/**
* Marker interface for keys.
*
* Objects and classes that extend this class must be marked with the [Serializable] annotation in
* order to be saved with by the [rememberNavBackStack] function.
*
* This class is required because [Serializable] is only an annotation and does not provide a way to
* link classes marked with the annotation together and provide a serializable that works with all
* of them, resulting it making it impossible to properly save and restore.
*/
public interface NavKey
/**
* Provides a [NavBackStack] that is automatically remembered in the Compose hierarchy across
* process death and configuration changes.
*
* This overload **does not take a [SavedStateConfiguration]**. It relies on the platform default:
* on **Android**, state is saved/restored using a **reflection-based serializer**; on **other
* platforms this will fail at runtime**. If you target non-Android platforms, use the overload that
* accepts a [SavedStateConfiguration] and register your serializers explicitly.
*
* ### When to use this overload
* - You are on **Android only** and want a simple API that uses reflection under the hood.
* - Your back stack elements use **closed polymorphism** (sealed hierarchies) or otherwise work
* with Android’s reflective serializer.
*
* ### Serialization requirements
* - Each element placed in the [NavBackStack] must be `@Serializable`.
* - For **closed polymorphism** (sealed hierarchies), the compiler knows all subtypes and generates
* serializers; Android’s reflection will also work.
* - For **open polymorphism** (interfaces or non-sealed hierarchies):
* - On Android, the reflection path can handle subtypes without manual registration.
* - On non-Android, this overload is **unsupported**; use the configuration overload and
* register all subtypes of [NavKey] in a [SerializersModule].
*
* @sample androidx.navigation3.runtime.samples.rememberNavBackStack_withReflection
* @param elements The initial keys of this back stack.
* @return A [NavBackStack] that survives process death and configuration changes on Android.
* @see NavBackStackSerializer
*/
@Composable
public fun rememberNavBackStack(vararg elements: NavKey): NavBackStack<NavKey> {
return rememberSerializable(
serializer = NavBackStackSerializer(elementSerializer = NavKeySerializer())
) {
NavBackStack(*elements)
}
}
