A protocol for automatically adding a dispose bag to any object that requires it. Uses associated objects.

HasDisposeBag.swift

//
//  HasDisposeBag.swift
//
//  Created by Pavan Kataria 26/09/2017
//  Copyright © 2017 Pavan Kataria. All rights reserved.

protocol HasDisposeBag {
    var disposeBag: DisposeBag { get }
}
private struct AssociatedKeys {
    static var disposeBag = "pk_disposeBag"
}
extension HasDisposeBag {
    var disposeBag: DisposeBag {
        get {
            if let disposeBag = objc_getAssociatedObject(self, &AssociatedKeys.disposeBag) as? DisposeBag {
                return disposeBag
            }
            objc_setAssociatedObject(self, &AssociatedKeys.disposeBag, DisposeBag(), .OBJC_ASSOCIATION_RETAIN)
            return self.disposeBag
        }
        set {
            objc_setAssociatedObject(self, &AssociatedKeys.disposeBag, newValue, .OBJC_ASSOCIATION_RETAIN)
        }
    }
}