It can be argued if PHP trying to be smart when dealing with types is a good thing or not (I say it's horrible but I have to live with it), but it does produce some funny results.

Today's adventure started with a PHP error message:

PHP Fatal error:  Call to undefined method stdClass::update()

My first though was: WTF? I didn't use stdClass anywhere! So I investigated the snipped that caused it a bit

<?php
// snip...

$feed = Feed::get($id);
$feed->status = $status;
$feed->update();

// snap...

Looks normal. Maybe Feed::get() has something wrong?

<?php
class Feed {
    // some other methods
    function get($id) {
        // snip...

        return $row ? new self($row['foo'] /*, ... */) : null;
    }
}

Okay, no way that thing can get me a stdClass object. Then I tried out what would happen if null would be returned, so the first snipped $feed->status = $status would operate on a variable holding null:

$ php -r '$a = null; $a->foo = "bar"; var_dump($a);'

When I saw the result, I facepalmed. Hard.

object(stdClass)#1 (1) {
  ["foo"]=>
  string(3) "bar"
}