Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to report
a bug at http://bugs.php.net/how-to-report.php

Do not pass any param to method. Just use $rc->newInstanceArgs();

Thank you for taking the time to write to me, but if this is not a bug then this is a bad design of the method.

I've double-checked the documentation available at http://php.net/manual/en/reflectionclass.newinstanceargs.php which said 'This function is currently not documented; only its argument list is available.' and said nothing about the numbers of the element in the given array.

If you want to make a factory function with vararg, then you don't want to case about the number of the parameters.

I think this should work:

function factory($className /* and other params here... */ ) {
  $rc = new ReflectionClass($className);
  $params = func_get_args();
  array_shift($params);
  return $rc->newInstanceArgs($param);
}

The new $className(...) construction doesn't work here.

What is the difference between
  class A {}
and
  class A { function __construct(){} }
from the view of the construction? Both can be constructed by a zero-arg constructor call, new A(). If I've an array containing zero elements, why should not the $rc->newInstanceArgs($array) works in the first case, even it does in the second?