I want to Cbor.dump a class and I need to pass TestClass.serializer(), but the type I receive is Any...

# ktor

[coder82]

I want to Cbor.dump a class and I need to pass TestClass.serializer(), but the type I receive is Any, is there a way to get that TestClass.serializer() at runtime without testing the type with when/is? But it looks like to me there is no way to do that as .dump requires the <T> at compile time

[coder82]

Here is my snippet in case you want to see what I am trying to do:

[diesieben07]

There is an extension function dump(obj: T) on BinaryFormat that uses reflection to find the serializer.

[diesieben07]

So you can just do Cbor.dump(value)

[coder82]

if I do that I get an exception

[coder82]

let me check which one

[coder82]

kotlinx.serialization.SerializationException: Can't locate argument-less serializer for class kotlin.Any. For generic classes, such as lists, please provide serializer explicitly.

[coder82]

I suspect that since it's any..

[coder82]

I suspect that since it's "Any", it can't figure it out

[diesieben07]

Ah, yeah, you need the actual class...
You can maybe use context.getContextualOrDefault(value::class) as the serializer

[diesieben07]

That will use the class that value has at runtime.

[coder82]

image.png

[coder82]

uhmm it looks like it wants to know the type

[diesieben07]

Yes you need an unsafe cast to SerializationStrategy<Any>

[coder82]

it worked, jeez

[coder82]

how i was supposed to know it

[coder82]

😄

[coder82]

do you work a lot with serialization?

[diesieben07]

No, never have 😄

[diesieben07]

well

[diesieben07]

i did once for a short experiment

[coder82]

I asked myself, I get an Any but the type at runtime is known, why woudn't this work

[diesieben07]

reified is a compile-time thing

[coder82]

that yes and actively using it successfully

[coder82]

but in this case T is not reified right? what do you mean?

[diesieben07]

BinaryFormat.dump(obj: T) has T reified. Since the compiler infers Any for T, it will use Any::class for the serializer lookup.

[coder82]

ah ok but we are using the other dump overload function:

[coder82]

or was yours just an observation relating to what we wrote beforehand

[diesieben07]

Yes, now we are.

[coder82]

ok

[diesieben07]

Yes

[coder82]

hey how do u get the flag by your username?

[coder82]

do i need to set the status or something?

[diesieben07]

Yes, thats my status message

[coder82]

I see

[coder82]

perfect, proud Italians here

[coder82]

😉