Singleton Trait for PHP

gistfile1.php

<?php
trait SingletonClass {
  protected static $instance;
	
	final public static function getInstance() {
		return isset(static::$instance) 
			? static::$instance 
			: static::$instance = new static;
	}
	
	final private function __construct() {
		$this->__init();
	}
	
	protected abstract function __init();
	
	final private function __wakeup() {}
	final private function __clone() {}
	
}