Hello everyone! Does

@Parcelize

works on Pair type as well? Or in the other hand, does it work on classes that implement

Serializable

. ? I tried on a sample app and it worked. But I have a crash in Crashlytics:

Fatal Exception: java.lang.RuntimeException

Parcelable encountered IOException writing serializable object (name = kotlin.Pair)

keyboard_arrow_up

Pair is Serializable so it works on Serializable classes. What's inside your Pair?

@Federico Piantoni

Pair<String, Int>

Sorry, I didn’t get! you meant so

@Parcelize

works on classes that implementing Serializable? Without

@Serializable

Sorry, I did not see the @

@Federico Piantoni What do you mean!?

If you would to create a parcelable Pair class, you can create own implementation of Pair with @Parcelable.

I did:

data class Pair2<out A : Parcelable, out B : Parcelable>(
    val first: A,
    val second: B
) : Parcelable {
    private val ff: A = first
    private val ss: B = second
    constructor(parcel: Parcel) : this(
        parcel.readValue(Parcelable::class.java.classLoader) as A,
        parcel.readValue(Parcelable::class.java.classLoader) as B
    )
    /**
     * Returns string representation of the [Pair] including its [first] and [second] values.
     */
    public override fun toString(): String = "($first, $second)"
    override fun writeToParcel(dest: Parcel, flags: Int) {
        dest.writeValue(ff)
        dest.writeValue(ss)
    }
    override fun describeContents(): Int {
        return 0
    }
    companion object CREATOR : Parcelable.Creator<Pair2<Parcelable, Parcelable>> {
        override fun createFromParcel(parcel: Parcel): Pair2<Parcelable, Parcelable> {
            return Pair2(parcel)
        }
        override fun newArray(size: Int): Array<Pair2<Parcelable, Parcelable>?> {
            return arrayOfNulls(size)
        }
    }
}

The point is as I mentioned in my first message, even without having custom Pair class, it worked on my hello project! Because of that I asked if @Parcelize works on Pair? And asked if @Parcelize works on

: Serializable

classes? Apart from all of them, I saw this too: https://youtrack.jetbrains.com/issue/KT-20742 Which made me to have doubts about the whole idea, and maybe I need to put both annotations over that class that has Pair field.

Serializable

is just an empty interface that indicates to users of this Object that it can be serialized. You can still have runtime errors when trying to serialize it. So I think a Serializable will not always work with

@Parcelize

out of the box :)