Test if a variable is serializable

I'm looking for an elegant way of testing if a variable is serializable. For example array( function() {} ) will fail to serialize.

I'm currently using the code below, but it seems to be a rather non-optimal way of doing it.

function isSerializable( $var )
{
    try {
        serialize( $var );
        return TRUE;
    } catch( Exception $e ) {
        return FALSE;
    }
}

var_dump( isSerializable( array() ) );                // bool(true)
var_dump( isSerializable( function() {} ) );          // bool(false)
var_dump( isSerializable( array( function() {} ) ) ); // bool(false)

The alternative could be:

function isSerializable ($value) {
  $return = true;
  $arr = array($value);

  array_walk_recursive($arr, function ($element) use (&$return) {
    if (is_object($element) && get_class($element) == 'Closure') {
      $return = false;
    }
  });

  return $return;
}

But from comments I think this is what you are looking for:

function mySerialize ($value) {
  $arr = array($value);

  array_walk_recursive($arr, function (&$element) {

    # do some special stuff (serialize closure) ...
    if (is_object($element) && get_class($element) == 'Closure') {
      $serializableClosure = new SerializableClosure($element);
      $element = $serializableClosure->serialize();
    }

  });

  return serialize($arr[0]);
}