Remove Any constraint on type parameter?

[svby]

Currently, the type parameter of Optional is constrained to not be nullable; however, if it weren't, it would allow an important distinction between no value and not present (e.g.: deserializing data).

Would this be possible (or make sense), and would it fit the design goals of this library?

[artem-zinnatullin]

Sorry, this issue totally went under my radar.

I'm afraid we can't make it Optional<Any?>. In Koptional null means None.

By allowing to hold Some(null) we will break a lot of existing use cases as well as functions that we provide:

• Optional.toNullable() right now only returnsnullif it isNone`
• fun <T : Any> T?.toOptional() will be broken completely, as right now it returns None if you call it on a null value

I'm going to close the issue for now, please feel free to comment, we might reopen it in future :)