Comparison operator in CI

[eluser]überfuzz[/eluser]
I'm trying to use a comparison operator instead of a if-statement. But I'm getting an error, I think it's a php-error. This is the code:

Code:

$page = (!isset($this->uri->segment(1)) ? 'home' : $this->uri->segment(1);

The error-message:

Fatal error: Can't use method return value in write context in /home/minister/public_html/application/views/all/menu.php on line 7

Is it a CI error, I seem to recall that I've been using this way of assigning values before. But now..?