_INFO(1, base, EventBase, 0) ZEND_ARG_INFO(0, socket) ZEND_ARG_INFO(0, options) ZEND_ARG_INFO(0, readcb) ZEND_ARG_INFO(0, writecb) ZEND_ARG_INFO(0, eventcb) ZEND_END_ARG_INFO(); PHP_ME(EventBufferEvent, __construct, arginfo_bufferevent__construct, ZEND_ACC_PUBLIC | ZEND_ACC_CTOR) There're no complains regarding references here: $b = new EventBufferEvent(new EventBase()); The reflection information only confirms that the code is right: $ php --rf eventbufferevent::__construct Method [ <internal:event, ctor> public method __construct ] { - Parameters [6] { Parameter #0 [ <required> EventBase &$base ] Parameter #1 [ <optional> $socket ] Parameter #2 [ <optional> $options ] Parameter #3 [ <optional> $readcb ] Parameter #4 [ <optional> $writecb ] Parameter #5 [ <optional> $eventcb ] } } Please help me to understand what's wrong with my code, or how do I force passing by reference? -- Ruslan Osmanov