Android type safe intents

SafeIntent.kt

private const val SHOW_GREETING_TOAST = "SHOW_GREETING_TOAST"
// alternatively, make this public for other activities to use
private var Intent.showGreetingToast: Boolean
    set(value) { putExtra(SHOW_GREETING_TOAST, value) }
    get() = getBooleanExtra(SHOW_GREETING_TOAST, false)

class MyActivity : Activity() {
    companion object {
        fun newIntent(context: Context, showGreetingToast: Boolean): Intent {
            val intent = Intent(context, MyActivity::class.java)
            intent.showGreetingToast = showGreetingToast
            return intent
        }
    }

    private val showGreetingToast by lazy { intent.showGreetingToast }

    override fun onCreate(savedInstanceState: Bundle?) {
        if (showGreetingToast) toast(android.R.string.ok)
    }
}