PHP 5.4: Accessor with trait example

php-5.4-accessor-with-trait.php

<?php
// Example code how to eliminate getter and setter methods
// with traits introduced from PHP 5.4

trait Accessors {
  public function __get($name) {
    if ($this->r_property[$name])
      return $this->$name;
    else
      trigger_error("Access to read protected property");
  }

  public function __set($name, $value) {
    if ($this->w_property[$name])
      $this->$name = $value;
    else 
      trigger_error("Access to write protected property");
  }
}

class OrderLine {
  use Accessors;

  private $r_property = array('price'=>1, 'amount'=>1);
  private $w_property = array('price'=>0, 'amount'=>1);

  protected $price;
  private $amount;
  private $tax = 1.15; // property without getter/setter

  public function getTotal() {
    return $this->price * $this->amount * $this->tax;
  }
}

$line = new OrderLine;

$line->price = 20;
$line->amount = 3;

echo "Total cost: ".$line->getTotal();
?>

How would you do inheritance with this (assuming you are using Accessor in both the parent and the child)? Or is it even possible?