asUntypedMap.kt

import com.google.gson.Gson
import com.google.gson.reflect.TypeToken

inline fun <I, reified O> I?.convert(): O? = this?.let { input ->
    try {
        Gson().let { gson ->
            gson.toJson(input).let { output ->
                gson.fromJson(output, object : TypeToken<O>() {}.type)
            }
        }
    } catch (_: Exception) {
        null
    } catch (_: Error) {
        null
    }
}

fun <T> T?.asUntypedMap(): Map<String, Any> = convert() ?: mapOf()

data class SomeDTO(
  val foo: Int = 30,
  val bar: String = "lorem ipsum"
)

fun main() {
  val someDTO = SomeDTO()
  val map = someDTO.asUntypedMap()
  print(map["foo"]) // 30
  print(map["bar"]) // lorem ipsum
}