Hello everyone! Does `@Parcelize` works on Pair t...

# android

[Dr.jacky]

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)

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[Federico Piantoni]

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

[Dr.jacky]

@Federico Piantoni Pair<String, Int>

Sorry, I didn’t get! you meant so @Parcelize works on classes that implementing Serializable? Without @Serializable

[Federico Piantoni]

Sorry, I did not see the @

[Dr.jacky]

@Federico Piantoni What do you mean!?

[Federico Piantoni]

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

[Dr.jacky]

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.

[Dr.jacky]

@sajadgarshasbi Any idea about this?

[Barco]

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 :)