AS3.0 Better Singletons

I’ve found a better more robust way of enforcing singletons in AS3.0

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package
{
	public class Singleton
	{
		public static var instance:Singleton;
 
		public static function getInstance():Singleton
		{
			if( instance == null ) instance = new Singleton( new SingletonEnforcer() );
			return instance;
		}
 
		public function Singleton( pvt:SingletonEnforcer )
		{
			// init class
		}
	}
}
 
internal class SingletonEnforcer{}

Note: The class “SingletonEnforcer” is actually placed within the same .as file as the Singleton class, but placed outside the package{} parenthesis, therefore, the class “SingletonEnforcer” can only be accessed from within this .as file, so if the Singleton’s constructor is called from anywhere else, you’ll get an error.