TapTrait.swift

import UIKit
import LeadKit
import RxSwift
import RxCocoa

typealias TapTrait = Void
typealias TapRelay = PublishRelay<TapTrait>
typealias TapDriver = Driver<TapTrait>

extension PublishRelay where Element == TapTrait {
    
    func tap() {
        accept(())
    }
    
    func asDriver() -> TapDriver {
        return asDriver(onErrorDriveWith: .empty())
    }
}

extension SharedSequenceConvertibleType where SharingStrategy == DriverSharingStrategy, E == TapTrait {
    
    func driveOnTap(_ closure: @escaping VoidBlock) -> Disposable {
        return drive(onNext: closure)
    }
}

let cancelTapRelay = TapRelay()

cancelTapRelay
    .asDriver()
    .driveOnTap {
        // code
    }
    .disposed(by: disposeBag)

cancelTapRelay.tap()