 	}
 
 
-	public func mapped<U: Hashable>(transform: (T) -> U) -> OrderedSet<U> {
+	@warn_unused_result
+	public func mapAsOrderedSet<U: Hashable>(@noescape transform: (T) -> U) -> OrderedSet<U> {
 		var newSet = OrderedSet<U>(minimumCapacity: count)
 		for element in orderedElements {
 			newSet.add(transform(element))



	public func intersected(set: OrderedSet<T>) -> OrderedSet<T> {
		return filtered { set.contains($0) }
	}



	}


	@warn_unused_result
	public func filterAsOrderedSet(@noescape includeElement: (T) -> Bool) -> OrderedSet<T> {
		var filteredElements = OrderedSet<T>()
		for element in orderedElements {
			if includeElement(element) {
