Swift type checking

main.swift

import UIKit

protocol Animal {}
class Cat : Animal {}
class Dog : Animal {}
class GreatDane : Dog {}

let c = Cat()
let d = Dog()
let gd = GreatDane()

func hereIsTheQuestion(object: Animal, tType: Animal.Type) -> Bool {
    // question: does object inherit from tType?
}

hereIsTheQuestion(object: c, tType: Dog.self) // should return false
hereIsTheQuestion(object: gd, tType: Dog.self) // should return true

import Foundation

class Animal: NSObject {}// You're forced to "buy into" NSObjectProtocol for `isKind(of:)`
class Cat : Animal {}
class Dog : Animal {}
class GreatDane : Dog {}

let c = Cat()
let d = Dog()
let gd = GreatDane()

func hereIsTheQuestion(object: Animal, tType: Animal.Type) -> Bool {
	object.isKind(of: tType)
//	print(object is tType)
	// question: does object inherit from tType?
}

func hereIsTheSolution<T: Animal>(object: Animal, ofType: T.Type) -> Bool {
	return object is T
}

print(hereIsTheSolution(object: c, ofType: Dog.self)) // should return false
print(hereIsTheSolution(object: gd, ofType: Dog.self)) // should return true

Thanks!

w/o NSObject

protocol Animal {}

class Dog: Animal {}
class Cat: Animal {}
class GermanShepard: Dog {}

var aDog: Animal = Dog()
var gs: Dog = GermanShepard()
var c: Cat = Cat()

print(aDog is Cat) // prints true
print(type(of: aDog)) // prints Dog

func check<T: Animal>(object: Animal, inType: T.Type) -> Bool {
    return object is T
}

check(object: c, inType: Dog.self) // prints false