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

"new" only supports literal names, variable-variables (one level of indirection only), and object instances (as if you get_class()ed them). That means no closures, which are objects and thus why new tried to create an instance of Closure. Meanwhile the parentheses you're using are not to invoke the closure but to pass arguments to the class's constructor.

  $classname = $class();
  new $classname();

Thanks for your explanation.

It seems logical to me that the $class variable is the instance of Closure and $class() is equivalent to the value returned (not the signature (Closure).

As for the function parameter :

$class = function(){
	return '\StdClass';
};

$factory = function($class) {
	return new $class();
};

$factory($class()); // object(StdClass)

Fortunately in this case $class parameter is the returned value of the Closure and not the signature (Closure).

After I speak as a user of PHP, maybe in the PHP engine that concept ( new $class() ) does not make sense.

In this case is not a bug but a feature request.

happy New Year ! :)

PS: sorry for my bad english

I change the bug report to feature request.