扩展另一个的PHP类如何继承私有函数？

Question

I am trying to extend a PHP class without rewriting the whole thing. Here is an example:

<?
$a = new foo();
print $a->xxx();
$b = new bar();
print $b->xxx();

class foo {
  const something = 10;

  public function xxx() {
    $this->setSomething();
    return $this->something;
  }

  private function setSomething() {
    $this->something = self::something;
  }
}

class bar extends foo {

  public function xxx() {
    $this->setSomething();
    $this->something++;
    return $this->something;
  }

}
?>

However when I run the script I get the following error:

Fatal error: Call to private method foo::setSomething() from context 'bar' in test.php on line 23

It would seem that bar is not inheriting the private function setSomething(). How would I fix this without modifying the foo class?

Answer 1

bar is inheriting the function alright, but it can't call it. That's the whole point of private methods, only the declaring class can call them.