Description:
------------
Array's don't convert as the documentation says and emit's an E_WARNING upon conversion.

the documentation says that when converting an scalar value to an array the result will be an array with 1 element, the original scalar value. however the scalar value is never converted and an E_WARNING is emitted instead. see code below.

a quote from the documentation:
"For any of the types: integer, float, string, boolean and resource, converting a value to an array results in an array with a single element with index zero and the value of the scalar which was converted. In other words, (array)$scalarValue is exactly the same as array($scalarValue)."

more interesting is that also the '(array)$scalarValue' does not work but if the scalar evaluates to NULL such as false or an empty string it does work. as in the test code i including below only test 2 works as expected. test 1 emits an E_WARNING and test 3 fails silently.

now either the documentation is out-of-date but i cannot imagine that this is the intended behaviour. especially test 3 is troublesome as an explicit cast of any kind should not fail silently.

Reproduce code:
---------------
<?php
error_reporting(E_ALL);

print("\n Test 1.\n");
$scalar = true;
var_dump($scalar);

$scalar[] = "A new element to the array";
var_dump($scalar);

print("\n Test 2. \n");
$scalar = false;
var_dump($scalar);

$scalar[] = "A new element to the array";
var_dump($scalar);

print("\n Test 3. \n");
$scalar = true;
var_dump($scalar);

(array)$scalar;
var_dump($scalar);

?>

Expected result:
----------------
//test 1.
bool(true);
array(1) {
 [0] =>
  bool(true);
 [1] =>
  string(26) "A new element to the array";
}

//for test 2.
bool(false);
array(1) {
 [0] =>
  string(26) "A new element to the array";
}

//for test3.
(bool)true;
array(1) {
 [0] =>
  bool(true);
}

Actual result:
--------------
 Test 1.
bool(true)

Warning: Cannot use a scalar value as an array in array_bug.php on line 6
bool(true)

 Test 2.
bool(false)
array(1) {
  [0]=>
  string(26) "A new element to the array"
}

 Test 3.
bool(true)
bool(true)