84 JSON value roundtrip

A @Serializable value has a checked JSON shape. toJson encodes its fields; fromJson<Note> decodes back to the declared type rather than leaving a dynamic tree.

import std.serialization.Serializable
import std.json.fromJson
import std.json.toJson

@Serializable()
value Note {
  String title
  Integer priority
}

main() {
  Note original = Note(title: "Learn Norm", priority: 2)
  String encoded = original.toJson()
  Note restored = encoded.fromJson<Note>()
  printLine(encoded)
  printLine(restored.title)
  printLine(restored.priority)
}

Expected output:

{"title":"Learn Norm","priority":2}
Learn Norm
2

Try it: Change priority to 3 and compare the encoded and decoded values.

Precise rules: JSON API.