Can custom serializers be defined like in Rust?

[DGolubets]

In Rust a (De)Serialize for type T handles high level (de)serialization of that type - very simple and yet powerful concept.
https://serde.rs/impl-serialize.html

In this library custom serializers are counterintuitive and less powerful because they are called on each field of the class rather than on the class type itself. And they don't allow for any control over serialization.

Custom serializer should allow you to control at least what you store and in what order.
E.g. I want to serialize an instance of A which can have subtypes B and C. I need to store some discriminator field so that I can pick correct type later for deserialization.