Protocol Extensions Dispatch

protocol_extensions_dispatch.swift

//: Playground - noun: a place where people can play

import UIKit

protocol Delegate {
    func foo();
}

extension Delegate {
    func foo() {
        print("\(self)")
        print("foo() in extension")
    }
}

class VC: Delegate {
    
}

class SubVC: VC {
    func foo() { // 为什么不是调用这里？
        print("foo() in SubVC")
    }
}

let vc:Delegate = SubVC()
vc.foo()