SebastianBoldt

let x: String? = "Hello Optional"
switch x {
  case .some(let value): print("Optional has an value of \(value)")
  case .none: print("nothing stored inside the enum")
}

SebastianBoldt

fileprivate func < <T : Comparable>(lhs: T?, rhs: T?) -> Bool {
  switch (lhs, rhs) {
  case let (l?, r?):
    return l < r
  case (nil, _?):
    return true
  default:
    return false
  }
}

SebastianBoldt

// Won't work
let x: String? = nil
let y: String? = "Hello Optional"
switch (x,y) {
   case .some(let a),.some(let b): print("Optional has an value of \(unwrappedX)")
   case .none: print("nothing stored inside the enum")
}

SebastianBoldt

let x: String? = "Hello Optional"
let y: String? = "Hello Optional"
switch (x,y) {
    case let (x?,y?): print("Values: \(x) & \(y)")
    default: print("Error")
}

SebastianBoldt

import Foundation

internal final class MulticastDelegate<T> {
	private var delegates = [Weak]()
	
	func add(_ delegate: T) {
		if Mirror(reflecting: delegate).subjectType is AnyClass {
			let weakValue = Weak(value: delegate as AnyObject)
			guard delegates.index(of: weakValue) == nil else {
				return

SebastianBoldt

SebastianBoldt

let cellProvider: (UICollectionView, IndexPath, Item) -> UICollectionViewCell? = { collectionView, indexPath, item in
  let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
  cell.backgroundColor = item.color
  return cell
}

SebastianBoldt

enum Section {
  case section1
  case section2
}

struct Item: Hashable {
  let name: String
}

SebastianBoldt

class ViewController: UIViewController {
    @IBOutlet var collectionview: UICollectionView!
    override func viewDidLoad() {
       super.viewDidLoad()
    }
}

SebastianBoldt

class ViewController: UIViewController {
    @IBOutlet var collectionview: UICollectionView!
    lazy var dataSource = UICollectionViewDiffableDataSource<Section, Item>(collectionView: self.collectionview,
                                                                            cellProvider: self.cellProvider)
    lazy var cellProvider: (UICollectionView, IndexPath, Item) -> UICollectionViewCell? = { collectionView, indexPath, item in
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
        cell.backgroundColor = item.color
        return cell
    }