Runtime optional protocol conformance research

gistfile1.swift

import Foundation
import CoreText
import SwiftUI
import PlaygroundSupport

typealias VoidHandler = @convention(block) () -> Void


@objc
protocol X {
    @objc optional func protoFunc(message: String, completionHandler: @escaping () -> Void)
}

class A: NSObject, X {
    
    @objc
    func aFunc(message: String,completionHandler: @escaping () -> Void) {
        print(1)
    }
    
    @objc
    func aFunc(message: String) {
        print(2)
    }
    
    @objc
    func aFunc() {
        print(2)
    }

    @objc
    func addClosure(_ closure: @escaping (_ message: NSString, _ completionHandler: () -> Void) -> Void) {
        
        let localBlock: @convention(block) (A, NSString, Any?) -> Void = {  (a, message, com) in
            print(1234)
            
            let blockPtr = UnsafeRawPointer(Unmanaged<AnyObject>.passUnretained(com as AnyObject).toOpaque())
            
            closure(message, unsafeBitCast(blockPtr, to: VoidHandler.self))
        }
        class_addMethod(A.self,
                        NSSelectorFromString("protoFuncWithMessage:completionHandler:"),
                        imp_implementationWithBlock(localBlock),
                        "v@:@@?")
    }
}
let d = A()
d.addClosure { message, com in
    print(message)
    com()
}


var mc: UInt32 = 0
let mcPointer = withUnsafeMutablePointer(to: &mc, { $0 })
let mlist = class_copyMethodList(object_getClass(d), mcPointer)!
//
//print("\(mc) methods")
//
//for i in 0...Int(mc) {
//    print(String(format: "Method #%d: %s", arguments: [i, sel_getName(method_getName(mlist[i]))]))
////    print(String(cString: method_getTypeEncoding(mlist[i])!))
//}



//d.perform(NSSelectorFromString("protoFuncWithMessage:completionHandler:"), with: "1", with: {})
//d.perform(NSSelectorFromString("protoFuncWithMessage:"), with: NSString(string: "123"))

//d.perform(NSSelectorFromString("protoFunc"))
//#selector(A.aFunc(message:)).description
Task { (d as X).protoFunc?(message: "1234565", completionHandler: { print("completed") }) }
//print(#selector(Y.protoFunc(message:)).description)
//print(#selector(X.protoFunc(message:)).description)
//    .protoFunc?(message: "123")
//print(String(cString: method_getTypeEncoding(class_getInstanceMethod(A.self, #selector(A.aFunc(message:)))!)!))

//var i = "123" as NSString