gistfile1.php

<?php
	
	trait Singleton
	{
		private static $_instance;

		public static function getInstance()
		{
			if(!(self::$_instance instanceof self))
			{
				self::$_instance = new self;
			}

			return self::$_instance;
		}
	}

	//and in another class

	class SomeShit 
	{
		use Singleton;
	}

	$singleton = SomeShit::getInstance();
	$singleton->foo = 'bar';
	var_dump($singleton);

	$singleton = SomeShit::getInstance();
	var_dump($singleton);