Agarunov

protocol Sequence {
    associatedtype SubSequence: Sequence
        where Iterator.Element == SubSequence.Iterator.Element, SubSequence.SubSequence == SubSequence

    // code
}

Agarunov

struct Pet {
    let name: String
}

let pets = [Pet(name: "Beethoven")]
let encoder = JSONEncoder()
try! encoder.encode(pets)

Agarunov

let array1: [String?] = ["Jon", "Snow", nil]
let array2: [String?] = ["Winter", "is", "coming", "!", nil]
array1 == array2 // false

Agarunov

extension Array: Equatable where Element: Equatable {
    static func ==(lhs: Array<Element>, rhs: Array<Element>) -> Bool {
        // do stuff
    }
}

Agarunov

struct Person: Codable {
    let firstName: String
    let lastName: String
}

let jsonData = """
{
    "first_name": "John",
    "last_name": "Watson"
}

Agarunov

let string = "Hello, World!"
let keyPath = \String.[string.startIndex]
string[keyPath: keyPath]

Agarunov

let friends = ["Ross", nil, "Joey", "Chandler"]

// Swift 4.0
let array1 = friends.flatMap { $0 } // ["Ross", "Joey", "Chandler"]

// Swift 4.1
let array2 = friends.compactMap { $0 } // ["Ross", "Joey", "Chandler"]

Agarunov

// Swift 4.1
#if targetEnvironment(simulator)
// Simulator!
#endif

// Swift 4.0
#if (arch(i386) || arch(x86_64)) && os(iOS)
// Simulator!
#else
// Device!

Agarunov

#if canImport(UIKit)
// UIKit is available!
import UIKit
#endif

Agarunov

// Declared inside framework
struct Point: Hashable {
    let x: Float
    let y: Float

    init(x: Float, y: Float) {
        self.x = x
        self.y = y
    }
}