Type-safe segues in Swift 4

UIViewController+Segue.swift

import UIKit

/// A Segue is a type-safe form of a UI segue.
protocol Segue
{
	/// The identifier of this segue
	var identifier: String { get }
}

extension UIViewController
{
	/// Perform a type-safe segue, optionally proviing a sender object.
	func performSegue(_ segue: Segue, sender: Any?)
	{
		self.performSegue(withIdentifier: segue.identifier, sender: sender)
	}
}

/// Automatically synthesizes identifiers from the raw value of entities that conform
/// to both RawRepresentable and Segue
extension Segue where Self: RawRepresentable, Self.RawValue == String
{
	var identifier: String
	{
		return rawValue
	}
}

ViewController.swift

class ViewController: UIViewController
{
	/// List of segues that are registered for this view controller.
	internal enum Segues: String, Segue
	{
		case showDetail, embedEventsList, embedCalendar
	}
	
	/// Invoked by some other entity to request the presentation of an event.
	func showDetail(for event: Event)
	{
		/// Invoke a type-safe segue.
		performSegue(Segues.showDetail, sender: event)
	}
}