Is there some type to represent anything that's Se...

# serialization

[Zyle Moore]

Is there some type to represent anything that's Serializable? For context, this isn't about an existing format like Json or Cbor. I'm trying to make a generic wrapper, but keep ending up at making the type Any and getting an error that no serializer for Any was found. I understand why, I'm just not quite sure how to get what I want with that being true. By default, something like
@Serializable data class Point(val x: Int, val y: Int)
will eventually make a call to beginStructure, two calls to encodeInt, and a call to endStructure. If I replace Int with any other primitive type, like Short, Double, Float, Long, the two calls in the middle will be the appropriate method for that type, encodeShort, encodeFloat , etc. I'm looking for something that behaves exactly the same way, but the encode method it calls is encodeSerializableValue instead of encodeInt. Or maybe even encodeInline . This example though doesn't use generics, so perhaps it's easier for the generator to map confidently.

In my generic wrapper example, I have a
@Serializable @JvmInline value class FieldValue<T : Any>(val value: T) : FieldToken
The idea being a very thin wrapper around some serializable value, that I can treat as a subtype of FieldToken . I have a containing class
@Serializable data class Record(val header: RecordHeader, val fields: List<FieldValue<Any>>) which is where my trouble comes in. I want to be able to serialize, roughly, something that looks like

[ "TES4", [ flags, formId, timestamp, versionControl, recordVersion, unknown ] ],// RecordHeader
  [ "HEDR", [ 1.7, 0, 0 ] ],// // FieldValue<(Float, Short, Short)>
  [ "CNAM", "Zymus" ],// FieldValue<NullTerminatedString>
  [ "SNAM", "TES4 JSON Tuple Example" ],// FieldValue<NullTerminatedString>
  [ "MAST", "Skyrim.esm" ],// FieldValue<NullterminatedString>
  [ "DATA", 0 ],// FieldValue<Long>
  [ "MAST", "Update.esm" ],// FieldValue<NullTerminatedString>
  [ "DATA", 0 ],// FieldValue<Long>
  [ "MAST", "Hearthfires.esm" ],// FieldValue<NullTerminatedString>
  [ "DATA", 0 ],// FieldValue<Long>
  [ "ONAM", [ 0 ] ],// FieldValue<List<Int>>
  [ "INTV", 0 ],// FieldValue<Int>
  [ "INCC", 0 ]// FieldValue<Short>

[Zyle Moore]

It looks like the Json serializer might achieve its polymorphism by grace of default .toString implementations in Kotlin; every primitive type supported returns effectively a JsonUnquotedLiteral with the default .toString implementation, and it's correct. The value stops being Any in the constructor, at which point the body: String (or content) becomes the source of truth. Writing the value also doesn't seem to actually rely on the provided type, but which type it doesn't freak out at while trying to write it as every type possible.

[CLOVIS]

> Is there some type to represent anything that's Serializable?
No, there isn't. It's not possible to know which types are serializable at compile-time because some serializers are registered only at runtime.