ReflectionParameter::canBePassedByValue

( excerpt from http://php.net/manual/en/reflectionparameter.canbepassedbyvalue.php )

public function canBePassedByValue();

Returns whether this parameter can be passed by value. Warning: This function is currently not documented; only its argument list is available.

Returns

• mixed - Returns TRUE if the parameter can be passed by value, FALSE otherwise. Returns NULL in case of an error.