ole

import SwiftUI

func `let`<Value, Return>(_ expression: Value, body: (Value) -> Return) -> Return {
  body(expression)
}

struct ContentView: View {
  var body: some View {
    GeometryReader { geometry in
      `let`(geometry.size.width / 2) { lineWidth in

ole

import Dispatch
import PlaygroundSupport

@propertyDelegate
struct Atomic<A> {
  private var _value: A
  private let queue = DispatchQueue(label: "property wrapper")

  init(initialValue: A) {
    _value = initialValue

ole

% mount
/dev/disk1s6 on / (apfs, local, journaled)
devfs on /dev (devfs, local, nobrowse)
/dev/disk1s5 on /System/Volumes/Data (apfs, local, journaled, nobrowse)
/dev/disk1s4 on /private/var/vm (apfs, local, journaled, nobrowse)
map -hosts on /net (autofs, nosuid, automounted, nobrowse)
map auto_home on /home (autofs, automounted, nobrowse)

% ls /System/Volumes/Data
Device	Users

ole

import Foundation

let data = Data([0, 0, 0, 0, 0, 0x11, 0x22, 0x33, 0x44, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
data.count

extension UnsafeRawBufferPointer {
    func loadUnaligned<T>(fromByteOffset offset: Int, as: T.Type) -> T {
        // Allocate correctly aligned memory and copy bytes there
        let alignedPointer = UnsafeMutableRawPointer.allocate(byteCount: MemoryLayout<T>.stride, alignment: MemoryLayout<T>.alignment)
        defer {

ole

// Type-safe date format strings using string interpolation
// Requires Swift 5.0.

import Foundation

enum DateFormatComponent {
    case era(AlphaStyle)
    case year(MinimumDigits)
    case yearForWeekOfYear(MinimumDigits)
    case quarter(AlphaNumericStyle)

ole

0.54–21.25
John Sundell Welcome to the very first episode of the Swift Community Podcast. A show for the Swift community by the Swift Community. I am one of your hosts, John Sindel. And with me, I have two wonderful co hosts, the first of which you might know as the host of the Swift coders podcast. Mr. Garric Nahapetian. How's going Garric?

21.38–24.27
Garric Nahapetian Excellent. Thank you so much for having me. How you doing?

24.46–35.97
John Sundell I'm doing great. And we also have our third and final co host for this episode. And it's none other than the creator of Swift itself. Mr Chris Lattner. How's it going, Chris?

35.98–40.75

ole

// Paste this into an iOS playground in Xcode and run
// Expected output:
// ParentVC: handled in ParentCoordinator
// ChildVC: handled in ChildCoordinator
// UIViewController: accountLogin() not handled

import UIKit

NSSetUncaughtExceptionHandler { exception in
    print("Exception: \(exception.name) — \(exception)")

ole

// Challenge: Fill out this extension
//
// I have a solution for this return type:
//
//     var headAndTail: (head: Element, tail: AnySequence<Element>)?
//
// I don't think it can be done with tail: SubSequence.
extension Sequence {
    /// Destructures `self` into the first element (head) and the rest (tail).
    /// Returns `nil` if the sequence is empty.

ole

import Foundation

/// An abstract class that makes building simple asynchronous operations easy.
/// Subclasses must override `main()` to perform any work and call `finish()`
/// when they are done. All `NSOperation` work will be handled automatically.
///
/// Source/Inspiration: https://stackoverflow.com/a/48104095/116862 and https://gist.github.com/calebd/93fa347397cec5f88233
open class AsyncOperation: Operation {
    public init(name: String? = nil) {
        super.init()

ole

import UIKit

/// A validation rule for text input.
public enum TextValidationRule {
    /// Any input is valid, including an empty string.
    case noRestriction
    /// The input must not be empty.
    case nonEmpty
    /// The enitre input must match a regular expression. A matching substring is not enough.
    case regularExpression(NSRegularExpression)