// Foo.swift
import Foundation

class Base: NSObject {
  @objc init(designated _: Int) {
    print("base designated")
    super.init()
  }
  @objc convenience init(convenience value: Int) {
    print("base convenience")
    self.init(designated: value)
  }
  @objc func doTheThing() {}
}

class Sub: Base {
  var value: Int
  @nonobjc @_nonoverride init(designated value: Int) {
    self.value = value
    super.init(designated: value)
  }
  override func doTheThing() {
    print("value = \(value)")
  }
}

// main.m
#import "Foo-Swift.h"

int main(void) {
  @autoreleasepool {
    Sub *sub = [[Sub alloc] initWithConvenience:42];
    [sub doTheThing]; // will print 0!
  }
}