Check if a class conforms to a protocol instead of using respondsToSelector like in obj-c

ConformsToProtol.swift

import UIKit

// the protocol
protocol LayerManagerDelegate: class {
    func doSomething()
}

// the class
class LayerManager {
    
    var layers = [CALayer]()
    
    init() {
        layers = [FirstLayer(), SecondLayer()]
    }
    
    func doSomeWork() {
        // iterate over our layers and do something with layers conforming to the LayerManagerDelegate protocol
        for someLayer in layers {
            if let layerManagerDelegate = someLayer as? LayerManagerDelegate {
                //layerManagerDelegate responds to the LayerManagerDelegate protocol =]
                layerManagerDelegate.doSomething()
            }
        }
    }
}

class FirstLayer: CALayer, LayerManagerDelegate {
    func doSomething() {
        print("I conform to the LayerManagerDelegate protocol")
    }
}

class SecondLayer: CALayer {
    func doSomethingElse() {
        print("I don't conform to the LayerManagerDelegate protocol")
    }
}

let layerManager = LayerManager()

layerManager.doSomeWork()