1. xxxLiteralConvertible
@taketo1024
2015/02/18 potatotips #14

3. http://maths4pg.connpass.com

4. 2014/10/18 「iOS 8 / Swift 勉強会 @ ヤフー」

5. import Foundation
struct Complex: Equatable, IntegerLiteralConvertible, FloatLiteralConvertible {
let x: Double
let y: Double
init(_ x: Double, _ y: Double) {
self.x = x
self.y = y
}
init(_ x: Double) {
self.x = x
self.y = 0
}
init(integerLiteral x: IntegerLiteralType) {
self.x = Double(x)
self.y = 0
}
init(floatLiteral x: FloatLiteralType) {
self.x = x
self.y = 0
}
init(r: Double, θ: Double) {
self.x = r * cos(θ)
self.y = r * sin(θ)
}
}
func == (z: Complex, w: Complex) -> Bool {
return z.x == w.x && z.y == w.y
}
func Re(a: Complex) -> Double {
return a.x
}
func Im(a: Complex) -> Double {

6. import Foundation
struct Complex: Equatable, IntegerLiteralConvertible, FloatLiteralConvertible {
let x: Double
let y: Double
init(_ x: Double, _ y: Double) {
self.x = x
self.y = y
}
init(_ x: Double) {
self.x = x
self.y = 0
}
init(integerLiteral x: IntegerLiteralType) {
self.x = Double(x)
self.y = 0
}
init(floatLiteral x: FloatLiteralType) {
self.x = x
self.y = 0
}
init(r: Double, θ: Double) {
self.x = r * cos(θ)
self.y = r * sin(θ)
}
}
func == (z: Complex, w: Complex) -> Bool {
return z.x == w.x && z.y == w.y
}
func Re(a: Complex) -> Double {
return a.x
}
func Im(a: Complex) -> Double {

7. import Foundation
struct Complex: Equatable, IntegerLiteralConvertible, FloatLiteralConvertible {
let x: Double
let y: Double
init(_ x: Double, _ y: Double) {
self.x = x
self.y = y
}
init(_ x: Double) {
self.x = x
self.y = 0
}
init(integerLiteral x: IntegerLiteralType) {
self.x = Double(x)
self.y = 0
}
init(floatLiteral x: FloatLiteralType) {
self.x = x
self.y = 0
}
init(r: Double, θ: Double) {
self.x = r * cos(θ)
self.y = r * sin(θ)
}
}
func == (z: Complex, w: Complex) -> Bool {
return z.x == w.x && z.y == w.y
}
func Re(a: Complex) -> Double {
return a.x
}
func Im(a: Complex) -> Double {

8. let z = 2 + 3 * i
こういう風に書ける
z

9. let z = 2 + 3 * iz
{
Complex(0, 1) 定数として定義してある
こういう風に書ける

10. let z = 2 + 3 * i
こういう風に書ける
{
Complex(3, 0) * Complex(0, 1)
z
{
Complex(0, 1)

11. let z = 2 + 3 * i
こういう風に書ける
{
Complex(3, 0) * Complex(0, 1)
{
z
{
Complex(0, 1)
Complex(2, 0) + Complex(3, 0) * Complex(0, 1)

12. let z = 2 + 3 * i
こういう風に書ける
{
Complex(3, 0) * Complex(0, 1)
{
Complex(2, 0) + Complex(3, 0) * Complex(0, 1)
z
let z: Complex = Complex(2, 0) + Complex(3, 0) * Complex(0, 1)
{
{
Complex(0, 1)

13. i * i == -1

14. i * i == -1
{
Complex(0, 1) * Complex(0, 1)

15. i * i == -1
{
Complex(0, 1) * Complex(0, 1)
{
Complex(0, 1) * Complex(0, 1) == Complex(1, 0)

16. いい感じだ！

17. let r = 2.0
let θ = M_PI / 4
let z = r * (cos(θ) + i * cos(θ))

18. let r = 2.0
let θ = M_PI / 4
let z = r * (cos(θ) + i * cos(θ))
！？

19. let i = Complex(0, 1)
let a = -1
i * i == a

20. let i = Complex(0, 1)
let a = -1
i * i == a
…？？？

21. import Foundation
struct Complex: Equatable, IntegerLiteralConvertible, FloatLiteralConvertible {
let x: Double
let y: Double
init(_ x: Double, _ y: Double) {
self.x = x
self.y = y
}
init(_ x: Double) {
self.x = x
self.y = 0
}
init(integerLiteral x: IntegerLiteralType) {
self.x = Double(x)
self.y = 0
}
init(floatLiteral x: FloatLiteralType) {
self.x = x
self.y = 0
}
init(r: Double, θ: Double) {
self.x = r * cos(θ)
self.y = r * sin(θ)
}
}
func == (z: Complex, w: Complex) -> Bool {
return z.x == w.x && z.y == w.y
}
func Re(a: Complex) -> Double {
return a.x
}
func Im(a: Complex) -> Double {

22. IntegerLiteralConvertible, FloatLiteralConvertible

23. IntegerLiteralConvertible, FloatLiteralConvertible

24. IntegerLiteralConvertible, FloatLiteralConvertible
リテラルからしか暗黙的キャストできない…

25. 残念だが仕方ない。

26. xxxLiteralConvertible
• ArrayLiteralConvertible
• BooleanLiteralConvertible
• DictionaryLiteralConvertible
• FloatLiteralConvertible
• NilLiteralConvertible
• IntegerLiteralConvertible
• StringLiteralConvertible
• UnicodeScalarLiteralConvertible

27. struct Matrix3x3<T>: ArrayLiteralConvertible {
init(arrayLiteral elements: T...) {
// ...
}
}
let m: Matrix3x3 = [1, 0, 0,
0, 1, 0,
0, 0, 1];
これぐらいのことはできる

28. さらに残念なことに、

29. let url: NSURL = “http://yahoo.co.jp”
let image: UIImage = “image.png"
let color: UIColor = 0x722F37

30. let url: NSURL = “http://yahoo.co.jp”
let image: UIImage = “image.png"
let color: UIColor = 0x722F37
↑ Swift 1.0 でできてたのが、1.1 でできなくなった…

31. 本当に残念。

32. Thanks...
Twitter: taketo1024
Blog: http://taketo1024.hateblo.jp/