Failed use of an anonymous inner class

gistfile1.swift

	override func loadView() {
		// Create a KAExerciseControlsDelegate implementation that invokes methods on the delegate
		// of this instance.
		weak var weakSelf = self
		class ViewDelegate: KAExerciseControlsDelegate {
			// Invokes the given block with the view controller and its delegate, if both are still
			// allocated.
			private func callControllerDelegate(caller: (ExerciseControlsViewDelegate, ExerciseControlsViewController) -> Void) {
				if let strongSelf = weakSelf, strongDelegate = strongSelf.delegate {
					caller(strongDelegate, strongSelf)
				}
			}

			@objc func exerciseControlsDidSelectCheckAnswer(controlsContainer: KAExerciseControlsView) {
				callControllerDelegate { $0.exerciseControlsViewController($1, didTapProgressButtonActionWithProgressType: .CheckAnswer) }
			}
			@objc func exerciseControlsDidSelectNextProblem(controlsContainer: KAExerciseControlsView) {
				callControllerDelegate { $0.exerciseControlsViewController($1, didTapProgressButtonActionWithProgressType: .NextProblem) }
			}
			@objc func exerciseControlsDidSelectEndOfTask(controlsContainer: KAExerciseControlsView) {
				callControllerDelegate { $0.exerciseControlsViewController($1, didTapProgressButtonActionWithProgressType: .EndOfTask) }
			}
			@objc func exerciseControlsDidSelectHints(controlsContainer: KAExerciseControlsView) {
				callControllerDelegate { $0.exerciseControlsViewControllerDidSelectHints($1) }
			}
			@objc func exerciseControlsDidSelectRelatedVideos(controlsContainer: KAExerciseControlsView) {
				callControllerDelegate { $0.exerciseControlsViewControllerDidSelectRelatedVideos($1) }
			}
			@objc func exerciseControlsDidSelectSkipProblem(controlsContainer: KAExerciseControlsView) {
				callControllerDelegate { $0.exerciseControlsViewControllerDidSelectSkipProblem($1) }
			}
		}

		view = KAExerciseControlsView(delegate: ViewDelegate(), shouldHideSkipProblemButton: shouldHideSkipProblemButton)
	}