json - io.circe.Encoder[scala.collection.immutable.Map[Int,Any]] 类型的发散隐式扩展

Question

我写了这段代码

import io.circe._, io.circe.generic.auto._, io.circe.parser._, io.circe.syntax._
Map(1 -> 1, 2 -> "a").asJson.toString

但我收到以下错误

cmd35.sc:1: diverging implicit expansion for type 
io.circe.Encoder[scala.collection.immutable.Map[Int,Any]]
starting with method encodeMapLike in object Encoder
val res35 = Map(1 -> 1, 2 -> "a").asJson.toString
                              ^

Answer 1

您不能Map[Int, Any]直接使用 circe 进行序列化。如果Int或String仅允许用于值，则使用此处的Map[Int, Either[Int, String]]自定义代替。Encoder